NGC 4651

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NGC 4651
Small ngc4651.jpg
NGC 4651. Note the umbrella-shaped stream.
Observation data (J2000 epoch)
Constellation Coma Berenices
Right ascension 12h 43m 42.6s[1]
Declination +16° 23′ 36″[1]
Redshift 788 ± 2 km/s[1]
Distance 72.0 Mly
Apparent magnitude (V) 11.39[1]
Type SA(rs)c[1]
Apparent size (V) 4′.0 × 2′.6[1]
Other designations
UGC 7901,[1] PGC 42833[1]
See also: Galaxy, List of galaxies
NGC 4651 imaged by the Hubble Space Telescope

NGC 4651 is a spiral galaxy located in the constellation of Coma Berenices that can be seen with amateur telescopes, at a distance not well determined that ranges from 35 million light years[2] to 72 million light years[3]


This member of the Virgo Cluster, located on its outskirts,[4] is known as the Umbrella Galaxy due to the umbrella-shaped structure that extends from its disk to the east and that it is composed of stellar streams, being the remmants of a much smaller galaxy that has been torn apart by NGC 4651's tidal forces,[2][5] something that explains why NGC 4651 has been included on Halton Arp's Atlas of Peculiar Galaxies as Arp 189 -galaxy with filaments-.

Studies using radiotelescopes of the distribution of its neutral hydrogen show distortions on NGC 4651's outer regions and a gas clump associated with a dwarf galaxy that may have born in the event that produced the mentioned stellar streams[6]

Unlike most spiral galaxies of the Virgo Cluster, NGC 4651 is rich in neutral hydrogen, also extending beyond the optical disk,[6] and its star formation is the typical for a galaxy of its type.[4]


  1. ^ a b c d e f g h "NASA/IPAC Extragalactic Database". Results for NGC 4651. Retrieved 2012-08-04. 
  2. ^ a b Nemiroff, R.; Bonnell, J., eds. (15 April 2010). "NGC 4651: The Umbrella Galaxy". Astronomy Picture of the Day. NASA. Retrieved 2012-08-04. 
  3. ^ Solanes, J. M.; Sanchis, T.; Salvador-Solé, E.; Giovanelli, R.; Haynes, M. P. (2002). "The Three-dimensional Structure of the Virgo Cluster Region from Tully-Fisher and H I Data". The Astronomical Journal. 124 (5): 2440–2452. Bibcode:2002AJ....124.2440S. arXiv:astro-ph/0208147Freely accessible. doi:10.1086/344074. 
  4. ^ a b Koopmann, R.; Kenney, J. D. P. (2004). "Hα Morphologies and Environmental Effects in Virgo Cluster Spiral Galaxies". The Astrophysical Journal. 613 (2): 866–885. Bibcode:2004ApJ...613..866K. arXiv:astro-ph/0406243Freely accessible. doi:10.1086/423191. 
  5. ^ "Stellar Tidal Streams in Spiral Galaxies of the Local Volume". Retrieved 2012-07-21. 
  6. ^ a b Chung, A.; Van Gorkom, J.H.; Kenney, J.F.P.; Crowl, Hugh; Vollmer, B. (2009). "VLA Imaging of Virgo Spirals in Atomic Gas (VIVA). I. The Atlas and the H I Properties". The Astronomical Journal. 138 (6): 1741–1816. Bibcode:2009AJ....138.1741C. doi:10.1088/0004-6256/138/6/1741.