CCD UBVRI photometry of NGC 6811

Yontan T., Bilir S., Bostanci Z. F., Ak T., Karaali S., Guver T., ...Daha Fazla

ASTROPHYSICS AND SPACE SCIENCE, cilt.355, ss.267-281, 2015 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 355
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1007/s10509-014-2175-5
  • Dergi Adı: ASTROPHYSICS AND SPACE SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.267-281
  • Anahtar Kelimeler: Galaxy: open cluster and associations: individual: NGC 6811, Stars: Hertzsprung Russell (HR) diagram, OPEN CLUSTER, RED-CLUMP, GIANTS, CALIBRATION, MAGNITUDE, STARS, METALLICITY, ISOCHRONES, MEMBERSHIP, EVOLUTION
  • İstanbul Üniversitesi Adresli: Evet

Özet

We present the results of CCD UBVRI observations of the open cluster NGC 6811 obtained on 18th July 2012 with the 1 m telescope at the TUBITAK National Observatory (TUG). Using these photometric results, we determine the structural and astrophysical parameters of the cluster. The mean photometric uncertainties are better than 0.02 mag in the V magnitude and B - V, V - R, and V - I colour indices to about 0.03 mag for U - B among stars brighter than magnitude V = 18. Cluster member stars were separated from the field stars using the Galaxia model of Sharma et al. (2011) together with other techniques. The core radius of the cluster is found to be r(c) = 3.60 arcmin. The astrophysical parameters were determined simultaneously via Bayesian statistics using the colour-magnitude diagrams V versus B - V, V versus V - I, V versus V - R, and V versus R - I of the cluster. The resulting most likely parameters were further confirmed using independent methods, removing any possible degeneracies. The colour excess, distance modulus, metallicity and the age of the cluster are determined simultaneously as E(B-V) = 0.05 +/- 0.01 mag, mu = 10.06 +/- 0.08 mag, [M/H] = -0.10 +/- 0.01 dex and t = 1.00 +/- 0.05 Gyr, respectively. Distances of five red clump stars which were found to be members of the cluster further confirm our distance estimation.