@article{a316276864e2418aa5eb9881e4a96ada,
title = "TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System",
abstract = "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 <100 Myr transiting planets from TESS. HD 109833 has a rotation period and Li abundance indicative of a young age (≲100 Myr), but a position and velocity on the outskirts of the new population, lower Li levels than similar members, and a color-magnitude diagram position below model predictions for 27 Myr. So, we cannot reject the possibility that HD 109833 is a young field star coincidentally nearby the population.",
author = "Wood, {Mackenna L.} and Mann, {Andrew W.} and Barber, {Madyson G.} and Bush, {Jonathan L.} and Kraus, {Adam L.} and Tofflemire, {Benjamin M.} and Andrew Vanderburg and Newton, {Elisabeth R.} and Feiden, {Gregory A.} and George Zhou and Bouma, {Luke G.} and Quinn, {Samuel N.} and Armstrong, {David J.} and Ares Osborn and Vardan Adibekyan and Mena, {Elisa Delgado} and Sousa, {Sergio G.} and Jonathan Gagn{\'e} and Fields, {Matthew J.} and Milburn, {Reilly P.} and Thao, {Pa Chia} and Schmidt, {Stephen P.} and Gnilka, {Crystal L.} and Howell, {Steve B.} and Law, {Nicholas M.} and Carl Ziegler and C{\'e}sar Brice{\~n}o and Ricker, {George R.} and Roland Vanderspek and Latham, {David W.} and Sara Seager and Winn, {Joshua N.} and Jenkins, {Jon M.} and Schlieder, {Joshua E.} and Osborn, {Hugh P.} and Twicken, {Joseph D.} and Ciardi, {David R.} and Huang, {Chelsea X.}",
note = "Funding Information: Observations in the paper made use of the High-Resolution Imaging instrument(s) Zorro. Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Zorro was mounted on the Gemini South telescope of the international Gemini Observatory, a program of NSF's NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. On behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigaci{\'o}n y Desarrollo (Chile), Ministerio de Ciencia, Tecnolog{\'i}a e Innovaci{\'o}n (Argentina), Minist{\'e}rio da Ci{\^e}ncia, Tecnologia e Inova{\c c}{\~o}es (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). Funding Information: This work is based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated by the Fundaci{\'o}n Galileo Galilei (FGG) of the Istituto Nazionale di Astrofisica (INAF) at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands, Spain). Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. The HARPS-N project has been funded by the Prodex Program of the Swiss Space Office (SSO), the Harvard University Origins of Life Initiative (HUOLI), the Scottish Universities Physics Alliance (SUPA), the University of Geneva, the Smithsonian Astrophysical Observatory (SAO), and the Italian National Astrophysical Institute (INAF), the University of St Andrews, Queens University Belfast, and the University of Edinburgh. D.J.A. acknowledges support from the STFC via an Ernest Rutherford Fellowship (ST/R00384X/1). The work of H.P.O. has been carried out within the framework of the NCCR PlanetS supported by the Swiss National Science Foundation under grants 51NF40_182901 and 51NF40_205606. Funding Information: This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA's Science Mission Directorate. We acknowledge the use of public TOI Release data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Funding Information: This research includes data from observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Minist{\'e}rio da Ci{\^e}ncia, Tecnologia e Inova{\c c}{\~o}es (MCTI/LNA) do Brasil, the US National Science Foundation's NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). Funding Information: This work was made possible by grants to A.W.M. from the TESS Guest Investigator Program (80NSSC21K1054), NASA{\textquoteright}s Astrophysics Data Analysis Program (80NSSC19K0583), and the NSF CAREER grant (AST-2143763). M.L.W. and M.G.B. were supported by the NC Space Grant Graduate Research program. S.N.Q. acknowledges support from the TESS GI Program under award 80NSSC21K1056. Publisher Copyright: {\textcopyright} 2023. The Author(s). Published by the American Astronomical Society.",
year = "2023",
month = mar,
day = "1",
doi = "10.3847/1538-3881/aca8fc",
language = "English (US)",
volume = "165",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "3",
}