Red Dwarf Stars 1.03

  From Earth, every star looks the very same. But do they? No, every star in this observable universe has its own identity. Every star is identified and graphed in a diagram called Hertzsprung-Russell diagram using the star’s mass and its temperature. Refer Star Classification for the details.   

Red Dwarf Stars are the smallest stars. Their spectral series is categorized from K5V to M5V. Red dwarfs do actually look red due to its lowest temperatures. Their surface temperature is just up-to 3500 degree Celsius. When compared with our Sun, they are far dimmer. As you can see in the H-R diagram, the red dwarfs are located at the end of the central main sequence stars. They are the coolest of all the stars. These red dwarfs have masses from about 0.08 to 0.06 times that of Sun.

Every star undergoes fusion, only by which the star lives. Likewise, the red dwarf stars are fusing all the hydrogen atoms right at this moment in their core. And due to its low temperature, they take this fusion process less seriously and consume all of their hydrogen, inside and outside their core. This extends their lifetime up-to trillion years. Sun-like stars have a lifetime of only 10-billion-year.

Since these stars are small and have their lifetime for trillions of years, Red dwarf stars are considered to be humans’ last hope. The astronomers say that 20 out of the 30 stars near Earth are red dwarfs. Out of all these red dwarf stars, there must be a habitable condition in a planet corresponding to this star system. The best example of a red dwarf star is our nearest star from our solar system, Proxima Centauri.

Proxima Centauri, a red dwarf star which has just one planet, “Proxima Centauri b“. This exoplanet is in the habitable zone of the star. This particular exoplanet and its star are way more interesting that it deserves special attention! But after TRAPPIST-1, astronomers announced that there is a possibility of a second planet where it could sustain life around one of these red dwarf stars.

As you have understood from the previous posts, stars do not shine and live forever! So, what could be the end of red dwarf stars? After a trillion of years, they will eventually burn all their fuel required for the fusion to take place. And they become as white dwarfs – these are the dead stars which no longer undergo fusion at their core.