Deep Barnard's Galaxy Through a Veil of Galactic Cirrus

[SkyViking]

Hi All,

I've been working on this image for quite a while since I had to gather the data over 5 different nights. This one really deserves a lot of data, so when it suddenly cleared again here on 26th/27th I decided to increase it to 13 1/2 hours in total. This is my deepest image to date. In the combined FITS L frame I measured the faintest stars to be close to 24.0, a new personal record for me. :):P
I have attached a small compressed image to this post, but for the full experience please check out the links below:

Link to 1600x1200 version (1.1MB): http://www.pbase.com/rolfolsen/image/145039519/original
Link to hi-res 75% size (2.2MB) http://www.pbase.com/rolfolsen/image/145039398/original

Image details:
Date: 17th, 18th, 19th, 26th and 27th July 2012
Exposure: LRGB: 470:114:112:112m, total 13hrs 28mins @ -30C
Telescope: 10" Serrurier Truss Newtonian f/5
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

About the image:
This image shows a deep view of Barnard's Galaxy (NGC 6822), an irregular dwarf galaxy that is one of the nearest neighbours to our Milky Way. This galaxy was discovered by astronomer Edward E. Barnard in 1884 and is located about 1.6 million light years away in the constellation Sagittarius. Despite boasting a meagre 10 million stars, and extending only one tenth the size of our Milky Way, NGC 6822 contains a full menagerie of hot red star forming HII regions, planetary nebulae, bright OB associations and dark clouds.
In 1925 the famous astronomer Edwin Hubble published his paper 'N.G.C. 6822, A Remote Stellar System' which was a detailed survey of this galaxy. Apart from describing five of its brightest HII regions Hubble also discovered 11 Cehepid variables in NGC 6822. This was one of the most important discoveries in galactic astronomy and enabled NGC 6822 to be the first galaxy beyond the Magellanic Clouds to have its distance measured and in turn greatly expanded the size of the known Universe at the time.
NGC 6822 is a challenging galaxy to photograph since it has a very low surface brightness. But still many of its brightest stars are resolved together with the various star forming regions and blue OB associations.
Also visible throughout this image is a thin veil of galactic cirrus, or Integrated Flux Nebula (IFN). This is gas and dust which is not directly illuminated by stars but rather reflect the extremely faint combined glow of the Milky Way. With its appearance as thin wispy filaments, similar to high altitude fair weather clouds, these ghostly structures are known as galactic cirrus.

Hope you enjoy the view. Comments and critique welcome as usual.

Regards,
Rolf

[allan gould]

The high res versions are stunning and the best amateur image I have seen of this galaxy. Really exceptional

[John Hothersall]

Cirrus is eyeopening and the red response is very strong presumable owing to the long amount of time you put into this.

John.

[Dennis]

Hi Rolf

A sublime image. Congratulations on the realisation of this marathon project - mag 24, gulp!

Cheers

Dennis

[petershah]

just beautiful

[multiweb]

Lots of Barnard around but this one has to be the deepest. Real nice Rolf. :thumbsup:

[RickS]

A great image, Rolf! Well worth all the time you put into it.

Cheers,
Rick.

[strongmanmike]

Another cool and interesting result Rolf, you have clearly pushed your data to the edge, which is great, so it looks to be quite deep as you say:eyepop:, nice work :thumbsup:. I detected some Cirrus in my Barnard from 2010 in much less exposure but it was further from the galaxy, your deepness has revealed it over the galaxy, actually Leo got this in his recent image too.

Not that it matters but is that guide error or star shape issues I see? I don't recall that elongation in you previous images..?

Looking foward to the next Rolf classic.

Mike

[Leonardo70]

Very nice Rolf.

All the best,
Leo

[Ross G]

An amazing photo Rolf!

Thanks.

Ross.

[marco]

Very nice Rolf, the high version is impressive, pity for the very little trailing. I also appreciate the text and analisys you always wrap up your images with.
Clear skies
Marco

[SkyViking]

Thank you very much Allan :) I couldn't really decide on the size but I think the 1600x1200 version is best as it gives a good view of both the galaxy and the surrounds, and the full res image is more suited for checking out details in the HII regions etc.


Thank you John, yes those HII regions are really blazing, I was surprised by that.


Thank you Dennis, it feels good having reached a new personal record. Now for mag 25... ;)


Thanks Peter :)


Thanks very much Marc, yes I was happy to be able to bring out so much faint stuff here.


Thanks Rick, it is my longest exposure yet and it certainly seems to have made a difference.


Thanks a lot Mike :) The cirrus is apparently also stronger down towards the lower right, just outside my FOV here.
Yes I think there is a bit of RA error, but maybe it could be from just one night's data, there are 5 nights in this image. I'm still using the standard Losmandy worms, so maybe I'll have to look into getting the Ovision ones.


Thank you Leo :)


Thanks Ross, glad you liked it.


Thanks very much Marco, I'm quite pleased with this result so it's good to hear you liked it too :)