Sh2-101, the Tulip Nebula, and the Cygnus X-1 Bow Shock

One of the most surprising things I learned as I headed down this road of astrophotography is that it would be possible to take a picture of Cygnus X-1—the first object ever confirmed to be a black hole. Lying 7,000 light years away with a mass of about 21 suns and accompanied by a closely orbiting blue supergiant companion star, scientists believe that Cygnus X-1 collapsed directly into a black hole without going through a supernova explosion.

The location of Cygnus X-1 is shown with the annotations in the image (click the overlay button to see the annotations). Two stars are apparent in the image, but it’s hard to believe that I was actually able to capture the accretion disk surrounding Cygnus X-1 and the black hole’s binary companion star—but I can dream, can’t I? Most likely, the brighter star is the binary companion and the small second star is either a foreground or background Milky Way star.

The blue arc above Cygnus X-1 is thought to be a bow shock created by one of the jets coming from the black hole colliding with the interstellar medium. The shape could be the result of the precession of the jet, creating an arc of colliding gasses.

Of course, I cannot possibly post an image containing Cygnus X-1 without mentioning the progressive rock song of that name released on the Rush album A Farewell to Kings in 1977:

So far, lost in this rather lengthy discussion of Cygnus X-1 is the main visual feature of this image: Sh2-101, the Tulip Nebula. Providing a stunning array of hues from ionized hydrogen, sulfur, and oxygen gas emissions, the Tulip is about 8,750 light years from Earth.