A revisit to the region of Collinder 132 using CdC and AC plates

R.B. ORELLANA; M.S. DE BIASI; I.H. BUSTOS FIERRO; J.H. CALDERÓN

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Año: 2009

0004-6361

Context. . Aims. Based on stellar positions and proper motions, we aim to re-analyse the region of the controversial open cluster Collinder 132. Methods. We have developed a model which analyse the proper motion distribution and the stellar density to find moving groups. The astrometric data were obtained from four Carte du Ciel (CdC) and one Astrogaphic Catalogue (AC) plates of the Córdoba Astronomical Observatory collection (Argentina). Results. We detected an open cluster from the field stars and calculated the mean proper motion and the membership probabilities of the stars of the region. We report new coordinates of its centre  a = 108°.347, d = -31°.011, the components of mean proper motion  macosd = -2.62 ± 0.44mas/yr, md = 4.79 ± 0.88mas/yr. 13 stars are astrometric members giving a value of 200 for the cluster angular diameter. 6 stars fulfill astrometric and photometric analysis for being cluster members and locate the cluster at 360pc from the Sun. We proposed a simple model for the analysis of the proper motion distribution of an association. We report the components of the association mean proper motion macosd = -1:38 ± 0.14mas/yr, md = 2.26 ± 0.16mas/yr. 149 astrometric members were found while 11 members have been located betweeen 417 and 660 pc from the Sun.