Owl Nebula (M97) in Ursa Major
The Owl Nebula (NGC 3587) in Ursa Major is the 97th object listed in Messiers catalog. It is one of the more complex planetary nebulae. Its appearance has been interpreted as that of a cylindrical torus shell, viewed oblique, so that the projected matter-poor ends of the cylinder correspond to the owl’s yes. This shell is enveloped by a fainter nebula of lower ionization. Its distance is estimated about 2000 lightyears.
This image is a combination of broadband- (LRGB) and narrowband- (Ha, OIII) filters to reveal the faint, outer shell and the details within the nebula. North is to the right.
[description from SEDS]