Messier 14
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Messier 14, from 2MASS |
|
| Observation data: J2000 epoch | |
|---|---|
| Class: | VIII |
| Constellation: | Ophiuchus |
| Right ascension: | 17h 37m 36.15s[1] |
| Declination: | -03° 14′ 45.3″[1] |
| Distance: | 30.3 kly (9.3 kpc) |
| Apparent magnitude (V): | +8.32[1] |
| Apparent dimensions (V): | 11.0′ |
| Physical characteristics | |
| Mass: | - (- M☉) |
| Radius: | 50 ly[2] |
| VHB: | - |
| Estimated age: | - |
| Notable features: | - |
| Other designations: | NGC 6402[1] |
| See also: Globular cluster, List of globular clusters | |
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 100,000 stars. At a brightness of magnitude 7.6 it can be easily observed with binoculars and medium sized telescopes begin to 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 spans about 100 light-years across.
A respectable total of 70 variable stars are known in M14, many of the W Virginis variety common in globular clusters. In 1938, a nova appeared in this globular cluster 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 5 times brighter than the brightest "normal" star in the cluster.
Slightly over 3° southwest of M14 lies the faint globular cluster NGC 6366.
[edit] External links
[edit] References
- ^ a b c d SIMBAD Astronomical Database. Results for NGC 6402. Retrieved on November 15, 2006.
- ^ distance × sin( diameter_angle / 2 ) = 50 ly. radius
