Abstract
The discovery of a warm sub-Saturn planet, TOI-257b (HD 19916b), is reported, utilizing data from NASA's Transiting Exoplanet Survey Satellite (TESS). The transit signal detected by TESS was confirmed as a planet through radial velocity observations. Analysis of TESS photometry, Minerva-Australis, FEROS, and HARPS radial velocities, alongside asteroseismic data, shows that TOI-257b has a mass of 0.138 ± 0.023 MJ (43.9 ± 7.3 M⊕), a radius of 0.639 ± 0.013 RJ (7.16 ± 0.15 R⊕), bulk density of 0.65+0.12-0.11 (cgs), and an orbital period of 18.38818 +0.00085 -0.00084 days. The planet orbits a late F-type star and there are hints of a second non-transiting sub-Saturn mass planet on a ∼71-day orbit. This discovery is significant as warm sub-Saturns are rare, making TOI-257b valuable for future studies on the formation and migration history of similar planetary systems.
| Original language | English |
|---|---|
| Pages (from-to) | 3704-3722 |
| Number of pages | 19 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 502 |
| Issue number | 3 |
| DOIs | |
| State | Published - Apr 1 2021 |
| Externally published | Yes |
ASJC Scopus Subject Areas
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- asteroseismology
- planetary systems
- stars: individual (TIC 200723869/TOI-257)
- techniques: photometric
- techniques: radial velocities
- techniques: spectroscopic