Here's why:

* Low Mass: Red dwarfs are much smaller and less massive than our Sun. They have about 8% to 50% of the Sun's mass.

* Long Lifespans: Due to their low mass, red dwarfs burn their hydrogen fuel very slowly, giving them incredibly long lifespans. Some estimates suggest they could live trillions of years.

* Large Number: Because of their longevity, red dwarfs have had plenty of time to form. They are the most numerous type of star in the Milky Way galaxy and likely other galaxies as well.

While they are the most numerous, red dwarfs are also the faintest and coolest stars. This makes them difficult to observe directly, especially from Earth.