2MASS J01542930+0053266 : A New Eclipsing M-dwarf Binary System

TL;DR

This paper reports the discovery and detailed characterization of a new eclipsing binary system composed of two M-dwarfs, providing precise measurements of their masses, radii, and activity, and discussing implications for stellar magnetic activity.

Contribution

It presents the first detailed analysis of 2MASS J01542930+0053266, including orbital parameters, stellar properties, and activity, highlighting the impact of binarity on magnetic phenomena in low-mass stars.

Findings

Masses and radii consistent with empirical relationships

Both stars exhibit H-alpha emission indicating magnetic activity

Binarity may enhance or prolong magnetic activity in M dwarfs

Abstract

We report on 2MASS J01542930+0053266, a faint eclipsing system composed of two M dwarfs. The variability of this system was originally discovered during a pilot study of the 2MASS Calibration Point Source Working Database. Additional photometry from the Sloan Digital Sky Survey yields an 8-passband lightcurve, from which we derive an orbital period of 2.6390157 +/- 0.0000016 days. Spectroscopic followup confirms our photometric classification of the system, which is likely composed of M0 and M1 dwarfs. Radial velocity measurements allow us to derive the masses (M_1 = 0.66 +/- 0.03 M_sun; M_2 = 0.62 +/- 0.03 M_sun) and radii (R_1 = 0.64 +/- 0.08 R_sun; R_2 = 0.61 +/- 0.09 R_sun) of the components, which are consistent with empirical mass-radius relationships for low-mass stars in binary systems. We perform Monte Carlo simulations of the lightcurves which allow us to uncover complicated degeneracies between the system parameters. Both stars show evidence of H-alpha emission, something not common in early-type M dwarfs. This suggests that binarity may influence the magnetic activity properties of low-mass stars; activity in the binary may persist long after the dynamos in their isolated counterparts have decayed, yielding a new potential foreground of flaring activity for next generation variability surveys.