This is the faintest emission nebula I’ve imaged so far in H-a. I usually can see a hint of the nebula with a five second centering shot at f/3.2 binned 6x6. Sh2-150 required a full 120 seconds to get even a glimpse of it. That puts it about 3.5 magnitudes dimmer than your common emission nebula. I mainly trusted the goto mount to point me to the right place in the sky.
I think Stewart Sharpless did the us imagers based in light-polluted skies a tremendous favor by cataloging his 234 H-II targets. I am starting to work my way through them and am finding some of the fainter ones to be quite challenging.
18 x 15 minutes = 4.5 hours via a 6 nm H-a filter and SXV-H9 binned 2x2 with 3/4 moon; Takahashi E-160 @f/3.2; guided with NP-101 and MX-716; AP1200GTO mount; acquisition AstroArt; processing ImagesPlus.
I started out with the mount “upside down” about 1.5 hours pre-meridian and acquired continuously for another 3 hours post-meridian without a meridian flip. The temperature was quite stable and I only had to refocus once during the period – that is most unusual for my f/3.2 astrograph.
http://home.att.net/~dpersyk/new.htm
Comments and suggestions to improve my New Images page format most welcome.
Thank you for visiting my site.
Clear skies,
Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL
I think Stewart Sharpless did the us imagers based in light-polluted skies a tremendous favor by cataloging his 234 H-II targets. I am starting to work my way through them and am finding some of the fainter ones to be quite challenging.
18 x 15 minutes = 4.5 hours via a 6 nm H-a filter and SXV-H9 binned 2x2 with 3/4 moon; Takahashi E-160 @f/3.2; guided with NP-101 and MX-716; AP1200GTO mount; acquisition AstroArt; processing ImagesPlus.
I started out with the mount “upside down” about 1.5 hours pre-meridian and acquired continuously for another 3 hours post-meridian without a meridian flip. The temperature was quite stable and I only had to refocus once during the period – that is most unusual for my f/3.2 astrograph.
http://home.att.net/~dpersyk/new.htm
Comments and suggestions to improve my New Images page format most welcome.
Thank you for visiting my site.
Clear skies,
Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
Hampshire, IL
