Basic Information
A Class C Star, also known as a Carbon Star, is a Red Giant Star. These are old stars, nearing the end of their stellar lives. They've converted all their Hydrogen into Helium, and have more Carbon and Carbon Dioxide than Oxygen. They've ballooned up to many times their previous size, and may have consumed many of the innermost planets in their system. They swell up so big, the gravity at their outer surface is greatly reduced, which results in stellar wind dispersing interstellar dust in the form of compounds similar to graphite. As they expand like this, they cool down. Eventually, this process leads to them collapsing into a White Dwarf.
Until then, they have a deep ruby red color, with a sooty or smoky appearance. Many carbon stars are also variable stars, with brightness changing gradually on a very long scale.
Class C Stars are currently rare, but in the distant future they may be more numerous. In a billion years or so, the Sun will become a Class C Star, inflating to such a size that the Earth itself is swallowed up in the star-fire.
Sources
Game and Story Use
- These are generally very old stars, so their systems may be a good place for precursors, nearly-extinct species, old ruins, ancient computer systems, crashed spaceships, run-away evolution, etc.
- All of which may be in danger of being destroyed if the star balloons up any larger than it already is.
- If your story is set in the very far future, you could feature the danger of the Earth getting destroyed by it's inflated sun.
- We're talking millions of years from now, so at that point humanity might be the precursors, as transhuman species have long since spread out into the galaxy.