학술논문
TESS Hunt for Young and Maturing Exoplanets (THYME) XI: An Earth-sized Planet Orbiting a Nearby, Solar-like Host in the 400Myr Ursa Major Moving Group
Document Type
Working Paper
Author
Capistrant, Benjamin K.; Soares-Furtado, Melinda; Vanderburg, Andrew; Jankowski, Alyssa; Mann, Andrew W.; Ross, Gabrielle; Srdoc, Gregor; Hinkel, Natalie R.; Becker, Juliette; Magliano, Christian; Limbach, Mary Anne; Stephan, Alexander P.; Nine, Andrew C.; Tofflemire, Benjamin M.; Kraus, Adam L.; Giacalone, Steven; Winn, Joshua N.; Bieryla, Allyson; Bouma, Luke G.; Ciardi, David R.; Collins, Karen A.; Covone, Giovanni; de Beurs, Zoë L.; Huang, Chelsea X.; Quinn, Samuel N.; Seager, Sara; Vanderspek, Roland K.; Jenkins, Jon M.; Kreidberg, Laura; Latham, David W.; Shporer, Avi; Twicken, Joseph D.; Wohler, Bill; Yarza, Ricardo; Ziegler, Carl
Source
Subject
Language
Abstract
Young terrestrial worlds are critical test beds to constrain prevailing theories of planetary formation and evolution. We present the discovery of HD 63433d - a nearby (22pc), Earth-sized planet transiting a young sunlike star (TOI-1726, HD 63433). HD 63433d is the third planet detected in this multiplanet system. The kinematic, rotational, and abundance properties of the host star indicate that it belongs to the young (414 $\pm$ 23 Myr) Ursa Major moving group, whose membership we update using new data from Gaia DR3 and TESS. Our transit analysis of the TESS light curves indicates that HD 63433 d has a radius of 1.1 $R_\oplus$ and closely orbits its host star with a period of 4.2 days. To date, HD 63433 d is the smallest confirmed exoplanet with an age less than 500 Myr, and the nearest young Earth-sized planet. Furthermore, the apparent brightness of the stellar host (V $\approx$ 6.9 mag) makes this transiting multiplanet system favorable to further investigations, including spectroscopic follow-up to probe atmospheric loss in a young Earth-sized world.
Comment: 24 pages, 7 figures, 6 tables. Accepted for publication in AJ. The first two authors contributed equally to the manuscript
Comment: 24 pages, 7 figures, 6 tables. Accepted for publication in AJ. The first two authors contributed equally to the manuscript