A CCD Search for Variable Stars of Spectral Type B in the Northern Hemisphere Open Clusters. VI. NGC 6910
Abstract
We present results of variability search in the field of the young open cluster NGC 6910. We found four beta Cep-type stars in the cluster, which makes it rather exceptional among the northern clusters observed in our project. Two of these beta Cep stars show three modes with amplitudes above the detection level, in the remaining two we detect single modes. We discuss the possibility that the large number of beta Cep stars in NGC 6910 is due to higher metallicity of the cluster. In addition, we found four other variables, one ellipsoidal or eclipsing binary and three that show irregular variations. The latter three stars have H alpha in emission.
We also provide VI_C photometry for 139 stars down to V=16.6 mag and H alpha photometry for 73 stars. Using this photometry we estimate the cluster age to be equal to 6+/-2 Myr, and the distance modulus, 11.0+/-0.3 mag. The reddening is high and variable across the cluster. In terms of the E(V-I_C) color-excess it amounts to 1.25-1.7 mag, corresponding to E(B-V) between 1.0 mag and 1.4 mag. The average reddening in the central field is E(V-I_ C=1.47+/-0.04 mag.- Publication:
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Acta Astronomica
- Pub Date:
- March 2004
- Bibcode:
- 2004AcA....54...33K
- Keywords:
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- Stars: early-type;
- Stars: oscillations;
- Stars: emission-line;
- Be;
- open clusters and associations: individual: NGC 6910}