On the Nature of the Stellar Group ESO442-SC04

MAIA, F.F.S.; SANTOS JR, JOÂO F.C.; CORRADI, W.J.B.; PIATTI, ANDRÉS E.

Boletín de la Asociación Argentina de Astronomía

G. Dubner, D. Garcia Lambas, A.E. Piatti

Año: 2009

We propose a definitive test on the real physical nature of ESO 442-SC04, an object which has been listed as a possible open cluster remnant (POCR) by Bica et al. (2001). In order to pursue such analysis, we carried out multi-object spectroscopy of stars in its inner area using GMOS at Gemini-South telescope. By determining their radial velocity and metallicity, in conjunction with 2MASS color-magnitude diagrams and proper motion analysis, we aim at evaluating if the stars form a physical system. Our analysis of the radial velocity data suggests that the stars are not dynamically bound, according to the large radial velocity dispersion (> 50 km/s).