Red Dwarfs

Real ones, I mean. These guys are very cool. They are 85% or so of the galaxy, but we can't see any with the naked eye, meaning that the sky we see is exceptional, not normal. They are between about 0.6 of the solar mass and something almost infinitesimal (but not quite - then you get brown dwarfs).

They burn, slowly and steadily, with surface temps of around 3000K and some of them, the smallest, presumably, with estimated lifespans of 6 trillion or so years. They just burn and burn and burn. They're not great candidates for inhabited planets because some of them seem to be a bit flary at times and a planet would need to be very close indeed to be "in the zone" for life.

These stars do not disturb the universe but are among its commonest objects; they make no waves, cause no black holes, but just plod on and on, in their little corners of space, doing their thing. For years and years and years. And we can't even see them as we look up at the night sky.

The forgotten men of the universe, quietly fiery, in every corner that is too small for us to see.