Class O stars are very large, hot and bright. Their power output is over a million times that of our sun. They burn out "quickly" (on the astronomical scale). They emit mostly UV light and have a bluish tinge to our eyes. They tend to not have planets, and other stars near O-class stars lack planets as well because of photoevaporation.
Named stars of Class O:
Game and Story Use
- In general, Class O stars are at the heart of a whole lot of nothing - having consumed or photoevaporated every potential planet within several light years of them. Combine that with the tendency for Class O stars to have lifetimes measured in just a few millions (instead of billions) of years, and you get a double-whammy. There's not much chance of life (as we know it) to come from them. Maybe energy beings would work.
- If there's much of anything near a Class O star, it's existence is a potential mystery for the PCs to investigate.
- You'll note that many of the stars in Orion are Class O's. And yet, Orion is a common region of space for aliens to come from in Pulp Sci-fi, Star Trek and Conspiracy Theory alike. A game using "Orions" as a race may just want to shy away from the standard stellar classification system entirely.
- And a game set far in the future might make a point of mentioning that the former "belt of Orion" only has one star left in it now.
- While a planetary system wouldn't be likely to form around (or near) a Class O star, it's possible a Class O might gradually approach another system.
- Which is exactly why the Class O star can come up as a hazard, but not as a star, on the Random Planetary System generator.
- The results of a close pass could be disastrous to the planets it affected, increasing the cancer rate, causing global warming and environmental catastrophe, or even disrupting planetary orbits.
- Luckily, Class O's don't last for long (on the stellar scale) and so don't get a chance to travel far and wide.
- On the other hand, a Class O gives off a lot of energy. If you can build a portable or cheap Dyson sphere, they might be highly contested but dangerous resources.