NGC2359 by Rod Pommier

NGC 2359 is an emission nebula lying 15,000 light-years from Earth and is approximately 30 light-years wide. The nebula is produced by the bright star near the center of the blue-green portion, which is WR47, a Wolf-Rayet star. Wolf-Rayet stars are rare, massive, luminous, and very hot, as they are in the phase of their life when they are fusing helium rather than hydrogen. They were previously red giants that  shed their outer shell, which is expanding outward. In NGC 2359, that shell can be seen as the “wings” on Thor’s Helmet. After shedding its outer shell, the star contracts and transforms into a Wolf-Rayet star which emits much fiercer stellar winds that drive additional stellar material outward in another expanding shell and this can be seen as the blue-green “helmet” portion of the nebula. That “helmet” portion of is expanding considerably faster than the “wings” portion and will eventually catch up to the “wings”, collide with them and burst them. This process has already occurred in the Crescent Nebula in Cygnus, which looks like a burst of fireworks from the collision.

Telescope: CDK 17

Mount: L500.

Camera: SBIG STL 11000M with Baader Planetarium Ha, R, G, and B filters.

Exposures:Ha:R:G:B =285:75:75:75 minutes = 8 hours, 30 minutes total exposure. All images completely unguided.