UGC 12158

UGC 12158 or PGC 69533 is an Sb-type barred spiral galaxy located approximately 384000000 ly away from Earth in the constellation of Pegasus. Its tight spiral disk spans approximately 140000 ly, whose scale at heliocentric distance is about 36.9 kiloparsecs per arcminute. It is also often stated to resemble the Milky Way in appearance, with a similar central bar and spiral arm structure.

2003 Supernova
On 15 December 2003, a 19.2v magnitude Type Ia supernova, was recorded on one of the spiral arms near the apparent centre in UGC 12158, and was designated as SN 2004EF. (Blue star within UGC 12158 in Starbox Hubble's Space Telescope image. ) It reached 17.5v magnitude on 4 September 2004 before fading from view. Optical spectra was obtained on 7 September 2004 confirming the Type I classification. No progenitor star was found on earlier survey images.