Focal Pointe Observatory
Astrophotography by Bob Franke

Recent Images
   Natural Color
   Narrow Band
Solar System
My Freeware
Tips & Tricks
Published Images
Local Weather


Send Email







M104 - The Sombrero Galaxy

           Click the full screen zoom button       ^
Click the image to Zoom and Pan    

Click here to view the image without Zoomify (2100 x 1400)


In the above image, ellipses are globular clusters, squares are planetary nebulae and circles are stars. The SIMBAD database identifies 200 globular clusters in the upper image. There are magnitude data for 93, with the blue magnitude ranging from 18 to 22.6. The faintest visible cluster, in the top image, is at magnitude 22.04... ranking 85th of the 93. None of the planetary nebulae are identified in the image.



12.5" RCOS @  ~f/9 (2880 mm fl) 0.64 arcsec / pixel.  Zoomify image scale is 0.64 to 1.79 arcsec / pixel.


Paramount ME


SBIG STL-11000 w/ internal filter wheel, AstroDon Gen I Filters

Acquisition Data

4/14/2010 to 5/15/2010 Chino Valley, AZ... with CCDAutoPilot3 & CCDSoft,  AOL guided @ 1.1 Hz.


Lum (no filter)  330 min (22 x 15 min, bin 1x1)

RGB                225 min ( 5 x 15 min each, bin 2x2)


  • CCDSoft, CCDStack, Photoshop CS w/ the Fits Liberator plugin. Noel Carboni's actions and Russell Croman's GradientXTerminator.

  • eXcalibrator for (u-g), (g-r) color calibration, using 8 stars from the SDSS-7 database.

  • PixFix32 (pre-beta) to repair hot/cold pixels and column defects.

  • CCDStack to calibrate, register, normalize, data reject, combine the sub exposures, LRGB color, and luminance deconvolution.

  • PhotoShop for LLRGB combine &  on-linear stretching.


North is to top. 

The Sombrero Galaxy was discovered in March of 1767 by Pierre Méchain. At a distance of 60 million light-years, the unbarred galaxy is locate in the constellation Virgo. Glowing brightly, at magnitude 9.1, M104 is an easy visual target for small backyard telescopes.

M104 features a prominent dust lane and a bright halo of stars and globular clusters. The galaxy has a relatively large number of globular clusters. Observational studies estimate a population of 1200 to 2000. Our galaxy only has about 160 globular clusters.