Barnards Galaxy

Barnard’s Galaxy is an irregular galaxy located in the constellation Sagittarius. At a distance of 1.6 million light-years, it makes it 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, my immediate thought is that it looked very similar to the Magellanic Clouds in structure.

My preference is more toward traditional RGB colour palette; however, I did gather both colour and Ha data for this target. I wanted to see if I could reveal some of the many H II areas and combine it with a traditional RGB colour palette.

After I created an Ha image, it was quite interesting to look at on its own. It shows a slight gradient across the galaxy, but more concentrated as you move towards the centre. Another nice surprise was the colour stars, including concentrations and clusters of blue stars similar to what I have seen in the Magellanic Clouds. This area almost looks like an arm is forming.

I think that if you were a resident of NGC 6822, the H II areas would be your favourite astronomical targets for imaging. The most prominent include the Bubble Nebula located in the lower right (blue in colour), and the Ring Nebula, which appears as a large circular ring.

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-Chr├ętien 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

Autore: Terry Robison (sito)