Integrated spectroscopy and individual spectra of stars of open cluster remnants and candidates

D.B. PAVANI, E. BICA, A.V. AHUMADA Y J.J. CLARIÁ

La Palma

Simposio; Stellar Populations as Building Blocks of Galaxies; 2006

Intituto Astrofísca de Canarias - España

The integrated light of open cluster remnants (OCRs) is expected to be similar tothat of open clusters of comparable ages. Despite erosion of the mass function in remnants as aconsequence of dynamical evolution, their integrated spectra could still be similar to those ofthe clusters of comparable age as long as a sufficient number of bright stars remain. In the presentwork we employ integrated spectroscopy and individual spectra of stars to analyze 8 OCRs andcandidates which were previously classified as open clusters and a new unclassified object. TheOCRs and possible open cluster remnants (POCRs) are underpopulated with respect to usual open clusters, but they show a significant density contrast of bright stars when compared to the Galactic field. The spectroscopic observations were carried out with the 2.15-m telescope at CASLEO (San Juan, Argentina) in the range 3800-6800 A, during 2003 and 2004. We deriveforeground interstellar reddening values and ages. We find in most of the sample that the derived properties are compatible with what should be expected for OCRs.