Wolf Rayet Nebula NGC 3199 Ha and HaRGB

[RobF (Rob)]

Now here's one that's taken a while to hatch
My very first Ha shots of NGC 3199 were taken back in late April this year. I couldn't believe some of the tantalising nebulosity that was teased out even in my dodgey urban skies, so I put this on the slate for RGB data at Wiruna (South Pacific Star Party) in May.

The processing was challenging, so I'd put it all away until I had lots more time. The HaRGB merge has been done using both techniques described at:
http://starizona.com/acb/ccd/software/ps_hargb.aspx

NGC 3199 is a ring shaped nebula with a central Wolf Rayet Star (WR 18). Much the material is believed ejected from this central star which is nearing the end of its life. Wolf Rayet stars can be up to 20 times the size of the sun, losing approx the mass of the earth each year.

Ha data: 20x5 min subs over 3 nights Brisbane April/May 2010
LRGB: 40:25:25:25 mins (all 5min subs, no binning) Wiruna 15/5/10
Taken with 8" Newt, MPCC, QHY9, Baader 7nm Ha, QHY (OB) RGB

3 shots presented:
HaRGB (blend of Starizona techniques 1 & 2)
HaRGB (Starizona "technique 1")
Ha data alone

Thanks for looking

[Stevec35 (Steve)]

Very nice Rob - you've certainly captured all the nebulosity. The only thing I would say is that the nebula seems a bit too red. There is a lot of OIII in the brighter parts of this nebula which biases the colour toward the blue but perhaps you need longer exposures for this to show.

Cheers

Steve

[RobF (Rob)]

Originally Posted by Stevec35

Very nice Rob - you've certainly captured all the nebulosity. The only thing I would say is that the nebula seems a bit too red. There is a lot of OIII in the brighter parts of this nebula which biases the colour toward the blue but perhaps you need longer exposures for this to show.

Cheers

Steve

Thanks Steve

Fair call re the colour - I haven't posted the pure RGB shot as much less nebulosity is visible, but the brighter parts of the neb are a blue/purple colour in that. Perhaps I need OIII NB to compete with the Ha. Ha/Red pushed too far toward the dreaded salmon pink. Something to consider for my next repro...

[Stevec35 (Steve)]

Did you try blending about 20-30% of the Ha into the blue? That might help.

Cheers

Steve

[multiweb (Marc)]

Great work on a faint one. Thanks for the processing link too.

[RobF (Rob)]

Originally Posted by Stevec35

Did you try blending about 20-30% of the Ha into the blue? That might help.

Cheers

Steve

No Steve. I had read a bit on people arguing the pros and cons of it. Sounds like a good plan for an object like this though where blue is an issue. Thanks

Originally Posted by multiweb

Great work on a faint one. Thanks for the processing link too.

Thanks Marc - I'm so glad I dug deep enough to buy a Ha to go with the CCD - its giving me so much pleasure (not that I have to convince you with all the great Ha shots you've managed )