Thor's Helmet is created by the brightest star inside the "bubble". This star
is a rare Wolf-Rayet star, a massive, hot blue giant whose high velocity solar
wind slams into the surrounding interstellar gas and dust and creates the intricate
patterns in this nebula. For another example of a bubble blown by a Wolf-Rayet star,
see the image of the "Bubble Nebula". Thor's Helmet is in the constellation Canis
Major. The main bubble is about 30 light years across, and it is 1500 light years
from earth.


Image data:
Telescope: 17" Planewave
Exposure: 20 hours through Oxygen-III and Hydrogen-Alpha filters
Location: Observatorio El Sauce, Chile