Astronomy:Messier 14

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Short description: Globular cluster in Ophiuchus
Messier 14
Messier 14.jpg
Globular cluster Messier 14 in Ophiuchus
Observation data (J2000 epoch)
ClassVIII[1]
ConstellationOphiuchus
Right ascension 17h 37m 36.15s[2]
Declination–03° 14′ 45.3″[2]
Distance30.3 kly (9.3 kpc)[3]
Apparent magnitude (V)7.6[4]
Apparent dimensions (V)11.0
Physical characteristics
Mass1.04×106[3] M
Radius50 ly[5]
Metallicity[math]\displaystyle{ \begin{smallmatrix}\left[\ce{Fe}/\ce{H}\right]\end{smallmatrix} }[/math] = –1.28[3] dex
Other designationsNGC 6402[2]
See also: Globular cluster, List of globular clusters

Messier 14 (also known as M14 or NGC 6402) is a globular cluster of stars 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.[6]

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.

Gallery

See also

References

  1. Shapley, Harlow; Sawyer, Helen B. (August 1927), "A Classification of Globular Clusters", Harvard College Observatory Bulletin 849 (849): 11–14, Bibcode1927BHarO.849...11S. 
  2. 2.0 2.1 2.2 "NGC 6402". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+6402. 
  3. 3.0 3.1 3.2 Boyles, J. et al. (November 2011), "Young Radio Pulsars in Galactic Globular Clusters", The Astrophysical Journal 742 (1): 51, doi:10.1088/0004-637X/742/1/51, Bibcode2011ApJ...742...51B. 
  4. "Messier 14". https://messier.seds.org/m/m014.html. 
  5. distance × sin( diameter_angle / 2 ) = 50 ly radius
  6. "Messier 14 | Messier Objects" (in en-US). 31 March 2015. https://www.messier-objects.com/messier-14/. 

External links

Coordinates: Sky map 17h 37m 36.15s, −03° 14′ 45.3″