We present CCD UBVI photometry of the intermediate age open cluster NGC 6939 for three TNG-DOLORES fields. The fields A and B cover the center of the cluster; the third one is located about 30arcmin away, and is used for field stars decontamination.The V-I, B-V and U-B color-magnitude diagrams (CMDs), obtained joining very different exposures show: i) a Main Sequence (MS) extending down to V = 24, much deeper (∼ 5 magnitudes) than any previous study; ii) a clearly defined Turn Off (TO) and iii) a well populated Red Giant Clump (RC) at about V = 13.
Memorie della Societa Astronomica Italiana
- Pub Date:
- Hertzsprung-Russell (HR) diagram;
- open clusters and associations: general;
- open clusters and associations: individual: NGC 6939;
- 4 pages, 4 figures, proceedings of "Stars in Galaxies", La Palma 2003. To appear in MmSAI. Uses mem.cls