Details

Autor(en) / Beteiligte

• Kanodia, Shubham
• Libby-Roberts, Jessica
• Cañas, Caleb I.
• Ninan, Joe P.
• Mahadevan, Suvrath
• Stefansson, Gudmundur
• Lin, Andrea S. J.
• Jones, Sinclaire
• Monson, Andrew
• Parker, Brock A.
• Kobulnicky, Henry A.
• Swaby, Tera N.
• Powers, Luke
• Beard, Corey
• Bender, Chad F.
• Blake, Cullen H.
• Cochran, William D.
• Dong, Jiayin
• Diddams, Scott A.
• Fredrick, Connor
• Gupta, Arvind F.
• Halverson, Samuel
• Hearty, Fred
• Logsdon, Sarah E.
• Metcalf, Andrew J.
• McElwain, Michael W.
• Morley, Caroline
• Rajagopal, Jayadev
• Ramsey, Lawrence W.
• Robertson, Paul
• Roy, Arpita
• Schwab, Christian
• Terrien, Ryan C.
• Wisniewski, John
• Wright, Jason T.

Titel

TOI-3757 b: A Low-density Gas Giant Orbiting a Solar-metallicity M Dwarf

Ist Teil von

• The Astronomical journal, 2022-09, Vol.164 (3), p.81

Ort / Verlag

Goddard Space Flight Center: The American Astronomical Society

Erscheinungsjahr

2022

Link zum Volltext

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• We present the discovery of a new Jovian-sized planet, TOI-3757 b, the lowest-density transiting planet known to orbit an M dwarf (M0V). This planet was discovered around a solar-metallicity M dwarf, using Transiting Exoplanet Survey Satellite photometry and confirmed with precise radial velocities from the Habitable-zone Planet Finder (HPF) and NEID. With a planetary radius of 12.0 (+0.4 -0.5) R⊕ and mass of 85.3 (+8.8 -8.7)M⊕, not only does this object add to the small sample of gas giants (∼10) around M dwarfs, but also its low density (ρ=0.27 +0.05 -0.04 g) provides an opportunity to test theories of planet formation. We present two hypotheses to explain its low density; first, we posit that the low metallicity of its stellar host (∼0.3 dex lower than the median metallicity of M dwarfs hosting gas giants) could have played a role in the delayed formation of a solid core massive enough to initiate runaway accretion. Second, using the eccentricity estimate of 0.14 ± 0.06, we determine it is also plausible for tidal heating to at least partially be responsible for inflating the radius of TOI-3757b b. The low density and large scale height of TOI-3757 b makes it an excellent target for transmission spectroscopy studies of atmospheric escape and composition (transmission spectroscopy measurement of ∼ 190). We use HPF to perform transmission spectroscopy of TOI-3757 b using the helium 10830 Å line. Doing this, we place an upper limit of 6.9% (with 90% confidence) on the maximum depth of the absorption from the metastable transition of He at ∼10830 Å, which can help constraint the atmospheric mass-loss rate in this energy-limited regime.