Messier 30

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Messier 30
Messier 30 Hubble WikiSky.jpg
M30 by Hubble Space Telescope; 3.5′ view
Credit: NASA/STScI/WikiSky
Observation data (J2000 epoch)
Class V[1]
Constellation Capricornus
Right ascension 21h 40m 22.12s[2]
Declination –23° 10′ 47.5″[2]
Distance Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value).[3][4]
Apparent magnitude (V) +7.7[5]
Physical characteristics
Mass 1.6×105[6] M☉
Metallicity –2.27[7] dex
Estimated age 12.93 Gyr[8]
Other designations M30, NGC 7099, GCl 122[5]
See also: Globular cluster, List of globular clusters

Messier 30 (also known as M30 or NGC 7099) is a globular cluster of stars in the southern constellation of Capricornus. It was discovered by the French astronomer Charles Messier in 1764, who described it as a circular nebula without a star. In the New General Catalogue, compiled during the 1880s, it was described as a "remarkable globular, bright, large, slightly oval." This cluster can be easily viewed with a pair of 10×50 binoculars,[9] forming a patch of hazy light some 4 arcminutes wide that is slightly elongated along the east-west axis.[9] With a larger instrument, individual stars can be resolved and the cluster will cover an angle of up to 12 arcminutes across with a compressed core one arcminute wide.[10] It is best observed around August.[9]

M30 is located at a distance of about 27,100 light-years from Earth,[4] and is about 93 light-years across.[10] The estimated age is roughly 12.93 billion years[8] and it has a combined mass of about 160,000 times the mass of the Sun.[6] The cluster is following a retrograde orbit through the inner galactic halo, suggesting that it was acquired from a satellite galaxy rather than forming within the Milky Way.[8] It is currently located at a distance of about 22.2 kly (6.8 kpc) from the center of the galaxy, compared to an estimated 26 kly (8.0 kpc) for the Sun.[11]

The M30 cluster has passed through a dynamic process called core collapse and now has a concentration of mass at its core of about a million times the Sun's mass per cubic parsec. This makes it one of the highest density regions in the Milky Way galaxy. Stars in such close proximity will experience a high rate of interactions that can create binary star systems, as well as a type of star called a blue straggler that is formed by mass transfer.[3] A process of mass segregation may have caused the central region to gain a greater proportion of higher mass stars, creating a color gradient with increasing blueness toward the middle of the cluster.[12]

References

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  3. ↑ 3.0 3.1 Lua error in package.lua at line 80: module 'strict' not found.
  4. ↑ 4.0 4.1 Lua error in package.lua at line 80: module 'strict' not found.
  5. ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
  6. ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.
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  8. ↑ 8.0 8.1 8.2 Lua error in package.lua at line 80: module 'strict' not found.
  9. ↑ 9.0 9.1 9.2 Lua error in package.lua at line 80: module 'strict' not found.
  10. ↑ 10.0 10.1 Lua error in package.lua at line 80: module 'strict' not found.
  11. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  12. ↑ Lua error in package.lua at line 80: module 'strict' not found.
File:M30map.png
Masp showing the location of M 30

External links

Coordinates: Sky map 21h 40m 22.03s, −23° 10′ 44.6″

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