Mon-735: a new low-mass pre-main-sequence eclipsing binary in NGC 2264
Abstract
We present Mon-735, a detached double-lined eclipsing binary (EB) member of the ∼3 Myr old NGC 2264 star-forming region, detected by Spitzer. We simultaneously model the Spitzer light curves, follow-up Keck/HIRES radial velocities, and the system's spectral energy distribution to determine self-consistent masses, radii, and effective temperatures for both stars. We find that Mon-735 comprises two pre-main-sequence M dwarfs with component masses of M = 0.2918 ± 0.0099 and 0.2661 ± 0.0095 M⊙, radii of R = 0.762 ± 0.022 and 0.748 ± 0.023 R⊙, and effective temperatures of Teff = 3260 ± 73 and 3213 ± 73 K. The two stars travel on circular orbits around their common centre of mass in P = 1.9751388 ± 0.0000050 d. We compare our results for Mon-735, along with another EB in NGC 2264 (CoRoT 223992193), to the predictions of five stellar evolution models. These suggest that the lower mass EB system Mon-735 is older than CoRoT 223992193 in the mass-radius diagram (MRD) and, to a lesser extent, in the Hertzsprung-Russell diagram (HRD). The MRD ages of Mon-735 and CoRoT 223992193 are ∼7-9 and 4-6 Myr, respectively, with the two components in each EB system possessing consistent ages.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 2020
- DOI:
- 10.1093/mnras/staa1016
- arXiv:
- arXiv:2004.04753
- Bibcode:
- 2020MNRAS.495.1531G
- Keywords:
-
- binaries: eclipsing;
- binaries: spectroscopic;
- stars: fundamental parameters;
- stars: low-mass;
- stars: pre-main-sequence;
- open clusters and associations: individual: NGC 2264;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 18 pages, 14 figures, 5 tables, accepted for publication in MNRAS