Jump to content

1565608528_ReflectionNebulositybanner.jpg.5b3647faf258fca0cd9c62694d6e7b71.jpg

Heart Nebula - HaSHO


Rodd
 Share

Recommended Posts

I have wanted to reshoot the Heart for years.  I Started this project during a 100% Moon.  Now I regret it.  While Ha can provide immediately satisfying results at a time when imaging would otherwise not even be contemplated, the dt is not without compromise.  Fortunately, the Heart is fairly bright as nebulae go.  Other than a mysterious rotation of the frames from night to night (discovered when trying to align a nights framing with previously collected data), the project went well.  I did have to reshoot the SII do to horrific seeing, which was a minor mystery.  Usually when seeing is really bad, my guiding rms errors are large and guiding is erratic.  Not so for the initial SII.  Guiding was good ( .4-.5 rms), polar alignment was normal, focus was typical, there was no wind, and yet FWHM values were 7-8".  Fortunately the next night was decent and I was able to reshoot.  With respect to the rotation issue--I use all threaded connections and they are all very tight.  Every other nut, bolt, and knob is as tight as I can get them.  The rotation seems to be off axis a bit--a star somewhere in the frame will be perfectly aligned, but stars a distance from the aligned star will have been rotated--the subs can still be registered with only minor edge cropping.  The biggest indication that something is not right is the fact that I have never seen this before ( and that subs from opposite sides of the meridian cannot be registered--A stack must be made from east subs and a stack made from west subs and the two stacks registered and combined...certainly not normal).  I try to avoid meridian flips--but they are unavoidable when a target starts the bight close to the meridian.

FSQ 106 with .6x reducer and ASI 1600: Ha 100 300sec; OIII 68 300 sec; SII 81 300 sec.  About 20 hours.

 

Image62h4.thumb.jpg.5fa587e475e343280db22bef993b7fe7.jpg

Edited by Rodd
  • Like 12
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.