Mon-735: a new low-mass pre-main-sequence eclipsing binary in NGC 2264

June 2020 • 2020MNRAS.495.1531G

Authors • Gillen, Edward • Hillenbrand, Lynne A. • Stauffer, John • Aigrain, Suzanne • Rebull, Luisa • Cody, Ann Marie

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 T_eff = 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.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2020MNRAS.495.1531G
• PDF http://academic.oup.com/mnras/pdf-lookup/doi/10.1093/mnras/staa1016
• PREPRINT http://arxiv.org/abs/2004.04753
• DATA https://archive.stsci.edu/mastbibref.php?bibcode=2020MNRAS.495.1531G
• DATA https://irsa.ipac.caltech.edu/bibdata/2020/G/2020MNRAS.495.1531G.html
• ELECTR https://doi.org/10.1093%2Fmnras%2Fstaa1016