TESS discovery of a super-Earth and three sub-Neptunes hosted by the bright, Sun-like star HD 108236
Creators: name: Daylan, Tansu
name: Pingle, Kartik
name: Wright, Jasmine
name: Guenther, Maximilian N.
name: Stassun, Keivan G.
name: Kane, Stephen R.
name: Vanderburg, Andrew
name: Jontof-Hutter, Daniel
name: Rodriguez, Joseph E.
name: Shporer, Avi
name: Huang, Chelsea
name: Mikal-Evans, Tom
name: Badenas-Agusti, Mariona
name: Collins, Karen A.
name: Rackham, Benjamin
name: Quinn, Sam
name: Cloutier, Ryan
name: Collins, Kevin I.
name: Guerra, Pere
name: Jensen, Eric L. N.
name: Kielkopf, John F.
name: Massey, Bob
name: Schwarz, Richard P.
name: Charbonneau, David
name: Lissauer, Jack J.
name: Irwin, Jonathan M.
name: Basturk, Ozgur
name: Fulton, Benjamin
name: Soubkiou, Abderahmane
name: Zouhair, Benkhaldoun
name: Howell, Steve
name: Ziegler, Carl
name: Briceno, Cesar
name: Law, Nicholas
name: Mann, Andrew W.
name: Scott, Nic
name: Furlan, Elise
name: Ciardi, David R.
name: Matson, Rachel
name: Hellier, Coel
name: Anderson, David R
name: Butler, R. Paul
name: Crane, Jeffery D.
name: Teske, Johanna K.
name: Shectman, Stephen A.
name: Kristiansen, Martti H.
name: Terentev, Ivan A.
name: Schwengeler, Hans Martin
name: Ricker, George R.
name: Vanderspek, Roland
name: Seager, S.
name: Winn, Joshua N.
name: Jenkins, Jon M.
name: Thompson, Zach Berta
name: Bouma, Luke
name: Fong, Willie
name: Furesz, Gabor
name: Henze, Christopher E.
name: Morgan, Ed
name: Quintana, Elisa
name: Ting, Eric B.
name: Twicken, Joseph D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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 $3.79523_{-0.00044}^{+0.00047}$ days and has a radius of $1.586\pm0.098$ $R_\oplus$. The outer planets are sub-Neptunes, with potential gaseous envelopes, having radii of $2.068_{-0.091}^{+0.10}$ $R_\oplus$, $2.72\pm0.11$ $R_\oplus$, and $3.12_{-0.12}^{+0.13}$ $R_\oplus$ and periods of $6.20370_{-0.00052}^{+0.00064}$ days, $14.17555_{-0.0011}^{+0.00099}$ days, and $19.5917_{-0.0020}^{+0.0022}$ days, respectively. With V and K$_{\rm s}$ 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 ($R_\star = 0.888 \pm 0.017$ R$_\odot$, $T_{\rm eff} = 5730 \pm 50$ K), making HD 108236 an exciting, opportune cosmic laboratory for testing models of planet formation and evolution.
description: accepted for publication in The Astronomical Journal