Variable Stars in the Open Cluster NGC 7142

Abstract

We present new discoveries of variable stars near the turnoff of the old open cluster NGC 7142. Contrary to previous studies, we detect eight contact or near contact eclipsing binaries (including three near the cluster turnoff), and most of these have good probability of being cluster members. We also identified one long-period variable that resides far to the red of the cluster giant branch, and four new detached eclipsing binaries. We have re-examined the question of distance and reddening for the cluster, and find that the distance is larger and reddening lower than in most previous studies. In turn this implies that NGC 7142 is probably slightly younger than M67, about 3 Gyr old. With an age of this size, NGC 7142 would be one of a small group of clusters with main sequence turnoff stars at the transition between convective and radiative cores.

18 figures, accepted to AJ

References in corpus (6)

• The Dartmouth Stellar Evolution Database
• A new standard: Age and distance for the open cluster NGC 6791 from the eclipsing binary member V20
• An Examination of Recent Transformations to the BV(RI)_C Photometric System from the Perspective of Stellar Models for Old Stars
• The transiting planet OGLE-TR-132b revisited with new spectroscopy and deconvolution photometry
• Bright Variable Stars in NGC 6819 - An Open Cluster in the Kepler Field
• Eclipsing Binaries in Open Clusters

Cited by in corpus (8)

• On the Origin of Sub-subgiant Stars. I. Demographics
• WOCS 40007: A Detached Eclipsing Binary near the Turnoff of the Open Cluster NGC 6819
• Catalogue of variable stars in open cluster fields
• Contact Binaries as Viable Distance Indicators: New, Competitive (V)JHKs Period-Luminosity Relations
• Analysis of Detached Eclipsing Binaries near the Turnoff of the Open Cluster NGC 7142
• The open cluster NGC 7142: interstellar extinction, distance and age
• WIYN Open Cluster Study LXXX: HDI CCD $UBVRI$ Photometry of the Old Open Cluster NGC 7142 and Comparison to M67
• Searching for Variable Stars in the Open Cluster NGC 2355 and Its Surrounding Region