Astrophysical parameters of 14 open clusters projected close to the Galactic plane

Universidade Federal do Rio Grande do Sul, Departamento de Astronomia, CP 15051, RS, Porto Alegre 91501-970, Brazil e-mail: denilso.camargo@ufrgs.br; [bica;charles]@if.ufrgs.br

Received: 29 June 2009
Accepted: 9 September 2009

Abstract

Aims. Astrophysical parameters (age, reddening, distance, core and cluster radii) of 14 open clusters (OCs) projected close to the Galactic plane are derived with 2MASS photometry. The OCs are Be 63, Be 84, Cz 6, Cz 7, Cz 12, Ru 141, Ru 144, Ru 172, FSR 101, FSR 1430, FSR 1471, FSR 162, FSR 178, and FSR 198. The OCs Be 63, Be 84, Ru 141, Ru 144, and Ru 172 are studied in more detail than in previous works, while the others have astrophysical parameters derived for the first time.

Methods. We analyse the colour-magnitude diagrams (CMDs) and stellar radial density profiles (RDPs) built after field-star decontamination and colour-magnitude filtered photometry. Field-star decontamination is applied to uncover the cluster's intrinsic CMD morphology, and colour-magnitude filters are used to isolate stars with a high probability of being cluster members in view of structural analyses.

Results. The open clusters of the sample are located at  kpc from the Sun and at Galactocentric distances  kpc, with age in the range 10 Myr to 1.5 Gyr and reddening  in the range  mag. The core and cluster radii are in the range  pc and  pc, respectively. Cz 6 and FSR 198 are the youngest OCs of this sample, with a population of pre-main sequence (PMS) stars, while FSR 178 is the oldest cluster.