Sharpless 2-132 - The Lion Nebula...

Object: Sharpless 2-132 (Sh2-132)
Type: Emission Nebula 
Constellation: Cepheus
Distance: 10400 light years

Date: October 8th and 9th, 2019
Equipment: ATIK 460EX with EFW2, Skywatcher f5.5 Esprit 100 ED refractor, Avalon Linear mount, guiding with Lodestar X2/PHD

Subframes: 12 x 600s H-alpha, 10 x 600s OIII (2x2 binned), 5 each of 150s 2x2 binned for RGB star colour, no flats/darks (hot pixel removal in Astroart).

This image is centred on a patch of sky located at the borders of the two constellations Cepheus and Lacerta, which are high overhead in the Milky Way during mid-Autumn evenings. Sharpless 2-132 is another faint H-alpha emission nebula catalogued by Stewart Sharpless, and is located in the Perseus arm of our Milky Way galaxy.  At that distance, the gas cloud is calculated to occupy a volume of space about 250 light years across.

Stellarium sky map showing location of Sh2-132

The nebula has been nicknamed the "Lion" nebula and (at a push) the form of a heraldic Lion passant can just be made out.

The framing above has cut off the unfortunate beast's legs however, which are outlined as some extended OIII nebulosity, and which I will have to revisit in the near future.

Entangled within the Lion's mane is GP Cephei, a Wolf-Rayet star. This quintuple star system contains a super-massive component that has consumed all of its hydrogen and is now fusing helium, and is destined to explode as a supernova. It radiates strongly in the ultraviolet and is responsible for the ionisation and excitation of the gases forming the Lion's head and producing the characteristic fluorescence of hydrogen and oxygen ions that give the nebula its colour. The system has also shed distinctive shells of gas, that can be seen at the centre of the Lion's body.