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The nebula Sh2-101 is better known as the Tulip Nebula. This nebula is strong in H-alpha emissions. The nebula has a distance of about 2000 lightyears from Earth.
This image also shows the famous Cygnus X-1 system. Cygnus X-1 is the brightest source of hard X-rays in our sky. It is a binary system, consisting of HDE 226868, a large blue super giant, and a companion that is thought to be a “black hole”. The more compact of the two objects in the system is thought to be between 20 and 35 solar masses. Since the largest possible mass of a neutron star can not exceed three solar masses, the compact object is almost certainly a black hole. HDE 226868, highlighted below, is an O9-B0 supergiant with a surface temperature of 31,000 kelvins, comprising about 20-40 solar masses. These two objects share an orbital periodicity of 5.6 days.
The matter being stripped off HDE 226868 by the black hole’s powerful gravity forms an accretion disk around the black hole, as well as forming an associated wind corona from the blue supergiant. This process results in the plentiful X-ray emissions that were first discovered 30 years ago. The distance to Cygnus X-1 is about 8,000 light years, or 2,500 parsecs.
(Source: Fleming Astrophotography)
This image shows the nebula in H-alpha with an overlay of RGB to get realistic star colors. This is more or less what the nebula would look like in true color.
The image was taken with the following equipment:
H-alpha (Astrodon 3nm): 13 x 1800 s
R,G,B (Astrodon): 4,5,10 x 600 s
Lum (Astrodon): 5 x 300 s
Total: 10 hours