Here's why:
* Cooler: Proxima Centauri is a red dwarf star, which are the coolest and smallest type of stars. Its surface temperature is around 2,700 degrees Celsius (4,890 degrees Fahrenheit), significantly cooler than the sun's surface temperature of 5,500 degrees Celsius (9,932 degrees Fahrenheit).
* Less luminous: Red dwarfs are also much less luminous than the sun. Proxima Centauri is only about 0.17% as luminous as the sun, meaning it emits far less light and energy.
It's important to note that while Proxima Centauri is cooler and less luminous than the sun, it's still a star and produces its own light and heat through nuclear fusion.
