Barnard's Galaxy is an irregular galaxy located in the constellation Sagittarius. At a distance of 1.6 million light-years, this is one of the closer galaxies to our Milky Way. In 1884, E.E. Barnard discovered this object through a six-inch refractor telescope. When I first observed this galaxy, I immediately thought it looked very similar to the Magellanic Clouds in structure. I prefer the traditional RGB colour palette; however, I did gather some Ha data for this target. I aimed to reveal some of the many H II areas and combine them with a traditional RGB colour palette.
After I created the Ha component of the image, it was interesting to look at on its own. It shows a slight gradient across the galaxy but is more concentrated as you move towards the centre. Another pleasant surprise was the colours of the stars, specifically, the concentrations and clusters of blue stars. They are similar to what I have seen in the Magellanic Clouds. This area almost looks like an arm is forming.
If you were a resident of NGC 6822, the H II areas would be some of your favourite astronomical targets for imaging. The most prominent include the Nebula located in the lower right with a slight bluish centre, and the Ring Nebula appears as a large red circular ring when the Ha is added to the image. Around the 2 o’clock position, another substantial emission area is red and blue.
To give some scale to the image, it is 17.38 X 16.75 arcmin in size. Our moon is around 30 arcmin across.
Exposure Details:- Lum 53 X 900 Binned 1X1
- Red 18 X 600
- Green 18 X 600
- Blue 12 X 600
- Ha 59 X 1200
Total time: 40.9 Hours
Instruments- Telescope: 10" Ritchey-Chrétien RCOS
- Camera: SBIG STL-11000 Mono
- Mount: Astro-Physics AP-900
- Focal Length....... 2310.00 mm
- Pixel size ........ 9.00 um
- Resolution ........ 0.82 arcsec/pix
Thanks for looking
Terry
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