The distance to the young cluster NGC 7129 and its age

Abstract

The dust cloud TGU H645 P2 and embedded in it young open cluster NGC 7129 are investigated using the results of medium-band photometry of 159 stars in the Vilnius seven-colour system down to V = 18.8 mag. The photometric data were used to classify about 50 percent of the measured stars in spectral and luminosity classes. The extinction A_V vs. distance diagram for the 20x20 arcmin area is plotted for 155 stars with two-dimensional classification from the present and the previous catalogues. The extinction values found range between 0.6 and 3.4 mag. However, some red giants, located in the direction of the dense parts of the cloud, exhibit the infrared extinction equivalent up to A_V = 13 mag. The distance to the cloud (and the cluster) is found to be 1.15 kpc (the true distance modulus 10.30 mag). For determining the age of NGC 7129, a luminosity vs. temperature diagram for six cluster members of spectral classes B3 to A1 was compared with the Pisa pre-main-sequence evolution tracks and the Palla birthlines. The cluster can be as old as about 3 Myr, but star forming continues till now as witnessed by the presence in the cloud of many younger pre-main-sequence objects identified with photometry from 2MASS, Spitzer and WISE infrared surveys.

8 pages, 6 fugures, full Table 1 online. Accepted for publication in MNRAS on 2013 November 30

References in corpus (22)

• The chemical composition of the Sun
• The PPMXL catalog of positions and proper motions on the ICRS. Combining USNO-B1.0 and 2MASS
• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• Evolutionary models for low-mass stars and brown dwarfs: uncertainties and limits at very young ages
• On the use of empirical bolometric corrections for stars
• The Pisa pre-main sequence tracks and isochrones. A database covering a wide range of Z, Y, mass, and age values
• K-Band Calibration of the Red Clump Luminosity
• The Initial Configuration of Young Stellar Clusters: A K-band Number Counts Analysis of the Surface Density of Stars
• New infrared star clusters in the Northern and Equatorial Milky Way with 2MASS
• Observed luminosity spread in young clusters and Fu Ori stars: a unified picture
• On the Reliability of Stellar Ages and Age Spreads Inferred from Pre-Main Sequence Evolutionary Models
• A Catalogue of infrared star clusters and stellar groups
• The Helium abundance and Delta Y / Delta Z in Lower Main Sequence stars
• The NGC 7129 Young Stellar Cluster: A Combined Spitzer, MMT, and 2MASS Census of Disks, Protostars, and Outflows
• Solar Neutrino Constraints on the BBN Production of Li
• A 13CO and C18O Survey of the Molecular Gas Around Young Stellar Clusters Within 1kpc of the Sun
• The 24-Micron View of Embedded Star Formation in NGC 7129
• Lithium-7 surface abundance in pre-MS stars. Testing theory against clusters and binary systems
• Pre-main sequence stars in the Cepheus flare region
• Catalogue of variable stars in open cluster fields
• A Chandra and Spitzer census of the young star cluster in the reflection nebula NGC 7129
• Near- And Mid-Infrared Imaging Study of Young Stellar Objects around LkH$\alpha$ 234

Cited by in corpus (10)

• Distances and Kinematics of Gould Belt Star-Forming Regions with Gaia DR2 results
• Molecular Cloud Cores with High Deuterium Fraction: Nobeyama Single-Pointing Survey
• Pulsational instability of pre-main sequence models from accreting protostars. I. Constraining the input physics for accretion with spectroscopic parameters and stellar pulsations
• A survey for variable young stars with small telescopes: First results from HOYS-CAPS
• An Optical Survey of the Partially Embedded Young Cluster in NGC 7129
• Time-monitoring Observations of Br$\gamma$ Emission from Young Stars
• Towards a better classification of unclear eruptive variables: the cases of V2492 Cyg, V350 Cep, and ASASSN-15qi
• Photoionization Models of the Inner Gaseous Disk of the Herbig Be Star BD+65 1637
• A long-term UBVRI photometric study of the pre-main sequence star V350 Cep
• Long-term photometric behavior of the PMS stars V977 Cep and V982 Cep in the vicinity of NGC 7129