M94 is a spiral galaxy in the constellation Canes Venatici, just below the handle of the "big dipper." In the 1920s Edwin Hubble, the American astronomer, using the 100" Hooker telescope on Mount Wilson in southern California determined that the innumerable "nebulae" (small "clouds") showing up on photographic plates were in fact other galaxies rather than gas clouds in our own galaxy.
Hubble classified galaxies based on their structure (spiral, barred spiral, lenticular, elliptical, and irregular). He noted that spiral galaxies can be distinguished by the brightness of their cores relative to their spiral arms. Spirals whose cores dominate the spiral arms he labeled "Sa" galaxies. Spirals with a core and arm structure of equal prominence he labeled "Sb" galaxies. Spirals whose arm structure overwhelmed the core he labeled "Sc" galaxies. M94 is an example of an Sa galaxy—a spiral galaxy whose nucleus, rather than its arms, is the dominant feature.
Spiral Galaxy M94
Date Taken:April 13, 2010
Location Taken: Conditions of Location:FWHM 2.28
Equipment Used:14.5" Ritchey-Chretien telescope, SBIG STL11000 CCD camera, Astrodon RGB filters, TCC, PIR, remote guide head used with Takahashi Sky90 for autoguiding, T-Point used for polar alignment (required for each imaging session due to my portable setup)
Processing Used:14 x 300 seconds luminance, 7 x 200 seconds RGB, guided, 1x1 binning, processed in Maxim DL and Photoshop (total exposure 2 hours 20 minutes).
Distance from Location:15 million light years
Constellation:Canes Venatici ("hunting dogs")
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