Western Veil Nebula NGC6960 (Witches Broom)

[SlipperySquid]

Hi again all,

This is my latest image since the Elephants trunk nebula, I've been picking away trying to acquire subs as and when I can but as well all know with the lack of darkness at the moment it's damn near impossible!!

Western Veil Nebula NGC6960 more commonly known as the "Witches Broom"

The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus. It constitutes the visible portions of the Cygnus Loop (radio source W78, or Sharpless 103), a large but relatively faint supernova remnant. The source supernova exploded some 5,000 to 8,000 years ago, and the remnants have since expanded to cover an area roughly 3 degrees in diameter (about 6 times the diameter, or 36 times the area, of the full moon). The distance to the nebula is not precisely known, but recent evidence from the Far Ultraviolet Spectroscopic Explorer (FUSE) supports a distance of about 1,470 light-years (Source Wikipedia)

Subs a mixture of 10(older data) and 15 minutes in Ha and OIII channels (did take SII but prefer the look of the Ha and OIII together) totaling about two hours in each channel (not a lot really, though I will be adding as and when I get the chance).

Imaging platform:

William Optics Megrez 72

Atik 16hr mono

Astronomik Narrow band filters (These may need to be changed as they are the older type that are giving halo's on bright stars)

HEQ5 mount running EQMOD.

Captured,stacked and aligned in MaximDl and processed in Photoshop CS4.

For comparison I've posted my original DSLR image I took when I first ventured in to the dark art of astrophotography!

Hope you all likey

[SlipperySquid]

Just noticed the gradients in the first image, looks like I need to redo my flats?

I used GradientXterminator on this next pic, I don't think I've lost much detail from the original image?

What do you think?

[foundaplanet]

Nice work.

I like the added history.

Thanks.

Col

[roundycat]

the gradient spoiled it completely. The re-work is much better. Why do you think flats will cure that sort of gradient or have I misunderstood?

Dennis

[SlipperySquid]

Sorry Dennis,

I was lead to believe that Flat's helped with gradients? Though on further reading (today ), there are so many different variables that can add gradients that flats won't eradicate it.

As they say "Every day's a school day"!

Matt.

[minte222]

STUNNING

[roundycat]

Matt, Flats are an essential part of the calibration process and you only have to look at the result of extensive post processing with and without flats to see the difference. They will take out most of the vignetting or hot spotting that occurs with 99% of the scope/camera combinations, 100% of the dust shadows whether they are on the lens, the filters or the CCD cover slip and, perhaps more importantly given that you can keep things clean with a little effort, flats will eradicate virtually all fixed pattern noise that is there due to irregularities across the chip surface that cause varying sensitivity.

Almost (perhaps entirely) without exception gradients are due to some sort of external effect such as a bright moon, streetlamp or general light pollution. None of this is the fault of the scope so flats won't touch it.

Dennis

Edit: interesting that your gradient was cyan. Not known to come from light pollution.

[carastro]

Beautiful image and colour.

Carole

[Space Oddity6]

Wow.

[Coolhandjo]

Very very nice! Awesome image to be proud of!

[SlipperySquid]

Thanks everyone for the great comments! It really spurs me on to produce more and hopefully higher quality images!

Dennis,

The gradient could be caused by the sky getting lighter on the OIII filter?