Red dwarf
A red dwarf is a kind of star. Red dwarf stars are smaller than half the size of the Sun. They are also cooler than most stars. Red dwarfs burn their fuel slowly, so they shine with less light (absolute magnitude) than hot stars.
Red dwarf stars are the most common in our galaxy, at least near our sun.[1] However, since red dwarf stars are cool and small, none can be found with the naked eye. The closest star to the Earth is named Proxima Centauri. The Latin word proxima means "nearest to". Proxima Centauri is a red dwarf.
Life and death
Red dwarfs can live trillions of years, much longer than brighter stars. A red dwarf dies when it burns all of its fuel. To start with, the fuel is the chemical element hydrogen. At present, no red dwarf star is known which has gone beyond this stage.[2]
Red dwarfs are small stars that are around 0.2 solar mass (the sun is equal to 1 solar mass). This is small for a star but is still 60,000 times the mass of the Earth. They are formed in nebulas, as all stars are, and originally they were protostars. They start their nuclear fusion about 100,000 years after being formed. This gives them their red glow. These stars burn at less than 4,000°K.
Even smaller stars are called brown dwarfs.
Red Dwarf Media
Proxima Centauri, the closest star to the Sun, at a distance of 4.2 ly (1.3 pc), is a red dwarf.
The predicted main-sequence lifetime of a red dwarf plotted against its mass relative to the Sun.
Gliese 623 is a pair of red dwarfs, with GJ 623a on the left and the fainter GJ 623b to the right of center.
Illustration depicting AU Mic, an M-type (spectral class M1Ve) red dwarf star less than 0.7% the age of the Sun. The dark areas represent huge sunspot-like regions.
An artist's impression of a planet with two exomoons orbiting in the habitable zone of a red dwarf.
References
- ↑ We cannot see them if they are in distant galaxies.
- ↑ Richmond, Michael (2004). "Late stages of evolution for low-mass stars". Rochester Institute of Technology. Retrieved 2007-09-19.