TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System

Autor: Mackenna L. Wood, Andrew W. Mann, Madyson G. Barber, Jonathan L. Bush, Adam L. Kraus, Benjamin M. Tofflemire, Andrew Vanderburg, Elisabeth R. Newton, Gregory A. Feiden, George Zhou, Luke G. Bouma, Samuel N. Quinn, David J. Armstrong, Ares Osborn, Vardan Adibekyan, Elisa Delgado Mena, Sergio G. Sousa, Jonathan Gagné, Matthew J. Fields, Reilly P. Milburn, Pa Chia Thao, Stephen P. Schmidt, Crystal L. Gnilka, Steve B. Howell, Nicholas M. Law, Carl Ziegler, César Briceño, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M. Jenkins, Joshua E. Schlieder, Hugh P. Osborn, Joseph D. Twicken, David R. Ciardi, Chelsea X. Huang
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: The Astronomical Journal, Vol 165, Iss 3, p 85 (2023)
Druh dokumentu: article
ISSN: 1538-3881
DOI: 10.3847/1538-3881/aca8fc
Popis: We report the discovery and characterization of a nearby (∼85 pc), older (27 ± 3 Myr), distributed stellar population near Lower Centaurus Crux (LCC), initially identified by searching for stars comoving with a candidate transiting planet from TESS (HD 109833; TOI 1097). We determine the association membership using Gaia kinematics, color–magnitude information, and rotation periods of candidate members. We measure its age using isochrones, gyrochronology, and Li depletion. While the association is near known populations of LCC, we find that it is older than any previously found LCC subgroup (10–16 Myr), and distinct in both position and velocity. In addition to the candidate planets around HD 109833, the association contains four directly imaged planetary-mass companions around three stars, YSES-1, YSES-2, and HD 95086, all of which were previously assigned membership in the younger LCC. Using the Notch pipeline, we identify a second candidate transiting planet around HD 109833. We use a suite of ground-based follow-up observations to validate the two transit signals as planetary in nature. HD 109833 b and c join the small but growing population of
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