Ultra-short-period Planets in K2 with Companions: A Double Transiting System for EPIC 220674823
Abstract
Two transiting planets have been identified orbiting K2 target EPIC 220674823. One object is an ultra-short-period planet (USP) with a period of just 0.57 days (13.7 hr), while the other has a period of 13.3 days. Both planets are small, with the former having a radius of {R}{{p}1}=1.5 {R}\oplus and the latter {R}{{p}2}=2.5 {R}\oplus . Follow-up observations, including radial velocity (with uncertainties of 110 m s-1) and high-resolution adaptive optics imagery, show no signs of stellar companions. EPIC 220674823 is the 12th confirmed or validated planetary system in which a USP (I.e., having an orbital period less than 1 day) is accompanied by at least one additional planet, suggesting that such systems may be common and must be accounted for in models for the formation and evolution of such extreme systems.
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 2017
- DOI:
- 10.3847/1538-3881/153/2/82
- arXiv:
- arXiv:1611.00397
- Bibcode:
- 2017AJ....153...82A
- Keywords:
-
- planetary systems;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 8 pages, 6 figures, 2 tables, accepted to AJ