That's how I understand it. The nebula itself is just short-lived "puff", and the white-dwarf stage comes long after the nebula has vanished. 2009/1/24 Jim Gibson <jimgibson00@yahoo.com>
This is an interesting thread. Funny how a person can pick up notions that are wrong. I always thought the barely visible white dot in the center of the Helix nebula was a white dwarf but it isn't; but if we keep looking it may be.
Wikipedia says: The Helix Nebula is an example of a planetary nebula, or 'planetary' formed at the end of a star's evolution. Gases from the star in the surrounding space appear, from our vantage point, as if we are looking down a helix structure. The remnant central stellar core, known as a planetary nebula nucleus or PNN, is destined to become a white dwarf star.
jg
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