Mice Galaxies

NGC 4676A / 4676B
The Mice Galaxies, NGC 4676A (right)/NGC 4676B (left)
Observation data (J2000 epoch)
Constellation	Coma Berenices
Right ascension	12h 46m 10.1s / 12h 46m 11.2s[1]
Declination	+30° 43′ 55″ / +30° 43′ 22″[1]
Redshift	6613 ± 8 / 6607 ± 7 km/s[1]
Distance	290 Mly (89 Mpc)[2]
Type	Irr / SB(s)0/a pec[1]
Apparent dimensions (V)	2′.3 × 0′.7 / 2′.2 × 0′.8[1]
Apparent magnitude (V)	14.7 / 14.4[1]
Notable features	Interacting galaxies
Other designations
Mice Galaxies,[1] IC 819 / 820,[1] UGC 7938 / 7939,[1] PGC 43062 / 43065,[1] Arp 242[1]
See also: Galaxy, List of galaxies

NGC 4676, or the Mice Galaxies, are two spiral galaxies in the constellation Coma Berenices. About 290 million light-years away,^[2] they are presently in the process of colliding and merging. Their name refers to the long tails produced by tidal action—the relative difference between gravitational pulls on the near and far parts of each galaxy—known here as a galactic tide. Members of the Coma cluster, it is a possibility that both galaxies have experienced collision, and will continue colliding until they coalesce.

The colors of the galaxy are peculiar. In the upper galaxy (NGC 4676A, to the right in the photo), a core with some dark markings is surrounded by a bluish white remnant of spiral arms. The tail is unusual, starting out blue and terminating in a more yellowish color, despite the fact that the beginning of each arm in virtually every spiral galaxy starts yellow and terminates in a bluish color. The lower galaxy (NGC 4676B, to the left) is closer to normal, with a yellowish core and two arcs; arm remnants underneath are bluish as well.

The galaxies were photographed in 2002 by the Hubble Space Telescope.^[3]

NGC 4676B (down-left) and NGC 4676A (up-right)

See also

• Antennae Galaxies
• Interacting galaxy
• NGC 7318

References

1. ^ ^{a b c d e f g h i j k} "NASA/IPAC Extragalactic Database". Results for NGC 4676A / 4676B. http://nedwww.ipac.caltech.edu/. Retrieved 2006-11-21. 
2. ^ ^{a b} Chien, Li-Hsin; Barnes, Joshua E., Kewley, Lisa J., Chambers, Kenneth, C. (May 2007). "Multiobject Spectroscopy of Young Star Clusters in NGC 4676". The Astrophysical Journal 660 (2): L105–L108. arXiv:astro-ph/0703510. Bibcode 2007ApJ...660L.105C. doi:10.1086/518215. 
3. ^ "Hubble's New Camera Delivers Breathtaking Views of the Universe". HubbleSite. 2002-04-30. http://hubblesite.org/newscenter/archive/releases/2002/11/image/d. Retrieved 2009-05-07. 

External links

• APOD: When Mice Collide (6/12/04)
• The Mice Galaxies

Coordinates: 12^h 46^m 10.1^s, +30° 43′ 55″