English

The open cluster King~1 in the second quadrant

Astrophysics of Galaxies 2017-08-02 v1

Abstract

We analyse the poorly-studied open cluster King~1 in the second Galactic quadrant. From wide-field photometry we have studied the spatial distribution of this cluster. We determined that the centre of King~1 is located at α2000=00h22m\alpha_{2000}=00^{\rm h}22^{\rm m} and δ2000=+64\degr23\arcmin\delta_{2000}=+64\degr23\arcmin. By parameterizing the stellar density with a King profile we have obtained a central density of ρ0=6.5±0.2\rho_{0}=6.5\pm0.2 star arcmin2^{-2} and a core radius of rcore=1\farcm9±0\farcm2r_{\rm core}=1\farcm9\pm0\farcm2. By comparing the observed color-magnitude diagram of King~1 with those of similar open clusters and with different sets of isochrones, we have estimated an age of 2.8±0.32.8\pm0.3 Gyr, a distance modulus of (mM)o=10.6±0.1(m-M)_{\rm o}=10.6\pm0.1 mag, and a reddening of E(BV)=0.80±0.05E(B-V)=0.80\pm0.05 mag. To complete our analysis we acquired medium resolution spectra for 189 stars in the area of King~1. From their derived radial velocities we determined an average velocity Vr\left\langle V_r\right\rangle =-53.1±\pm3.1 km s1^{-1}. From the strength of the infrared \mbox{Ca\,{\sc ii}} lines in red giants we have determined an average metallicity of [M/H]\left\langle [M/H]\right\rangle=+0.07±\pm0.08 dex. From spectral synthesis we have also estimated an α\alpha-elements abundance of [α/M]\left\langle [\alpha/M]\right\rangle=-0.10±\pm0.08 dex.

Keywords

Cite

@article{arxiv.1706.04863,
  title  = {The open cluster King~1 in the second quadrant},
  author = {R. Carrera and L. Rodríguez Espinosa and L. Casamiquela and L. Balaguer Nuñez and C. Jordi and C. Allende Prieto and P. B. Stetson},
  journal= {arXiv preprint arXiv:1706.04863},
  year   = {2017}
}

Comments

14 pages, 18 figures, table 1 will be available at CDS, Accepted for publication at MNRAS

R2 v1 2026-06-22T20:19:43.731Z