NGC281

[Ouroboros]

NGC281 Pac-Man Nebula.  Yes, I know it’s rotated, but that’s how I prefer it.  
 

 

The three hours of OSC data was obtained in Cornwall in September 2022 with my ZWO ASI2600MC on my SW 80ED.  I processed it last year but wasn’t happy with the result.  Since then I’ve developed some of my processing skills and acquired some of Russell Croman’s add-ons to Pixinsight.  I am quite pleased I managed to preserve and boost the dust. I’m less content with the colour and detail of Pacman nebula itself.

I would welcome comments and suggestions. 

The previous 2022 version looked like this …

[Fegato]

I like that - not seen a Pacman with surrounding dust before. You encourage me to have a go at it in broadband, I'd sort of written it off as an interesting target for my RASA.

I'm not so bothered about the colour - I like the way it blends in to the surrounding dust. In Pixinsight I might have tried a Range Mask to just highlight the bright parts of the image (i.e. just the Pacman area) and boost the saturation there a bit. But you don't want to spoil that blending with the dust.

I guess it's not particularly sharp... you could try some sharpening, but I must admit I rarely try this as I'm never really happy with the results. And after all, it is "nebulosity"!  Maybe it might benefit from some more data, depending on the speed of your system, but 3 hours is a fair bit for broadband?  

 

[Ouroboros]

1 hour ago, Fegato said:

I like that - not seen a Pacman with surrounding dust before. You encourage me to have a go at it in broadband, I'd sort of written it off as an interesting target for my RASA.

I'm not so bothered about the colour - I like the way it blends in to the surrounding dust. In Pixinsight I might have tried a Range Mask to just highlight the bright parts of the image (i.e. just the Pacman area) and boost the saturation there a bit. But you don't want to spoil that blending with the dust.

I guess it's not particularly sharp... you could try some sharpening, but I must admit I rarely try this as I'm never really happy with the results. And after all, it is "nebulosity"!  Maybe it might benefit from some more data, depending on the speed of your system, but 3 hours is a fair bit for broadband?  

 

Thanks for your comments. The dust surprised me too. I assume it’s the OSC that pulls it in. When I first re-processed it I didn’t notice the dust until I was well down the processing path. I then realised I might have killed some of the dust when I did DBE at the very very start.  This is a very rich area for stars and the dust was completely obscured behind them when I first applied DBE.   So I went back and started processing from square 1.  The first thing I did was to separate the stars. This is something I normally only do after spectrophotometric calibration, blurXterminator and noiseXterminator, and just before stretching to non-linear. I did the DBE on the starless image by carefully avoiding the dusty bits.   I then recombined with the star image and carried on with colour calibration, blurxterminator etc.   Anyway, I think that workflow worked with this particular image. 

You’re right, the image is disappointingly soft - especially Pacman itself. I had several goes with rangemasks doing just as you suggest. It was a matter of applying just enough before some ugly artefacts crept in.  I used local histogram equalisation and dark structure enhance script. It’s a lot better than where it started, but a tad under sharp I agree. More data might help. Actually, I’ve recentky bought an Ha/OIII dual band filter so it might be worth trying that. 

Where the range masking really helped was in applying TGVN noise reduction to the dust.