Messier 14 (also known as M14 or NGC 6402) is a w:globular cluster in the w:constellation w:Ophiuchus. It was discovered by w:Charles Messier in w:1764.

M14
Messier 14, from 2MASS
Observation data (J2000 epoch)
ClassVIII
ConstellationOphiuchus
Right ascension17h 37m 36.15s[1]
Declination-03° 14′ 45.3″[1]
Distance30.3 kly (9.3 kpc)
Apparent magnitude (V)+8.32[1]
Apparent dimensions (V)11.0′
Physical characteristics
Mass- kg (- M)
Radius50 ly[2]
VHB-
Estimated age-
Notable features-
Other designationsNGC 6402[1]

At a distance of about 30,000 light-years, M14 contains several hundreds of thousands of w:stars. At an w:apparent magnitude +7.6 it can be easily observed with w:binoculars. Medium-sized w:telescopes will show some hint of the individual stars of which the brightest is of magnitude +14.

The total w:luminosity of M14 is in the order of 400,000 times that of the w:Sun corresponding to an w:absolute magnitude of -9.12. The shape of the cluster is decidedly elongated. M14 is about 100 light-years across.

A respectable total of 70 w:variable stars is known in M14, many of the W Virginis variety common in globular clusters. In w:1938, a w:nova appeared although this was not discovered until w:photographic plates from that time were studied in w: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.

Messier 14. Courtesy Hunter Wilson

References

  1. a b c d "SIMBAD Astronomical Database". Results for NGC 6402. Retrieved 2006-11-15.
  2. distance × sin( diameter_angle / 2 ) = 50 ly. radius