Red Dwarf Star
Red Dwarf is a small and relatively cool star from 'K' or 'M' class. It is very difficult to see Red Dwarf directly with naked eye because of their very low luminosity although they are present a lot in the space. Generally Red Dwarf Weighed about one third of Sun or even 8% to 10% .
The surface temperature of red dwarfs is about 3500°c and very little amount of visible light emit from them and even sometimes the intensity of light emission can be 1/10000 of Sun. The age of red dwarfs is more than any type of star because they use their hydrogen fuel very slowly. Due to less mass the gravitational pull also less in their core and the Helium produced by the thermonuclear fusion of hydrogen is constantly remixed throughout the star, avoiding its build up in the core and prolonging the period of fusion. Red Dwarfs therefore devolop very slowly maintaining a constant luminosity and spectral type for trillions of years, until their fuel depleted.
On the other hand big stars use their fuel so fast and evolute themselves fast. Because of comparatively short age of Universe no red dwarfs exist at advanced stages of evolution, like transition to a Red Giant and to a White Dwarf. Scientist have not found any Red Dwarf evolute into a new type of star.
At a distance of 4.2 light years from Sun in a triple star system "Proximus Centauri (class M5 star) revolving around the collective centre of gravity a perfect example of Red Dwarf weighed only 0.1 solar mass with 0.6 % luminosity of sun .
Writer : Sanjay Majumder