M94 (NGC 4736)
M94. Image credit: NOAO/AURA/NSF.
M94 (NGC 4736) is an unusual spiral galaxy (type Sab) in the constellation Canes Venatici. The bright inner region of M94 is surrounded by a ring in which active star formation is taking place as indicated by the presence of luminous, blue clusters. Exterior to this is another, much fainter, ring comprised of an older yellowish stellar population. In the outskirts, this region ends again in a ring with moderate star formation activity, so that M94 is one of a relatively rare class of galaxies in which two waves of star formation are evident. In long exposures, a further very faint ring, about 15 arcmin across, can be seen. According to one theory, the outward moving rings and bursts of star formation are generated by a rotating bar of stars in the galaxy's nucleus.1
|angular size||11' × 9'|
|distance||15 million light-years
(4.5 million pc)
|position||RA 12h 50m 53s,
Dec +41° 07' 12"
|other designations||UGC 7996, PGC 43495|
1. C. Munoz-Tunon, N. Caon, J. Aguerri, L. Alfonso. "The Inner Ring of NGC 4736: Star Formation on a Resonant Pattern." Astronomical Journal, 127, 58–74 (2004).