Nightscapes & Deep Sky Colors
Astrophotography © Brian A. Morganti
Sh2-101 Tulip Nebula
Mouse over the above image to see the designations of the various objects
The Tulip Nebula, or Sharpless 101 (Sh2-101) is an emission nebula located in the constellation Cygnus about 2 degrees southwest of NGC6888. It is so named because it appears to resemble the outline of a tulip when imaged photographically. It was catalogued by astronomer Stewart Sharpless in his 1959 catalog of nebulae. It lies at a distance of about 6,000 light-years
The Tulip nebula, at least in the field seen from earth, is in close proximity to micro-quasar Cygnus X-1, site of one of the first suspected black holes. Cygnus X-1 is the brighter of the two stars (lower star) in close vertical proximity just to the right of the Tulip nebula in the image presented here (mouse over for arrow designation).
Cygnus X-1 (aka HDE 226868) is a large blue super
giant, and its companion - 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 which is unseen, is almost
certainly a black hole. HDE 226868 is an O9-B0 supergiant with a
surface temperature of 31,000 Kelvin, comprising about 20-40 solar
masses. These two objects share an orbital periodicity of 5.6 days.
Bernard's dark nebula (B 146) can be seen obscuring the red emission nebula in the upper left portion of this image.