Barnard’s Loop (Sh 2-276)
Acquisition 2018-02-14, Denholm Observatory
This image captures about half of the structure known as “Barnard’s Loop”. Barnard’s Loop is a huge semi-circular shaped emission nebula in the constellation Orion and part of the even larger molecular hydrogen cloud that covers much of the constellation. The remainder of the “loop” extends down and to the right.
The distance to Barnard’s loop is estimated somewhere between 500ly and 1500ly, so at 10° in angular size, that makes the actual size somewhere between 100ly and 300ly. The apparent magnitude is listed as 5, but with that light being spread out over the total area, it barely stands out against the background sky – even in a photograph. This long exposure photograph required careful “stretching” to exaggerate the emission nebula.
Also in the field of view is the Orion Nebula, Horse Head Nebula and the Flame Nebula.
Canon T2i with Astrodon IR/UV filter inside
Astronomik UHC EOS Clip Filter
Canon 70-200L lens at 100mm f/2.8
26 x 480s at ISO1600 (total integration 3hrs 28m)
Skywatcher EQ5 Pro
Guided with Short Tube 80, Point Grey Chameleon, Metaguide
Acquisition with Backyard EOS
Processing with PixInsight (Mask creation with Photoshop CS5)