A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18

Crossfield, Ian J. M.; Waalkes, William; Newton, Elisabeth R.; Narita, Norio; Muirhead, Philip S.; Ment, Kristo; Matthews, Elisabeth C.; Kraus, Adam L.; Kostov, Veselin B.; Kosiarek, Molly R.; Kane, Stephen R.; Isaacson, Howard; Halverson, Samuel; Gonzales, Erica J.; Everett, Mark E.; Dragomir, Diana; Collins, Karen A.; Chontos, Ashley; Berardo, David; Winters, Jennifer G.; Winn, Joshua N.; Scott, Nicholas J.; Rojas-Ayala, Bárbara; Rizzuto, Aaron C.; Petigura, Erik A.; Peterson, Merrin S.; Močnik, Teo; Evans, T. M.; Mehrle, Nicholas; Matson, Rachel A.; Kuzuhara, Masayuki; Irwin, Jonathan; Huber, Daniel; Huang, Chelsea X.; Howell, Steve B.; Howard, Andrew W.; Hirano, Teruyuki; Fulton, Benjamin J.; Dupuy, Trent J.; Dressing, Courtney D.; Dalba, Paul A.; Charbonneau, David; Burt, Jennifer; Berta-Thompson, Zachory K.; Benneke, Björn; Watanabe, Noriharu; Twicken, Joseph D.; Tamura, Motohide; Schlieder, Joshua E.; Seager, Sara; Rose, Mark; Ricker, G.; Quintana, Elisa V.; Lépine, Sébastien; Latham, David W.; Kotani, Takayuki; Jenkins, Jon M.; Hori, Yasunori; Colón, Knicole D.; Caldwell, Douglas A.

doi:10.3847/2041-8213/ab3d30

Cited by 52 publications

(24 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As of 19 November 2020, TESS had discovered 82 confirmed planets and ∼60% of them belong to multi-planet systems. A non-exhaustive list of the multi-planet systems discovered by TESS includes HD 15337 (Gandolfi et al 2019), TOI-125 (Quinn et al 2019), HD 21749 (Dragomir et al 2019), HR 858 (Vanderburg et al 2019), LP 791-18 (Crossfield et al 2019), L98-59 (Kostov et al 2019), TOI-421 (Carleo et al 2020), HD 63433 (Mann et al 2020), and TOI-700 . Following the completion of its prime mission on 5 July 2020, TESS was extended for a further 27 months.…”

Section: Introductionmentioning

confidence: 99%

CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii

Bonfanti

Delrez

Hooton

et al. 2021

A&A

View full text Add to dashboard Cite

Context. The detection of a super-Earth and three mini-Neptunes transiting the bright (V = 9.2 mag) star HD 108236 (also known as TOI-1233) was recently reported on the basis of TESS and ground-based light curves. Aims. We perform a first characterisation of the HD 108236 planetary system through high-precision CHEOPS photometry and improve the transit ephemerides and system parameters. Methods. We characterise the host star through spectroscopic analysis and derive the radius with the infrared flux method. We constrain the stellar mass and age by combining the results obtained from two sets of stellar evolutionary tracks. We analyse the available TESS light curves and one CHEOPS transit light curve for each known planet in the system. Results. We find that HD 108236 is a Sun-like star with R⋆ = 0.877 ± 0.008 R⊙, M⋆ = 0.869−0.048+0.050 M⊙, and an age of 6.7−5.1+4.0 Gyr. We report the serendipitous detection of an additional planet, HD 108236 f, in one of the CHEOPS light curves. For this planet, the combined analysis of the TESS and CHEOPS light curves leads to a tentative orbital period of about 29.5 days. From the light curve analysis, we obtain radii of 1.615 ± 0.051, 2.071 ± 0.052, 2.539−0.065+0.062, 3.083 ± 0.052, and 2.017−0.057+0.052 R⊕ for planets HD 108236 b to HD 108236 f, respectively. These values are in agreement with previous TESS-based estimates, but with an improved precision of about a factor of two. We perform a stability analysis of the system, concluding that the planetary orbits most likely have eccentricities smaller than 0.1. We also employ a planetary atmospheric evolution framework to constrain the masses of the five planets, concluding that HD 108236 b and HD 108236 c should have an Earth-like density, while the outer planets should host a low mean molecular weight envelope. Conclusions. The detection of the fifth planet makes HD 108236 the third system brighter than V = 10 mag to host more than four transiting planets. The longer time span enables us to significantly improve the orbital ephemerides such that the uncertainty on the transit times will be of the order of minutes for the years to come. A comparison of the results obtained from the TESS and CHEOPS light curves indicates that for a V ~ 9 mag solar-like star and a transit signal of ~500 ppm, one CHEOPS transit light curve ensures the same level of photometric precision as eight TESS transits combined, although this conclusion depends on the length and position of the gaps in the light curve.

show abstract

Section: Introductionmentioning

confidence: 99%

CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii

Bonfanti

Delrez

Hooton

et al. 2021

A&A

View full text Add to dashboard Cite

show abstract

“…The TESS mission (Ricker et al 2014(Ricker et al , 2015 is designed to overcome this problem by detecting transiting planet candidates orbiting bright stars positioned across almost the entire sky. Among those, planet candidates orbiting nearby M-dwarf stars, at a distance of a few tens of parsecs, present a special opportunity, as their typical high proper motion and small size make it easier to rule out false-positive scenarios (e.g., Crossfield et al 2019;Vanderspek et al 2019). This quickly clears the way for follow-up studies including mass measurement and atmospheric characterization.…”

Section: Introductionmentioning

confidence: 99%

GJ 1252 b: A 1.2 R_⊕ Planet Transiting an M3 Dwarf at 20.4 pc

Shporer

Collins

Astudillo-Defru

et al. 2020

ApJL

Self Cite

View full text Add to dashboard Cite

We report the discovery of GJ1252b, a planet with a radius of 1.193±0.074 Å R and an orbital period of 0.52days around an M3-type star (0.381±0.019  M , 0.391±0.020  R ) located 20.385±0.019 pc away. We use Transiting Exoplanet Survey Satellite (TESS) data, ground-based photometry and spectroscopy, Gaia astrometry, and high angular resolution imaging to show that the transit signal seen in the TESS data must originate from a transiting planet. We do so by ruling out all false-positive scenarios that attempt to explain the transit signal as originating from an eclipsing stellar binary. Precise Doppler monitoring also leads to a tentative mass measurement of 2.09±0.56M ⊕ . The host star proximity, brightness (V=12.19 mag, K=7.92 mag), low stellar activity, and the system's short orbital period make this planet an attractive target for detailed characterization, including precise mass measurement, looking for other objects in the system, and planet atmosphere characterization.Unified Astronomy Thesaurus concepts: Exoplanet astronomy (486); M dwarf stars (982); Exoplanets (498)

show abstract

“…Periodograms of the WASP-South data in each observing season, along with (right) folds of the data on the 24.9-d modulation (marked by orange ticks).obtained and carefully ruled out the false positive scenarios below followingVanderspek et al (2019),Crossfield et al (2019), andShporer et al (2019).…”

mentioning

confidence: 99%

LHS 1815b: The First Thick-disk Planet Detected by TESS

Gan

Shporer

Livingston

et al. 2020

Self Cite

View full text Add to dashboard Cite

We report the first discovery of a thick-disk planet, LHS 1815b (TOI-704b, TIC 260004324), detected in the TESS survey. LHS 1815b transits a bright (V = 12.19 mag, K = 7.99 mag) and quiet M dwarf located 29.87 ± 0.02 pc away with a mass of 0.502 ± 0.015 M and a radius of 0.501 ± 0.030 R . We validate the planet by combining space and ground-based photometry, spectroscopy, and imaging. The planet has a radius of 1.088 ± 0.064 R ⊕ with a 3σ mass upper-limit of 8.7 M ⊕ . We analyze the galactic kinematics and orbit of the host star LHS 1815 and find that it has a large probability (P thick /P thin = 6482) to be in the thick disk 2 with a much higher expected maximal height (Z max = 1.8 kpc) above the Galactic plane compared with other TESS planet host stars. Future studies of the interior structure and atmospheric properties of planets in such systems using for example the upcoming James Webb Space Telescope (JWST), can investigate the differences in formation efficiency and evolution for planetary systems between different Galactic components (thick and thin disks, and halo).

show abstract

A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18

Cited by 52 publications

References 104 publications

CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii

CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii

GJ 1252 b: A 1.2 R_⊕ Planet Transiting an M3 Dwarf at 20.4 pc

LHS 1815b: The First Thick-disk Planet Detected by TESS

Contact Info

Product

Resources

About

A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18

Cited by 52 publications

References 104 publications

CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii

CHEOPS observations of the HD 108236 planetary system: a fifth planet, improved ephemerides, and planetary radii

GJ 1252 b: A 1.2 R⊕ Planet Transiting an M3 Dwarf at 20.4 pc

LHS 1815b: The First Thick-disk Planet Detected by TESS

Contact Info

Product

Resources

About

GJ 1252 b: A 1.2 R_⊕ Planet Transiting an M3 Dwarf at 20.4 pc