ABSTRACT

A planetary nebula in the constellation Cygnus, position RA 19 h 44.8 m, dec. +50° 31'. It is ½' in diameter and of eighth magnitude, with a tenth-magnitude central star. It gets its name because it tends to vanish when looked at directly through a small telescope, when light from the central star swamps the nebula, and reappears when viewed with averted vision.