NGC 6561
| AladinLite | |
| Constellation | Sagittarius |
|
Position equinox : J2000.0 |
|
|---|---|
| Right ascension | 18 h 10 m 30.8 s |
| declination | -16 ° 43 ′ 32 ″ |
| Appearance
|
|
| Angular expansion | 15.0 ' |
| Physical data
|
|
| Radial velocity | −17.93 km / s |
| distance | 11000 ly (3400 pc ) |
| diameter | 50 ly |
| history | |
| Discovered by | Wilhelm Herschel |
| Discovery time | June 27, 1786 |
| Catalog names | |
| NGC 6561 • GC 4385 • H VIII 54 • h 1997 • COCD 433 | |
NGC 6561 is an open star cluster or group of stars in the constellation Sagittarius and about 11,000 light years from Earth. It was discovered on June 27, 1786 by Wilhelm Herschel with an 18.7-inch reflector telescope, who noted "a coarsely scattered cluster of considerably large stars. The place is that of a small triangle".
Web links
- NGC 6561. SIMBAD, accessed September 15, 2016 .
- NGC 6561. DSO Browser, accessed September 15, 2016 .
Individual evidence
- ↑ NASA / IPAC EXTRAGALACTIC DATABASE
- ↑ WEBDA page on NGC 6561
- ↑ Auke Slotegraaf: NGC 6561. Deep Sky Observer's Companion, accessed on September 15, 2016 (English).
- ↑ Seligman