quiz- What is the difference between red dwarf, white dwarfsand black dwarf stars ?
Answers
Answer:
Red dwarf star, also called M dwarf or M-type star, the most numerous type of star in the universe and the smallest type of hydrogen-burning star.
Red dwarf stars have masses from about 0.08 to 0.6 times that of the Sun. (Objects smaller than red dwarf stars are called brown dwarfs and do not shine through the thermonuclear fusion of hydrogen.) Lighter stars are much more plentiful than heavier stars, and red dwarfs are thus the most numerous type of star. In the Milky Way Galaxy, about three-fourths of the stars are red dwarfs. The proportion is even higher in elliptical galaxies.
Stars that burn hydrogen through thermonuclear fusion are classified into seven spectral types on the basis of their surface temperature. These stars also lie in the Hertzsprung-Russell diagram, which plots stellar luminosities against temperature on a line called the main sequence. Red dwarfs are the coolest main-sequence stars, with a spectral type of M and a surface temperature of about 2,000–3,500 K. Because these stars are so cool, spectral lines of molecules such as titanium oxide, which would be disassociated in hotter stars, are quite prominent. Red dwarfs are also the dimmest stars, with luminosities between about 0.0001 and 0.1 times that of the Sun.
Because of its low luminosity, a red dwarf’s habitable zone (the region near a star where liquid water could be found on a planet’s surface) is very close to the star. A planet in that region would orbit the red dwarf every few weeks and thus would often transit its star. Also, the transits would be quite noticeable, since a red dwarf’s small radius means that more of the star would be covered by the passing planet. Such a planet, Proxima Centauri b, was discovered in 2016 around the nearest star to the Sun, Proxima Centauri.
Explanation:
The Red dwarfs are the most common type of stars in the milky way. These are smallest and coolest kind of star. From our earth no individual red dwarfs can be observed. These start has low luminosity, very low mass, relatively low pressure, a low fusion rate, henceforth a low temperature. Proxima Centuri is the nearest star to the sun, is a red dwarf.
The white dwarf star are mostly composed of electron degenerated matter. White dwarfs are very dense in mass comparable to that of sun. No such fusion occurs in a white dwarf. The white faint luminosity occurs from the emission of thermal energy stored in the steller core of white dwarf. These stars are thought to be the final evolutionary stage of stars.
The black dwarf stars are theoretical steller remnants. It is considered that no such black dwarf is found still as a it is the utmost stage of a stellar body. A white dwarf would take upto 14 billion years to convert into a black dwarf, that time span is nearly equal to the age of universe. The concept is still now hypothetical and under research.