|Right Ascension||12 : 36.8 (h:m)
|Declination||+13 : 10 (deg:m)
|Visual Brightness||9.5 (mag)
|Apparent Dimension||9.5x4.5 (arc min)
Discovered 1781 by Charles Messier.
M90 is one of the larger (9.5x4.5') spirals in the Virgo Cluster of Galaxies. It has tightly wounded, smooth bright spiral arms, which appear to be completely "fossil", meaning that currently no star formation appears to take place, with the only exception of the inner disk region, near the darker dust lanes. J.D. Wray speculates that this galaxy may be on the way to evolve into a state similar to M64, and then into a lenticular (S0) system.
Although M90 is conspicuous and big, Holmberg has derived quite a low value for its mass, which implies that this may be a very low density galaxy.
The image in this page is a CCD photograph from the collection maintained by Greg Bothun at the University of Oregon. More information on this image is available.
As it is approaching us at 383 km/sec, it must have the very high peculiar velocity of nearly 1500 km/sec through the Virgo cluster into the direction pointing to us, and possibly is just in process of escaping the cluster; some sources have speculated it may already have left the cluster and be now a considerable distance nearer to us. Only one Messier galaxy is faster in approaching us, M86.
M90 was included by Halton C. Arp in his Atlas of Peculiar Galaxies as No. 76 because it is a "Spiral with a High Surface Brightness Companion", 14-mag IC 3583, which is well visible in larger-field views of this galaxy such as the DSSM image of this galaxy, and appears somewhat distorted.
Last Modification: 16 Jan 2000, 20:00 MET