Deep Sky Object of the Month

The unusual planetary nebula NGC 6302 in Scorpius, sometimes called the Bug Nebula. POSS/DSS photo

A drawing of NGC 6302 made in June 1991 by Robert Kerwin using an 8" reflector.

NGC 6302, also known as the Bug Nebula, is a fascinating and unusual object in Scorpius. Often classified as a planetary nebula, it bears little resemblance to other planetaries, even when seen through a small telescope. At low magnifications, this object looks much like a galaxy with a bright, almost stellar core that is offset slightly to the east. At higher powers, both ends of the nebula appear to fan out. The west end appears brighter than the east end but is more diffuse. The eastern segment is shorter, fainter and somewhat more sharply defined. The glow may also appear somewhat uneven. An OIII filter may give a moderate contrast boost. The object has a high surface brightness, so don't be afraid to crank up the magnification, if conditions allow.

This nebula has been the object of much study. Even its classification as a planetary nebula is in doubt. On deep photographs, the basic structure is two lobes of gas separated by a well-defined dark lane. This suggests that NGC 6302 is similar to other bipolar objects. In this model, a central star is surrounded by a dense disk of gas and dust. Two powerful streams of gas are ejected from the central star at right angles to the disk at velocities up to 800 km/s.

How to get there:

This nebula is about midway between Lambda and Mu Scorpii.

Finder chart for NGC 6302