Location of Photo:
Burke-Gaffney Observatory, St. Mary's University, Halifax, NS
Date/Time of photo:
Several nights from 7 Dec 2016 to 3 Apr 2018
Planewave Model CDK24 (Corrected Dall-Kirkham) reflector, aperture 0.61 meters (24 inch), at f/6.5. Apogee Aspen CG16M CCD camera binned 2 x 2 (2048 x 2048 pixels). Astrodon Gen II Series-E filters
Thor's Helmet is a wind-blown bubble around the Wolf-Rayet star WR7 that is unique in its morphology. The central bubble with its fine filaments principally contains interstellar material that has been swept up by the fast wind streaming away from the central star. Interactions with a nearby molecular cloud mask the outer regions of the bubble to the southeast (north is up, east is to the left), and additional interactions with the surroundings are apparent in the reddish-colored ionization fronts on the outer edges of the spiral-like features emanating from near the surface of the bubble. At an adopted distance of 11,960 lys, this cropped image is 78.7 x 80.1 lys in extent; the central bubble spans roughly 16 lys. Recent research based on the high 26Al/27Al and low 60Fe/56Fe ratios found at the time of solar system formation suggests that the Sun may have arisen from triggered star formation in the swept-up shell of an ancient Wolf Rayet bubble.