Science papers where I am co-author …
Wittrock J M; Plavchan P; Cale B L; Barclay T; Gilbert E A; Ludwig M R; Schwarz R P; Mekarnia D; Triaud A; Abe L; Suarez O; Guillot T; Conti D M; Collins K A; Waite I A; Kielkopf J F; Collins K I; Dreizler S; Mufti M E; Feliz D; Gaidos E; Geneser C; Horne K; Kane S R; Lowrance P J; Martioli E; Radford D J; Reefe M A; Roccatagliata V; Shporer A; Stassun K G; Stockdale C; Tan T; Tanner A; Vega L D
Validating AU Microscopii d with Transit Timing Variations (Miscellaneous)
2023, (arXiv:2302.04922 [astro-ph]).
AU Mic is a young (22 Myr) nearby exoplanetary system that exhibits excess TTVs that cannot be accounted for by the two known transiting planets nor stellar activity. In this work, we present the validation of the candidate planet AU Mic d. We add 18 new transits and nine midpoint times in an updated TTV analysis to prior work. We perform the joint modeling of transit light curves using EXOFASTv2 and extract the transit midpoint times. Next, we construct an O-C diagram and use Exo-Striker to model the TTVs. We generate TTV log-likelihood periodograms to explore possible solutions for the period of planet d and then follow those up with detailed TTV and RV MCMC modeling and stability tests. We find several candidate periods for AU Mic d, all of which are near resonances with AU Mic b and c of varying order. Based on our model comparisons, the most-favored orbital period of AU Mic d is 12.73812+/-0.00128 days (T_C,d=2458333.32110+/-0.35836 BJD), which puts the three planets near a 4:6:9 mean-motion orbital resonance. The mass for d is M_d=1.013+/-0.146 M_E, making this planet Earth-like in mass. The presence of orbital resonances in a very young system implies that compact planetary systems can develop resonant chains very early on, which can quickly establish the stability of the systems. Additional TTV observation of the AU Mic system are needed to further constrain the planetary masses, search for possible transits of AU Mic d, and detect possible additional planets beyond AU Mic c.
Christian S; Vanderburg A; Becker J; Yahalomi D A; Pearce L; Zhou G; Collins K A; Kraus A L; Stassun K G; Beurs Z; Ricker G R; Vanderspek R K; Latham D W; Winn J N; Seager S; Jenkins J M; Abe L; Agabi K; Amado P J; Baker D; Barkaoui K; Benkhaldoun Z; Benni P; Berberian J; Berlind P; Bieryla A; Esparza-Borges E; Bowen M; Brown P; Buchhave L A; Burke C J; Buttu M; Cadieux C; Caldwell D A; Charbonneau D; Chazov N; Chimaladinne S; Collins K I; Combs D; Conti D M; Crouzet N; Leon J P; Deljookorani S; Diamond B; Doyon R; Dragomir D; Dransfield G; Essack Z; Evans P; Fukui A; Gan T; Esquerdo G A; Gillon M; Girardin E; Guerra P; Guillot T; Habich E K K; Henriksen A; Hoch N; Isogai K I; Jehin E; Jensen E L N; Johnson M C; Livingston J H; Kielkopf J F; Kim K; Kawauchi K; Krushinsky V; Kunzle V; Laloum D; Leger D; Lewin P; Mallia F; Massey B; Mori M; McLeod K K; Mékarnia D; Mireles I; Mishevskiy N; Tamura M; Murgas F; Narita N; Naves R; Nelson P; Osborn H P; Palle E; Parviainen H; Plavchan P; Pozuelos F J; Rabus M; Relles H M; López C R; Quinn S N; Schmider F; Schlieder J E; Schwarz R P; Shporer A; Sibbald L; Srdoc G; Stibbards C; Stickler H; Suarez O; Stockdale C; Tan T; Terada Y; Triaud A; Tronsgaard R; Waalkes W C; Wang G; Watanabe N; Wenceslas M; Wingham G; Wittrock J; Ziegler C
A Possible Alignment Between the Orbits of Planetary Systems and their Visual Binary Companions (Journal Article)
In: arXiv:2202.00042 [astro-ph], 2022, (arXiv: 2202.00042).
Astronomers do not have a complete picture of the effects of wide-binary companions (semimajor axes greater than 100 AU) on the formation and evolution of exoplanets. We investigate these effects using new data from Gaia EDR3 and the TESS mission to characterize wide-binary systems with transiting exoplanets. We identify a sample of 67 systems of transiting exoplanet candidates (with well-determined, edge-on orbital inclinations) that reside in wide visual binary systems. We derive limits on orbital parameters for the wide-binary systems and measure the minimum difference in orbital inclination between the binary and planet orbits. We determine that there is statistically significant difference in the inclination distribution of wide-binary systems with transiting planets compared to a control sample, with the probability that the two distributions are the same being 0.0037. This implies that there is an overabundance of planets in binary systems whose orbits are aligned with those of the binary. The overabundance of aligned systems appears to primarily have semimajor axes less than 700 AU. We investigate some effects that could cause the alignment and conclude that a torque caused by a misaligned binary companion on the protoplanetary disk is the most promising explanation.
Giacalone S; Dressing C D; Hedges C; Kostov V B; Collins K A; Jensen E L N; Yahalomi D A; Bieryla A; Ciardi D R; Howell S B; Lillo-Box J; Barkaoui K; Winters J G; Matthews E; Livingston J H; Quinn S N; Safonov B S; Cadieux C; Furlan E; Crossfield I J M; Mandell A M; Gilbert E A; Kruse E; Quintana E V; Ricker G R; Seager S; Winn J N; Jenkins J M; Adkins B D; Baker D; Barclay T; Barrado D; Batalha N M; Belinski A A; Benkhaldoun Z; Buchhave L A; Cacciapuoti L; Chontos A; Christiansen J L; Cloutier R; Collins K I; Conti D M; Cutting N; Dixon S; Doyon R; Mufti M E; Esparza-Borges E; Essack Z; Fukui A; Gan T; Gary K; Ghachoui M; Gillon M; Girardin E; Glidden A; Gonzales E J; Guerra P; Horch E P; Helminiak K G; Howard A W; Huber D; Irwin J M; Isopi G; Jehin E; Kagetani T; Kane S R; Kawauchi K; Kielkopf J F; Lewin P; Luker L; Lund M B; Mallia F; Mao S; Massey B; Matson R A; Mireles I; Mori M; Murgas F; Narita N; O`Dwyer T; Petigura E A; Polanski A S; Pozuelos F J; Palle E; Parviainen H; Plavchan P P; Relles H M; Robertson P; Rose M E; Rowden P; Roy A; Savel A B; Schlieder J E; Schnaible C; Schwarz R P; Sefako R; Selezneva A; Skinner B; Stockdale C; Strakhov I A; Tan T; Torres G; Tronsgaard R; Twicken J D; Vermilion D; Waite I A; Walter B; Wang G; Ziegler C; Zou Y
Validation of 13 Hot and Potentially Terrestrial TESS Planets (Journal Article)
In: arXiv:2201.12661 [astro-ph], 2022, (arXiv: 2201.12661).
The James Webb Space Telescope (JWST) will be able to probe the atmospheres and surface properties of hot, terrestrial planets via emission spectroscopy. We identify 18 potentially terrestrial planet candidates detected by the Transiting Exoplanet Survey Satellite (TESS) that would make ideal targets for these observations. These planet candidates cover a broad range of planet radii ($R_textbackslashrm p textbackslashsim 0.6 - 2.0 R_textbackslashoplus$) and orbit stars of various magnitudes ($K_s = 5.78 - 10.78$, $V = 8.4 - 15.69$) and effective temperatures ($T_textbackslashrm eff textbackslashsim 3000 - 6000$ K). We use ground-based observations collected through the TESS Follow-up Observing Program (TFOP) and two vetting tools -- DAVE and TRICERATOPS -- to assess the reliabilities of these candidates as planets. We validate 13 planets: TOI-206 b, TOI-500 b, TOI-544 b, TOI-833 b, TOI-1075 b, TOI-1411 b, TOI-1442 b, TOI-1693 b, TOI-1860 b, TOI-2260 b, TOI-2411 b, TOI-2427 b, and TOI-2445 b. Seven of these planets (TOI-206 b, TOI-500 b, TOI-1075 b, TOI-1442 b, TOI-2260 b, TOI-2411 b, and TOI-2445 b) are ultra-short-period planets. TOI-1860 is the youngest ($133 textbackslashpm 26$ Myr) solar twin with a known planet to date. TOI-2260 is a young ($321 textbackslashpm 96$ Myr) G dwarf that is among the most metal-rich ([Fe/H] = $0.22 textbackslashpm 0.06$ dex) stars to host an ultra-short-period planet. With an estimated equilibrium temperature of $textbackslashsim 2600$ K, TOI-2260 b is also the fourth hottest known planet with $R_textbackslashrm p textless 2 textbackslash, R_textbackslashoplus$.
Wittrock J M; Dreizler S; Reefe M A; Morris B M; Plavchan P P; Lowrance P J; Demory B; Ingalls J G; Gilbert E A; Barclay T; Cale B L; Collins K A; Collins K I; Crossfield I J M; Dragomir D; Eastman J D; Mufti M E; Feliz D; Gagne J; Gaidos E; Gao P; Geneser C S; Hebb L; Henze C E; Horne K D; Jenkins J M; Jensen E L N; Kane S R; Kaye L; Martioli E; Monsue T A; Palle E; Quintana E V; Radford D J; Roccatagliata V; Schlieder J E; Schwarz R P; Shporer A; Stassun K G; Stockdale C; Tan T; Tanner A M; Vanderburg A; Vega L D; Wang S
Transit Timing Variations for AU Microscopii b & c (Journal Article)
In: arXiv:2202.05813 [astro-ph], 2022, (arXiv: 2202.05813).
We explore the transit timing variations (TTVs) of the young (22 Myr) nearby AU Mic planetary system. For AU Mic b, we introduce three Spitzer (4.5 $textbackslashmu$m) transits, five TESS transits, 11 LCO transits, one PEST transit, one Brierfield transit, and two transit timing measurements from Rossiter-McLaughlin observations; for textbackslashaumic c, we introduce three textbackslashtess Cycle transits. We present two independent TTV analyses. First, we use EXOFASTv2 to jointly model the Spitzer and ground-based transits and to obtain the midpoint transit times. We then construct an O-C diagram and model the TTVs with Exo-Striker. Second, we reproduce our results with an independent photodynamical analysis. We recover a TTV mass for AU Mic c of 10.8$textasciicircum+2.3_-2.2$ M$_E$. We compare the TTV-derived constraints to a recent radial-velocity (RV) mass determination. We also observe excess TTVs that do not appear to be consistent with the dynamical interactions of b and c alone, and do not appear to be due to spots or flares. Thus, we present a hypothetical non-transiting "middle-d" candidate exoplanet that is consistent with the observed TTVs, the candidate RV signal, and would establish the AU Mic system as a compact resonant multi-planet chain in a 4:6:9 period commensurability. These results demonstrate that the AU Mic planetary system is dynamically interacting producing detectable TTVs, and the implied orbital dynamics may inform the formation mechanisms for this young system. We recommend future RV and TTV observations of AU Mic b and c to further constrain the masses and to confirm the existence of possible additional planet(s).
Almenara J M; Bonfils X; Otegi J F; Attia O; Turbet M; Astudillo-Defru N; Collins K A; Polanski A S; Bourrier V; Hellier C; Ziegler C; Bouchy F; Briceño C; Charbonneau D; Cointepas M; Collins K I; Crossfield I; Delfosse X; Díaz R F; Dorn C; Doty J P; Forveille T; Gaisné G; Gan T; Helled R; Hesse K; Jenkins J M; Jensen E L N; Latham D W; Law N; Mann A W; Mao S; McLean B; Murgas F; Myers G; Seager S; Shporer A; Tan T G; Twicken J D; Winn J
GJ 3090 b: one of the most favourable mini-Neptune for atmospheric characterisation (Journal Article)
In: A&A, vol. 665, pp. A91, 2022, ISSN: 0004-6361, 1432-0746, (arXiv:2207.14121 [astro-ph]).
We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy Radial velocity Planet Searcher radial velocities. Seeing-limited photometry and speckle imaging rule out nearby eclipsing binaries. Additional transits were observed with the LCOGT, Spitzer, and ExTrA telescopes. We characterise the star to have a mass of 0.519 $textbackslashpm$ 0.013 M$_textbackslashodot$ and a radius of 0.516 $textbackslashpm$ 0.016 R$_textbackslashodot$. We modelled the transit light curves and radial velocity measurements and obtained a planetary mass of 3.34 $textbackslashpm$ 0.72 M$_textbackslashoplus$, a radius of 2.13 $textbackslashpm$ 0.11 R$_textbackslashoplus$, and a mean density of 1.89$textasciicircum+0.52_-0.45$ g/cm$textasciicircum3$. The low density of the planet implies the presence of volatiles, and its radius and insolation place it immediately above the radius valley at the lower end of the mini-Neptune cluster. A coupled atmospheric and dynamical evolution analysis of the planet is inconsistent with a pure H-He atmosphere and favours a heavy mean molecular weight atmosphere. The transmission spectroscopy metric of 221$textasciicircum+66_-46$ means that GJ 3090 b is the second or third most favourable mini-Neptune after GJ 1214 b whose atmosphere may be characterised. At almost half the mass of GJ 1214 b, GJ 3090 b is an excellent probe of the edge of the transition between super-Earths and mini-Neptunes. We identify an additional signal in the radial velocity data that we attribute to a planet candidate with an orbital period of 13 days and a mass of 17.1$textasciicircum+8.9_-3.2$ M$_textbackslashoplus$, whose transits are not detected.
Cacciapuoti L; Inno L; Covone G; Kostov V B; Barclay T; Quintana E V; Colon K D; Stassun K G; Hord B; Giacalone S; Kane S R; Hoffman K; Rowe J; Wang G; Collins K I; Collins K A; Tan T; Gallo F; Magliano C; Ienco R M; Rabus M; Ciardi D R; Furlan E; Howell S B; Gnilka C L; Scott N J; Lester K V; Ziegler C; Briceño C; Law N; Mann A W; Burke C J; Quinn S N; Ciaramella A; Luca P D; Fiscale S; Rotundi A; Marcellino L; Galletti A; Bifulco I; Oliva F; Spencer A; Kaltenegger L; McDermott S; Essack Z; Jenkins J M; Wohler B; Winn J N; Seager S; Vanderspek R; Zhou G; Shporer A; Dragomir D; Fong W
TESS discovery of a super-Earth and two sub-Neptunes orbiting the bright, nearby, Sun-like star HD 22946 (Miscellaneous)
2022, (arXiv:2209.09597 [astro-ph]).
We report the Transiting Exoplanet Survey Satellite (TESS) discovery of a three-planet system around the bright Sun-like star HDtextasciitilde22946(V=8.3 mag),also known as TICtextasciitilde100990000, located 63 parsecs away.The system was observed by TESS in Sectors 3, 4, 30 and 31 and two planet candidates, labelled TESS Objects of Interest (TOIs) 411.01 (planet $c$) and 411.02 (planet $b$), were identified on orbits of 9.57 and 4.04 days, respectively. In this work, we validate the two planets and recover an additional single transit-like signal in the light curve, which suggests the presence of a third transiting planet with a longer period of about 46 days.We assess the veracity of the TESS transit signals and use follow-up imaging and time series photometry to rule out false positive scenarios, including unresolved binary systems, nearby eclipsing binaries or background/foreground stars contaminating the light curves. Parallax measurements from Gaia EDR3, together with broad-band photometry and spectroscopic follow-up by TFOP allowed us to constrain the stellar parameters of TOI-411, including its radius of$1.157textbackslashpm0.025R_textbackslashodot$. Adopting this value, we determined the radii for the three exoplanet candidates and found that planet $b$ is a super-Earth, with a radius of $1.72textbackslashpm0.10R_textbackslashoplus$, while planet $c$ and $d$ are sub-Neptunian planets, with radii of$2.74textbackslashpm0.14R_textbackslashoplus$ and $3.23textbackslashpm0.19R_textbackslashoplus$ respectively. By using dynamical simulations, we assessed the stability of the system and evaluated the possibility of the presence of other undetected, non-transiting planets by investigating its dynamical packing. We find that the system is dynamically stable and potentially unpacked, with enough space to host at least one more planet between $c$ and $d$.(Abridged)
Mann C R; Lafrenière D; Dragomir D; Quinn S N; Tan T; Collins K A; Howell S B; Ziegler C; Mann A W; Stassun K G; Kristiansen M H; Osborn H; Boyajian T; Eisner N; Hellier C; Ricker G R; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; McLean B; Rowden P; Torres G; Caldwell D A; Collins K I; Schwarz R P
Validation of TOI-1221 b, a warm sub-Neptune exhibiting TTVs around a Sun-like star (Miscellaneous)
2022, (arXiv:2209.13651 [astro-ph]).
We present a successful validation of the long-period ($91.68278textasciicircum+0.00032_-0.00041$ days) transiting sub-Neptune planet TOI-1221 b (TIC 349095149.01) around a Sun-like (m$_textbackslashrm V$=10.5) star. We combine textbackslashit TESS light curve measurements and ground-based time-series photometry from PEST (0.3textasciitildem) and LCOGT (1.0textasciitildem) to analyze the transit light curves and rule out nearby stars as potential eclipsing binary contaminants. High-contrast imaging from SOAR and Gemini/Zorro rule out nearby stellar contaminants down to $textbackslashDelta$mag = 5 at separation $r = 0.1"$. Reconnaissance spectroscopy from CHIRON sets a planetary upper limit on the mass of the object (1.1 and 3.5 M$_textbackslashrm Jup$ at 1$textbackslashsigma$ and 3$textbackslashsigma$, respectively) and shows no sign of a spectroscopic binary companion. We fit a planetary radius $R_textbackslashrm p/R_textbackslashstar=0.02679textasciicircum+0.00067_-0.00056$ corresponding to $R_textbackslashrm p = 2.91textasciicircum+0.13_-0.12 R_textbackslashoplus$, placing it in the sub-Neptune regime. It's orbital semi-major axis of $a=0.404textasciicircum+0.026_-0.023$ au predicts an insolation of $S = 5.57textasciicircum+0.75_-0.68textbackslash S_textbackslashoplus$, suggesting a moderate equilibrium temperature of $T_textbackslashrm eq =$ 400 K given a Neptune-like model. In analyzing 8 transits, we find significant evidence (textgreater $5textbackslashsigma$) of sinusoidal transit timing variations with amplitude of $23.0textasciicircum+5.2_-4.1$ minutes, and a super-period of $485textasciicircum+15_-19$ days. We find a false positive probability from TRICERATOPS of FPP $ = 0.0014 textbackslashpm 0.0003$ as well as other qualitative and quantitative evidence to support the statistical validation of TOI-1221 b.
Sha L; Vanderburg A M; Huang C X; Armstrong D J; Brahm R; Giacalone S; Wood M L; Collins K A; Nielsen L D; Hobson M J; Ziegler C; Howell S B; Torres-Miranda P; Mann A W; Zhou G; Delgado-Mena E; Rojas F I; Abe L; Trifonov T; Adibekyan V; Sousa S G; Fajardo-Acosta S B; Guillot T; Howard S; Littlefield C; Hawthorn F; Schmider F; Eberhardt J; Tan T; Osborn A; Schwarz R P; Strøm P; Jordán A; Wang G; Henning T; Massey B; Law N; Stockdale C; Furlan E; Srdoc G; Wheatley P J; Navascués D B; Lissauer J J; Stassun K G; Ricker G R; Vanderspek R K; Latham D W; Winn J N; Seager S; Jenkins J M; Barclay T; Bouma L G; Christiansen J; Guerrero N; Rose M E
TESS spots a mini-neptune interior to a hot saturn in the TOI-2000 system (Miscellaneous)
2022, (arXiv:2209.14396 [astro-ph]).
Hot jupiters (P textless 10 d, M textgreater 60 $textbackslashmathrmM_textbackslashoplus$) are almost always found alone around their stars, but four out of hundreds known have inner companion planets. These rare companions allow us to constrain the hot jupiter's formation history by ruling out high-eccentricity tidal migration. Less is known about inner companions to hot Saturn-mass planets. We report here the discovery of the TOI-2000 system, which features a hot Saturn-mass planet with a smaller inner companion. The mini-neptune TOI-2000 b ($2.64textasciicircum+0.11_-0.12 textbackslash,textbackslashmathrmR_textbackslashoplus$, $10.3 textbackslashpm 2.2 textbackslash,textbackslashmathrmM_textbackslashoplus$) is in a 3.10-day orbit, and the hot saturn TOI-2000 c ($7.97 textbackslashpm 0.12 textbackslash,textbackslashmathrmR_textbackslashoplus$, $75.7 textbackslashpm 3.8 textbackslash,textbackslashmathrmM_textbackslashoplus$) is in a 9.13-day orbit. Both planets transit their host star TOI-2000 (TIC 371188886
Olmschenk G; Bennett D P; Bond I A; Zang W; Jung Y K; Yee J C; Bachelet E; Abe F; Barry R K; Bhattacharya A; Fujii H; Fukui A; Hirao Y; Silva S I; Itow Y; Kirikawa R; Kondo I; Koshimoto N; Matsubara Y; Matsumoto S; Miyazaki S; Munford B; Muraki Y; Okamura A; Ranc C; Rattenbury N J; Satoh Y; Sumi T; Suzuki D; Toda T; Tristram P J; Vandorou K; Yama H; Albrow M D; Cha S; Chung S; Gould A; Han C; Hwang K; Kim D; Kim H; Kim S; Lee C; Lee D; Lee Y; Park B; Pogge R W; Ryu Y; Shin I; Shvartzvald Y; Christie G; Cooper T; Drummond J; Green J; Hennerley S; McCormick J; Monard L A G; Natusch T; Porritt I; Tan T; Mao S; Maoz D; Penny M T; Zhu W; Bozza V; Cassan A; Dominik M; Hundertmark M; Jaimes R F; Kruszyńska K; Rybicki K A; Street R A; Tsapras Y; Wambsganss J; Wyrzykowski Ł; Zieliński P; Rau G
MOA-2020-BLG-208: Cool Sub-Saturn Planet Within Predicted Desert (Miscellaneous)
2022, (arXiv:2210.02436 [astro-ph]).
We analyze the MOA-2020-BLG-208 gravitational microlensing event and present the discovery and characterization of a new planet with an estimated sub-Saturn mass. With a mass ratio $q = 3.17textasciicircum+0.28_-0.26 textbackslashtimes 10textasciicircum-4$ and a separation $s = 1.3807textasciicircum+0.0018_-0.0018$, the planet lies near the peak of the mass-ratio function derived by the MOA collaboration (Suzuki et al. 2016), near the edge of expected sample sensitivity. For these estimates we provide results using two mass law priors: one assuming that all stars have an equal planet-hosting probability, and the other assuming that planets are more likely to orbit around more massive stars. In the first scenario, we estimate that the lens system is likely to be a planet of mass $m_textbackslashmathrmplanet = 46textasciicircum+42_-24 textbackslash; M_textbackslashoplus$ and a host star of mass $M_textbackslashmathrmhost = 0.43textasciicircum+0.39_-0.23 textbackslash; M_textbackslashodot$, located at a distance $D_L = 7.49textasciicircum+0.99_-1.13 textbackslash; textbackslashmathrmkpc$. For the second scenario, we estimate $m_textbackslashmathrmplanet = 69textasciicircum+37_-34 textbackslash; M_textbackslashoplus$, $M_textbackslashmathrmhost = 0.66textasciicircum+0.35_-0.32 textbackslash; M_textbackslashodot$, and $D_L = 7.81textasciicircum+0.93_-0.93 textbackslash; textbackslashmathrmkpc$. As a cool sub-Saturn-mass planet, this planet adds to a growing collection of evidence for revised planetary formation models and qualifies for inclusion in the extended MOA-II exoplanet microlensing sample.
Miller N J; Maxted P F L; Graczyk D; Tan T G; Southworth J
Fundamental effective temperature measurements for eclipsing binary stars -- II. The detached F-type eclipsing binary CPD-54 810 (Miscellaneous)
2022, (arXiv:2210.06325 [astro-ph]).
CPD-54 810 is a double-lined detached eclipsing binary containing two mid-F type dwarfs on an eccentric 26-day orbit. We perform a combined analysis of the extensive photometry obtained by the TESS space mission along with previously published observations to obtain a full orbital and physical solution for the system. We measure the following model-independent masses and radii: M1 = 1.3094+/-0.0051 Msun
Leon J P; Livingston J H; Jenkins J S; Vines J I; Wittenmyer R A; Clark J T; Winn J I M; Addison B; Ballard S; Bayliss D; Beichman C; Benneke B; Berardo D A; Bowler B P; Brown T; Bryant E M; Christiansen J; Ciardi D; Collins K A; Collins K I; Crossfield I; Deming D; Dragomir D; Dressing C D; Fukui A; Gan T; Giacalone S; Gill S; alez Alvarez E G; Hesse K; Horner J; Howell S B; Jenkins J M; Kane S R; Kendall A; Kielkopf J F; Kreidberg L; Latham D W; Liu H; Lund M B; Matson R; Matthews E; Mengel M W; Morales F; Mori M; Narita N; Nishiumi T; Okumura J; Plavchan P; Quinn S; Rabus M; Ricker G; Rudat A; Schlieder J; Schwarz R P; Seager S; Shporer A; Smith A M S; Sphorer A; Stassun K; Tamura M; Tan T G; Tinney C G; Vanderspek R; Gorjian V; Werner M W; West R G; Wright D; Zhang H; Zhou G
A sub-Neptune transiting the young field star HD 18599 at 40 pc (Miscellaneous)
2022, (arXiv:2210.08179 [astro-ph]).
Transiting exoplanets orbiting young nearby stars are ideal laboratories for testing theories of planet formation and evolution. However, to date only a handful of stars with age textless1 Gyr have been found to host transiting exoplanets. Here we present the discovery and validation of a sub-Neptune around HD 18599, a young (300 Myr), nearby (d=40 pc) K star. We validate the transiting planet candidate as a bona fide planet using data from the TESS, Spitzer, and Gaia missions, ground-based photometry from IRSF, LCO, PEST, and NGTS, speckle imaging from Gemini, and spectroscopy from CHIRON, NRES, FEROS, and Minerva-Australis. The planet has an orbital period of 4.13 d, and a radius of 2.7Rearth. The RV data yields a 3-sigma mass upper limit of 30.5Mearth which is explained by either a massive companion or the large observed jitter typical for a young star. The brightness of the host star (Vtextasciitilde9 mag) makes it conducive to detailed characterization via Doppler mass measurement which will provide a rare view into the interior structure of young planets.
Yee S W; Winn J N; Hartman J D; Bouma L G; Zhou G; Quinn S N; Latham D W; Bieryla A; Rodriguez J E; Collins K A; Alfaro O; Barkaoui K; Beard C; Belinski A A; Benkhaldoun Z; Benni P; Bernacki K; Boyle A W; Butler R P; Caldwell D A; Chontos A; Christiansen J L; Ciardi D R; Collins K I; Conti D M; Crane J D; Daylan T; Dressing C D; Eastman J D; Essack Z; Evans P; Everett M E; Fajardo-Acosta S; Forés-Toribio R; Furlan E; Ghachoui M; Gillon M; Hellier C; Helm I; Howard A W; Howell S B; Isaacson H; Jehin E; Jenkins J M; Jensen E L N; Kielkopf J F; Laloum D; Leonhardes-Barboza N; Logsdon S E; Lubin J; Lund M B; MacDougall M G; Mann A W; Maslennikova N A; Massey B; McLeod K K; Muñoz J A; Newman P; Orlov V; Plavchan P; Popowicz A; Pozuelos F J; Pritchard T A; Radford D J; Reefe M; Ricker G R; Rudat A; Safonov B S; Schwarz R P; Schweiker H; Scott N J; Seager S; Shectman S A; Stockdale C; Tan T; Teske J K; Thomas N B; Timmermans M; Vanderspek R; Vermilion D; Watanabe D; Weiss L M; West R G; Zandt J V; Zejmo M; Ziegler C
The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets (Miscellaneous)
2022, (arXiv:2210.15473 [astro-ph]).
NASA's Transiting Exoplanet Survey Satellite (TESS) mission promises to improve our understanding of hot Jupiters by providing an all-sky, magnitude-limited sample of transiting hot Jupiters suitable for population studies. Assembling such a sample requires confirming hundreds of planet candidates with additional follow-up observations. Here, we present twenty hot Jupiters that were detected using TESS data and confirmed to be planets through photometric, spectroscopic, and imaging observations coordinated by the TESS Follow-up Observing Program (TFOP). These twenty planets have orbital periods shorter than 7 days and orbit relatively bright FGK stars ($10.9 textless G textless 13.0$). Most of the planets are comparable in mass to Jupiter, although there are four planets with masses less than that of Saturn. TOI-3976 b, the longest period planet in our sample ($P = 6.6$ days), may be on a moderately eccentric orbit ($e = 0.18textbackslashpm0.06$), while observations of the other targets are consistent with them being on circular orbits. We measured the projected stellar obliquity of TOI-1937A b, a hot Jupiter on a 22.4 hour orbit with the Rossiter-McLaughlin effect, finding the planet's orbit to be well-aligned with the stellar spin axis ($textbartextbackslashlambdatextbar = 4.0textbackslashpm3.5textasciicircumtextbackslashcirc$). We also investigated the possibility that TOI-1937 is a member of the NGC 2516 open cluster, but ultimately found the evidence for cluster membership to be ambiguous. These objects are part of a larger effort to build a complete sample of hot Jupiters to be used for future demographic and detailed characterization work.
Kokori A; Tsiaras A; Edwards B; Jones A; Pantelidou G; Tinetti G; Bewersdorff L; Iliadou A; Jongen Y; Lekkas G; Nastasi A; Poultourtzidis E; Sidiropoulos C; Walter F; Wünsche A
ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations (Miscellaneous)
2022, (arXiv:2209.09673 [astro-ph]).
The ExoClock project has been created with the aim of increasing the efficiency of the Ariel mission. It will achieve this by continuously monitoring and updating the ephemerides of Ariel candidates over an extended period, in order to produce a consistent catalogue of reliable and precise ephemerides. This work presents a homogenous catalogue of updated ephemerides for 450 planets, generated by the integration of $textbackslashsim$18000 data points from multiple sources. These sources include observations from ground-based telescopes (ExoClock network and ETD), mid-time values from the literature and light-curves from space telescopes (Kepler/K2 and TESS). With all the above, we manage to collect observations for half of the post-discovery years (median), with data that have a median uncertainty less than one minute. In comparison with literature, the ephemerides generated by the project are more precise and less biased. More than 40textbackslash% of the initial literature ephemerides had to be updated to reach the goals of the project, as they were either of low precision or drifting. Moreover, the integrated approach of the project enables both the monitoring of the majority of the Ariel candidates (95textbackslash%), and also the identification of missing data. The dedicated ExoClock network effectively supports this task by contributing additional observations when a gap in the data is identified. These results highlight the need for continuous monitoring to increase the observing coverage of the candidate planets. Finally, the extended observing coverage of planets allows us to detect trends (TTVs - Transit Timing Variations) for a sample of 19 planets. All products, data, and codes used in this work are open and accessible to the wider scientific community.
Clark J; Addison B; Okumura J; Vach S; Heitzmann A; Rodriguez J; Wright D; Clerte M; Brown C; Fetherolf T; Wittenmyer R; Plavchan P; Kane S; Horner J; Kielkopf J; Shporer A; Tinney C; Hui-Gen L; Ballard S; Bowler B; Mengel M; Zhou G; Lee A; David A; Heim J; Lee M; Sevilla V; Zafar N; Hinkel N; Allen B; Bayliss D; Berberyan A; Berlind P; Bieryla A; Bouchy F; Brahm R; Bryant E; Christiansen J; Ciardi D; Ciardi K; Collins K; Dallant J; Davis A; Diaz M; Dressing C; Esquerdo G; Harre J; Howell S; Jenkins J; Jensen E; Jones M; Jordan A; Latham D; Lund M; McCormac J; Nielsen L; Otegi J; Quinn S; Radford D; Ricker G; Schwarz R; Seager S; Smith A; Stockdale C; Tan T; Udry S; Vanderspek R; Gunther M; Wang S; Wingham G; Winn J
Spinning up a Daze: TESS Uncovers a Hot Jupiter orbiting the Rapid-Rotator TOI-778 (Miscellaneous)
2022, (arXiv:2212.08242 [astro-ph]).
NASA's Transiting Exoplanet Survey Satellite (TESS) mission, has been uncovering a growing number of exoplanets orbiting nearby, bright stars. Most exoplanets that have been discovered by TESS orbit narrow-line, slow-rotating stars, facilitating the confirmation and mass determination of these worlds. We present the discovery of a hot Jupiter orbiting a rapidly rotating ($vtextbackslashsin(i)= 35.1textbackslashpm1.0$km/s) early F3V-dwarf, HD115447 (TOI-778). The transit signal taken from Sectors 10 and 37 of TESS's initial detection of the exoplanet is combined with follow-up ground-based photometry and velocity measurements taken from Minerva-Australis, TRES, CORALIE and CHIRON to confirm and characterise TOI-778b. A joint analysis of the light curves and the radial velocity measurements yield a mass, radius, and orbital period for TOI-778b of $2.76textasciicircum+0.24_-0.23$Mjup, $1.370textbackslashpm0.043$Rjup and $textbackslashsim4.63$ days, respectively. The planet orbits a bright ($V = 9.1$mag) F3-dwarf with $M=1.40textbackslashpm0.05$Msun, $R=1.70textbackslashpm0.05$Rsun, and $textbackslashlog g=4.05textbackslashpm0.17$. We observed a spectroscopic transit of TOI-778b, which allowed us to derive a sky-projected spin-orbit angle of $18textasciicircumtextbackslashcirctextbackslashpm11textasciicircumtextbackslashcirc$, consistent with an aligned planetary system. This discovery demonstrates the capability of smaller aperture telescopes such as Minerva-Australis to detect the radial velocity signals produced by planets orbiting broad-line, rapidly rotating stars.
Rodriguez J E; Quinn S N; Zhou G; Vanderburg A; Nielsen L D; Wittenmyer R A; Brahm R; Reed P A; Huang C X; Vach S; Ciardi D R; Oelkers R J; Stassun K G; Hellier C; Gaudi B S; Eastman J D; Collins K A; Bieryla A; Christian S; Latham D W; Wright D J; Matthews E; Gonzales E J; Ziegler C; Dressing C D; Howell S B; Tan T; Wittrock J; Plavchan P; McLeod K K; Baker D; Wang G; Radford D; Schwarz R P; Esposito M; Ricker G R; Vanderspek R K; Seager S; Winn J N; Jenkins J M; Addison B; Anderson D R; Barclay T; Beatty T G; Berlind P; Bouchy F; Bowen M; Bowler B P; Brasseur C E; Briceño C; Calkins M L; Chaturvedi P; Chaverot G; Chimaladinne S; Christiansen J L; Collins K; Crossfield I J M; Eastridge K; Espinoza N; Esquerdo G A; Feliz D; Fenske T; Fong W; Gan T; Gill H; Gordon L; Granados A; Grieves N; Guenther E W; Guerrero N; Henning T; Henze C E; Hesse K; Hobson M J; Horner J; James D J; Jensen E L N; Jimenez M; Jordán A; Kane S R; Kielkopf J; Kim K; Kuhn R B; Latouf N; Law N M; Levine A M; Lund M B; Mann A W; Mao S; Matson R A; McDermott S; Mengel M W; Mink J; Newman P; O'Dwyer T; Okumura J; Palle E; Pepper J; Quintana E V; Sarkis P; Savel A; Schlieder J E; Schnaible C; Shporer A; Sefako R; Seidel J; Siverd R J; Skinner B; Stalport M; Stevens D J; Stibbard C; Tinney C G; West R G; Yahalomi D A; Zhang H
TESS Delivers Five New Hot Giant Planets Orbiting Bright Stars from the Full Frame Images (Journal Article)
In: arXiv:2101.01726 [astro-ph], 2021, (arXiv: 2101.01726).
We present the discovery and characterization of five hot and warm Jupiters -- TOI-628 b (TIC 281408474; HD 288842), TOI-640 b (TIC 147977348), TOI-1333 b (TIC 395171208, BD+47 3521A), TOI-1478 b (TIC 409794137), and TOI-1601 b (TIC 139375960) -- based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The five planets were identified from the full frame images and were confirmed through a series of photometric and spectroscopic follow-up observations by the $TESS$ Follow-up Observing Program (TFOP) Working Group. The planets are all Jovian size (R$_textbackslashrm P$ = 1.01-1.77 R$_textbackslashrm J$) and have masses that range from 0.85 to 6.33 M$_textbackslashrm J$. The host stars of these systems have F and G spectral types (5595 $textbackslashle$ T$_textbackslashrm eff$ $textbackslashle$ 6460 K) and are all relatively bright (9 $textlessVtextless$ 10.8, 8.2 $textlessKtextless$ 9.3) making them well-suited for future detailed characterization efforts. Three of the systems in our sample (TOI-640 b, TOI-1333 b, and TOI-1601 b) orbit subgiant host stars (log g$_*$ $textless$4.1). TOI-640 b is one of only three known hot Jupiters to have a highly inflated radius (R$_textbackslashrm P$ textgreater 1.7R$_textbackslashrm J$, possibly a result of its host star's evolution) and resides on an orbit with a period longer than 5 days. TOI-628 b is the most massive hot Jupiter discovered to date by $TESS$ with a measured mass of $6.31textasciicircum+0.28_-0.30$ M$_textbackslashrm J$ and a statistically significant, non-zero orbital eccentricity of e = $0.074textasciicircum+0.021_-0.022$. This planet would not have had enough time to circularize through tidal forces from our analysis, suggesting that it might be remnant eccentricity from its migration. The longest period planet in this sample, TOI-1478 b (P = 10.18 days), is a warm Jupiter in a circular orbit around a near-Solar analogue. NASA's $TESS$ mission is continuing to increase the sample of well-characterized hot and warm Jupiters, complementing its primary mission goals.
Powell B P; Kostov V B; Rappaport S A; Borkovits T; Zasche P; Tokovinin A; Kruse E; Latham D W; Montet B T; Jensen E L N; Jayaraman R; Collins K A; Masek M; Hellier C; Evans P; Tan T; Schlieder J E; Torres G; Smale A P; Friedman A H; Barclay T; Gagliano R; Quintana E V; Jacobs T L; Gilbert E A; Kristiansen M H; Colon K D; LaCourse D M; Olmschenk G; Omohundro M; Schnittman J D; Schwengeler H M; Barry R K; Terentev I A; Boyd P; Schmitt A R; Quinn S N; Vanderburg A; Palle E; Armstrong J; Ricker G R; Vanderspek R; Seager S; Winn J N; Jenkins J M; Caldwell D A; Wohler B; Shiao B; Burke C J; Daylan T; Villasenor J
TIC 168789840: A Sextuply-Eclipsing Sextuple Star System (Journal Article)
In: arXiv:2101.03433 [astro-ph], 2021, (arXiv: 2101.03433).
We report the discovery of a sextuply-eclipsing sextuple star system from TESS data, TIC 168789840, also known as TYC 7037-89-1, the first known sextuple system consisting of three eclipsing binaries. The target was observed in Sectors 4 and 5 during Cycle 1, with lightcurves extracted from TESS Full Frame Image data. It was also previously observed by the WASP survey and ASAS-SN. The system consists of three gravitationally-bound eclipsing binaries in a hierarchical structure of an inner quadruple system with an outer binary subsystem. Follow-up observations from several different observatories were conducted as a means of determining additional parameters. The system was resolved by speckle interferometry with a 0."42 separation between the inner quadruple and outer binary, inferring an estimated outer period of textasciitilde2 kyr. It was determined that the fainter of the two resolved components is an 8.217 day eclipsing binary, which orbits the inner quadruple that contains two eclipsing binaries with periods of 1.570 days and 1.306 days. MCMC analysis of the stellar parameters has shown that the three binaries of TIC 168789840 are "triplets", as each binary is quite similar to the others in terms of mass, radius, and Teff. As a consequence of its rare composition, structure, and orientation, this object can provide important new insight into the formation, dynamics, and evolution of multiple star systems. Future observations could reveal if the intermediate and outer orbital planes are all aligned with the planes of the three inner eclipsing binaries.
Ikwut-Ukwa M; Rodriguez J E; Quinn S N; Zhou G; Vanderburg A; Ali A; Bunten K; Gaudi B S; Latham D W; Howell S B; Huang C X; Bieryla A; Collins K A; Carmichael T W; Rabus M; Eastman J D; Collins K I; Tan T; Schwarz R P; Myers G; Stockdale C; Kielkopf J F; Radford D J; Oelkers R J; Jenkins J M; Ricker G R; Seager S; Vanderspek R K; Winn J N; Burt J; Butler R P; Calkins M L; Crane J D; Gnilka C L; Esquerdo G A; Fong W; Kreidberg L; Mink J; Rodriguez D R; Schlieder J E; Schectman S; Shporer A; Teske J; Ting E B; Villasenor J N; Yahalomi D A
Two Massive Jupiters in Eccentric Orbits from the TESS Full Frame Images (Journal Article)
In: arXiv:2102.02222 [astro-ph], 2021, (arXiv: 2102.02222).
We report the discovery of two short-period massive giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30-minute cadence Full Frame Images and confirmed using ground-based photometric and spectroscopic follow-up observations from TESS's Follow-up Observing Program Working Group. We find that TOI-558 b, which transits an F-dwarf ($M_textbackslashstar=1.349textasciicircum+0.064_-0.065textbackslash M_textbackslashodot$, $R_textbackslashstar=1.496textasciicircum+0.042_-0.040textbackslash R_textbackslashodot$, $T_eff=6466textasciicircum+95_-93$ K, age $1.79textasciicircum+0.91_-0.73$ Gyr) with an orbital period of 14.574 days, has a mass of $3.61textbackslashpm0.15textbackslash M_J$, a radius of $1.086textasciicircum+0.041_-0.038textbackslash R_J$, and an eccentric (e=$0.300textasciicircum+0.022_-0.020$) orbit. TOI-559 b transits a G-dwarf ($M_textbackslashstar=1.026textbackslashpm0.057textbackslash M_textbackslashodot$, $R_textbackslashstar=1.233textasciicircum+0.028_-0.026textbackslash R_textbackslashodot$, $T_eff=5925textasciicircum+85_-76$ K, age $1.79textasciicircum+0.91_-0.73$ Gyr) in an eccentric (e=$0.151textbackslashpm0.011$) 6.984-day orbit with a mass of $6.01textasciicircum+0.24_-0.23textbackslash M_J$ and a radius of $1.091textasciicircum+0.028_-0.025textbackslash R_J$. Our spectroscopic follow-up also reveals a long-term radial velocity trend for TOI-559, indicating a long-period companion. The statistically significant orbital eccentricity measured for each system suggests that these planets migrated to their current location through dynamical interactions. Interestingly, both planets are also massive ($textgreater3textbackslash M_J$), adding to the population of massive hot Jupiters identified by TESS. Prompted by these new detections of high-mass planets, we analyzed the known mass distribution of hot Jupiters but find no significant evidence for multiple populations. TESS should provide a near magnitude-limited sample of transiting hot Jupiters, allowing for future detailed population studies.
Newton E R; Mann A W; Kraus A L; Livingston J H; Vanderburg A; Curtis J L; Thao P C; Hawkins K; Wood M L; Rizzuto A C; Soubkiou A; Tofflemire B M; Zhou G; Crossfield I J M; Pearce L A; Collins K A; Conti D M; Tan T; Villeneuva S; Spencer A; Dragomir D; Quinn S N; Jensen E L N; Collins K I; Stockdale C; Cloutier R; Hellier C; Benkhaldoun Z; Ziegler C; Briceño C; Law N; Benneke B; Christiansen J L; Gorjian V; Kane S R; Kreidberg L; Morales F Y; Werner M W; Twicken J D; Levine A M; Ciardi D R; Guerrero N M; Hesse K; Quintana E V; Shiao B; Smith J C; Torres G; Ricker G R; Vanderspek R; Seager S; Winn J N; Jenkins J M; Latham D W
TESS Hunt for Young and Maturing Exoplanets (THYME) IV: Three small planets orbiting a 120 Myr-old star in the Pisces--Eridanus stream (Journal Article)
In: AJ, vol. 161, no. 2, pp. 65, 2021, ISSN: 1538-3881, (arXiv: 2102.06049).
Young exoplanets can offer insight into the evolution of planetary atmospheres, compositions, and architectures. We present the discovery of the young planetary system TOI 451 (TIC 257605131, Gaia DR2 4844691297067063424). TOI 451 is a member of the 120-Myr-old Pisces--Eridanus stream (Psc--Eri). We confirm membership in the stream with its kinematics, its lithium abundance, and the rotation and UV excesses of both TOI 451 and its wide binary companion, TOI 451 B (itself likely an M dwarf binary). We identified three candidate planets transiting in the TESS data and followed up the signals with photometry from Spitzer and ground-based telescopes. The system comprises three validated planets at periods of 1.9, 9.2 and 16 days, with radii of 1.9, 3.1, and 4.1 Earth radii, respectively. The host star is near-solar mass with V=11.0 and H=9.3 and displays an infrared excess indicative of a debris disk. The planets offer excellent prospects for transmission spectroscopy with HST and JWST, providing the opportunity to study planetary atmospheres that may still be in the process of evolving.
Zang W; Han C; Kondo I; Yee J C; Lee C; Gould A; Mao S; de Almeida L; Shvartzvald Y; Zhang X; Albrow M D; Chung S; Hwang K; Jung Y K; Ryu Y; Shin I; Cha S; Kim D; Kim H; Kim S; Lee D; Lee Y; Park B; Pogge R W; Drummond J; Tan T; Júnior J D N; Maoz D; Penny M T; Zhu W; Bond I A; Abe F; Barry R; Bennett D P; Bhattacharya A; Donachie M; Fujii H; Fukui A; Hirao Y; Itow Y; Kirikawa R; Koshimoto N; Li M C A; Matsubara Y; Muraki Y; Miyazaki S; Ranc C; Rattenbury N J; Satoh Y; Shoji H; Sumi T; Suzuki D; Tanaka Y; Tristram P J; Yamawaki T; Yonehara A; Petric A; Burdullis T; Fouqué P
An Earth-mass Planet in a Time of Covid-19: KMT-2020-BLG-0414Lb (Journal Article)
In: arXiv:2103.01896 [astro-ph], 2021, (arXiv: 2103.01896).
We report the discovery of KMT-2020-BLG-0414Lb, with a planet-to-host mass ratio $q_2 = 0.9$--$1.2 textbackslashtimes 10textasciicircum-5 = 3$--$4textasciitildeq_textbackslashoplus$ at $1textbackslashsigma$, which is the lowest mass-ratio microlensing planet to date. Together with two other recent discoveries ($4 textbackslashlesssim q/q_textbackslashoplus textbackslashlesssim 6$), it fills out the previous empty sector at the bottom of the triangular $(textbackslashlog s, textbackslashlog q)$ diagram, where $s$ is the planet-host separation in units of the angular Einstein radius $textbackslashtheta_textbackslashrm E$. Hence, these discoveries call into question the existence, or at least the strength, of the break in the mass-ratio function that was previously suggested to account for the paucity of very low-$q$ planets. Due to the extreme magnification of the event, $A_textbackslashrm maxtextbackslashsim 1450$ for the underlying single-lens event, its light curve revealed a second companion with $q_3 textbackslashsim 0.05$ and $textbartextbackslashlog s_3textbar textbackslashsim 1$, i.e., a factor $textbackslashsim 10$ closer to or farther from the host in projection. The measurements of the microlens parallax $textbackslashpi_textbackslashrm E$ and the angular Einstein radius $textbackslashtheta_textbackslashrm E$ allow estimates of the host, planet, and second companion masses, $(M_1, M_2, M_3) textbackslashsim (0.3M_textbackslashodot, 1.0M_textbackslashoplus, 17M_J)$, the planet and second companion projected separations, $(a_textbackslashperp,2, a_textbackslashperp,3) textbackslashsim (1.5, 0.15textasciitildetextbackslashrm ortextasciitilde15)$textasciitildeau, and system distance $D_textbackslashrm L textbackslashsim 1$ kpc. The lens could account for most or all of the blended light ($I textbackslashsim 19.3$) and so can be studied immediately with high-resolution photometric and spectroscopic observations that can further clarify the nature of the system. The planet was found as part of a new program of high-cadence follow-up observations of high-magnification events. The detection of this planet, despite the considerable difficulties imposed by Covid-19 (two KMT sites and OGLE were shut down), illustrates the potential utility of this program.
Desidera S; Chauvin G; Bonavita M; Messina S; LeCoroller H; Schmidt T; Gratton R; Lazzoni C; Meyer M; Schlieder J; Cheetham A; Hagelberg J; Bonnefoy M; Feldt M; Lagrange A -M; Langlois M; Vigan A; Tan T G; Hambsch F -J; Millward M; Alcala J; Benatti S; Brandner W; Carson J; Covino E; Delorme P; D'Orazi V; Janson M; Rigliaco E; Beuzit J -L; Biller B; Boccaletti A; Dominik C; Cantalloube F; Fontaniv C; Galicher R; Henning T; Lagadec E; Ligi R; Maire A -L; Menard F; Mesa D; Muller A; Samland M; Schmid H M; Sissa E; Turatto M; Udry S; Asensio-Torres A Z R; Kopytova T; Rickman E; Abe L; Antichi J; Baruffolo A; Baudoz P; Baudrand J; Blanchard P; Bazzon A; Buey T; Carbillet M; Carle M; Charton J; Cascone E; Claudi R; Costille A; Deboulbe A; De Caprio V; Dohlen K; Fantinel D; Feautrier P; Fusco T; Gigan P; Giro E; Gisler D; Gluck L; Hubin N; Hugot E; Jaquet M; Kasper M; Madec F; Magnard Y; Martinez P; Maurel D; Mignant D L; Moller-Nilsson O; Llored M; Moulin T; Origne A; Pavlov A; Perret D; Petit C; Pragt J; Puget P; Rabou P; Ramon J; Rigal F; Rochat S; Roelfsema R; Rousset G; Roux A; Salasnich B; Sauvage J -F; Sevin A; Soenke C; Stadler E; Suarez M; Weber L; Wildi F
The SPHERE infrared survey for exoplanets (SHINE)- I Sample definition and target characterization (Journal Article)
In: arXiv:2103.04366 [astro-ph], 2021, (arXiv: 2103.04366).
Large surveys with new-generation high-contrast imaging instruments are needed to derive the frequency and properties of exoplanet populations with separations from $textbackslashsim$5 to 300 AU. A careful assessment of the stellar properties is crucial for a proper understanding of when, where, and how frequently planets form, and how they evolve. The sensitivity of detection limits to stellar age makes this a key parameter for direct imaging surveys. We describe the SpHere INfrared survey for Exoplanets (SHINE), the largest direct imaging planet-search campaign initiated at the VLT in 2015 in the context of the SPHERE Guaranteed Time Observations of the SPHERE consortium. In this first paper we present the selection and the properties of the complete sample of stars surveyed with SHINE, focusing on the targets observed during the first phase of the survey (from February 2015 to February 2017). This early sample composed of 150 stars is used to perform a preliminary statistical analysis of the SHINE data, deferred to two companion papers presenting the survey performance, main discoveries, and the preliminary statistical constraints set by SHINE. Based on a large database collecting the stellar properties of all young nearby stars in the solar vicinity (including kinematics, membership to moving groups, isochrones, lithium abundance, rotation, and activity), we selected the original sample of 800 stars that were ranked in order of priority according to their sensitivity for planet detection in direct imaging with SPHERE. The properties of the stars that are part of the early statistical sample were revisited, including for instance measurements from the GAIA Data Release 2.
Trifonov T; Caballero J A; Morales J C; Seifahrt A; Ribas I; Reiners A; Bean J L; Luque R; Parviainen H; Pallé E; Stock S; Zechmeister M; Amado P J; Anglada-Escudé3 G; Azzaro M; Barclay T; Béjar V J S; Bluhm P; Casasayas-Barris N; Cifuentes C; Collins K A; Collins K I; Cortés-Contreras M; de Leon J; Dreizler S; Dressing C D; Esparza-Borges E; Espinoza N; Fausnaugh M; Fukui A; Hatzes A P; Hellier C; Henning T; Henze C E; Herrero E; Jeffers S V; Jenkins J M; Jensen E L N; Kaminski A; Kasper D; Kossakowski D; Kürster M; Lafarga M; Latham D W; Mann A W; Molaverdikhani K; Montes D; Montet B T; Murgas F; Narita N; Oshagh M; Passegger V M; Pollacco D; Quinn S N; Quirrenbach A; Ricker G R; López C R; Sanz-Forcada J; Schwarz R P; Schweitzer A; Seager S; Shporer A; Stangret M; Stürmer J; Tan T G; Tenenbaum P; Twicken J D; Vanderspek R; Winn J N
A nearby transiting rocky exoplanet that is suitable for atmospheric investigation (Journal Article)
In: Science, vol. 371, no. 6533, pp. 1038–1041, 2021, ISSN: 0036-8075, 1095-9203, (arXiv: 2103.04950).
Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of textasciitilde8.1 parsecs, has a J-band magnitude of textasciitilde7.2, and is observable from both hemispheres of Earth. On the basis of these properties and the planet's short orbital period and high equilibrium temperature, we show that this terrestrial planet is suitable for emission and transit spectroscopy.
Dong J; Huang C X; Dawson R I; Foreman-Mackey D; Collins K A; Quinn S N; Lissauer J J; Beatty T G; Quarles B; Sha L; Shporer A; Guo Z; Kane S R; Abe L; Barkaoui K; Benkhaldoun Z; Brahm R A; Bouchy F; Carmichael T W; Collins K I; Conti D M; Crouzet N; Dransfield G; Evans P; Gan T; Ghachoui M; Gillon M; Grieves N; Guillot T; Hellier C; Jehin E; Jensen E L; Jordan A; Kamler J; Kielkopf J; Mekarnia D; Nielsen L D; Pozuelos F J; Radford D J; Schmider F; Schwarz R P; Stockdale C; Tan T; Timmermans M; Triaud A H; Wang G; Ricker G R; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; Mireles I; Yahalomi D; Morgan E H; Vezie M; Quintana E V; Rose M E; Smith J C; Shiao B
Warm Jupiters in TESS Full-Frame Images: A Catalog and Observed Eccentricity Distribution for Year 1 (Journal Article)
In: arXiv:2104.01970 [astro-ph], 2021, (arXiv: 2104.01970).
Warm Jupiters -- defined here as planets larger than 6 Earth radii with orbital periods of 8--200 days -- are a key missing piece in our understanding of how planetary systems form and evolve. It is currently debated whether Warm Jupiters form in situ, undergo disk or high eccentricity tidal migration, or have a mixture of origin channels. These different classes of origin channels lead to different expectations for Warm Jupiters' properties, which are currently difficult to evaluate due to the small sample size. We take advantage of the textbackslashTESS survey and systematically search for Warm Jupiter candidates around main-sequence host stars brighter than the textbackslashTESS-band magnitude of 12 in the Full-Frame Images in Year 1 of the textbackslashTESS Prime Mission data. We introduce a catalog of 55 Warm Jupiter candidates, including 19 candidates that were not originally released as textbackslashTESS Objects of Interest (TOIs) by the textbackslashTESS team. We fit their textbackslashTESS light curves, characterize their eccentricities and transit-timing variations (TTVs), and prioritize a list for ground-based follow-up and textbackslashTESS Extended Mission observations. Using hierarchical Bayesian modeling, we find the preliminary eccentricity distributions of our Warm-Jupiter-candidate catalog using a Beta distribution, a Rayleigh distribution, and a two-component Gaussian distribution as the functional forms of the eccentricity distribution. Additional follow-up observations will be required to clean the sample of false positives for a full statistical study, derive the orbital solutions to break the eccentricity degeneracy, and provide mass measurements.
Bryant E M; Bayliss D; Santerne A; Wheatley P J; Nascimbeni V; Ducrot E; Burdanov A; Acton J S; Alves D R; Anderson D R; Armstrong D J; Awiphan S; Cooke B F; Burleigh M R; Casewell S L; Delrez L; Demory B; Eigmüller P; Fukui A; Gan T; Gill S; Gillon M; Goad M R; Tan T; Günther M N; Hardee B; Henderson B A; Jehin E; Jenkins J S; Kosiarek M; Lendl M; Moyano M; Murray C A; Narita N; Niraula P; Odden C E; Palle E; Parviainen H; Pedersen P P; Pozuelos F J; Rackham B V; Sebastian D; Stockdale C; Tilbrook R H; Thompson S J; Triaud A H M J; Udry S; Vines J I; West R G; de Wit J
A transit timing variation observed for the long-period extremely low density exoplanet HIP 41378f (Journal Article)
In: arXiv:2104.03159 [astro-ph], 2021, (arXiv: 2104.03159).
HIP 41378 f is a temperate $9.2textbackslashpm0.1 R_textbackslashoplus$ planet with period of 542.08 days and an extremely low density of $0.09textbackslashpm0.02$ g cm$textasciicircum-3$. It transits the bright star HIP 41378 (V=8.93), making it an exciting target for atmospheric characterization including transmission spectroscopy. HIP 41378 was monitored photometrically between the dates of 2019 November 19 and November 28. We detected a transit of HIP 41378 f with NGTS, just the third transit ever detected for this planet, which confirms the orbital period. This is also the first ground-based detection of a transit of HIP 41378 f. Additional ground-based photometry was also obtained and used to constrain the time of the transit. The transit was measured to occur 1.50 hours earlier than predicted. We use an analytic transit timing variation (TTV) model to show the observed TTV can be explained by interactions between HIP 41378 e and HIP 41378 f. Using our TTV model, we predict the epochs of future transits of HIP 41378 f, with derived transit centres of T$_C,4 = 2459355.087textasciicircum+0.031_-0.022$ (May 2021) and T$_C,5 = 2459897.078textasciicircum+0.114_-0.060$ (Nov 2022).
Grieves N; Bouchy F; Lendl M; Carmichael T; Mireles I; Shporer A; McLeod K K; Collins K A; Brahm R; Stassun K G; Gill S; Bouma L G; Guillot T; Cointepas M; Santos L A D; Casewell S L; Jenkins J M; Henning T; Nielsen L D; Psaridi A; Udry S; Ségransan D; Eastman J D; Zhou G; Abe L; Agabi A; Charbonneau D; Collins K I; Colon K D; Crouzet N; Dransfield G; Evans P; Goeke R F; Hart R; Irwin J M; Jensen E L N; Jordán A; Kielkopf J F; Latham D W; Marie-Sainte W; Mékarnia D; Nelson P; Quinn S N; Radford D J; Rodriguez D R; Rowden P; Schmider F; Schwarz R P; Smith J C; Stockdale C; Suarez O; Tan T; Triaud A H M J; Waalkes W; Wingham G
Populating the brown dwarf and stellar boundary: Five stars with transiting companions near the hydrogen-burning mass limit (Journal Article)
In: arXiv:2107.03480 [astro-ph], 2021, (arXiv: 2107.03480).
We report the discovery of five transiting companions near the hydrogen-burning mass limit in close orbits around main sequence stars originally identified by the Transiting Exoplanet Survey Satellite (TESS) as TESS Objects of Interest (TOIs): TOI-148, TOI-587, TOI-681, TOI-746, and TOI-1213. Using TESS and ground-based photometry as well as radial velocities from the CORALIE, CHIRON, TRES, and FEROS spectrographs, we found the companions have orbital periods between 4.8 and 27.2 days, masses between 77 and 98 $textbackslashmathrmM_Jup$, and radii between 0.81 and 1.66 $textbackslashmathrmR_Jup$. These targets have masses near the uncertain lower limit of hydrogen core fusion ($textbackslashsim$73-96 $textbackslashmathrmM_Jup$), which separates brown dwarfs and low-mass stars. We constrained young ages for TOI-587 (0.2 $textbackslashpm$ 0.1 Gyr) and TOI-681 (0.17 $textbackslashpm$ 0.03 Gyr) and found them to have relatively larger radii compared to other transiting companions of a similar mass. Conversely we estimated older ages for TOI-148 and TOI-746 and found them to have relatively smaller companion radii. With an effective temperature of 9800 $textbackslashpm$ 200 K, TOI-587 is the hottest known main-sequence star to host a transiting brown dwarf or very low-mass star. We found evidence of spin-orbit synchronization for TOI-148 and TOI-746 as well as tidal circularization for TOI-148. These companions add to the population of brown dwarfs and very low-mass stars with well measured parameters ideal to test formation models of these rare objects, the origin of the brown dwarf desert, and the distinction between brown dwarfs and hydrogen-burning main sequence stars.
Osborn A; Armstrong D J; Cale B; Brahm R; Wittenmyer R A; Dai F; Crossfield I J M; Bryant E M; Adibekyan V; Cloutier R; Collins K A; Mena E D; Fridlund M; Hellier C; Howell S B; King G W; Lillo-Box J; Otegi J; Sousa S; Stassun K G; Matthews E C; Ziegler C; Ricker G; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; Acton J S; Addison B C; Anderson D R; Ballard S; Barrado D; Barros S C C; Batalha N; Bayliss D; Barclay T; Benneke B; Berberian Jr. J; Bouchy F; Bowler B P; Briceño C; Burke C J; Burleigh M R; Casewell S L; Ciardi D; Collins K I; Cooke B F; Demangeon O D S; Díaz R F; Dorn C; Dragomir D; Dressing C; Dumusque X; Espinoza N; Figueira P; Fulton B; Furlan E; Gaidos E; Geneser C; Gill S; Goad M R; Gonzales E J; Gorjian V; Günther M N; Helled R; Henderson B A; Henning T; Hogan A; Hojjatpanah S; Horner J; Howard A W; Hoyer S; Huber D; Isaacson H; Jenkins J S; Jensen E L N; Jordán A; Kane S R; Kidwell Jr. R C; Kielkopf J; Law N; Lendl M; Lund M; Matson R A; Mann A W; McCormac J; Mengel M W; Morales F Y; Nielsen L D; Okumura J; Osborn H P; Petigura E A; Plavchan P; Pollacco D; Quintana E V; Raynard L; Robertson P; Rose M E; Roy A; Reefe M; Santerne A; Santos N C; Sarkis P; Schlieder J; Schwarz R P; Scott N J; Shporer A; Smith A M S; Stibbard C; Stockdale C; Strøm P A; Twicken J D; Tan T; Tanner A; Teske J; Tilbrook R H; Tinney C G; Udry S; Villaseñor J N; Vines J I; Wang S X; Weiss L M; West R G; Wheatley P J; Wright D J; Zhang H; Zohrabi F
TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet (Journal Article)
In: arXiv:2108.02310 [astro-ph], 2021, (arXiv: 2108.02310).
We present the bright (V$_mag = 9.12$), multi-planet system TOI-431, characterised with photometry and radial velocities. We estimate the stellar rotation period to be $30.5 textbackslashpm 0.7$ days using archival photometry and radial velocities. TOI-431b is a super-Earth with a period of 0.49 days, a radius of 1.28 $textbackslashpm$ 0.04 R$_textbackslashoplus$, a mass of $3.07 textbackslashpm 0.35$ M$_textbackslashoplus$, and a density of $8.0 textbackslashpm 1.0$ g cm$textasciicircum-3$; TOI-431d is a sub-Neptune with a period of 12.46 days, a radius of $3.29 textbackslashpm 0.09$ R$_textbackslashoplus$, a mass of $9.90textasciicircum+1.53_-1.49$ M$_textbackslashoplus$, and a density of $1.36 textbackslashpm 0.25$ g cm$textasciicircum-3$. We find a third planet, TOI-431c, in the HARPS radial velocity data, but it is not seen to transit in the TESS light curves. It has an $M textbackslashsin i$ of $2.83textasciicircum+0.41_-0.34$ M$_textbackslashoplus$, and a period of 4.85 days. TOI-431d likely has an extended atmosphere and is one of the most well-suited TESS discoveries for atmospheric characterisation, while the super-Earth TOI-431b may be a stripped core. These planets straddle the radius gap, presenting an interesting case-study for atmospheric evolution, and TOI-431b is a prime TESS discovery for the study of rocky planet phase curves.
Silverstein M L; Schlieder J E; Barclay T; Hord B J; Jao W; Vrijmoet E H; Henry T J; Cloutier R; Kostov V B; Kruse E; Winters J G; Irwin J M; Kane S R; Stassun K G; Huang C; Kunimoto M; Tey E; Vanderburg A; Astudillo-Defru N; Bonfils X; Brasseur C E; Charbonneau D; Ciardi D R; Collins K A; Collins K I; Conti D M; Crossfield I J M; Daylan T; Doty J P; Dressing C D; Gilbert E A; Horne K; Jenkins J M; Latham D W; Mann A W; Matthews E; Paredes L A; Quinn S N; Ricker G R; Schwarz R P; Seager S; Sefako R; Shporer A; Smith J C; Stockdale C; Tan T; Torres G; Twicken J D; Vanderspek R; Wang G; Winn J N
The LHS 1678 System: Two Earth-Sized Transiting Planets and an Astrometric Companion Orbiting an M Dwarf Near the Convective Boundary at 20 pc (Journal Article)
In: arXiv:2110.12079 [astro-ph], 2021, (arXiv: 2110.12079).
We present the TESS discovery of the LHS 1678 (TOI-696) exoplanet system, comprised of two approximately Earth-sized transiting planets and a likely astrometric brown dwarf orbiting a bright ($V_J$=12.5, $K_s$=8.3) M2 dwarf at 19.9 pc. The two TESS-detected planets are of radius 0.70$textbackslashpm$0.04 $R_textbackslashoplus$ and 0.98$textbackslashpm$0.06 $R_textbackslashoplus$ in 0.86-day and 3.69-day orbits, respectively. Both planets are validated and characterized via ground-based follow-up observations. HARPS RV monitoring yields 97.7 percentile mass upper limits of 0.35 $M_textbackslashoplus$ and 1.4 $M_textbackslashoplus$ for planets b and c, respectively. The astrometric companion detected by the CTIO/SMARTS 0.9m has an orbital period on the order of decades and is undetected by other means. Additional ground-based observations constrain the companion to being a high-mass brown dwarf or smaller. Each planet is of unique interest; the inner planet has an ultra-short period, and the outer planet is in the Venus zone. Both are promising targets for atmospheric characterization with the JWST and mass measurements via extreme-precision radial velocity. A third planet candidate of radius 0.9$textbackslashpm$0.1 $R_textbackslashoplus$ in a 4.97-day orbit is also identified in multi-Cycle TESS data for validation in future work. The host star is associated with an observed gap in the lower main sequence of the Hertzsprung-Russell diagram. This gap is tied to the transition from partially- to fully-convective interiors in M dwarfs, and the effect of the associated stellar astrophysics on exoplanet evolution is currently unknown. The culmination of these system properties makes LHS 1678 a unique, compelling playground for comparative exoplanet science and understanding the formation and evolution of small, short-period exoplanets orbiting low-mass stars.
Barragán O; Armstrong D J; Gandolfi D; Carleo I; Vidotto A A; D'Angelo C V; Oklopčić A; Isaacson H; Oddo D; Collins K; Fridlund M; Sousa S G; Persson C M; Hellier C; Howell S; Howard A; Redfield S; Eisner N; Georgieva I Y; Dragomir D; Bayliss D; Nielsen L D; Klein B; Aigrain S; Zhang M; Teske J; Twicken J D; Jenkins J; Esposito M; Van Eylen V; Rodler F; Adibekyan V; Alarcon J; Anderson D R; Murphy J M A; Barrado D; Barros S C C; Benneke B; Bouchy F; Bryant E M; Butler P; Burt J; Cabrera J; Casewell S; Chaturvedi P; Cloutier R; Cochran W D; Crane J; Crossfield I; Crouzet N; Collins K I; Dai F; Deeg H J; Deline A; Demangeon O D S; Dumusque X; Figueira P; Furlan E; Gnilka C; Goad M R; Goffo E; Gutiérrez-Canales F; Hadjigeorghiou A; Hartman Z; Hatzes A P; Harris M; Henderson B; Hirano T; Hojjatpanah S; Hoyer S; Kabáth P; Korth J; Lillo-Box J; Luque R; Marmier M; Močnik T; Muresan A; Murgas F; Nagel E; Osborne H L M; Osborn A; Osborn H P; Palle E; Raimbault M; Ricker G R; Rubenzahl R A; Stockdale C; Santos N C; Scott N; Schwarz R P; Shectman S; Raimbault M; Seager S; Ségransan D; Serrano L M; Skarka M; Smith A M S; Šubjak J; Tan T G; Udry S; Watson C; Wheatley P J; West R; Winn J N; Wang S X; Wolfgang A; Ziegler C
The young HD 73583 (TOI-560) planetary system: Two 10-M$_textbackslashoplus$ mini-Neptunes transiting a 750-Myr-old, bright, and active K dwarf (Journal Article)
In: arXiv:2110.13069 [astro-ph], 2021, (arXiv: 2110.13069).
We present the discovery and characterisation of two transiting planets discovered by TESS in the light curves of the young and bright (V=9.67) star HD 73583 (TOI-560). We perform an intensive spectroscopic and photometric space- and ground-based follow-up in order to confirm and characterise the system. We found that HD 73583 is a young (750 Myr) active star with a rotational period of $12.1$ d and a mass and radius of $ 0.71 M_textbackslashodot$ and $0.66 R_textbackslashodot$, respectively. HD 73583 b ($P_textbackslashrm b=$ $6.4$d) has a mass and radius of $10 M_textbackslashoplus$ and $2.83 textbackslashpm 0.10 R_textbackslashoplus$, respectively, that gives a density of $2.43 textbackslashrm gtextbackslash,cmtextasciicircum-3$. HD 73583 c ($P_textbackslashrm c= 18.9$ d) has a mass and radius of $9.6 M_textbackslashoplus$ and $2.37 R_textbackslashoplus$, respectively, this translates to a density of $3.97 textbackslashrm gtextbackslash,cmtextasciicircum-3$. Both planets are consistent with worlds made of a solid core surrounded by a thick envelope. Because of their youth and host star brightness, they both are excellent candidates to perform transmission spectroscopy studies and search for mass-loss signatures. We expect atmospheric mass-loss rates of $2.4 textbackslashtimes 10textasciicircum10textbackslash,textbackslashrm gtextbackslash,stextasciicircum-1$ and $5.4 textbackslashtimes 10textasciicircum9textbackslash,textbackslashrm gtextbackslash,stextasciicircum-1$ for HD73583 b and c, respectively. We expect that the detection of evaporating signatures on H and He would be challenging, but doable with present and future instruments.
Mufti M E; Plavchan P P; Isaacson H; Cale B L; Feliz D L; Reefe M A; Hellier C; Stassun K; Eastman J; Polanski A; Crossfield I J M; Gaidos E; Kostov V; Villasenor J; Schlieder J E; Bouma L G; Collins K I; Wittrock J M; Zohrabi F; Lee R A; Sohani A; Berberian J; Vermilion D; Newman P; Geneser C; Tanner A; Batalha N M; Dressing C; Fulton B; Howard A W; Huber D; Kane S R; Petigura E A; Robertson P; Roy A; Weiss L M; Behmard A; Beard C; Chontos A; Dai F; Dalba P A; Fetherolf T; Giacalone S; Hill M L; Hirsch L A; Holcomb R; Lubin J; Mayo A; Movcnik T; Murphy J M A; Rosenthal L J; Rubenzahl R A; Scarsdale N; Stockdale C; Collins K; Cloutier R; Relles H; Tan T; Scott N J; Hartman Z; Matthews E; Ciardi D; Gonzales E; Matson R A; Beichman C; Furlan E; Gnilka C L; Howell S B; Ziegler C; Briceno C; Law N; Mann A W; Rabus M; Johnson M C; Christiansen J; Kreidberg L; Werner M W; Berardo D A; Deming D; Gorjian V; Morales F Y; Benneke B; Dragomir D; Wittenmyer R A; Ballard S; Bowler B P; Horner J; Kielkopf J; Liu H; Shporer A; Tinney C G; Zhang H; Wright D J; Addison B C; Mengel M W; Okumura J
TOI 560 : Two Transiting Planets Orbiting a K Dwarf Validated with iSHELL, PFS and HIRES RVs (Journal Article)
In: arXiv:2112.13448 [astro-ph], 2021, (arXiv: 2112.13448).
We validate the presence of a two-planet system orbiting the 0.2--1.4 Gyr K4 dwarf TOI 560 (HD 73583). The system consists of an inner moderately eccentric transiting mini-Neptune (TOI 560 b, $P = 6.397438 textbackslashpm 0.000037$ days, $e=0.294textasciicircum0.13_0.062$) initially discovered in the Sector 8 textbackslashtesstextbackslash mission observations, and a transiting mini-Neptune (TOI 560 c, $P = 18.8779 textbackslashpm 0.0016$ days) discovered in the Sector 34 observations, in a rare 1:3 orbital resonance. We utilize photometric data from textbackslashtesstextbackslash, textbackslashtextitSpitzer, and ground-based follow-up observations to confirm the ephemerides and period of the transiting planets and vet false positive scenarios. We obtain follow-up spectroscopy and corresponding precise radial velocities (RVs) with the iSHELL spectrograph at the NASA Infrared Telescope Facility and the HIRES Spectrograph at Keck Observatory to validate the planetary nature of these signals, which we combine with published PFS RVs from Magellan Observatory. We place upper limits on the masses of both planets of $textless$2.1 and $textless$4.1 M$_Nep$ for b and c, respectively. We apply a Gaussian Processes (GP) model to the textbackslashtesstextbackslash light curves to place priors on a chromatic radial velocity GP model to constrain the stellar activity of the TOI 560 host star. TOI 560 is a nearby moderately young multi-planet system with two planets suitable for atmospheric characterization with James Webb Space Telescope (JWST) and other upcoming missions. In particular, it will undergo six transit pairs separated by $textless$6 hours before June 2027.
Kaye L; Vissapragada S; Günther M N; Aigrain S; Mikal-Evans T; Jensen E L N; Parvianinen H; Pozuelos F J; Abe L; Acton J S; Agabi A; Alves D R; Anderson D R; Armstrong D J; Barkaoui K; Barragán O; Benneke B; Boyd P T; Brahm R; Bruni I; Bryant E M; Burleigh M R; Casewell S L; Ciardi D; Cloutier R; Collins K A; Collins K I; Conti D M; Crossfield I J M; Crouzet N; Daylan T; Dragomir D; Dransfield G; Fabrycky D; Fausnaugh M; Füürész G; Gan T; Gill S; Gillon M; Goad M R; Gorjian V; Greklek-McKeon M; Guerrero N; Guillot T; Jehin E; Jenkins J S; Lendl M; Kamler J; Kane S R; Kielkopf J F; Kunimoto M; Marie-Sainte W; McCormac J; Mékarnia D; Morales F Y; Moyano M; Palle E; Parmentier V; Relles H M; Schmider F; Schwarz R P; Seager S; Smith A M S; Tan T; Taylor J; Triaud A H M J; Twicken J D; Udry S; Vines J I; Wang G; Wheatley P J; Winn J N
Transit Timings Variations in the three-planet system: TOI-270 (Journal Article)
In: Monthly Notices of the RAS, 2021.
Addison B C; Wright D J; Nicholson B A; Cale B; Mocnik T; Huber D; Plavchan P; Wittenmyer R A; Vanderburg A; Chaplin W J; Chontos A; Clark J T; Eastman J D; Ziegler C; Brahm R; Carter B D; Clerte M; Espinoza N; Horner J; Bentley J; Kane S R; Kielkopf J F; Laychock E; Mengel M W; Okumura J; Stassun K G; Bedding T R; Bowler B P; Burnelis A; Collins M; Crossfield I; Davis A B; Evensberget D; Heitzmann A; Howell S B; Law N; Mann A W; Marsden S; O'Connor J; Shporer A; Stevens C; Tinney C G; Tylor C; Wang S; Zhang H; Henning T; Kossakowski D; Ricker G; Sarkis P; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; Mireles I; Rowden P; Pepper J; Daylan T; Schlieder J E; Collins K A; Collins K I; Tan T; Ball W H; Basu S; Buzasi D L; Campante T L; Corsaro E; González-Cuesta L; Davies G R; a R A G; Guo Z; Handberg R; Hekker S; Hey D R; Kallinger T; Kawaler S D; Kayhan C; Kuszlewicz J S; Lund M N; Lyttle A; Mathur S; Miglio A; Mosser B; Nielsen M B; Serenelli A M; Aguirre V S; Themessl N
TOI-257b (HD 19916b): A Warm sub-Saturn on a Moderately Eccentric Orbit Around an Evolved F-type Star (Journal Article)
In: arXiv:2001.07345 [astro-ph], 2020, (arXiv: 2001.07345).
We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial-velocity observations with the Minerva-Australis telescope array. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of $M_P=0.134textasciicircum+0.023_-0.022$$textbackslashrmM_J$ ($42.6textasciicircum+7.3_-7.0$$textbackslashrmM_textbackslashoplus$), a radius of $R_P=0.626textasciicircum+0.013_-0.012$$textbackslashrmR_J$ ($7.02textasciicircum+0.15_-0.13$$textbackslashrmR_textbackslashoplus$), and an orbit with eccentricity $0.242textasciicircum+0.040_-0.065$ and period $18.38827textbackslashpm0.00072$$textbackslashrmdays$. TOI-257b orbits a bright ($textbackslashmathrmV=7.570$mag) somewhat evolved late F-type star with $M_*=1.390textbackslashpm0.046$$textbackslashrmM_textbackslashodot$, $R_*=1.888textbackslashpm0.033$$textbackslashrmR_textbackslashodot$, $T_textbackslashrm eff=6075textbackslashpm90$$textbackslashrmK$, and $vtextbackslashsini=11.3textbackslashpm0.5$km/s. Additionally, we statistically validate a second non-transiting sub-Saturn mass planet on a $textbackslashsim71$day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.
Nielsen L D; Brahm R; Bouchy F; Espinoza N; Turner O; Rappaport S; Pearce L; Ricker G; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; Acton J S; Bakos G; Barclay T; Barkaoui K; Bhatti W; Briceño C; Bryant E M; Burleigh M R; Ciardi D R; Collins K A; Collins K I; Cooke B F; Csubry Z; Santos L A; Eigmüller P; Fausnaugh M M; Gan T; Gillon M; Goad M R; Guerrero N; Hagelberg J; Hart R; Henning T; Huang C X; Jehin E; Jenkins J S; Jordàn A; Kielkopf J F; Kossakowski D; Lavie B; Law N; Lendl M; de Leon J P; Lovis C; Mann A W; Marmier M; McCormac J; Mori M; Moyano M; Narita N; Osip D; Otegi J F; Pepe F; Pozuelos F J; Raynard L; Relles H M; Sarkis P; Segransan D; Seidel J V; Shporer A; Stalport M; Stockdale C; Suc V; Tamura M; Tan T G; Tilbrook R H; Ting E B; Trifonov T; Udry S; Vanderburg A; Wheatley P J; Wingham G; Zhan Z; Ziegler C
Three Short Period Jupiters from TESS (Journal Article)
In: arXiv:2003.05932 [astro-ph], 2020, (arXiv: 2003.05932).
We report the confirmation and mass determination of three hot Jupiters discovered by the Transiting Exoplanet Survey Satellite (TESS) mission: HIP 65Ab (TOI-129, TIC-201248411) is an ultra-short-period Jupiter orbiting a bright (V=11.1 mag) K4-dwarf every 0.98 days. It is a massive 3.213 +/- 0.078 Mjup planet in a grazing transit configuration with impact parameter b = 1.17 +0.10/-0.08. As a result the radius is poorly constrained, 2.03 +0.61/-0.49 Rjup. We perform a full phase-curve analysis of the TESS data and detect both illumination- and ellipsoidal variations as well as Doppler boosting. HIP 65A is part of a binary stellar system, with HIP 65B separated by 269 AU (3.95 arcsec on sky). TOI-157b (TIC 140691463) is a typical hot Jupiter with a mass 1.18 +/- 0.13 Mjup and radius 1.29 +/- 0.02 Rjup. It has a period of 2.08 days, which corresponds to a separation of just 0.03 AU. This makes TOI-157 an interesting system, as the host star is an evolved G9 sub-giant star (V=12.7). TOI-169b (TIC 183120439) is a bloated Jupiter orbiting a V=12.4 G-type star. It has a mass of 0.79 +/- 0.06 Mjup and radius 1.09 +0.08/-0.05 Rjup. Despite having the longest orbital period (P=2.26 days) of the three planets, TOI-169b receives the most irradiation and is situated on the edge of the Neptune desert. All three host stars are metal rich with Fe/H ranging from 0.18 - 0.24.
Armstrong D J; Lopez T A; Adibekyan V; Booth R A; Bryant E M; Collins K A; Emsenhuber A; Huang C X; King G W; Lillo-box J; Lissauer J J; Matthews E C; Mousis O; Nielsen L D; Osborn H; Otegi J; Santos N C; Sousa S G; Stassun K G; Veras D; Ziegler C; Acton J S; Almenara J M; Anderson D R; Barrado D; Barros S C C; Bayliss D; Belardi C; Bouchy F; Briceno C; Brogi M; Brown D J A; Burleigh M R; Casewell S L; Chaushev A; Ciardi D R; Collins K I; Colón K D; Cooke B F; Crossfield I J M; Díaz R F; Deleuil M; Mena E D; Demangeon O D S; Dorn C; Dumusque X; Eigmuller P; Fausnaugh M; Figueira P; Gan T; Gandhi S; Gill S; Goad M R; Guenther M N; Helled R; Hojjatpanah S; Howell S B; Jackman J; Jenkins J S; Jenkins J M; Jensen E L N; Kennedy G M; Latham D W; Law N; Lendl M; Lozovsky M; Mann A W; Moyano M; McCormac J; Meru F; Mordasini C; Osborn A; Pollacco D; Queloz D; Raynard L; Ricker G R; Rowden P; Santerne A; Schlieder J E; Seager S; Sha L; Tan T; Tilbrook R H; Ting E; Udry S; Vanderspek R; Watson C A; West R G; Wilson P A; Winn J N; Wheatley P; Villasenor J N; Vines J I; Zhan Z
A remnant planetary core in the hot Neptunian desert (Journal Article)
In: arXiv:2003.10314 [astro-ph], 2020, (arXiv: 2003.10314).
The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to major uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary pathways provide a new route to understanding planetary interiors. We present the discovery of TOI-849b, the remnant core of a giant planet, with a radius smaller than Neptune but an anomalously high mass $M_p=40.8textasciicircum+2.4_-2.5M_textbackslashoplus$ and density of $5.5textbackslashpm0.8$gcm$textasciicircum-3$, similar to the Earth. Interior structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than $3.9textasciicircum+0.8_-0.9$% of the total mass of the planet. TOI-849b transits a late G type star (T$_textbackslashrm mag=11.5$) with an orbital period of 18.4 hours, leading to an equilibrium temperature of 1800K. The planet's mass is larger than the theoretical threshold mass for runaway gas accretion. As such, the planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it avoided substantial gas accretion, perhaps through gap opening or late formation. Photoevaporation rates cannot provide the mass loss required to reduce a Jupiter-like gas giant, but can remove a few $M_textbackslashoplus$ hydrogen and helium envelope on timescales of several Gyr, implying that any remaining atmosphere is likely to be enriched by water or other volatiles from the planetary interior. TOI-849b represents a unique case where material from the primordial core is left over from formation and available to study.
Huang C X; Quinn S N; Vanderburg A; Becker J; Rodriguez J E; Pozuelos F J; Gandolfi D; Zhou G; Mann A W; Collins K A; Crossfield I; Barkaoui K; Collins K I; Fridlund M; Gillon M; Gonzales E J; Günther M N; Henry T J; Howell S B; James H; Jao W; Jehin E; Jensen E L N; Kane S R; Lissauer J J; Matthews E; Matson R A; Paredes L A; Schlieder J E; Stassun K G; Shporer A; Sha L; Tan T; Georgieva I; Mathur S; Palle E; Persson C M; Van Eylen V; Ricker G R; Vanderspek R K; Latham D W; Winn J N; Seager S; Jenkins J M; Burke C J; Goeke R F; Rinehart S; Rose M E; Ting E B; Torres G; Wong I
TESS spots a hot Jupiter with an inner transiting Neptune (Journal Article)
Hot Jupiters are rarely accompanied by other planets within a factor of a few
in orbital distance. Previously, only two such systems have been found. Here,
we report the discovery of a third system using data from the Transiting
Exoplanet Survey Satellite (TESS). The host star, TOI-1130, is an 11th
magnitude K-dwarf in the Gaia G band. It has two transiting planets: a
Neptune-sized planet ($3.65textbackslashpm 0.10$ $R_E$) with a 4.1-day period, and a hot
Jupiter ($1.50textasciicircum+0.27_-0.22$ $R_J$) with an 8.4-day period. Precise
radial-velocity observations show that the mass of the hot Jupiter is
$0.974textasciicircum+0.043_-0.044$ $M_J$. For the inner Neptune, the data provide only
an upper limit on the mass of 0.17 $M_J$ (3$σ$). Nevertheless, we are
confident the inner planet is real, based on follow-up ground-based photometry
and adaptive optics imaging that rule out other plausible sources of the TESS
transit signal. The unusual planetary architecture of and the brightness of the
host star make TOI-1130 a good test case for planet formation theories, and an
attractive target for future spectroscopic observations.
Hirao Y; Bennett D P; Ryu Y; Koshimoto N; Udalski A; Yee J C; Sumi T; Bond I A; Shvartzvald Y; Abe F; Barry R K; Bhattacharya A; Donachie M; Fukui A; Itow Y; Kondo I; Li M C A; Matsubara Y; Matsuo T; Miyazaki S; Muraki Y; Nagakane M; Onishi K; Ranc C; Rattenbury N J; Suematsu H; Shibai H; Sullivan D J; Suzuki D; Tristram P J; Yonehara A; Skowron J; Poleski R; Mroz P; Szymanski M K; Soszynski I; Kozlowski S; Pietrukowicz P; Ulaczyk K; Rybicki K; Iwanek P; Albrow M D; Chung S; Gould A; Han C; Hwang K; Jung Y K; Shin I; Zang W; Cha S; Kim D; Kim H; Kim S; Lee C; Lee D; Lee Y; Park B; Pogge R W; Beichman C A; Bryden G; Novati S C; Carey S; Gaudi B S; Henderson C B; Zhu W; Bachelet E; Bolt G; Christie G; Hundertmark M; Natusch T; Maoz D; McCormick J; Street R A; Tan T; Tsapras Y; Jorgensen U G; Dominik M; Bozza V; Skottfelt J; Snodgrass C; Ciceri S; Jaimes R F; Evans D F; Peixinho N; Hinse T C; Burgdorf M J; Southworth J; Rahvar S; Sajadian S; Rabus M; von Essen C; Fujii Y I; Campbell-White J; Lowry S; Helling C; Mancini L; Haikala L; Kandori R
OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet orbiting M-dwarf Host in the Inner Galactic Disk (Journal Article)
In: arXiv:2004.09067 [astro-ph], 2020, (arXiv: 2004.09067).
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the $textbackslashit Spitzer$ satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary lens with a planet/host mass ratio of $q=7.0 textbackslashtimes 10textasciicircum-4$ from the light-curve modeling. The ground-only and $textbackslashit Spitzer$-"only" data each provide very strong one-dimensional (1-D) constraints on the 2-D microlens parallax vector $textbackslashbftextbackslashpi_textbackslashrm E$. When combined, these yield a precise measurement of $textbackslashbftextbackslashpi_textbackslashrm E$, and so of the masses of the host $M_textbackslashrm host=0.56textbackslashpm0.07textbackslash,M_textbackslashodot$ and planet $M_textbackslashrm planet = 0.41 textbackslashpm 0.05textbackslash,M_textbackslashrm Jup$. The system lies at a distance $D_textbackslashrm L=5.2 textbackslashpm 0.5 textbackslash textbackslashrm kpc$ from the Sun toward the Galactic bulge, and the host is more likely to be a dusk population star according to the kinematics of the lens. The projected separation of the planet from the host is $a_textbackslashperp = 3.5 textbackslashpm 0.3 textbackslash textbackslashrm au$, i.e., just over twice the snow line. The Galactic-disk kinematics are established in part from a precise measurement of the source proper motion based on OGLE-IV data. By contrast, the $textbackslashit Gaia$ proper-motion measurement of the source suffers from a catastrophic $10textbackslash,textbackslashsigma$ error.
Jordán A; Bakos G Á; Bayliss D; Bento J; Bhatti W; Brahm R; Csubry Z; Espinoza N; Hartman J D; Henning T; Mancini L; Penev K; Rabus M; Sarkis P; Suc V; de Val-Borro M; Zhou G; Butler R P; Teske J; Crane J; Shectman S; Tan T G; Thompson I; Wallace J J; Lázár J; Papp I; Sári P
HATS-37Ab and HATS-38b: Two Transiting Hot Neptunes in the Desert (Journal Article)
In: arXiv:2007.07135 [astro-ph], 2020, (arXiv: 2007.07135).
We report the discovery of two transiting Neptunes by the HATSouth survey. The planet HATS-37Ab has a mass of 0.099 +- 0.042 M_J (31.5 +- 13.4 M_earth) and a radius of 0.606 +- 0.016 R_J, and is on a P = 4.3315 days orbit around a V = 12.266 mag, 0.843 M_sun star with a radius of 0.877 R_sun. We also present evidence that the star HATS-37A has an unresolved stellar companion HATS-37B, with a photometrically estimated mass of 0.654 M_sun.The planet HATS-38b has a mass of 0.074 +- 0.011 M_J (23.5 +- 3.5 M_earth) and a radius of 0.614 +- 0.017 R_J, and is on a P = 4.3750 days orbit around a V = 12.411 mag, 0.890 M_sun star with a radius of 1.105 R_sun. Both systems appear to be old, with isochrone-based ages of 11.46 +0.79-1.45 Gyr, and 11.89 +- 0.60 Gyr, respectively. Both HATS-37Ab and HATS-38b lie in the Neptune desert and are thus examples of a population with a low occurrence rate. They are also among the lowest mass planets found from ground-based wide-field surveys to date.
Borkovits T; Rappaport S A; Tan T G; Gagliano R; Jacobs T; Huang X; Mitnyan T; Hambsch F -J; Kaye T; Maxted P F L; Pál A; Schmitt A R
The Compact Triply Eclipsing Triple Star TIC 209409435 Discovered with TESS (Journal Article)
In: Monthly Notices of the Royal Astronomical Society, vol. 496, no. 4, pp. 4624–4636, 2020, ISSN: 0035-8711, 1365-2966, (arXiv: 2006.10449).
We report the discovery in $TESS$ Sectors 3 and 4 of a compact triply eclipsing triple star system. TIC 209409435 is a previously unknown eclipsing binary with a period of 5.717 days, and the presence of a third star in an outer eccentric orbit of 121.872 day period was found from two sets of third-body eclipses and from eclipse timing variations. The latter exhibit signatures of strong 3rd-body perturbations. After the discovery, we obtained follow-up ground-based photometric observations of several binary eclipses as well as another of the third-body eclipses. We carried out comprehensive analyses, including the simultaneous photodynamical modelling of $TESS$ and ground-based lightcurves (including both archival WASP data, and our own follow-up measurements), as well as eclipse timing variation curves. Also, we have included in the simultaneous fits multiple star spectral energy distribution data and theoretical PARSEC stellar isochrones. We find that the inner binary consists of near twin stars of mass 0.90 $M_textbackslashodot$ and radius 0.88 $R_textbackslashodot$. The third star is just 9% more massive and 18% larger in radius. The inner binary has a rather small eccentricity while the outer orbit has $e = 0.40$. The inner binary and outer orbit have inclination angles within 0.1$textasciicircumtextbackslashcirc$ and 0.2$textasciicircumtextbackslashcirc$ of 90$textasciicircumtextbackslashcirc$, respectively. The mutual inclination angle is $textbackslashlesssim 1/4textasciicircumtextbackslashcirc$. All of these results were obtained without radial velocity observations.
Burt J A; Nielsen L D; Quinn S N; Mamajek E E; Matthews E C; Zhou G; Seidel J V; Huang C X; Lopez E; Soto M; Otegi J; Stassun K G; Kreidberg L; Collins K A; Eastman J D; Rodriguez J E; Halverson S P; Teske J K; Wang S X; Butler R P; Bouchy F; Dumusque X; Segransen D; Shectman S A; Crane J D; Feng F; Montet B T; Feinstein A D; Beletski Y; Flowers E; Gtextbackslash"unther M N; Daylan T; Collins K I; Conti D M; Gan T; Jensen E L N; Kielkopf J F; Tan T G; Helled R; Dorn C; Haldemann J; Lissauer J J; Ricker G R; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; Twicken J D; Smith J C; Tenenbaum P; Cartwright S; Barclay T; Pepper J; Esquerdo G; Fong W
TOI-824 b: A New Planet on the Lower Edge of the Hot Neptune Desert (Journal Article)
In: arXiv:2008.11732 [astro-ph], 2020, (arXiv: 2008.11732).
We report the detection of a transiting hot Neptune exoplanet orbiting TOI-824 (SCR J1448-5735), a nearby (d = 64 pc) K4V star, using data from the textbackslashtextitTransiting Exoplanet Survey Satellite (TESS). The newly discovered planet has a radius, $R_textbackslashrmp$ = 2.93 $textbackslashpm$ 0.20 R$_textbackslashoplus$, and an orbital period of 1.393 days. Radial velocity measurements using the Planet Finder Spectrograph (PFS) and the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph confirm the existence of the planet and we estimate its mass to be $M_textbackslashrmp$ = 18.47 $textbackslashpm$ 1.84 M$_textbackslashoplus$. The planet's mean density is $textbackslashrho_textbackslashrmp$ = 4.03$textasciicircum+0.98_-0.78$ g cm$textasciicircum-3$ making it more than twice as dense as Neptune. TOI-824 b's high equilibrium temperature makes the planet likely to have a cloud free atmosphere, and thus an excellent candidate for follow up atmospheric studies. The detectability of TOI-824 b's atmosphere from both ground and space is promising and could lead to the detailed characterization of the most irradiated, small planet at the edge of the hot Neptune desert that has retained its atmosphere to date.
Cunningham J C; Felix D L; Dixon D M; Stassun K G; Siverd R J; Zhou G; tan T; James D; Kuhn R B; Kounkel M
A KELT-TESS Eclipsing Binary in a Young Triple System Associated with a "Stellar String" Theia 301 (Journal Article)
In: arXiv:2009.03872 [astro-ph], 2020, (arXiv: 2009.03872).
HD 54236 is a nearby, wide common-proper-motion visual pair that has been previously identified as likely being very young by virtue of strong X-ray emission and lithium absorption. Here we report the discovery that the brighter member of the wide pair, HDtextasciitilde54236A, is itself an eclipsing binary (EB), comprising two near-equal solar-mass stars on a 2.4 d orbit. It represents a potentially valuable opportunity to expand the number of benchmark-grade EBs at young stellar ages. Using new observations of Ca2H&K emission and lithium absorption in the wide K-dwarf companion, HD 54236B, we obtain a robust age estimate of 225 +/- 50 Myr for the system. This age estimate and Gaia proper motions show HD 54236 is associated with Theiatextasciitilde301, a newly discovered local "stellar string", which itself may be related to the AB Dor moving group through shared stellar members. Applying this age estimate to ABtextasciitildeDor itself alleviates reported tension between observation and theory that arises for the luminosity of the 90M_Jup star/brown dwarf AB Dor C when younger age estimates are used.
Weiss L M; Dai F; Huber D; Brewer J; Collins K A; Ciardi D R; Matthews E C; Ziegler C; Howell S B; Batalha N M; Crossfield I J M; Dressing C; Fulton B; Howard A W; Isaacson H; Kane S R; Petigura E A; Robertson P; Roy A; Rubenzahl R A; Claytor Z R; Stassun K G; Chontos A; Giacalone S; Dalba P A; Mocnik T; Hill M L; Beard C; Murphy J M A; Rosenthal L J; Behmard A; van Zandt J; Lubin J; Kosiarek M R; Lund M B; Christiansen J L; Matson R A; Beichman C A; Schlieder J E; Gonzales E J; Briceño C; Law N; Mann A W; Collins K I; Evans P; Fukui A; Jensen E L N; Murgas F; Narita N; Palle E; Parviainen H; Schwarz R P; Tan T; Jenkins J; Ricker G; Winn J N
The TESS-Keck Survey II: Masses of Three Sub-Neptunes Transiting the Galactic Thick-Disk Star TOI-561 (Journal Article)
In: arXiv:2009.03071 [astro-ph], 2020, (arXiv: 2009.03071).
We report the discovery of TOI-561, a multiplanet system containing an ultra-short period planet (USP), based on photometry from the NASA TESS Mission and ground-based follow-up. This bright ($V=10.2$) star hosts three small transiting planets: TOI-561 b (TOI-561.02
Luque R; Serrano L M; Molaverdikhani K; Nixon M C; Livingston J H; Guenther E W; Pallé E; Madhusudhan N; Nowak G; Korth J; Cochran W D; Hirano T; Chaturvedi P; Goffo E; Albrecht S; Barragán O; Briceño C; Cabrera J; Charbonneau D; Cloutier R; Collins K A; Collins K I; Colón K D; Crossfield I J M; Csizmadia S; Dai F; Deeg H J; Esposito M; Fridlund M; Gandolfi D; Georgieva I; Glidden A; Goeke R F; Grziwa S; Hatzes A P; Henze C E; Howell S B; Irwin J; Jenkins J M; Jensen E L N; Kábath P; Kidwell Jr. R C; Kielkopf J F; Knudstrup E; Lam K W F; Latham D W; Lissauer J J; Mann A W; Matthews E C; Mireles I; Narita N; Paegert M; Persson C M; Redfield S; Ricker G R; Rodler F; Schlieder J E; Scott N J; Seager S; Šubjak J; Tan T G; Ting E B; Vanderspek R; Van Eylen V; Winn J N; Ziegler C
A planetary system with two transiting mini-Neptunes near the radius valley transition around the bright M dwarf TOI-776 (Journal Article)
In: arXiv:2009.08338 [astro-ph], 2020, (arXiv: 2009.08338).
We report the discovery and characterization of two transiting planets around the bright M1 V star LP 961-53 (TOI-776
Brahm R; Nielsen L D; Wittenmyer R A; Wang S; Rodriguez J E; Espinoza N; Jones M I; Jordán A; Henning T; Hobson M; Kossakowski D; Rojas F; Sarkis P; Schlecker M; Trifonov T; Shahaf S; Ricker G; Vanderspek R; Latham D W; Seager S; Winn J N; Jenkins J M; Addison B C; Bakos G Á; Bhatti W; Bayliss D; Berlind P; Bieryla A; Bouchy F; Bowler B P; Briceño C; Brown T M; Bryant E M; Caldwell D A; Charbonneau D; Collins K A; Davis A B; Esquerdo G A; Fulton B J; Guerrero N M; Henze C E; Hogan A; Horner J; Huang C X; Irwin J; Kane S R; Kielkopf J; Mann A W; Mazeh T; McCormac J; McCully C; Mengel M W; Mireles I; Okumura J; Plavchan P; Quinn S N; Rabus M; Saesen S; Schlieder J E; Segransan D; Shiao B; Shporer A; Siverd R J; Stassun K G; Suc V; Tan T; Torres P; Tinney C G; Udry S; Vanzi L; Vezie M; Vines J I; Vuckovic M; Wright D J; Yahalomi D A; Zapata A; Zhang H; Ziegler C
TOI-481 b & TOI-892 b: Two long period hot Jupiters from the Transiting Exoplanet Survey Satellite (Journal Article)
In: arXiv:2009.08881 [astro-ph], 2020, (arXiv: 2009.08881).
We present the discovery of two new 10-day period giant planets from the Transiting Exoplanet Survey Satellite ($TESS$) mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481 b and TOI-892 b have similar radii ($0.99textbackslashpm0.01$ $textbackslashrm R_J$ and $1.07textbackslashpm0.02$ $textbackslashrm R_J$, respectively), and orbital periods (10.3311 days and 10.6266 days, respectively), but significantly different masses ($1.53textbackslashpm0.03$ $textbackslashrm M_J$ versus $0.95textbackslashpm0.07$ $textbackslashrm M_J$, respectively). Both planets orbit metal-rich stars ([Fe/H]= $+0.26textbackslashpm 0.05$ dex and [Fe/H] = $+0.24 textbackslashpm 0.05$ dex, for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a $textbackslashrm M_textbackslashstar$ = $1.14textbackslashpm0.02$ $textbackslashrm M_textbackslashodot$, $textbackslashrm R_textbackslashstar$ = $1.66textbackslashpm0.02$ $textbackslashrm R_textbackslashodot$ G-type star ($T_textbackslashrm eff$ = $5735 textbackslashpm 72$ K), that with an age of 6.7 Gyr, is in the turn-off point of the main sequence. TOI-892, on the other hand, is a F-type dwarf star ($T_textbackslashrm eff$ = $6261 textbackslashpm 80$ K), which has a mass of $textbackslashrm M_textbackslashstar$ = $1.28textbackslashpm0.03$ $textbackslashrm M_textbackslashodot$, and a radius of $textbackslashrm R_textbackslashstar$ = $1.39textbackslashpm0.02$ $textbackslashrm R_textbackslashodot$. TOI-481 b and TOI-892 b join the scarcely populated region of transiting gas giants with orbital periods longer than 10 days, which is important to constrain theories of the formation and structure of hot Jupiters.
Sha L; Huang C X; Shporer A; Rodriguez J E; Vanderburg A; Brahm R; Hagelberg J; Matthews E C; Ziegler C; Livingston J H; Stassun K G; Wright D J; Crane J D; Espinoza N; Bouchy F; Bakos G Á; Collins K A; Zhou G; Bieryla A; Hartman J D; Wittenmyer R A; Nielsen L D; Plavchan P; Bayliss D; Sarkis P; Tan T; Cloutier R; Mancini L; Jordán A; Wang S; Henning T; Narita N; Penev K; Teske J K; Kane S R; Mann A W; Addison B C; Tamura M; Horner J; Barbieri M; Burt J A; Díaz M R; Crossfield I J M; Dragomir D; Drass H; Feinstein A D; Zhang H; Hart R; Kielkopf J F; Jensen E L N; Montet B T; Ottoni G; Schwarz R P; Rojas F; Nespral D L F; Torres P; Mengel M W; Udry S; Zapata A; Snoddy E; Okumura J; Ricker G R; Vanderspek R K; Latham D W; Winn J N; Seager S; Jenkins J M; Colón K D; Henze C E; Krishnamurthy A; Ting E B; Vezie M; Villanueva S
TOI-954 b and EPIC 246193072 b: Short-Period Saturn-Mass Planets that Test Whether Irradiation Leads to Inflation (Journal Article)
In: arXiv:2010.14436 [astro-ph], 2020, (arXiv: 2010.14436).
We report the discovery of two short-period Saturn-mass planets, one transiting the G subgiant TOI-954 (TIC 44792534, $ V = 10.343 $, $ T = 9.78 $) observed in TESS Sectors 4 & 5, and one transiting the G dwarf EPIC 246193072 ($ V = 12.70 $, $ K = 10.67 $) observed in K2 Campaigns 12 & 19. We confirm and characterize these two planets with a variety of ground-based archival and follow-up observations, including photometry, reconnaissance spectroscopy, precise radial velocity, and high-resolution imaging. Combining all available data, we find that TOI-954 b has a radius of $0.852_-0.062textasciicircum+0.053 textbackslash, R_textbackslashmathrmJ$ and a mass of $0.174_-0.017textasciicircum+0.018 textbackslash, M_textbackslashmathrmJ$ and is in a 3.68 d orbit, while EPIC 246193072 b has a radius of $0.774_-0.024textasciicircum+0.026 textbackslash, R_textbackslashmathrmJ$ and a mass of $0.260_-0.022textasciicircum+0.020 textbackslash, M_textbackslashmathrmJ$ and is in a 12.46 d orbit. As TOI-954 b is 30 times more irradiated than EPIC 246193072 b but is more or less of the same size, these two planets provide an opportunity to test whether irradiation leads to inflation of Saturn-mass planets and contribute to future comparative studies that explore Saturn-mass planets at contrasting points in their lifetimes.
Teske J; Wang S X; Wolfgang A; Gan T; Plotnykov M; Armstrong D J; Butler R P; Cale B; Crane J D; Howard W; Jensen E L N; Law N; Shectman S A; Plavchan P; Valencia D; Vanderburg A; Ricker G; Vanderspek R; Latham D W; Seager S; Winn J W; Jenkins J M; Adibekyan V; Barrado D; Barros S C C; Brown D J A; Bryant E M; Burt J; Caldwell D A; Charbonneau D; Cloutier R; Collins K A; Collins K I; Colon N D; Conti D M; Demangeon O D S; Eastman J D; Elmufti M; Feng F; Flowers E; Guerrero N M; Hojjatpanah S; Irwin J M; Isopi G; Lillo-Box J; Mallia F; Massey B; Mori M; Mullally S E; Narita N; Nishiumi T; Osborn A; Paegert M; de Leon J P; Quinn S N; Reefe M; Schwarz R P; Shporer A; Soubkiou A; Sousa S G; Stockdale C; Strøm P A; Tan T; Tenenbaum P; Wheatley P J; Wittrock J; Yahalomi D A; Zohrabi F; Zouhair B
The Magellan-TESS Survey I: Survey Description and Mid-Survey Results (Journal Article)
In: arXiv:2011.11560 [astro-ph], 2020, (arXiv: 2011.11560).
One of the most significant revelations from Kepler is that roughly one-third of Sun-like stars host planets which orbit their stars within 100 days and are between the size of Earth and Neptune. How do these super-Earth and sub-Neptune planets form, what are they made of, and do they represent a continuous population or naturally divide into separate groups? Measuring their masses and thus bulk densities can help address these questions of their origin and composition. To that end, we began the Magellan-TESS Survey (MTS), which uses Magellan II/PFS to obtain radial velocity (RV) masses of 30 transiting exoplanets discovered by TESS and develops an analysis framework that connects observed planet distributions to underlying populations. In the past, RV measurements of small planets have been challenging to obtain due to the faintness and low RV semi-amplitudes of most Kepler systems, and challenging to interpret due to the potential biases in the existing ensemble of small planet masses from non-algorithmic decisions for target selection and observation plans. The MTS attempts to minimize these biases by focusing on bright TESS targets and employing a quantitative selection function and multi-year observing strategy. In this paper, we (1) describe the motivation and survey strategy behind the MTS, (2) present our first catalog of planet mass and density constraints for 25 TESS Objects of Interest (TOIs; 20 in our population analysis sample, five that are members of the same systems), and (3) employ a hierarchical Bayesian model to produce preliminary constraints on the mass-radius (M-R) relation. We find qualitative agreement with prior mass-radius relations but some quantitative differences (abridged). The the results of this work can inform more detailed studies of individual systems and offer a framework that can be applied to future RV surveys with the goal of population inferences.
Zhou G; Quinn S N; Irwin J; Huang C X; Collins K A; Bouma L G; Khan L; Landrigan A; Vanderburg A M; Rodriguez J E; Latham D W; Torres G; Douglas S T; Bieryla A; Esquerdo G A; Berlind P; Calkins M L; Buchhave L A; Charbonneau D; Collins K I; Kielkopf J F; Jensen E L N; Tan T; Hart R; Carter B; Stockdale C; Ziegler C; Law N; Mann A W; Howell S B; Matson R A; Scott N J; Furlan E; White R J; Hellier C; Anderson D R; West R G; Ricker G; Vanderspek R; Seager S; Jenkins J M; Winn J N; Mireles I; Rowden P; Yahalomi D A; Wohler B; Brasseur C E; Daylan T; Coloń K D
Two young planetary systems around field stars with ages between 20-320 Myr from TESS (Journal Article)
In: arXiv:2011.13349 [astro-ph], 2020, (arXiv: 2011.13349).
Planets around young stars trace the early evolution of planetary systems. We report the discovery and validation of two planetary systems with ages $textbackslashlesssim 300$ Myr from observations by the Transiting Exoplanet Survey Satellite. TOI-251 is a 40-320 Myr old G star hosting a 2.74 +0.18/-0.18 REarth mini-Neptune with a 4.94 day period. TOI-942 is a 20-160 Myr old K star hosting a system of inflated Neptune-sized planets, with TOI-942b orbiting with a period of 4.32 days, with a radius of 4.81 +0.20/-0.20 REarth, and TOI-942c orbiting in a period of 10.16 days with a radius of 5.79 +0.19/-0.18 REarth. Though we cannot place either host star into a known stellar association or cluster, we can estimate their ages via their photometric and spectroscopic properties. Both stars exhibit significant photometric variability due to spot modulation, with measured rotation periods of $textbackslashsim 3.5$ days. These stars also exhibit significant chromospheric activity, with age estimates from the chromospheric calcium emission lines and X-ray fluxes matching that estimated from gyrochronology. Both stars also exhibit significant lithium absorption, similar in equivalent width to well-characterized young cluster members. TESS has the potential to deliver a population of young planet-bearing field stars, contributing significantly to tracing the properties of planets as a function of their age.
Giacalone S; Dressing C D; Jensen E L N; Collins K A; Ricker G R; Vanderspek R; Seager S; Winn J N; Jenkins J M; Barclay T; Barkaoui K; Cadieux C; Charbonneau D; Collins K I; Conti D M; Doyon R; Evans P; Ghachoui M; Gillon M; Guerrero N M; Hart R; Jehin E; Kielkopf J F; McLean B; Murgas F; Palle E; Parviainen H; Pozuelos F J; Relles H M; Shporer A; Socia Q; Stockdale C; Tan T; Torres G; Twicken J D; Waalkes W C; Waite I A
Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates (Journal Article)
In: arXiv:2002.00691 [astro-ph], 2020, (arXiv: 2002.00691).
We present TRICERATOPS, a new Bayesian tool that can be used to vet and validate TESS Objects of Interest (TOIs). We test the tool on 68 TOIs that have been previously confirmed as planets or rejected as astrophysical false positives. By looking in the false positive probability (FPP) -- nearby false positive probability (NFPP) plane, we define criteria that TOIs must meet to be classified as validated planets (FPP textless 0.015 and NFPP textless 10textasciicircum-3), likely planets (FPP textless 0.5 and NFPP textless 10textasciicircum-3), and likely nearby false positives (NFPP textgreater 10textasciicircum-1). We apply this procedure on 384 unclassified TOIs and statistically validate 12, classify 125 as likely planets, and classify 52 as likely nearby false positives. Of the 12 statistically validated planets, 9 are newly validated. TRICERATOPS is currently the only TESS vetting and validation tool that models transits from nearby contaminant stars in addition to the target star. We therefore encourage use of this tool to prioritize follow-up observations that confirm bona fide planets and identify false positives originating from nearby stars.
Johns D; Reed P; Rodriguez J; Pepper J; Stassun K; Penev K; Gaudi B S; Labadie-Bartz J; Fulton B; Quinn S; Eastman J; Ciardi D; Hirsch L; Stevens D; Stevens C; Oberst T; Cohen D; Jensen E; Benni P; Villanueva S; Murawski G; Bieryla A; Latham D; Vanaverbeke S; Dubois F; Rau S; Logie L; Rauenzahn R; Wittenmyer R; Zambelli R; Bayliss D; Beatty T; Collins K; Colon K; Curtis I; Evans P; Gregorio J; James D; DePoy D; Johnson M; Joner M; Kasper D; Kielkopf J; Kuhn R; Lund M; Manner M; Marshall J; McLeod K; Penny M; Relles H M; Siverd R; Stephens D; Stockdale C; Tan T; Trueblood M; Trueblood P; Yao X
KELT-23b: A Hot Jupiter Transiting a Near-Solar Twin Close to the TESS and JWST Continuous Viewing Zones (Journal Article)
In: arXiv:1903.00031 [astro-ph], 2019, (arXiv: 1903.00031).
We announce the discovery of KELT-23b, a hot Jupiter transiting the relatively bright ($V=10.3$) star BD+66 911 (TYC 4187-996-1), and characterize the system using follow-up photometry and spectroscopy. A global fit to the system yields $T_eff=5900textbackslashpm49 K$, $M_*=0.945textasciicircum+0.060_-0.054 M_textbackslashodot$, $R_*=0.995textbackslashpm0.015 R_textbackslashodot$, $L_*=1.082textasciicircum+0.051_-0.048 L_textbackslashodot$, log$g_*=4.418textasciicircum+0.026_-0.025$ (cgs), and $textbackslashleft[textbackslashrm Fe/textbackslashrm Htextbackslashright]=-0.105textbackslashpm49$. KELT-23b is a hot Jupiter with mass $M_P=0.938textasciicircum+0.045_-0.042 M_textbackslashrm J$, radius $R_P=1.322textbackslashpm0.025 R_textbackslashrm J$, and density $textbackslashrho_P=0.504textasciicircum+0.038_-0.035$ g cm$textasciicircum-3$. Intense insolation flux from the star has likely caused KELT-23b to become inflated. The time of inferior conjunction is $T_0=2458149.40776textbackslashpm0.00091textasciitildetextbackslashrm BJD_TDB$ and the orbital period is $P=2.255353textasciicircum+0.000031_-0.000030$ days. Due to strong tidal interactions, the planet is likely to spiral into its host within roughly a Gyr. This system has one of the highest positive ecliptic latitudes of all transiting planet hosts known to date, placing it near the Transiting Planet Survey Satellite and James Webb Space Telescope continuous viewing zones. Thus we expect it to be an excellent candidate for long-term monitoring and follow-up with these facilities.
Osborn H P; Kenworthy M; Rodriguez J E; de Mooij E J W; Kennedy G M; Relles H; Gomez E; Hippke M; Banfi M; Barbieri L; Becker I; Benni P; Berlind P; Bieryla A; Bonnoli G; Boussier H; Brincat S; Briol J; Burleigh M; Butterley T; Calkins M L; Chote P; Ciceri S; Deldem M; Dhillon V S; Dose E; Dubois F; Dvorak S; Esquerdo G A; Evans D; Berangez S F D; Fossey S; Güenther M N; Hall J; Hambsch J; Casas E H; Hills K; James R; Kafka S; Killestein T L; Kotnik C; Latham D W; Lemay D; Lewin P; Littlefair S; Lopresti C; Mallonn M; Mancini L; Marchini A; McCormac J J; Murawski G; Myers G; Papini R; Popov V; Quadri U; Quinn S N; Raynard L; Rizzuti L; Roa J; Robertson J; Salvaggio F; Scholz A; Sfair R; Smith A M S; Southworth J; Tan T G; Vanaverbeke S; Waagen E O; Watson C; West R; Wheatley P J; Wilson R W; Winter O C; Zhou G
The PDS 110 observing campaign - photometric and spectroscopic observations reveal eclipses are aperiodic (Journal Article)
In: Monthly Notices of the Royal Astronomical Society, vol. 485, no. 2, pp. 1614–1625, 2019, ISSN: 0035-8711, 1365-2966, (arXiv: 1901.07981).
PDS 110 is a young disk-hosting star in the Orion OB1A association. Two dimming events of similar depth and duration were seen in 2008 (WASP) and 2011 (KELT), consistent with an object in a closed periodic orbit. In this paper we present data from a ground-based observing campaign designed to measure the star both photometrically and spectroscopically during the time of predicted eclipse in September 2017. Despite high-quality photometry, the predicted eclipse did not occur, although coherent structure is present suggesting variable amounts of stellar flux or dust obscuration. We also searched for RV oscillations caused by any hypothetical companion and can rule out close binaries to 0.1 $M_textbackslashodot$. A search of Sonneberg plate archive data also enabled us to extend the photometric baseline of this star back more than 50 years, and similarly does not re-detect any deep eclipses. Taken together, they suggest that the eclipses seen in WASP and KELT photometry were due to aperiodic events. It would seem that PDS 110 undergoes stochastic dimmings that are shallower and shorter-duration than those of UX Ori variables, but may have a similar mechanism.
Zhou G; Huang C; Bakos G; Hartman J; Latham D; Quinn S; Collins K; Winn J; Kovacs G; Csubry Z; Bhatti W; Penev K; Bieryla A; Esquerdo G; Berlind P; Calkins M; de Val-Borro M; Noyes R; Lázár J; Papp I; Sari P; Kovacs T; Buchhave L A; Szklenár T; Beky B; Johnson M; Stassun K; Shporer A; Wong I; Espinoza N; Bayliss D; Howell S; Hellier C; Anderson D; West R; Brown D; Schanche N; Barkaoui K; Pozuelos F; Gillon M; Jehin E; Benkhaldoun Z; Daassou A; Ricker G; Vanderspek R; Seager S; Jenkins J; Lissauer J; Collins K; Gan T; Hart R; Horne K; Kielkopf J; Nielsen L; Nishiumi T; Narita N; Palle E; Relles H; Sefako R; Tan T; Davies M; Goeke R F; Guerrero N; Haworth K; Villanueva S
Two new HATNet hot Jupiters around A stars, and the first glimpse at the occurrence rate of hot Jupiters from TESS (Journal Article)
In: arXiv:1906.00462 [astro-ph], 2019, (arXiv: 1906.00462).
Wide field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their parent stars. We report the discovery of HAT-P-69 b (TOI 625.01) and HAT-P-70 b (TOI 624.01), two new hot Jupiters around A stars from the HATNet survey which have also been observed by the Transiting Exoplanet Survey Satellite (TESS). HAT-P-69 b has a mass of 3.73 (+0.61/-0.59) Mjup and a radius of 1.626 (+0.032/-0.025) Rjup, and is in a prograde 4.79-day orbit around a star of mass 1.698+/-0.025 Msun and radius 1.854 (+0.043/-0.022) Rsun. HAT-P-70 b has a radius of 1.87 (+0.15/-0.10) Rjup and a mass constraint of textless6.78 (3sigma) Mjup, and is in a retrograde 2.74-day orbit around a star of mass 1.890 (+0.010/-0.013) Msun and radius 1.858 (+0.119/-0.091) Rsun. We use the confirmation of these planets around relatively massive stars as an opportunity to explore the occurrence rate of hot Jupiters as a function of stellar mass. We define a sample of 47,126 main-sequence stars brighter than Tmag=10 that yields 31 giant planet candidates, including 18 confirmed planets, 3 candidates, and 10 false positives. We find a net hot Jupiter occurrence rate of 0.45+/-0.10% within this sample, consistent with the rate measured by Kepler for FGK stars. When divided into stellar mass bins, we find the occurrence rate to be 0.71+/-0.31% G stars, 0.43+/-0.15% for F stars, and 0.32+/-0.12% for A stars. Thus, at this point, we cannot discern any statistically significant trend in the occurrence of hot Jupiters with stellar mass.
Rodriguez J E; Eastman J D; Zhou G; Quinn S N; Beatty T G; Penev K; Johnson M C; Cargile P A; Latham D W; Bieryla A; Collins K A; Dressing C D; Ciardi D R; Relles H M; Murawski G; Nishiumi T; Yonehara A; Lund M B; Stevens D J; Stassun K G; Gaudi B S; Colón K D; Pepper J; Narita N; Awiphan S; Chuanraksasat P; Benni P; Ishimaru R; Yoshida F; Zambelli R; Garrison L H; Wilson M L; Cornachione M A; Wang S X; Labadie-Bartz J; Rodríguez R; Siverd R J; Yao X; Bayliss D; Berlind P; Calkins M L; Christiansen J L; Cohen D H; Conti D M; Curtis I A; Depoy D L; Esquerdo G A; Evans P; Feliz D; Fulton B J; Gregorio J; Holoien T W S; James D J; Jayasinghe T; Jang-Condell H; Jensen E L N; Johnson J A; Joner M D; Kielkopf J F; Kuhn R B; Manner M; Marshall J L; McLeod K K; McCrady N; Oberst T E; Oelkers R J; Penny M T; Reed P A; Sliski D H; Shappee B J; Stephens D C; Stockdale C; Tan T; Trueblood M; Trueblood P; Villanueva Jr. S; Wittenmyer R A; Wright J T
KELT-24b: A 5M$_textbackslashrm J$ Planet on a 5.6 day Well-Aligned Orbit around the Young V=8.3 F-star HD 93148 (Journal Article)
In: arXiv:1906.03276 [astro-ph], 2019, (arXiv: 1906.03276).
We present the discovery of KELT-24 b, a massive hot Jupiter orbiting a bright (V=8.3 mag
Mancini L; Sarkis P; Henning T; Bakos G A; Bayliss D; Bento J; Bhatti W; Brahm R; Csubry Z; Espinoza N; Hartman J; Jordan A; Penev K; Rabus M; Suc V; de Val-Borro M; Zhou G; Chen G; Damasso M; Southworth J; Tan T G
The highly inflated giant planet WASP-174b (Journal Article)
In: arXiv:1909.08674 [astro-ph], 2019, (arXiv: 1909.08674).
The transiting exoplanetary system WASP-174 was reported to be composed by a main-sequence F star (V=11.8 mag) and a giant planet, WASP-174b (orbital period 4.23 days). However only an upper limit was placed on the planet mass (textless1.3 Mj), and a highly uncertain planetary radius (0.7-1.7 Rj) was determined. We aim to better characterise both the star and the planet and precisely measure their orbital and physical parameters. In order to constrain the mass of the planet, we obtained new measurements of the radial velocity of the star and joined them with those from the discovery paper. Photometric data from the HATSouth survey and new multi-band, high-quality (precision reached up to 0.37textasciitildemmag) photometric follow-up observations of transit events were acquired and analysed for getting accurate photometric parameters. We fit the model to all the observations, including data from the TESS space telescope, in two different modes: incorporating the stellar isochrones into the fit, and using an empirical method to get the stellar parameters. The two modes resulted to be consistent with each other to within 2 sigma. We confirm the grazing nature of the WASP-174b transits with a confidence level greater than 5 sigma, which is also corroborated by simultaneously observing the transit through four optical bands and noting how the transit depth changes due to the limb-darkening effect. We estimate that textasciitilde76% of the disk of the planet actually eclipses the parent star at mid-transit of its transit events. We find that WASP-174b is a highly-inflated hot giant planet with a mass of 0.330 Mj and a radius of 1.435 Rj, and is therefore a good target for transmission-spectroscopy observations. With a density of 0.135 g/cmtextasciicircum3, it is amongst the lowest-density planets ever discovered with precisely measured mass and radius.