Messier 89, NGC 4552

Messier 89 (also known as NGC 4552) is an elliptical galaxy in the constellation Virgo, in the core of the Coma-Virgo Supercluster. It was discovered by Charles Messier in 1781.

Messier 89 is smaller and fainter than M 87. It is of visual magnitude 9.8 and appears 4' across, to the WSW of a faint star. Small instruments show a bright nucleus embedded within a well-concentrated, hazy center 1' in diameter that fades out to a diffuse periphery. M 89 is a beautiful example of an elliptical galaxy of type E0, and appears nearly exactly circular.

Assuming that M 89 is 65 million light years away - the same distance as the Virgo Cluster's center - then its absolute magnitude is -21.7, a luminosity of 40 billion Suns; and its true diameter over 64,000 light years. M 89 contains about 250 billion solar masses, and its red shift indicates that it is moving away from us at 130 miles per second.

M 89 also has a large population of globular clusters compared to the Milky Way's 150-200; a 2006 survey estimates that there are 2,000 globulars within 25' of M 89.

Current observations indicate that M 89 is nearly perfectly spherical in shape. This would be unusual, as most other known elliptical galaxies are relatively elongated. However, it is possible that M 89 is oriented in such a way that it appears spherical but is in fact elliptical.

While M 89 looks like the prototype of a normal E0 galaxy, it is also known as a weak radio source. The galaxy also features a surrounding structure of gas and dust, extending up to 150,000 light-years in the northwestern and southern directions. A jet of heated particles extends 100,000 light-years outward. This may be a smaller galaxy, disrupted by gravitational forces during an encounter with M 89, or an indication that M 89 may have been an active quasar or radio galaxy.