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Title: TESS Hunt for Young and Maturing Exoplanets (THYME). X. A Two-planet System in the 210 Myr MELANGE-5 Association
Abstract Young (<500 Myr) planets are critical to studying how planets form and evolve. Among these young planetary systems, multiplanet 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 ± 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 (NotchandLOCoR). We find that the planets are 2.10 ± 0.09R⊕and 2.88 ± 0.10R⊕and orbit their host star every 4.18 and 17.95 days, respectively. With their bright (K= 9.1 mag), small (R*= 0.44R⊙), and cool (Teff= 3326 K) host star, these planets represent excellent candidates for atmospheric characterization with JWST.  more » « less
Award ID(s):
2143763
PAR ID:
10577513
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publisher / Repository:
The Astronomical Journal // ArXiV
Date Published:
Journal Name:
The Astronomical Journal
Volume:
168
Issue:
1
ISSN:
0004-6256
Page Range / eLocation ID:
41
Subject(s) / Keyword(s):
Exoplanet astronomy (486) Transit photometry (1709) Stellar ages (1581) Young star clusters (1833) Stellar activity (1580) Transit timing variation method (1710)
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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