Messier Objects

M100: Spiral Galaxy (Coma Berenices) RA: 12h 22.5m / DEC: +15° 49'.4
Instrument: 10-inch Starfinder

M100 is a real showpiece. It's also the third stop on your tour of the Virgo cluster. This face-on galaxy shows obvious spiral structure with moderate aperture under decent skies. It's located about two degrees northeast of 5.1 magnitude 6 Comae Berenices. M99 resides 1.7 degrees to the southeast. M100 is flanked by a 6.7 magnitude star 45' to the east and another star of similar brightness 35' to the southwest. A 10th magnitude GSC star hugs eastern edge of this Sc-type galaxy in my drawing. The sketch, derived from a 129X view in the 10-inch, shows M100 as a 5'x4' oval with a distinctive S-pattern spiral structure. The galaxy brightens near the core. NGC 4312 is visible 18' to the south. M100 has a visual magnitude of 9.4 and should be an easy target under typical suburban skies with a 6-inch or larger telescope.

Click on the button to see a map of the Virgo cluster.

Virgo Cluster

M99 M101


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Revised: February 10, 2002 [WDF]