Detección de cúmulos abiertos en regiones extensas del cielo usando parámetros astrométricos

PAÍZ, L., ; DE BIASI, MARÍA SILVINA; ORELLANA R.B.

Florianópolis,

Congreso; XIV Latin American Regional IAU Meeting; 2013

We developed a non-parametric method for iden-tifying open clusters in extensive areas of the sky us-ing position and stellar proper motions. Two binarycodes were established from the analysis of the em-pirical probability density functions in position andproper motion, after eliminating field stars contam-ination. For each star, these codes provided a pa-rameter indicating the star belongingness to spaceand proper motion overdensities. The method wastested in a region of 4◦×5◦ where Collinder 140 andCollinder 132 are located. 1300 stars up to the mag-nitude R=11 were obtained from UCAC2 and itssupplement UCAC2 BSS catalogue. We detected 6stellar groups having spatial and proper motion over-densities. A detailed analysis revealed that 3 of themcould be open clusters. We confirmed that one ofthem is Collinder 140, for which mean coordinates(¯,¯)=(110.8◦,-32.0◦), a radius of about 12? andmean proper motion components (¯μcos,¯μ)=(9,4)mas/yr were obtained, in good agreement with theliterature. The other two possible clusters havemembers fainter than magnitude 10.0 and they arenot found in the literature. Related to Collinder 132,the low density of the data used in the area did notallow to detect it.