This odd duo of a red giant and a white dwarf is called a symbiotic system. The red giant is also a Mira Variable, a pulsating red giant, that is far away from its partner. It could take as much as 100 years for the two to orbit around each other. Astronomers speculate that the interaction between these two stars may have sparked episodic outbursts of material, creating the gaseous bubbles that form the nebula. As a result, an accretion disk of material forms around the white dwarf and spirals onto its hot surface.
Gas continues to build up on the surface until it sparks an eruption, blowing material into space.
Astronomers speculate that the hourglass-shaped nebulae represent two separate outbursts that occurred several thousand years apart. The jets of material in the lower left and upper right corners may have been accelerated by the white dwarf's accretion disk and probably are part of the older eruption. The nebula, located in the Southern Hemisphere constellation of Centaurus, is a few thousand light-years from Earth. This image, taken in May 1999, captures the glow of nitrogen gas energized by the white dwarf's intense radiation. Inc. All Rights Reserved.