Open cluster detection in extensive sky regions using astrometric parameters

L.G. PAÍZ; M.S. DE BIASI; R.B. ORELLANA

Florianópolis

Congreso; XIV Latin American Regional IAU Meeting; 2013

Instituto de Astronomía, Universidad Nacional Autónoma de México

We developed a non-parametric method for identifying open clusters in large areas of the sky using stellar position and proper motions. Two binary codes were established from the analysis of the empirical probability density functions in position and proper motion, after eliminating field stars contamination. For each star, these codes provided a parameter indicating the star belongingness to spatial and proper motion overdensities. The method was tested in a region of 4◦×5◦ where Collinder 140 and Collinder 132 are located. 1300 stars up to the magnitude R=11 were obtained from UCAC2 and its supplement UCAC2 BSS catalogue. We detected six stellar groups having spatial and proper motion overdensities. A detailed analysis revealed that three of them could be open clusters. We confirmed that one of them is Collinder 140, for which mean coordinates (RA,DE)=(110.8º,-32.0º), a radius of about 12? and mean proper motion components (PMRA,PMDE)=(9,4) mas/yr were obtained, in good agreement with the literature. The other two possible clusters have members fainter than magnitude 10.0 and they are not found in the literature. Related to Collinder 132, the low density of the data used in the area did not allow to detect it.