Category Archives: Astrophotography

Rosette Nebula and Christmas Tree Cluster

Taken last Saturday night in Toronto, on that second clear, warm night we got.

A region of high star birth activity in the Milky Way band (which is why the area is packed with stars), the Rosette and friends are only seen in the winter. Thanks to Toronto’s near-perennial cloudy skies and cold temps, I had written off getting to see it. So this was a natural target to go after on the rare clear night.

The deep red light is given off by Hydrogen gas that’s being activated by the UV radiation from newborn stars in the heart of the nebula. If you look closely you will see dark streaks in the Rosette; those are dust lanes that block light.

There is much more structure hidden in this region; I got only about two hours and a bit worth of light-gathering.

Very pretty part of the sky. Looking forward to adding more light to this image to see even more detail.

GEM 28, ASIAIR.
Canon Rebel T3i (Halpha-modified)
Rokinon 135mm at f/2.8; ISO 800
Optolong L-enhance filter.
67 subs x 2 min; 40 darks; 31 flats (8s); 24 flat darks.

Processed in Pixinsight. Separated stars and applied contrast to base image before adding reduced (Bill Blanshan, soft star reduction 2 iterations). Touch denoise in Topaz. Final curves in Lightroom to bring out the nebulosity on the right and raise texture of rosette.