Horsehead M20
The Trifid Nebula		 Horsehead

(These are very large files - Broadband recommended on anything over the 50% size)

(Click on image for 50% Resolution)

(Click here for 100% of full size - 2.55MB)

(Click here for my 2003 image taken with my AP155EDF and ST-8XE)

(Click here for my 2001 image taken with my Vixen 102mm Flourite and ST-237a)



Date: May 29, 2006
Exposure: LRGB 150:60:60:60 : 15 X 600s L, 6 x 600s R,G,B
Processing: CCDSoftV5 for image acquisition, CCDStack for Image calibration,(5 flats each LRGB, Bias subtracted and Sigma Clip combined, 20 bias frames Sigma Clip combined, 10-900s darks Sigma Clip combined), alignment, normalization, color combining. PixInsight for background correction and color gradient removal. Photoshop CS for final color balance and jpg conversion. CCDAutoPilot3 used to collect data over multiple nights.
Conditions: Fair, skys were hazy, hot, humid.
Scope: RCOS 16" Truss @ f/8.4
Camera: SBIG STL-11000, -15°, OAG for Guiding w/Remote Guide Head
Comments: I have been chasing this one for many years. This time of year in SC, you can expect a lot of hot, humid nights with thunderstorms, so collecting the data is hit and miss over many many nights. M20 is also fairly low in the South for me and always a test of the equipment. This is the highest res I have attempted on this object and the atmosphere really affected the star shapes. However, the detail came out better than I expected, so it is an improvement over my previous attempts. The anitblooming of the STL-11000 let me take 10 min subs and this helped the image S/N, especially in the L frames.