25 Jan
2009
25 Jan
'09
8:24 p.m.
I need to add that I don't think residual heat emmanating from a white dwarf is going to ionize nebular material. It's got to be energy from a pre-white-dwarf stage star that's doing it, while there is still some dying shreds of fusion taking place and some fairly energetic particles from a remnant solar-wind are still in play. On Sun, Jan 25, 2009 at 8:18 PM, Chuck Hards <chuck.hards@gmail.com> wrote:
Also, I need to research this, but I'm not sure that planetary nebula are illuminated by the central star, but by the expelled material colliding with material ejected previously. These are glowing, ionized nebula, not merely reflection nebula.