the.com/brown dwarf
A star that almost made it, too big for a planet, too shy for fusion.
means A substellar object heavier than a planet but too light to sustain hydrogen fusion, so it glows faintly on leftover heat rather than burning like a true star.
from The 'dwarf' comes from the standard astronomical habit of calling small, dense stars dwarfs (white dwarf, red dwarf). 'Brown' was proposed in the 1970s by astronomer Jill Tarter as a deliberately vague color — these objects aren't actually brown, since no pigment fits an object this hot; the name was chosen simply to mark a class darker and cooler than red dwarfs, the dimmest true stars. The term stuck as a convenient fiction rather than a description anyone ever saw with their eyes.
- fusion fail
- Too small to fuse hydrogen like real stars
- mass range
- 13 to 80 times Jupiter's mass, roughly
- cools forever
- Dims and cools over billions of years, never stabilizing
- nickname
- Astronomers call them failed stars, slightly rude