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TOI-1408: Discovery and Photodynamical Modeling of a Small Inner Companion to a Hot Jupiter Revealed by Transit Timing Variations
- Source :
- The Astrophysical Journal Letters, Vol 971, Iss 2, p L28 (2024)
- Publication Year :
- 2024
- Publisher :
- IOP Publishing, 2024.
-
Abstract
- We report the discovery and characterization of a small planet, TOI-1408 c, on a 2.2 day orbit located interior to a previously known hot Jupiter, TOI-1408 b ( P = 4.42 days, M = 1.86 ± 0.02 M _Jup , R = 2.4 ± 0.5 R _Jup ) that exhibits grazing transits. The two planets are near 2:1 period commensurability, resulting in significant transit timing variations (TTVs) for both planets and transit duration variations for the inner planet. The TTV amplitude for TOI-1408 c is 15% of the planet’s orbital period, marking the largest TTV amplitude relative to the orbital period measured to date. Photodynamical modeling of ground-based radial velocity (RV) observations and transit light curves obtained with the Transiting Exoplanet Survey Satellite and ground-based facilities leads to an inner planet radius of 2.22 ± 0.06 R _⊕ and mass of 7.6 ± 0.2 M _⊕ that locates the planet into the sub-Neptune regime. The proximity to the 2:1 period commensurability leads to the libration of the resonant argument of the inner planet. The RV measurements support the existence of a third body with an orbital period of several thousand days. This discovery places the system among the rare systems featuring a hot Jupiter accompanied by an inner low-mass planet.
Details
- Language :
- English
- ISSN :
- 20418213 and 20418205
- Volume :
- 971
- Issue :
- 2
- Database :
- Directory of Open Access Journals
- Journal :
- The Astrophysical Journal Letters
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.bd9a4751ba304fe8acac0d46be3bce19
- Document Type :
- article
- Full Text :
- https://doi.org/10.3847/2041-8213/ad65fd