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 $\sim$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 $M=0.2918\pm 0.0099$ and $0.2661\pm 0.0095$ ${\mathrm{M}}_{\odot }$, radii of $R=0.762\pm 0.022$ and $0.748\pm 0.023$ ${\mathrm{R}}_{\odot }$, and effective temperatures of $T_{\mathrm{eff}}=3260\pm 73$ and $3213\pm 73$ $\mathrm{K}$. The two stars travel on circular orbits around their common centre of mass in $P=1.9751388\pm 0.0000050$ days. 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 $\sim$7-9 and 4-6 Myr, respectively, with the two components in each EB system possessing consistent ages.

18 pages, 14 figures, 5 tables, accepted for publication in MNRAS

References in corpus (26)

• The Dartmouth Stellar Evolution Database
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Improving PARSEC models for very low mass stars
• A spin-down clock for cool stars from observations of a 2.5-billion-year-old cluster
• Magnetospheric accretion-ejection processes in the classical T Tauri star AA
• Kinematic and Spatial Substructure in NGC 2264
• Zodiacal Exoplanets in Time (ZEIT) IV: seven transiting planets in the Praesepe cluster
• Mapping accretion and its variability in the young open cluster NGC 2264: a study based on u-band photometry
• Fitting the young main-sequence; distances, ages and age spreads
• The CARMENES search for exoplanets around M dwarfs. Activity indicators at visible and near-infrared wavelengths
• Empirical Tests of Pre-Main-Sequence Stellar Evolution Models with Eclipsing Binaries
• Age Determination in Upper Scorpius with Eclipsing Binaries
• New low-mass eclipsing binary systems in Praesepe discovered by K2
• CSI 2264: Characterizing Young Stars in NGC 2264 with Short-Duration, Periodic Flux Dips in their Light Curves
• Self-Consistent Magnetic Stellar Evolution Models of the Detached, Solar-Type Eclipsing Binary EF Aquarii
• The Monitor project: Rotation of low-mass stars in the open cluster M34
• NGTS clusters survey. I. Rotation in the young benchmark open cluster Blanco 1
• From discs to planetesimals I: evolution of gas and dust discs
• The Monitor project: JW 380 -- a 0.26, 0.15 Msol pre main sequence eclipsing binary in the Orion Nebula Cluster
• The CORALIE survey for southern extrasolar planets XVIII. Three new massive planets and two low mass brown dwarfs at separation larger than 5 AU
• The Factory and the Beehive III: PTFEB132.707+19.810, a Low-Mass Eclipsing Binary in Praesepe Observed by PTF and K2
• Pulsating pre-main sequence stars in IC 4996 and NGC 6530
• CoRoT 223992193: Investigating the variability in a low-mass, pre-main sequence eclipsing binary with evidence of a circumbinary disk
• Deep VLA Images of the HH 124 IRS Radio Cluster and its Surroundings and a New Determination of the Distance to NGC 2264
• THOR 42: A touchstone $\sim$24 Myr-old eclipsing binary spanning the fully-convective boundary
• Fundamental properties of the pre-main sequence eclipsing stars of MML 53 and the mass of the tertiary