Messier 73
| Asterism | |
|---|---|
| Messier 73 | |
|
|
| 2MASS image of Messier 73 | |
| Constellation | Aquarius |
|
Position equinox : J2000.0 |
|
| Right ascension | 20h 59m |
| declination | −12 ° 38 ′ |
| Further data | |
| Brightness (visual) |
9.0 mag |
| Angular expansion |
2.8 ' |
| history | |
| discovery | |
| Date of discovery |
October 4, 1780 |
| Catalog names | |
| M 73 • NGC 6994 • C 2056-128 • OCl 89 • Cr 426 | |
| Aladin previewer | |
Messier 73 (also known as NGC 6994 ) is a +9.0 mag bright, random arrangement of stars, a star pattern, or asterism , with an angular extent of 2.8 'in the constellation Aquarius .
For a long time it was not clear whether Messier 73 is a “real” open star cluster, ie a group of physically bound stars, or just a random pattern. In the meantime, by measuring the proper motions and radial velocities, it has been proven that Messier 73 is neither an open star cluster nor the remnant of one, but rather a random fluctuation of the star density on this line of sight.
Individual evidence
- ↑ SIMBAD
- ↑ a b Messier 73 at SEDS
- ↑ https://cseligman.com/text/atlas/ngc69a.htm#6994
- ^ M. Odenkirchen, C. Soubiran: NGC 6994 - clearly not a physical stellar ensemble ; in: Astronomy and Astrophysics, Vol. 383, pp. 163ff. bibcode : 2002A & A ... 383..163O
- ↑ DB Pavani, E. Bica: Characterization of open cluster remnants ; in: Astronomy and Astrophysics, Vol. 468, Issue 1, pp. 139ff. bibcode : 2007A & A ... 468..139P
Web links
Commons : Messier 73 - album with pictures, videos and audio files
