White Dwarf
- November 25, 2021
- Posted by: OptimizeIAS Team
- Category: DPN Topics
No Comments
White Dwarf
Subject – Science and Tech
Context – White dwarf with fastest spin: one rotation every 25 seconds
Concept –
- A white dwarf is a star that has burnt up all of its fuel and shed its outer layers, now undergoing a process of shrinking and cooling over millions of years.
- Such stars have very high density.
- A typical white dwarf is half the size of our Sun and has a surface gravity 1,00,000 times that of Earth.
- Stars like our sun fuse hydrogen in their cores into helium through nuclear fusion reactions.
- Fusion in a star’s core produces heat and outward pressure (they bloat up as enormous red giants), but this pressure is kept in balance by the inward push of gravity generated by a star’s mass.
- When the hydrogen, used as fuel, vanishes and fusion slows, gravity causes the star to collapse in on itself into white dwarfs.
- A white dwarf star that completes a full rotation once every 25 seconds is the fastest spinning confirmed white dwarf, according to a team of astronomers.
LAMOST J024048.51+195226.9 — or J0240+1952
- This particular star, named LAMOST J024048.51+195226.9 — or J0240+1952 —is the size of the Earth but is thought to be at least 200,000 times more massive.
- It is part of a binary star system; its immense gravity is pulling material from its larger companion star in the form of plasma.