What do you think it would mean for a star to be in a specific luminosity class? I mean…does that mean they go to school to learn how to be bright?
(Ha, ha…yeah, I know, bad astronomy pun.)
Stars can be sorted in a lot of ways—and a good thing, too, because there are literally trillions upon trillions of them. Astronomers would be lost if we couldn’t sort them into groups to study.
They can be sorted according to spectral type (composition and temperature), apparent visual magnitude (how bright they look to the naked eye from Earth), and absolute visual magnitude (how bright they would look to the naked eye from ten parsecs away).
They can also be sorted according to their absolute bolometric magnitude (how bright they would look from ten parsecs away if the human eye could see all types of radiation).
And…they can even be sorted according to their luminosity. Continue reading