With brilliant Oxygen III clouds in blue and a spectacular pink core, Adriano Almeida’s image of the Crescent Nebula wins our Photo of the Week on January 28, 2022.

NGC 6888 is an emission nebula located in the constellation Cygnus, approximately 5,000 light-years away from Earth. It is commonly referred to as the “Crescent Nebula.” It is the result of a type of star known as a Wolf-Rayet, which means it is nearing the end of its lifespan, causing it to rapidly lose mass at a high rate. Wolf-Rayet stars are quite rare.

The Crescent Nebula has been shedding its outer layers into space at a rate equivalent to the mass of the Sun approximately every 10,000 years. The rapid ejection of materials creates a dense shell that gives the nebula its shape.

Adriano Almeida began capturing this image of the Crescent Nebula on September 27, 2021, in Mississauga, Ontario. He used a ZWO ASI1600MM camera along with a Celestron EHD 9.25-inch telescope and a 0.7× reducer lens to capture the image at a focal ratio of f7. It took a total of 16 hours and 40 minutes of data gathering to assemble the photo.

Almeida combined Hydrogen-alpha and Oxygen III filters to generate a high-quality simulated luminance channel, then assembled the data as a L+HOO composition.

Honourable mention

This week’s honourable mention goes to Ron Brecher, who imaged an emission nebula known as the Rosette Nebula. It is located 5,200 light-years away from Earth, and can be found in the constellation Monoceros, the Unicorn.

The Rosette Nebula is a stellar nursery, and within the centre of the Rosette is NGC 2244. The stars within NCG 2244 are responsible for the nebula’s glow. These stars formed about four million years ago as a result of nebular material and stellar winds clearing a hole in the nebula’s centre.