TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System
TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System
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DOI：
10.3847/1538-3881/aca8fc
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发表时间：
2022-12
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通讯作者：
M. Wood;A. Mann;Madyson G. Barber;Jonathan L. Bush;A. Kraus;B. Tofflemire;A. Vanderburg;E. Newton;G. Feiden;G. Zhou;L. Bouma;S. Quinn;David J Armstrong;A. Osborn;V. Adibekyan;E. D. Mena;S. Sousa;Jonathan Gagn'e;M. J. Fields;Reilly P. Milburn;P. C. Thao;S. P. Schmidt;C. Gnilka;S. Howell;N. Law;C. Ziegler;C. Briceño;G. Ricker;R. Vanderspek;D. Latham;S. Seager;J. Winn;J. Jenkins;J. Schlieder;H. Osborn;J. Twicken;D. Ciardi;Chelsea X. Huang
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作者：
M. Wood;A. Mann;Madyson G. Barber;Jonathan L. Bush;A. Kraus;B. Tofflemire;A. Vanderburg;E. Newton;G. Feiden;G. Zhou;L. Bouma;S. Quinn;David J Armstrong;A. Osborn;V. Adibekyan;E. D. Mena;S. Sousa;Jonathan Gagn'e;M. J. Fields;Reilly P. Milburn;P. C. Thao;S. P. Schmidt;C. Gnilka;S. Howell;N. Law;C. Ziegler;C. Briceño;G. Ricker;R. Vanderspek;D. Latham;S. Seager;J. Winn;J. Jenkins;J. Schlieder;H. Osborn;J. Twicken;D. Ciardi;Chelsea X. Huang
我们报告了在下半人马座十字座 (LCC) 附近发现并描述了一个附近 (∼85 pc)、较古老 (27 ± 3 Myr) 的分布式恒星群，最初是通过搜索与来自 TESS (HD 109833; TOI 1097) 的候选凌日行星共移的恒星来识别的。我们使用盖亚运动学、颜色幅度信息和候选成员的轮换周期来确定协会成员资格。我们使用等时线、陀螺年代学和锂消耗来测量它的年龄。虽然这种关联接近已知的 LCC 群体，但我们发现它比之前发现的任何 LCC 亚群（10-16 Myr）都要古老，并且位置和速度都不同。除了 HD 109833 周围的候选行星之外，该协会还包含围绕三颗恒星 YSES-1、YSES-2 和 HD 95086 的四个直接成像的行星质量伴星，所有这些行星之前都被指定为较年轻的 LCC 的成员。使用Notch管道，我们确定了HD 109833周围的第二个候选凌日行星。我们使用一套地面后续观测来验证这两个凌日信号本质上是行星信号。 HD 109833 b 和 c 加入了来自 TESS 的小于 100 Myr 的过境行星，数量虽小但不断增长。 HD 109833 的旋转周期和 Li 丰度表明年龄较小（≲100 Myr），但位置和速度位于新种群的郊区，Li 水平低于类似成员，并且颜色幅度图位置低于 27 Myr 的模型预测。因此，我们不能否认HD 109833是一颗年轻的恒星，恰好位于其族群附近。
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.