A revisit to the regions of some van den Bergh open clusters

ORELLANA R.B; DE BIASI, M.S.; PAÍZ, L. G.; BUSTOS FIERRO, I.H.; CALDERÓN J.H.

NEW ASTRONOMY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 36 p. 70 - 79

1384-1076

We present results of a study that combines photometry and astrometryfor the open clusters vdB80, vdB85 and vdB130. We apply a model whichanalyses the proper motion distribution and the stellar density to find thekinematic parameters and stellar membership in the region of the mentionedopen clusters. The astrometric data are obtained from UCAC4 catalogue.For each cluster, we report the centre coordinates, the components of meanproper motion, the angular diameter and the astrometric members. Theyare: vdB80: = 97.◦73938 ± 0.◦00846, = −9.◦66953 ± 0.◦01177, μcos =−2.13±0.47mas/yr, μ = −0.95±0.47mas/yr, 12′, 15 members; vdB85: =101.◦71670 ± 0.◦00808, = 1.◦34392 ± 0.◦01253, μcos = 0.89 ± 0.43mas/yr,μ = 3.24±0.43mas/yr, 8′, 9 members; vdB130: = 304.◦44001±0.◦01407, =39.◦32745±0.◦00726, μcos = −4.14±0.25mas/yr, μ = −5.15±0.25mas/yr,8.6′, 9 members. We analyse the incidence of the proper motion errors inthe determination of the cluster parameters and of the stellar membershipand find that they are not significantly changed. We finally compare theastrometric members with the photometric ones given in the literature.