* Astronomy

Title: The open cluster King~1 in the second quadrant
Author: R. Carrera (1,2), L. Rodríguez Espinosa (1,2), L. Casamiquela (3), L. Balaguer Nuñez (3), C. Jordi (3), C. Allende Prieto (1,2), P. B. Stetson (4) ((1) Instituto de Astrofísica de Canarias (2) Departamento de Astrofísica, Universidad de La Laguna (3) Departament de Física Quántica i Astrofísica, Institut Ciéncies Cosmos (ICCUB), Universitat de Barcelona (4) National Research Council)

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 alpha2000=00h22m and \delta_{2000}=+64° 23'. By parameterizing the stellar density with a King profile we have obtained a central density of rho_{0}=6.5±0.2 star arcmin^-2 and a core radius of r_{core}=1.9'±0.2'. By comparing the observed colour-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±0.3 Gyr, a distance modulus of (m-M)o=10.6±0.1 mag, and a reddening of E(B-V)=0.80±0.05 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)=-53.1±3.1 km s^-1. From the strength of the infrared Ca II lines in red giants we have determined an average metallicity of ([M/H])=+0.07±0.08 dex. From spectral synthesis we have also estimated an -elements abundance of ([alpha/M])=-0.10±0.08 dex.

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