Whirlpool galaxy

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Whirlpool galaxy
Whirlpool Galaxy (M51A or NGC 5194). The smaller object in the upper right is M51B or NGC 5195. Credit: NASA/ESA
Observation data (J2000 epoch)
ConstellationCanes Venatici[1]
Right ascension 13h 29m 52.7s[2]
Declination+47° 11′ 43″[2]
Redshift463 ± 3 km/s[2]
Distance23 ± 4 Mly (7.1 ± 1.2 Mpc)[3][4]
Apparent magnitude (V)8.4[5]
TypeSA(s)bc pec[2]
Size~60,000ly in diameter[6]
Apparent size (V)11′.2 × 6′.9[2]
Notable featuresInteracting with NGC 5195[7]
Other designations
Question Mark Galaxy,[2] Rosse's Galaxy,[2] M51a,[2] NGC 5194,[2] UGC 8493,[2] PGC 47404,[2] VV 001a,[2] VV 403,[2] Arp 85,[2] GC 3572[2]
See also: Galaxy, List of galaxies

The Whirlpool galaxy, is also known as Messier 51a, M51a, or NGC 5194. It is a large galaxy with well-defined spiral arms, with a smaller companion galaxy. They have been through a collision,[8] and are still interacting.[7]

The Whirlpool was the first galaxy to be classified as a spiral galaxy.[9] Different methods put its distance as between 15 to 35 million light-years. Recently it was estimated to be 23 ± 4 million light-years from the Milky Way.[3] Messier 51 is one of the best known galaxies in the sky.[10]

Its spiral arms are so impressive and well-defined that it is called a "grand design" spiral galaxy.[11] It has an active galactic nucleus,[12] no doubt fuelled by a massive black hole.

The galaxy and its companion, NGC 5195, are easily seen by amateur astronomers, in the constellation Canes Venatici. The two galaxies can be seen with binoculars.[13] The Whirlpool galaxy is also a popular target for professional astronomers. They study its galaxy structure (particularly the spiral arms) and galaxy interactions.

References[change | change source]

  1. Dreyer J.L.E. 1988 (1988). In Sinnott R.W (ed.). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters. Sky Publishing Corporation/Cambridge University Press. ISBN 0-933346-51-4.{{cite book}}: CS1 maint: numeric names: authors list (link)
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 "NASA/IPAC Extragalactic Database". Results for NGC 5194. Retrieved 2006-12-06.
  3. 3.0 3.1 Takáts K. & Vinkó J. 2006. (2006). "Distance estimate and progenitor characteristics of SN 2005cs in M51". Monthly Notices of the Royal Astronomical Society. 372 (4): 1735–1740. arXiv:astro-ph/0608430. Bibcode:2006MNRAS.372.1735T. doi:10.1111/j.1365-2966.2006.10974.x. S2CID 18062981.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  4. "Distance Results for MESSIER 051". NASA/IPAC Extragalactic Database. Retrieved 2011-06-06.
  5. "M51". SEDS.org.
  6. http://www.nasa.gov/multimedia/imagegallery/image_feature_2457.html#.VIX_OGf0DDE Retrieved Dec-2014
  7. 7.0 7.1 Arp H. 1966 Atlas of peculiar galaxies. Astrophysical Journal Supplement 14, 1–20. [1]
  8. When galaxies collide, they actually move through each other. This causes gravitational effects, and leads to an increase in star formation.
  9. "Whirlpool Galaxy: First Spiral Galaxy". Universe for Facts. Archived from the original on 17 December 2014. Retrieved 21 December 2014.
  10. Scalzi, John 2003. (2003). The Rough Guide to the Universe. Rough Guides. pp. 250. ISBN 1-85828-939-4.{{cite book}}: CS1 maint: numeric names: authors list (link)
  11. Elmegreen D.M. & Elmegreen B.G. 1987 (1987). "Arm classifications for spiral galaxies". Astrophysical Journal. 314: 3–9. Bibcode:1987ApJ...314....3E. doi:10.1086/165034.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  12. Matsushita, Satoki; Muller, Sebastien & Lim, Jeremy 2007 (2007). "Jet-disturbed molecular gas near the Seyfert 2 nucleus in M51". Astronomy & Astrophysics. 468 (A&A Letters Special Issue): L49–L52. arXiv:0704.0947. Bibcode:2007A&A...468L..49M. doi:10.1051/0004-6361:20067039. S2CID 15471799.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  13. Nemiroff, Robert & Bonnell, Jerry 2000. "M51: The Whirlpool Galaxy". Astronomy Picture of the Day. NASA. Retrieved 2007-04-22.{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)