View Single Post
  #7  
Old 25-08-2011, 03:56 PM
sjastro's Avatar
sjastro
Registered User

sjastro is offline
 
Join Date: Jun 2007
Posts: 2,926
Quote:
Originally Posted by Alchemy View Post
Faint little beast to pull out, had a go at this a while back but can't say I was impressed with my results.

Re the seeing, I'm assuming you didn't do this monday or Tuesday as the seeing was pretty good at my place, particularly tuesday.

Didn't bother last night as when I got home at 10 pm there was some very thin haze around.

Its been nice to have some clear skies, they have been few and far between for a long time now. Imagers from south of the divide have not put up much work.

Always enjoy looking at your work Steven as you do like the different and diverse.
Hello Clive. I took the L images on Tuesday. Seeing was average. The colour images were taken last night and I to deal with high level clouds.
I've boosted the red channel in the H-Alpha regions as a result to bring out the detail.

Quote:
Originally Posted by atalas View Post
Nice work Steven.
Thanks for the comment Louie.

Quote:
Originally Posted by gregbradley View Post
Very good Steven.

Not too often imaged. 7 hours at F5 and an ST10 shows how dim this one is.

Greg.
Hi Greg. Actually my original target was going to be SagDig which makes Barnard's Dwarf superluminous by comparison.

Quote:
Originally Posted by madbadgalaxyman View Post
Thank you, Steven, for an interesting image of NGC 6822.

According to Sidney van den Bergh in his encyclopedic book "The Galaxies of the Local Group" (Cambridge University Press), N6822 is over two mags less luminous than the LMC. (measured in the V-band)

Yet it still looks complex and interesting, as we are very fortunate to be located in the same galaxy group.

NGC 6822 is a more typical dwarf irregular galaxy than the LMC, in that it is low surface brightness and its overall rate of star formation is very low.
Barnard's Galaxy is not particularly blue either, in the optical regime, with an optical color of B-V equals 0.79
(the LMC is much more blue, at B-V = 0.52)

Some impressive Large Telescope images of N6822 and other members of the Local Group can be found at the website of the Local Group Survey:

http://www.lowell.edu/users/massey/lgsurvey

One of the more interesting multi-wavelength observations of NGC 6822 concerns the relationship of the optical image to the vast and distended cloud of HI (neutral atomic hydrogen) in which the galaxy is embedded:

Here is an image which overlays DSS (optical) with the borders of this disk of cold atomic gas:

Attachment 99582

The gaseous part of N6822 is a completely different shape and size compared to the optical part! Also, the vast gaseous disk has only formed stars in its very central part......

cheers,
the bad galaxy man
It's good to provide a technical description along with an image. I should perhaps do more of that. Thanks for providing the detail Robert.

Quote:
Originally Posted by rogerg View Post
That's a tough one to image and make look good. Your results aren't bad considering. 4 hours L is a decent time.
Thanks Roger.
Reply With Quote