MB 3

For other uses, see MB-3 (disambiguation).

MB 3 is a dwarf spheroidal galaxy discovered in 1997 and located about 10 million light-years away from the Earth. It was discovered during an optical survey of the IC 342/Maffei group to which the galaxy is a member. MB3 is a companion galaxy of Dwingeloo 1 and situated in the Zone of Avoidance.^[4] MB 3 is thought to be a member of the IC 342/Maffei Group, a galaxy group adjacent to the Local Group.^[2]

MB 3
Observation data (J2000 epoch)
Constellation	Cassiopeia
Right ascension	02h 55m 42.7s[1]
Declination	+58° 51′ 37″[1]
Distance	~10 Mly (~ 3 Mpc)[2]
Group or cluster	IC 342/Maffei
Apparent magnitude (V)	17.33 (V-band)[3]
Characteristics
Type	dSph
Apparent size (V)	~ 1.9′[1]
Notable features	Companion of Dwingeloo 1
Other designations
2MASX J02554290+5851394, KK98-021, PGC 166069

The visible diameter of MB 3 is approximately 1.9′, which at the distance of 3 Mpc corresponds to about 2 kpc. In optical images it appears as a highly flattened diffuse oval located approximately 9.2′ to the southwest of Dwingeloo 1.^[3] No neutral or molecular hydrogen has been detected in it, which is consistent with its classification as a dwarf spheroidal galaxy.^[4]