Messier 54
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Globular cluster Messier 54 |
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| Image of the center of Messier 54 using the Hubble Space Telescope | |
| AladinLite | |
| Constellation | Sagittarius |
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Position equinox : J2000.0 , epoch : J2000.0 |
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| Right ascension | 18 h 55 m 03.28 s |
| declination | −30 ° 28 ′ 43 ″ |
| Appearance | |
| Concentration class | III |
| Brightness (visual) | 8.37 likes |
| Brightness (B-band) | 9.20 mag |
| Angular expansion | 9.1 ' |
| Physical data | |
| Integrated spectral type | F7 / F8 |
| Redshift | 0.000473 ± 0.000002 |
| Radial velocity | (141.9 ± 0.5) km / s |
| distance | 87.4 kLj (26.8 kpc ) |
| diameter | 300 ly |
| history | |
| discovery | Charles Messier |
| Discovery date | July 24, 1778 |
| Catalog names | |
| M 54 • NGC 6715 • C 1851-305 • GCl 104 • | |
Messier 54 (also known as NGC 6715 ) is an 8.4 mag bright globular cluster with an area of 9.1 'in the constellation Sagittarius , south of the star Sigma Sagittarii . M 54 is not easily observed in Central Europe because of its southern position.
The globular cluster has gained special attention since it was known that it does not belong to the globular cluster system of the Milky Way, but is associated with the Sagittarius dwarf galaxy . Since this galaxy, which is the closest neighbor of our Milky Way after the Canis Major dwarf galaxy , was not discovered until 1993, Messier 54 was previously considered to be a globular cluster of the Milky Way. Together with Messier 79 , who is associated with the Canis Major dwarf galaxy, it is therefore the longest known extra-galactic globular cluster.
Web links
Individual evidence
- ↑ a b c d e SIMBAD query
- ^ NED data for the Messier Objects
- ↑ a b Messier 54 at SEDS
- ↑ https://cseligman.com/text/atlas/ngc67.htm#6715
