PixInsight Forum (historical)

PixInsight => Gallery => Topic started by: greg.dulaney on 2020 January 23 17:59:55

Title: Horsehead and Flame Nebula Artifact?
Post by: greg.dulaney on 2020 January 23 17:59:55

I have a greenish 3 pointed "artifact" I think, see circled area in attachment.  I'm a Pixinsight novice so I don't know if I've introduced something here.  When I review others work with this object I don't see this structure.  I imaged the Rosette Nebula earlier in the evening with the same setup as below, CCD untouched.  There is no "artifact" in the Rosette.

Taken with a RASA 8, QHY12, 24 x 300 sec subs, PHD2 guiding, Pixinsight Batch Preprocessing and post-processing.

Title: Re: Horsehead and Flame Nebula Artifact?
Post by: pfile on 2020 January 23 19:28:02

that's a schmidt ghost... happens with bright stars (like alnitak) and certain types of reflecting telescopes...

rob

Title: Re: Horsehead and Flame Nebula Artifact?
Post by: greg.dulaney on 2020 January 24 04:24:36

Thanks!  Am I stuck with it or is there a method to process it out?

Title: Re: Horsehead and Flame Nebula Artifact?
Post by: John_Gill on 2020 January 29 06:25:46

Hi,

I have the same issue with a Celestron 8"EdgeHD.
You can try and create a mask over the strange reflection, invert the mask and adjust the color and brightness.

Good luck
John