Object Analysis

The Lemon Slice Nebula (IC 3568) is a planetary nebula in the constellation Camelopardalis. It is one of the most perfectly spherical planetary nebulae known, located roughly 4,500 light-years from Earth. Its name comes from its bright yellow-green core and the almost perfectly circular outer shell that looks like a slice of citrus fruit.

The nebula has a diameter of about 0.4 light-years. It consists of a bright, dense inner core and a fainter, diffuse outer halo. The central star is a magnitude 12 white dwarf. Unlike many other planetary nebulae that are distorted into bipolar or "butterfly" shapes, the Lemon Slice suggests a very steady and uniform ejection of gas.

Because of its simplicity and high symmetry, IC 3568 is often used as a standard model for studying the ionization of gas in planetary nebulae. The lack of complexity suggests the central star is likely a single star without the magnetic or binary complications that warp other stellar remnants into chaotic shapes.