Three Small Planets Transiting the Bright Young Field Star K2-233
Abstract
We report the detection of three small transiting planets around the young K3 dwarf K2-233 (2MASS J15215519-2013539) from observations during Campaign 15 of the K2 mission. The star is relatively nearby (d = 69 pc) and bright (V = 10.7 mag, K s = 8.4 mag), making the planetary system an attractive target for radial velocity follow-up and atmospheric characterization with the James Webb Space Telescope. The inner two planets are hot super-Earths (R b = 1.40 ± 0.06 {R}\oplus , R c = 1.34 ± 0.08 {R}\oplus ), while the outer planet is a warm sub-Neptune (R d = 2.6 ± 0.1 {R}\oplus ). We estimate the stellar age to be {360}-140+490 Myr based on rotation, activity, and kinematic indicators. The K2-233 system is particularly interesting given recent evidence for inflated radii in planets around similarly aged stars, a trend potentially related to photo-evaporation, core cooling, or both mechanisms.
- Publication:
-
The Astronomical Journal
- Pub Date:
- May 2018
- DOI:
- 10.3847/1538-3881/aabde8
- arXiv:
- arXiv:1803.05056
- Bibcode:
- 2018AJ....155..222D
- Keywords:
-
- planetary systems;
- planets and satellites: gaseous planets;
- planets and satellites: physical evolution;
- planets and satellites: terrestrial planets;
- stars: individual: EPIC 249622103;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted to AJ. 15 pages, 6 figures, 3 tables