How a dead star turned green
Ordinary stars pour out green light, but every other color comes too, so they look red, white or blue, never green. WD J1330+6435, a white dwarf about 280 light-years away, has a helium atmosphere squeezed up to the density of water, and rocky rubble from its old planets rains into it. Jostled by that dense helium, sodium swallows yellow, orange and red, calcium bites off the violet, and what's left peaks in green. It's far too faint to see by eye, so astronomers ran its measured spectrum through a model of human color vision, and the verdict is the most vivid green star yet.
- 0:00 A green star
- 0:09 Meet WD J1330+6435
- 0:17 Why stars aren't green
- 0:28 Inside the dead star
- 0:38 Planet rubble rains in
- 0:45 Sodium steals the light
- 0:55 The rainbow breakdown
- 1:01 How astronomers know
- 1:12 One way to go green