Messier 28
From Wikipedia, the free encyclopedia
| Messier 28 | |
 |
|
| Observation data (J2000 epoch) | |
|---|---|
| Class | IV |
| Constellation | Sagittarius |
| Right ascension | 18h 24m 32.89s[1] |
| Declination | -24° 52′ 11.4″[1] |
| Distance | 18.3 kly (5.6 kpc) |
| Apparent magnitude (V) | +7.66[1] |
| Apparent dimensions (V) | 11′.2 |
| Physical characteristics | |
| Mass | kg ( M ) |
| Radius | 30 ly[2] |
| Notable features | Contains pulsar |
| Other designations | M 28, NGC 6626, GCl 94[1] |
| See also: Globular cluster, List of globular clusters | |
Messier 28 (also known as M28 or NGC 6626) is a globular cluster in the constellation Sagittarius. It was discovered by Charles Messier in 1764.
M28 is at a distance of about 18,000 to 19,000 light-years away from Earth. 18 RR Lyrae type variable stars have been observed in this cluster. In 1986, M28 became the first globular cluster where a millisecond pulsar was discovered (by the Lovell Telescope at Jodrell Bank Observatory).[3]
[edit] External links
[edit] References
- ^ a b c d SIMBAD Astronomical Database. Results for NGC 6626. Retrieved on 2006-11-16.
- ^ distance × sin( diameter_angle / 2 ) = 30 ly. radius
- ^ JBO - Stars. Jodrell Bank Observatory. Retrieved on 2007-06-01.
 |
This star cluster–related article is a stub. You can help Wikipedia by expanding it. |
