Messier 106

Messier 106
M106 and its anomalous arms. Composite of IR (red) and optical light (Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team))
Observation data (J2000 epoch)
ConstellationCanes Venatici
Right ascension12h 18m 57.5s
Declination+47° 18 14
Redshift448 ± 3 km/s
Distance23.7 ± 1.5 Mly (7 ± 0.5 Mpc)
Apparent magnitude (V)8.4
Characteristics
TypeSAB(s)bc
Size151,700 ly (46.53 kpc) (estimated)
Apparent size (V)18′.6 × 7′.2
Notable featuresMegamaser galaxy, Seyfert II galaxy.
Other designations
M 106, NGC 4258, UGC 7353, PGC 39600.

Messier 106 (also known as NGC 4258) is an intermediate spiral galaxy in the constellation Canes Venatici. It was discovered by Pierre Méchain in 1781. M106 is at a distance of about 22 to 25 million light-years away from Earth. M106 contains an active nucleus classified as a Type 2 Seyfert, and the presence of a central supermassive black hole has been demonstrated from radio-wavelength observations of the rotation of a disk of molecular gas orbiting within the inner light-year around the black hole. NGC 4217 is a possible companion galaxy of Messier 106. Besides the two visible arms, it has two "anomalous arms" detectable using an X-ray telescope.