1. A survey of Probable Open Cluster Remnants in the Galactic disk S. Villanova & G. Carraro, Universita’ di Padova

2. De la Fuente Marcos, 1997, 1998, 1999 Collinder 21

3. photometric catalogs of stars in Possible OCRs. photometric catalogs of stars in Possible OCRs. astrometric data from UCAC2/USNO-B1 catalogs. astrometric data from UCAC2/USNO-B1 catalogs. radial velocity from high resolution spectra radial velocity from high resolution spectra Probe the nature of the aggregate, its membership, the dynamical status, age, distance and binary fraction. METHOD:

4. . Provide observational constraints for Nbody models of clusters evolution and dissolution Discover remnants of old clusters, to increase the sample of very old open clusters in the Galactic disk FINAL GOALS:

5. NGC 1901 : a genuine cluster remnant A DSS Map Vector point diagram

6. Age = 0.5±0.1 Gyr Member number = 11 distance = 450±30 pc = 2.4±0.4 km/sec mass = 40 solar masses IMF slope = -1.65 binaries number: 2±1 NGC 1901: cont. Radial velocities CMD

7. NGC 1901: cont. An example of spectra Present-day Mass function

8. NGC 5385: a false detection A DSS map Vector point diagram

9. Simply a chance overdensity along the line sight….. NGC 5385: cont. Radial velocities CMD

10. CONCLUSIONS & FUTURE PERSPECTIVES Build up a sample of OCRs as an observational workbench for N-body models aiming at understanding cluster evolution, evaporation, and the formation of field stars Enlarge the sample of old clusters to probe the chemical and dynamical evolution of the Galactic disk during its infancy