Messier 98, NGC 4192

Messier 98 (NGC 4192) is a beautiful spiral galaxy seen edge-on in the southern part of Coma Berenices, and a member of the Virgo Cluster of Galaxies.

M 98 was discovered in 1781 by Pierre Mechain and confirmed later the same year by Charles Messier. Along with M 99 and M 100, Messier cataloged M 98 immediately before publishing the third, final edition of his list, and remarked that M 98 was the faintest of the three.

At visual magnitude 10.1, Messier 98 is actually one of the faintest objects in Messier's catalog. M 98 can be best located by starting from the 5th-magnitude star 6 Comae Berenices. The galaxy measures 9.5' x 3.2' in size; it has a bright, irregularly-concentrated disk, and a mottled central area with a 1' diameter core and starlike nucleus.

M 98 is a type Sb spiral galaxy seen nearly edge-on. In larger telescopes, it displays a chaotic, diffuse disk, containing some blue regions of newly formed stars, and a huge quantity of occulting dust, which reddens the light of the small, bright, central nucleus.

M 98 is a member of the Coma-Virgo Galaxy Cluster, which is estimated to be 65 to 70 million light years away. The galaxy's true diameter is at least 185,000 light years, and its absolute magnitude is -21.8, a luminosity of 85 billion Suns.

M 98 is one of the handful of Coma-Virgo galaxies with a blue shift rather than a red shift; it is approaching us with a velocity of 140 km/sec. Because of this, some have speculated that M 98 could be a foreground galaxy rather than a cluster member. However, M 98's blue shift is one of the strongest arguments that it actually is a member! In the massive, dense Virgo Cluster, infall velocity and close encounter motion may easily sum to more than 1200 km/sec. This motion is directed toward us, by chance, resulting in the blue shift measured in the spectrum of this galaxy.