(click for larger image)


Catalogue and alternative designations The mask nebula


Type Planetary nebula
Position  15 09 25, -55 33 04
Constellation Circinus
Camera and Telescope STXL6303 and F9 36.8 cm Ritchey Chretien
Focal Ratio F9
Exposure Details HaOIIILRGB image with Hydrogen Alpha = 460 minutes, Oxygen III = 270 minutes and Luminance = Red = Green = Blue = 30 minutes with all binned 1x1. Astrodon and Chroma filters 
Description This is a faint planetary nebula in Circinus. It is called the "mask nebula" because it resembles a ski mask. The following description is adapted from Don Goldman's website. Don appears to be one of the few people to have ever imaged this thing.

"The Mask nebula is a bipolar planetary nebula (PN G321.6+02.2) about 6500 light years distant. It is about 8 arcminutes in length, including the bright core that looks like a ski mask, and the extensions. According to Corradi et al. ("A New, Evolved Bipolar Planetary Nebula", Astron. Astrophys., v224, 276-280, 1997), it is an evolved planetary nebula with a kinematic age of >12,000 years, very large in size at about 13 light years across, and has a very hot, yet unobserved central star that is hotter than 130,000K."