Messier 50

Messier 50 or M 50, also known as NGC 2323, is an open cluster of stars in the constellation Monoceros. It was recorded by G. D. Cassini before 1711 and independently discovered by Charles Messier on April 5, 1772 while observing Biela's Comet. It is sometimes described as a 'heart-shaped' figure or a blunt arrowhead.[3]

M50 is at a distance of about 3,000 light-years away from Earth[2] and is located near the edge of the CMa OB1 association.[4] It has a core radius of 5.9 ly (1.8 pc)[6] and spans 17.8 ly (5.46 pc).[4] The cluster has a 508 confirmed members with a combined mass of more than 285 M, for a stellar density of 1.3 stars per cubic parsec.[4] It is around 140 million years old,[1] with two high-mass white dwarfs[7] and two chemically peculiar stars.[8]

Messier 50
Canis Major constellation map
Messier 50 can be located 8° north and 3° east of Sirius
Observation data (J2000 epoch)
Right ascension 07h 02m 47.5s[1]
Declination−08° 20′ 16″[1]
Distance2,870 ly (881 pc)[2]
Apparent magnitude (V)5.9[3]
Apparent dimensions (V)16.0[3]
Physical characteristics
Mass> 285 M[4] M
Radius8.9 ly (2.73 pc)[4]
Estimated age140[1] Myr
Other designationsC 0700-082, M50, NGC 2323, OCl 559[5]


Sirius Mirzam M41


  1. ^ a b c d Frolov, V. N.; et al. (February 2012), "Investigation of the open star cluster NGC 2323 (M50) based on the proper motions and photometry of its constituent stars", Astronomy Letters, 38 (2): 74–86, Bibcode:2012AstL...38...74F, doi:10.1134/S106377371202003X.
  2. ^ a b Kharchenko, N. V.; et al. (2005), "Astrophysical parameters of Galactic open clusters", Astronomy and Astrophysics, 438 (3): 1163–1173, arXiv:astro-ph/0501674, Bibcode:2005A&A...438.1163K, doi:10.1051/0004-6361:20042523.
  3. ^ a b c Thompson, Robert; Thompson, Barbara (2007), Illustrated Guide to Astronomical Wonders: From Novice to Master Observer, DIY science, O'Reilly Media, Inc., p. 321, ISBN 978-0596526856
  4. ^ a b c d e Claria, J. J.; et al. (February 1998), "Photometric study of the open cluster NGC 2323", Astronomy and Astrophysics Supplement, 128: 131–138, Bibcode:1998A&AS..128..131C, doi:10.1051/aas:1998130
  5. ^ "M 50". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 27 November 2018.
  6. ^ Sharma, Saurabh; et al. (May 2008), "Mass Functions and Photometric Binaries in Nine Open Clusters", The Astronomical Journal, 135 (5): 1934–1945, arXiv:0803.0122, Bibcode:2008AJ....135.1934S, doi:10.1088/0004-6256/135/5/1934.
  7. ^ Cummings, Jeffrey D.; et al. (February 2016), "Two Massive White Dwarfs from NGC 2323 and the Initial-Final Mass Relation for Progenitors of 4 to 6.5 M", The Astrophysical Journal, 818 (1): 13, arXiv:1601.03053, Bibcode:2016ApJ...818...84C, doi:10.3847/0004-637X/818/1/84, 84.
  8. ^ Paunzen, E.; et al. (April 2014), "Photoelectric search for peculiar stars in open clusters. XV. Feinstein 1, NGC 2168, NGC 2323, NGC 2437, NGC 2547, NGC 4103, NGC 6025, NGC 6633, Stock 2, and Trumpler 2", Astronomy & Astrophysics, 564: 8, arXiv:1403.3538, Bibcode:2014A&A...564A..42P, doi:10.1051/0004-6361/201423521, A42.

External links

Coordinates: Sky map 07h 03.2m 00s, −08° 20′ 00″

List of Edmonton Oilers records

This is a list of franchise records for the Edmonton Oilers of the National Hockey League.

List of NGC objects (2001–3000)

This is a list of NGC objects 2001–3000 from the New General Catalogue (NGC). The astronomical catalogue is composed mainly of star clusters, nebulae, and galaxies. Other objects in the catalogue can be found in the other subpages of the list of NGC objects.

The constellation information in these tables is taken from The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer, which was accessed using the "VizieR Service". Galaxy types are identified using the NASA/IPAC Extragalactic Database. The other data of these tables are from the SIMBAD Astronomical Database unless otherwise stated.

List of open clusters

This is a list of open clusters located in the Milky Way. An open cluster is a gravitationally bound association of up to a few thousand stars that all formed from the same giant molecular cloud. There are over 1,000 known open clusters in the Milky Way galaxy, but the actual total may be up to ten times higher. The estimated half lives of clusters, after which half the original cluster members will have been lost, range from 150 million to 800 million years, depending on the original density.

Messier object

The Messier objects are a set of 110 astronomical objects cataloged by the French astronomer Charles Messier in his Catalogue des Nébuleuses et des Amas d'Étoiles ("Catalogue of Nebulae and Star Clusters").

Because Messier was interested in finding only comets, he created a list of non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as the Messier catalogue. This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier number.

The catalogue includes some astronomical objects that can be observed from Earth's Northern Hemisphere such as deep-sky objects, a characteristic which makes the Messier objects extremely popular targets for amateur astronomers.A preliminary version first appeared in the Memoirs of the French Academy of Sciences in 1771,

and the last item was added in 1966 by Kenneth Glyn Jones, based on Messier's observations.

The first version of Messier's catalogue contained 45 objects and was published in 1774 in the journal of the French Academy of Sciences in Paris. In addition to his own discoveries, this version included objects previously observed by other astronomers, with only 17 of the 45 objects being Messier's.

By 1780 the catalogue had increased to 80 objects. The final version of the catalogue containing 103 objects was published in 1781 in the Connaissance des Temps for the year 1784.

However, due to what was thought for a long time to be the incorrect addition of Messier 102, the total number remained 102. Other astronomers, using side notes in Messier's texts, eventually filled out the list up to 110 objects.The catalogue consists of a diverse range of astronomical objects, ranging from star clusters and nebulae to galaxies. For example, Messier 1 is a supernova remnant, known as the Crab Nebula, and the great spiral Andromeda Galaxy is M31. Many further inclusions followed in the next century when the first addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding Messier's side note in his 1781 edition exemplar of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967.

See also

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