NGC 6997
Number of stars per data source
Reference 191 : 57 stars
Reference 379 : 2699 stars
Reference 510 : 5295 stars
References
- 191
- Skiff B.
- (1998) Priv. Comm.
- Coordinates from the GSC and USNO-A1.0 catalogues in the field of open clusters
-
- 379
- Villanova S., Baume G., Carraro G., Geminale A.
- (2004) Astron. Astrophys. 419, 149
- Optical photometry and spectral classification in the field of the open cluster NGC 6996 in the North America Nebula
- 2004A&A...419..149V
- 510
- Maciejewski G., Niedzielski A.
- (2007) Astron. Astrophys. 467, 1065
- CCD BV survey of 42 open clusters
- 2007A&A...467.1065M