Messier 104, or NGC 4594, is also known as the Sombrero Galaxy.  When you look at it, you can certainly understand why.   I remember first seeing this in an astronomy textbook back in the 80s.   It was a black-and-white photo, but it was so cool.  That book is still on my bookshelf.  However, revisiting that image is impressive in many ways.  First, it stirs my interest in the universe and all its treasures.  It reminds me that we have come such a long way in a relatively short time frame.  With very modest equipment, amateurs can produce such beautiful renditions of these stellar objects.

The Sombrero Galaxy is an unbarred spiral galaxy located in the Virgo constellation.  It’s very bright, with an apparent magnitude of 9.98 and is 29.3 light years from us.  You can see this object from a dark location with a simple pair of binoculars.  A larger instrument around a 10 to 12-inch scope will reveal the dark dust lane. 

That dark dust lane crosses in front of the galaxy, forming a symmetrical ring around the bulge.  The ring contains most of the cold hydrogen gas and dust of Messier 104, and is the primary site of starburst activity in this galaxy.

The galaxy is receding from us at an incredible speed of 1024 km/s.  The American astronomer Vesto Slipher first measured the recession velocity at the Lowell Observatory in 1912.  It was the largest redshift ever measured in a galaxy at that time.

When I first combined the data to create a colour component of the image using separate Red, Green, and Blue filters, it was striking how red/brown this area is.  The halo is massive and extends away from the galaxy for some distance.  But it definitely has a dirty brown look about it.  That dirty brown was something I wanted to retain and convey in this rendition.  My other goal was to try and reveal any structure within the massive halo, if possible.  Performing an initial stretch of the raw data, the galaxy is hidden in an enormous ball of light.  There is little to see of the galaxy itself other than that signature bold dark symmetrical ring.  Fortunately, many image-processing software packages exist that can help us look further into the great ball of light and reveal just a little more structure.   The final goal what to present and preserve that massive halo, to have that through the eyepiece feel about it.  Highlighting the bright halo slowly decaying only to blend into space while still revealing the inner features of the galaxy.

Hopefully, the object retains a natural appearance.  With any luck, I hope it looks like you rolled down the window in your space cruiser and took a happy snap of a galaxy through the portal.  I think that would be the greatest compliment any astrophotographer could receive.  The final image is a crop from a full frame, as the target is not that large in a small scope.  If you look carefully, one or two tiny galaxies may be hidden within the glow.  The Sombrero Galaxy’s vast halo may extend for 10,000 light years beyond the spiral structure.

Instruments Used:

• 10 Inch RCOS fl 9.1
• Astro Physics AP-900 Mount
• SBIG STL 11000m
• FLI Filter Wheel
• Astrodon Lum, Red, Green, Blue Filters

Exposure Details

• Lum  79 X 900 seconds
• Blue   11 X 900 seconds
• Green  12 X 900 seconds
• Red  17 X 900 seconds

Total Time: 29.75 Hours

Thanks for looking