White Dwarf

Question 1

What began our knowledge of white dwarfs?

Answer 1

Our knowledge of white dwarfs began in 1850 with the discovery of a companion to Sirius, called Sirius B.
The only way it could be both hot and faint was for Sirius B to be very, very small, and so they were called white dwarf stars.

Question 2

Sizes of white dwarfs

Answer 2

the gas inside a white dwarf was too dense to behave as an ideal gas and, instead, was degenerate.
if you increase the mass, the star gets larger, its radius increases. However, for white dwarfs, the opposite is true, increasing the mass shrinks the star.

Question 3

What is a white dwarf star?

Answer 3

A white dwarf is whatstarslike the Sun become after they have exhausted their nuclear fuel.
This core becomes a very hot white dwarf, with a temperature exceeding 100,000Kelvin. Unless it isaccretingmatter from a nearby star, the white dwarf cools down over the next billion years or so.

Question 4

Characteristics

Answer 4

Roughly the same size as Earth.
The more mass they have, the smaller they are.
Binary system

Question 5

Binary system

Answer 5

Not all white dwarfs exist in isolation, and a white dwarf that is accreting material from a companion star in abinary systemcan give rise to several different eruptive phenomena.

Question 6

Evolution of white dwarfs

Answer 6

Once a white dwarfs contracts to its final size, it no longer has any nuclear fuel available to burn. 
Cooling:
Radiating its energy outward
Neutrino cooling 
A slow process  black dwarfs

Question 7

When and bye ho were white dwarfs discovered?

Answer 7

White dwarfs were discovered in the 18th century byWilliam Herschel.