TESS Discovery of a Super-Earth and Three Sub-Neptunes Hosted by the Bright, Sun-like Star HD 108236
Tansu Daylan, Kartik Pinglé, Jasmine Wright, Maximilian N. Günther, Keivan G. Stassun, Stephen R. Kane, Andrew Vanderburg, Daniel Jontof-Hutter, Joseph E. Rodriguez, Avi Shporer, Chelsea X. Huang, Thomas Mikal-Evans, Mariona Badenas-Agusti, Karen A. Collins, Benjamin V. Rackham, Samuel N. Quinn, Ryan Cloutier, Kevin I. Collins, Pere Guerra, Eric L. N. Jensen, John F. Kielkopf, Bob Massey, Richard P. Schwarz, David Charbonneau, Jack J. Lissauer, Jonathan M. Irwin, Özgür Baştürk, Benjamin Fulton, Abderahmane Soubkiou, Benkhaldoun Zouhair, Steve B. Howell, Carl Ziegler, César Briceño, Nicholas Law, Andrew W. Mann, Nic Scott, Elise Furlan, David R. Ciardi, Rachel Matson, Coel Hellier, David R. Anderson, R. Paul Butler, Jeffrey D. Crane, Johanna K. Teske, Stephen A. Shectman, Martti H. Kristiansen, Ivan A. Terentev, Hans Martin Schwengeler, George R. Ricker, Roland Vanderspek, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Zachory K. Berta-Thompson, Luke G. Bouma, William Fong, Gabor Furesz, Christopher E. Henze, Edward H. Morgan, Elisa Quintana, Eric B. Ting, Joseph D. Twicken
Abstract
Abstract We report the discovery and validation of four extrasolar planets hosted by the nearby, bright, Sun-like (G3V) star HD 108236 using data from the Transiting Exoplanet Survey Satellite (TESS). We present transit photometry, reconnaissance, and precise Doppler spectroscopy, as well as high-resolution imaging, to validate the planetary nature of the objects transiting HD 108236, also known as the TESS Object of Interest (TOI) 1233. The innermost planet is a possibly rocky super-Earth with a period of days and has a radius of 1.586 ± 0.098 R ⊕ . The outer planets are sub-Neptunes, with potential gaseous envelopes, having radii of R ⊕ , 2.72 ± 0.11 R ⊕ , and R ⊕ and periods of days, days, and days, respectively. With V and K s magnitudes of 9.2 and 7.6, respectively, the bright host star makes the transiting planets favorable targets for mass measurements and, potentially, for atmospheric characterization via transmission spectroscopy. HD 108236 is the brightest Sun-like star in the visual ( V ) band known to host four or more transiting exoplanets. The discovered planets span a broad range of planetary radii and equilibrium temperatures and share a common history of insolation from a Sun-like star ( R ⋆ = 0.888 ± 0.017 R ⊙ , T eff = 5730 ± 50 K), making HD 108236 an exciting, opportune cosmic laboratory for testing models of planet formation and evolution.