* Smaller size: Red dwarfs are much smaller and less massive than our Sun.

* Slow burning: Their lower mass means they burn their nuclear fuel (hydrogen) much more slowly.

* Low energy output: They emit far less energy than larger stars, which also contributes to their longer lifespans.

Here's a breakdown of the connection between star size and lifespan:

* Large stars: Burn their fuel quickly and have short lives (millions of years). They end their lives in spectacular supernova explosions.

* Medium-sized stars: Like our Sun, have lifespans of billions of years. They eventually become white dwarfs.

* Small stars (red dwarfs): Have lifespans measured in trillions of years.

Since the universe is only about 13.8 billion years old, no red dwarf has yet reached the end of its life. They are the longest-lived stars we know about, and they will continue to shine for an incredibly long time!