Canon XSi, modded, Total (HaR)GB 81 min. = RGB 19x3 min., Ha 6x4 min., ISO 1600
Baader MPCC, Baader 7nm Ha Filter
LXD75-SN10 OTA, EQ6 mount, guided w/PHD and EQMOD

The Tulip Nebula, or Sharpless 101 (Sh2-101) is an emission nebula located in the constellation Cygnus, about a 2 degrees southwest of NGC6888, the “Crescent Nebula”, and inside the Orion spiral arm of our galaxy, in which our own solar system lays as well. It was catalogued by astronomer Stewart Sharpless in his 1959 catalog of nebulae. It lies at a distance of about 8,000 light-years (7.6ª1016 km; 4.7ª1016 mi) from Earth.

The Tulip nebula, at least in the field seen from earth, is in close proximity to Cygnus X-1, the brightest source of hard X-rays in our sky, and site of one of the first suspected black holes. This first X-ray source in Cygnus, was discovered by the Giacconi group shortly after their discovery of Sco X-1, and also by a group at the Naval Research Laboratory. Over the years the location of this X-ray source became more accurately determined. The X-ray source was found to lie very close to the position of a 9th magnitude blue star called HD 226868. This was confirmed when a radio flare was detected, at the same time as a jump in the X-ray brightness, and found to be from the same direction.

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 (in this image - the left star of the bright couple located almost directly under the left side of the Tulip) 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.

The texts above were composed of several sources, including Neil Fleming's site, Wikipedia, and others.