Messier 2

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Globular cluster
Messier 2
Image of the center of Messier 2 using the Hubble Space Telescope. Angle of view 2.4 '× 2.4'
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
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

  1. ↑ a b SIMBAD query
  2. ↑ 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 .
  3. ^ NED
  4. ↑ Deep-Sky Corner _ Aqr _ Globular cluster M2 (NGC 7089) .htm
  5. ↑ Klaus-Peter Schröder in: Stars and Space September 2013 p. 70ff
  6. ↑ Seligman
  7. ↑ messier.obspm.fr

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