Nightscapes & Deep Sky Colors

Astrophotography Brian A. Morganti

Sh2-101 Tulip Nebula

w/Cygnus X-1


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.
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.

Bernard's dark nebula (B 146) can be seen obscuring the red emission nebula in the upper left portion of this image.


  • Date & Location:  September 9th/10th, 2012 - Bernville, PA

  • Weather:  Calm, Temperature range 61F to 53F (9:20pm to 1:40am)

  • Sky Conditions:  Mostly clear with patchy cirrus clouds, average transparency. 

  • SQM-L: 20.37 start - 20.44 finish

  • Optics:  TeleVue NP101is Refractor with focal reducer @ 432mm f4.3

  • Filter:  Hutech IDAS-LPS (Light Pollution Suppression)

  • Mount:  AstroPhysics AP900GTO

  • Guiding:  Orion SSAG @5 seconds

  • Camera:  Canon T1i (500d) Hap Griffin modified - Baader UV/IR

  • Exposure:  8 & 10 minute subs  @ ISO800 - 3 hours 19 minutes total exposure

  • Calibration Frames:  Master Dark & Bias 60F

  • Processing:  Images Plus 4.50b, PS CS6, GradientXTerminator, NIK filter tools 

  • Comments:  Image scale is cropped to about 50% of the original captured image in order to show more detail within the Tulip Nebula. 


Astrophotography  -  Nightscapes & Deep Sky Colors