Barnard 72 - Snake in the dark

Barnard 72 - The Snake Nebula

The Snake Nebula (also known as Barnard 72 and S Nebula) is a dark nebula in the Ophiuchus constellation (the Serpent Bearer). It is a small but readily apparent S-shaped dust lane that snakes out in front of the Milky Way star clouds from the north-north-west edge of the bowl of the Pipe Nebula. A good view in a 4" to 6" telescope requires clear dark skies. It is part of the much larger Dark Horse Nebula (also known as Pipe Nebula). To the lower left side of the Snake Nebula is found Barnard 68. [1]

This dark nebula is a series of dark absorption clouds made up of Interstellar dust. Interstellar dust grains - composed predominantly of carbon - absorb visible starlight and reradiate much of it in the infrared. This absorption causes stars behind the clouds to be obscured from view, hence the appearance of starless voids on the sky. This nebula is the same type of Coal Sack Nebula, in Crux constellation. Molecular clouds like the Snake Nebula are places where new stars are likely to form. The Snake Nebula lies about 650 light-years away and spans the angular width of a full moon. [2]

The Snake Nebula was cataloged by Edward Emerson Barnard (*1857 +1923). The astronomer Barnard compiled a list of dark nebulae known as the Barnard Catalogue of Dark Markings in the Sky, or the Barnard Catalogue for short. The nebulae listed by Barnard have become known as Barnard objects. A 1919 version of the catalogue listed 182 nebulae; by the time of the 1927 version, it listed 369. [2]

Distance: 650 light-years
RA/DEC (J2000): 17:23:39.0 -23:41:42 [3]

Sources:
[1] wikipedia
[2] http://apod.nasa.gov/
[3] http://cds.u-strasbg.fr/cgi-bin/Sesame

This picture was taken in 6th Meeting Brazilian of Astrophotography in July, 2013 - Alto Paraíso de Goiás - Chapada dos Veadeiros - Goiás - Brazil.

Technical data
ISO 800, total exposure of 01h35m (19 subs), darks, flats and biases applied.

Equipment
- Equatorial Mount Orion Atlas EQ-G
- Refractor Triplet Meade 80mm APO F6
- Canon DSLR 500D unmodded
- Auto guided with Orion Starshoot and Refractor Orion 80mm
- Astro-Tech Field Flattener 2"

Software
Capture: BackyardEOS
Processing: PixInsight 1.8 and Adobe Photoshop CS5