Messier 14
Messier 14 | |
---|---|
Messier 14, from 2MASS | |
Observation data (J2000 epoch) | |
Class | VIII[1] |
Constellation | Ophiuchus |
Right ascension | 17h 37m 36.15s[2] |
Declination | –03° 14′ 45.3″[2] |
Distance | 30.3 kly (9.3 kpc)[3] |
Apparent magnitude (V) | +8.32[2] |
Apparent dimensions (V) | 11.0′ |
Physical characteristics | |
Mass | ×106 1.04[3] M☉ |
Radius | 50 ly[4] |
Metallicity | = –1.28[3] dex |
Other designations | NGC 6402[2] |
Messier 14 (also known as M14 or NGC 6402) is a globular cluster in the constellation Ophiuchus. It was discovered by Charles Messier in 1764.
At a distance of about 30,000 light-years, M14 contains several hundred thousand stars. At an apparent magnitude of +7.6 it can be easily observed with binoculars. Medium-sized telescopes will show some hint of the individual stars of which the brightest is of magnitude +14.
The total luminosity of M14 is in the order of 400,000 times that of the Sun corresponding to an absolute magnitude of -9.12. The shape of the cluster is decidedly elongated. M14 is about 100 light-years across.
A total of 70 variable stars are known in M14, many of the W Virginis variety common in globular clusters. In 1938, a nova appeared, although this was not discovered until photographic plates from that time were studied in 1964. It is estimated that the nova reached a maximum brightness of magnitude +9.2, over five times brighter than the brightest 'normal' star in the cluster.
Slightly over 3° southwest of M14 lies the faint globular cluster NGC 6366.
References
- ↑ Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin (849): 11–14, Bibcode:1927BHarO.849...11S.
- 1 2 3 4 "SIMBAD Astronomical Database". Results for NGC 6402. Retrieved 2006-11-15.
- 1 2 3 Boyles, J.; et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal 742 (1): 51, arXiv:1108.4402, Bibcode:2011ApJ...742...51B, doi:10.1088/0004-637X/742/1/51.
- ↑ distance × sin( diameter_angle / 2 ) = 50 ly radius
External links
Wikimedia Commons has media related to Messier 14. |
- SEDS Messier pages on M14
- M14, Galactic Globular Clusters Database page
- Messier 14 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
|
|
Coordinates: 17h 37m 36.15s, −03° 14′ 45.3″