1. TESS Hunt for Young and Maturing Exoplanets (THYME) X: a two-planet system in the 210 Myr MELANGE-5 Association
- Author
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Thao, Pa Chia, Mann, Andrew W., Barber, Madyson G., Kraus, Adam L., Tofflemire, Benjamin M., Bush, Jonathan L., Wood, Mackenna L., Collins, Karen A., Vanderburg, Andrew, Quinn, Samuel N., Zhou, George, Newton, Elisabeth R., Ziegler, Carl, Law, Nicholas, Barkaoui, Khalid, Pozuelos, Francisco J., Timmermans, Mathilde, Gillon, Michaël, Jehin, Emmanuël, Schwarz, Richard P., Gan, Tianjun, Shporer, Avi, Horne, Keith, Sefako, Ramotholo, Suarez, Olga, Mekarnia, Djamel, Guillot, Tristan, Abe, Lyu, Triaud, Amaury H. M. J., Radford, Don J., Murillo, Ana Isabel Lopez, Ricker, George R., Winn, Joshua N., Jenkins, Jon M., Bouma, Luke G., Fausnaugh, Michael, Guerrero, Natalia M., and Kunimoto, Michelle
- Subjects
Astrophysics - Earth and Planetary Astrophysics - Abstract
Young (<500 Myr) planets are critical to studying how planets form and evolve. Among these young planetary systems, multi-planet configurations are particularly useful as they provide a means to control for variables within a system. Here, we report the discovery and characterization of a young planetary system, TOI-1224. We show that the planet-host resides within a young population we denote as MELANGE-5 . By employing a range of age-dating methods -- isochrone fitting, lithium abundance analysis, gyrochronology, and Gaia excess variability -- we estimate the age of MELANGE-5 to be 210$\pm$27 Myr. MELANGE-5 is situated in close proximity to previously identified younger (80 -110 Myr) associations, Crius 221 and Theia 424/Volans-Carina, motivating further work to map out the group boundaries. In addition to a planet candidate detected by the TESS pipeline and alerted as a TESS Object of Interest, TOI-1224 b, we identify a second planet, TOI-1224 c, using custom search tools optimized for young stars (Notch and LOCoR). We find the planets are 2.10$\pm$0.09$R_\oplus$ and 2.88$\pm$0.10$R_\oplus$ and orbit their host star every 4.18 and 17.95 days, respectively. With their bright ($K$=9.1 mag), small ($R_{*}$=0.44R$_{\odot}$), and cool ($T_{eff}$ =3326K) host star, these planets represent excellent candidates for atmospheric characterization with JWST., Comment: Accepted for publication in The Astronomical Journal; 33 pages, 17 figures, 9 tables
- Published
- 2024