TOI-954 b and K2-329 b: Short-period Saturn-mass Planets that Test whether Irradiation Leads to Inflation

Sha, Lizhou; Huang, Chelsea X.; Shporer, Avi; Rodriguez, Joseph E.; Vanderburg, Andrew; Brahm, Rafael; Hagelberg, Janis; Matthews, Elisabeth C.; Ziegler, Carl; Livingston, John H.; Stassun, Keivan G.; Wright, Duncan J.; Crane, Jeffrey D.; Espinoza, Néstor; Bouchy, François; Bakos, Gáspár Á.; Collins, Karen A.; Zhou, George; Bieryla, Allyson; Hartman, Joel D.; Wittenmyer, Robert A.; Nielsen, Louise D.; Plavchan, Peter; Bayliss, Daniel; Sarkis, Paula; Tan, Thiam-Guan; Cloutier, Ryan; Mancini, Luigi; Jordán, Andrés; Wang, Sharon; Henning, Thomas; Narita, Norio; Penev, Kaloyan; Teske, Johanna K.; Kane, Stephen R.; Mann, Andrew W.; Addison, Brett C.; Tamura, Motohide; Horner, Jonathan; Barbieri, Mauro; Burt, Jennifer A.; Díaz, Matías R.; Crossfield, Ian J. M.; Dragomir, Diana; Drass, Holger; Feinstein, Adina D.; Zhang, Hui; Hart, Rhodes; Kielkopf, John F.; Jensen, Eric L. N.; Montet, Benjamin T.; Ottoni, Gaël; Schwarz, Richard P.; Rojas, Felipe; Nespral, David; Torres, Pascal; Mengel, Matthew W.; Udry, Stéphane; Zapata, Abner; Snoddy, Erin; Okumura, Jack; Ricker, George R.; Vanderspek, Roland K.; Latham, David W.; Winn, Joshua N.; Seager, Sara; Jenkins, Jon M.; Colón, Knicole D.; Henze, Christopher E.; Krishnamurthy, Akshata; Ting, Eric B.; Vezie, Michael; Villanueva, Steven
Bibliographical reference

The Astronomical Journal

Advertised on:
2
2021
Number of authors
73
IAC number of authors
2
Citations
9
Refereed citations
7
Description
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 and 5 and one transiting the G dwarf K2-329 (EPIC 246193072, V = 12.70, K = 10.67) observed in K2 campaigns 12 and 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 ${0.852}_{-0.062}^{+0.053}\,{R}_{{\rm{J}}}$ and a mass of ${0.174}_{-0.017}^{+0.018}$ MJ and is in a 3.68 day orbit, while K2-329 b has a radius of ${0.774}_{-0.024}^{+0.026}\,{R}_{{\rm{J}}}$ and a mass of ${0.260}_{-0.022}^{+0.020}$ MJ and is in a 12.46 day orbit. As TOI-954 b is 30 times more irradiated than K2-329 b but more or less 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.