@article {28387,
	title = {A Hot Saturn Orbiting an Oscillating Late Subgiant Discovered by TESS},
	volume = {157},
	year = {2019},
	month = {2019/06/1},
	pages = {245},
	abstract = {We present the discovery of HD 221416 b, the first transiting planet identified by the Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology of the host star is possible. HD 221416 b (HIP 116158, TOI-197) is a bright (V = 8.2 mag), spectroscopically classified subgiant that oscillates with an average frequency of about 430 μHz and displays a clear signature of mixed modes. The oscillation amplitude confirms that the redder TESS bandpass compared to Kepler has a small effect on the oscillations, supporting the expected yield of thousands of solar-like oscillators with TESS 2 minute cadence observations. Asteroseismic modeling yields a robust determination of the host star radius (R <SUB>*</SUB> = 2.943 {\textpm} 0.064 R <SUB>⊙</SUB>), mass (M <SUB>*</SUB> = 1.212 {\textpm} 0.074 M <SUB>⊙</SUB>), and age (4.9 {\textpm} 1.1 Gyr), and demonstrates that it has just started ascending the red-giant branch. Combining asteroseismology with transit modeling and radial-velocity observations, we show that the planet is a {\textquotedblleft}hot Saturn{\textquotedblright} (R <SUB>p</SUB> = 9.17 {\textpm} 0.33 R <SUB>(+)</SUB>) with an orbital period of \~{}14.3 days, irradiance of F = 343 {\textpm} 24 F <SUB>(+)</SUB>, and moderate mass (M <SUB>p</SUB> = 60.5 {\textpm} 5.7 M <SUB>(+)</SUB>) and density (ρ <SUB>p</SUB> = 0.431 {\textpm} 0.062 g cm<SUP>-3</SUP>). The properties of HD 221416 b show that the host-star metallicity-planet mass correlation found in sub-Saturns (4-8 R <SUB>(+)</SUB>) does not extend to larger radii, indicating that planets in the transition between sub-Saturns and Jupiters follow a relatively narrow range of densities. With a density measured to \~{}15\%, HD 221416 b is one of the best characterized Saturn-size planets to date, augmenting the small number of known transiting planets around evolved stars and demonstrating the power of TESS to characterize exoplanets and their host stars using asteroseismology.},
	keywords = {asteroseismology, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics, planets and satellites: fundamental parameters, planets and satellites: individual: HD 221416 b, stars: fundamental parameters, techniques: photometric},
	isbn = {0004-6256},
	url = {https://ui.adsabs.harvard.edu/abs/2019AJ....157..245H},
	author = {Huber, Daniel and Chaplin, William J. and Chontos, Ashley and Kjeldsen, Hans and Christensen-Dalsgaard, J{\o}rgen and Bedding, Timothy R. and Ball, Warrick and Brahm, Rafael and Espinoza, Nestor and Henning, Thomas and Jord{\'a}n, Andr{\'e}s and Sarkis, Paula and Knudstrup, Emil and Albrecht, Simon and Grundahl, Frank and Fredslund Andersen, Mads and Pall{\'e}, Pere L. and Crossfield, Ian and Fulton, Benjamin and Howard, Andrew W. and Isaacson, Howard T. and Weiss, Lauren M. and Handberg, Rasmus and Lund, Mikkel N. and Serenelli, Aldo M. and R{\o}rsted Mosumgaard, Jakob and Stokholm, Amalie and Bieryla, Allyson and Buchhave, Lars A. and Latham, David W. and Quinn, Samuel N. and Gaidos, Eric and Hirano, Teruyuki and Ricker, George R. and Vanderspek, Roland K. and Seager, Sara and Jenkins, Jon M. and Winn, Joshua N. and Antia, H. M. and Appourchaux, Thierry and Basu, Sarbani and Bell, Keaton J. and Benomar, Othman and Bonanno, Alfio and Buzasi, Derek L. and Campante, Tiago L. and {\c C}elik Orhan, Z. and Corsaro, Enrico and Cunha, Margarida S. and Davies, Guy R. and Deheuvels, Sebastien and Grunblatt, Samuel K. and Hasanzadeh, Amir and Di Mauro, Maria Pia and Garc{\'\i}a, Rafael A. and Gaulme, Patrick and Girardi, L{\'e}o and Guzik, Joyce A. and Hon, Marc and Jiang, Chen and Kallinger, Thomas and Kawaler, Steven D. and Kuszlewicz, James S. and Lebreton, Yveline and Li, Tanda and Lucas, Miles and Lundkvist, Mia S. and Mann, Andrew W. and Mathis, St{\'e}phane and Mathur, Savita and Mazumdar, Anwesh and Metcalfe, Travis S. and Miglio, Andrea and Monteiro, M{\'a}rio J. P. F. G. and Mosser, Benoit and Noll, Anthony and Nsamba, Benard and Ong, Jia Mian Joel and {\"O}rtel, S. and Pereira, Filipe and Ranadive, Pritesh and R{\'e}gulo, Clara and Rodrigues, Tha{\'\i}se S. and Roxburgh, Ian W. and Silva Aguirre, Victor and Smalley, Barry and Schofield, Mathew and Sousa, S{\'e}rgio G. and Stassun, Keivan G. and Stello, Dennis and Tayar, Jamie and White, Timothy R. and Verma, Kuldeep and Vrard, Mathieu and Y{\i}ld{\i}z, M. and Baker, David and Bazot, Micha{\"e}l and Beichmann, Charles and Bergmann, Christoph and Bugnet, Lisa and Cale, Bryson and Carlino, Roberto and Cartwright, Scott M. and Christiansen, Jessie L. and Ciardi, David R. and Creevey, Orlagh and Dittmann, Jason A. and Do Nascimento, J. -D., Jr. and Van Eylen, Vincent and F{\"u}r{\'e}sz, Gabor and Gagn{\'e}, Jonathan and Gao, Peter and Gazeas, Kosmas and Giddens, Frank and Hall, Oliver J. and Hekker, Saskia and Ireland, Michael J. and Latouf, Natasha and LeBrun, Danny and Levine, Alan M. and Matzko, William and Natinsky, Eva and Page, Emma and Plavchan, Peter and Mansouri-Samani, Masoud and McCauliff, Sean and Mullally, Susan E. and Orenstein, Brendan and Garcia Soto, Aylin and Paegert, Martin and van Saders, Jennifer L. and Schnaible, Chloe and Soderblom, David R. and Szab{\'o}, R{\'o}bert and Tanner, Angelle and Tinney, C. G. and Teske, Johanna and Thomas, Alexandra and Trampedach, Regner and Wright, Duncan and Yuan, Thomas T. and Zohrabi, Farzaneh}
}
