Messier 2
Globular cluster Messier 2 |
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Image of the center of Messier 2 using the Hubble Space Telescope . Angle of view 2.4 '× 2.4' | |
AladinLite | |
Constellation | Aquarius |
Position equinox : J2000.0 , epoch : J2000.0 |
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Right ascension | 21 h 33 m 27 s |
declination | −00 ° 49 ′ 24 ″ |
Appearance | |
Concentration class | II |
Brightness (visual) | 6.3 mag |
Angular expansion | 16.0 ' |
Physical data | |
Affiliation | Milky Way |
Integrated spectral type | F4 |
Redshift | (−22 ± 7) · 10 −6 |
Radial velocity | −6.7 km / s |
distance | 11.1 kpc |
diameter | 150 ly |
Age | 12 billion years |
history | |
discovery | Giovanni Domenico Maraldi / Charles Messier |
Discovery date | September 11, 1746 / September 11, 1760 |
Catalog names | |
M 2 • NGC 7089 • C 2130-010 • GCl 121 • |
Messier 2 ( M2 for short , also NGC 7089) is a type II galactic globular cluster in the constellation Aquarius on the ecliptic . It is located around 50,000 light years from the solar system in the inner halo of the Milky Way and has a diameter of around 150 light years .
With around 100,000 members, it is one of the more star-rich and compact globular clusters, its age is estimated to be 12 billion years. The brightest stars are yellow and red giants with an absolute magnitude of −3 mag. In them the heavy elements are around 100 times rarer than in the sun, which was formed more than seven billion years later .
It has the highest space velocity of all known globular clusters of the inner halo and orbits the galactic center on a very eccentric orbit that will carry it around 150,000 light years out into the outer areas of the halo over the next billion years.
Observation history
Messier 2 was discovered by Giovanni Domenico Maraldi on September 11, 1746 . In 1760 Charles Messier discovered him independently. A variable star of the RV Tauri type was discovered in the globular cluster in 1897 by the French astronomer Chevremont .
swell
- ↑ a b SIMBAD query
- ↑ Harlow Shapley, Helen B. Sawyer: A Classification of Globular Clusters . In: Harvard College Observatory Bulletin . tape 849 , 1927, pp. 11-14 , bibcode : 1927BHarO.849 ... 11S .
- ^ NED
- ↑ Deep-Sky Corner _ Aqr _ Globular cluster M2 (NGC 7089) .htm
- ↑ Klaus-Peter Schröder in: Stars and Space September 2013 p. 70ff
- ↑ Seligman
- ↑ messier.obspm.fr