Bibcode
Nies, Molly; Mireles, Ismael; Bouchy, François; Dragomir, Diana; Nicholson, Belinda A.; Eisner, Nora L.; Sousa, Sergio G.; Collins, Karen A.; Howell, Steve B.; Ziegler, Carl; Hellier, Coel; Addison, Brett; Ballard, Sarah; Bowler, Brendan P.; Briceño, César; Clark, Catherine A.; Conti, Dennis M.; Dumusque, Xavier; Edwards, Billy; Gnilka, Crystal L.; Hobson, Melissa; Horner, Jonathan; Kane, Stephen R.; Kielkopf, John; Lavie, Baptiste; Law, Nicholas; Lendl, Monika; Littlefield, Colin; Liu, Huigen; Mann, Andrew W.; Mengel, Matthew W.; Oddo, Dominic; Okumura, Jack; Palle, Enric; Plavchan, Peter; Psaridi, Angelica; Santos, Nuno C.; Schwarz, Richard P.; Shporer, Avi; Wittenmyer, Robert A.; Wright, Duncan J.; Zhang, Hui; Watanabe, David; Medina, Jennifer V.; Villaseñor, Joel; Ting, Eric B.; Christiansen, Jessie L.; Winn, Joshua N.; Stassun, Keivan G.; Seager, S.; Latham, David W.; Ricker, George R.
Referencia bibliográfica
Monthly Notices of the Royal Astronomical Society
Fecha de publicación:
11
2024
Número de citas
0
Número de citas referidas
0
Descripción
We report the discovery and validation of HD 21520 b, a transiting planet found with Transiting Exoplanet Survey Satellite and orbiting a bright G dwarf (V = 9.2, $T_{\rm eff} = 5871 \pm 62$ K, $R_{\star } = 1.04\pm 0.02\, {\rm R}_{\odot }$). HD 21520 b was originally alerted as a system (TOI-4320) consisting of two planet candidates with periods of 703.6 and 46.4 d. However, our analysis supports instead a single-planet system with an orbital period of $25.1292\pm 0.0001$ d and radius of $2.70 \pm 0.09\, {\rm R}_{{\oplus }}$. Three full transits in sectors 4, 30, and 31 match this period and have transit depths and durations in agreement with each other, as does a partial transit in sector 3. We also observe transits using CHEOPS and LCOGT. SOAR and Gemini high-resolution imaging do not indicate the presence of any nearby companions, and MINERVA-Australis and CORALIE radial velocities rule out an on-target spectroscopic binary. Additionally, we use ESPRESSO radial velocities to obtain a tentative mass measurement of $7.9^{+3.2}_{-3.0}\, {\rm M}_{{\oplus }}$, with a 3$\sigma$ upper limit of 17.7 ${\rm M}_{{\oplus }}$. Due to the bright nature of its host and likely significant gas envelope of the planet, HD 21520b is a promising candidate for further mass measurements and for atmospheric characterization.