SH2-101

This complex and stunning area of nebulosity (Sh2-101) is commonly known as the “Tulip Nebula”.  It is located in Cygnus, about a couple of degrees southwest of NGC6888, the “Crescent Nebula”.

This area is strong in Ha and SII emissions, and is located about 2,000 light years away from us.  Sh2-101 lies inside the Orion spiral arm of our galaxy, as does our own solar system.

The star believed to be fueling the emissions of the Tulip nebula is HDE 227018.

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 (Bowyer et al. 1965).  The distance to Cygnus X-1 is about 8,000 light years, or 2,500 parsecs.

These images were processed by incorporating Ha, SII, and RGB data, taken over several nights during May of 2007.  Taken with a TMB 203 F/7, and an STL-6303 camera equipped with Astrodon filters.

Dates Taken:
- 5/4/2007 through 5/9/2007

Equipment Used:
- TMB 203 F/7
- SBIG STL-6303
- Paramount ME
- FLI PDF
- Astrodon 50mm filters

Exposures:
- Ha:  10x30 minute subs, totaling 5 hours
- SII: 7x30 minute subs, totaling 3 hours, 30 minutes
- RGB:  6x8 minute subs each channel, 48 minutes per channel, or two hours and 24 minutes in total

Processing:
This image was done up as an Ha/SII + RGB image.

First processed as an Ha/sG/SII narrowband image.  The Ha was assigned to red, the SII to blue, and I used Noel Carboni's Photoshop Actions to synthesize the green data.

The RGB was processed traditionally, and incorporated into the Ha/sG/SII image in two steps:  The main RGB nebulosity was incorporated at a fairly low opacity, while the RGB stars were incorporated in at 100%, in "color" blend mode.

See http://www.flemingastrophotography.com/sh2101.html for further images and additional details.