Which star is cooler and less luminous than the sun?

Red dwarfs, such as Proxima Centauri, are cooler and less luminous than the Sun. They have surface temperatures typically ranging from about 2,500 to 4,000 Kelvin, compared to the Sun's surface temperature of approximately 5,800 Kelvin. Additionally, their luminosity is considerably lower, often less than 1% of the Sun's brightness. These stars are the most common type in the universe.