NGC 6613
Number of stars per data source
Reference 12 : 21 stars
Reference 50 : 5 stars
References
- 12
- Lindoff U.
- (1971) Astron. Astrophys. 15, 439
- The open clusters NGC 6613 (M18) and NGC 6716
- 1971A&A....15..439L
- 50
- Cannon A.J., Pickering E.C.
- (1918-1924), Ann. Obs. Harvard Coll. Obs. 91 to 99 and 100
- Henry Draper catalogue and extension
-