M100 Spiral Galaxy


Messier 100 (NGC4321) is a spiral galaxy in the southern part of constellation Coma Berenices. It is one of the brightest galaxies in the Virgo cluster. Scroll down to read about a supernova in M100.

M100 is approximately 55 million light-years distant from Earth and has a diameter of 160,000 light years, 60% larger than our own Milky Way. The edge-on galaxy to the right is NGC4312.

In addition to NGC4312, scores of other galaxies are visible. Click the Full-Size Image button and look for fuzzy smudges of light. Some are bright, but most are very faint. Some are elliptical, while others are nearly circular. It's awe-inspiring to consider that each smudge is a galaxy with hundreds of millions, if not billions of stars. And how many Earth-like planets?

TMB-130SS APO refractor at f/7 on an Astro-Physics 1200 equatorial mount
SBIG ST-8XM camera
SBIG CFW-10 filter wheel with Astrodon filters
Guiding: 60mm f/5 refractor and ST-402 camera
Imaging and autoguiding with MaxIm DL 4.62
Luminance   1 hour (13 x 5 min), unbinned, -25°C
Red   1 hour (13 x 5 min.), binned 2x2, -25°C
Green   1 hour (13 x 5 min.), binned 2x2, -25°C
Blue   1 hour (13 x 5 min.), binned 2x2, -25°C
Processing Image calibration, registration, sigma-reject, mean-combine in CCDStack.
Levels, curves, highpass filter, color-combine in Photoshop CS3.
Date and Location 11 April, 2010    Montpelier, VA    N 37° 49' 12", W 77° 42' 06"

In 2006 a supernova exploded in M100. It can be seen in the left photo. An enlagement (right) of the 2010 photo above shows no trace of the supernovaa. (The star near the crosshairs in the right image is the small star next to the supernova in the left photo.)