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.