Why do white dwarfs get bigger?
To do this as a white dwarf packs on more mass, it must squeeze its electrons together ever more tightly. Astronomers had observed evidence of this size trend in a small number of white dwarfs. But data on thousands more of them now show that the rule holds up across a sweeping range of white dwarf masses.
Why do scientists estimate the mass of solo white dwarfs?
So the greater a white dwarf’s mass is compared to its radius, the more extreme this stretching. This trait allowed scientists to estimate the mass of solo white dwarfs.
What happens when a white dwarf becomes a gravitational redshift?
It’s known as a gravitational redshift. As light escapes a strong gravitational field, like the one around a dense white dwarf, the length of its waves stretch. The denser and more massive the white dwarf, the longer — and redder — its light becomes.
What drives a white dwarf supernova?
These supernovas are thought to develop when a white dwarf gets so massive and compact that it explodes. But no one is sure precisely what drives that stellar pyrotechnic event. The team examined the sizes and masses of more than 3,000 white dwarf stars.
How does the size of a white dwarf depend on its mass?
How does the size of a white dwarf depend on its mass? White dwarfs are typical mass of a star's mass but with small radius. A typical white dwarf would have the mass of the Sun and radius of Earth. The density is so high that a teaspoon of its material can weigh as much as a truck on Earth.
Why do white dwarfs get smaller with more mass?
Degenerate matter has other unusual properties. For example, the more massive a white dwarf is, the smaller it is. This is because the more mass a white dwarf has, the more its electrons must squeeze together to maintain enough outward pressure to support the extra mass.
What is the mass of a white dwarf?
The heaviest observed white dwarf has a mass of around 1.2 solar masses, while the lightest weighs only about 0.15 solar masses. Not all white dwarfs exist in isolation, and a white dwarf that is accreting material from a companion star in a binary system can give rise to several different eruptive phenomena.
How does mass play a role in the life cycle of a star?
A star's life cycle is determined by its mass. The larger its mass, the shorter its life cycle. A star's mass is determined by the amount of matter that is available in its nebula, the giant cloud of gas and dust from which it was born.
How does a white dwarf keep from collapsing?
To keep from collapsing under its own weight, a white dwarf must create a strong outward pressure. To do this as a white dwarf packs on more mass, it must squeeze its electrons together ever more tightly. Astronomers had observed evidence of this size trend in a small number of white dwarfs. But data on thousands more of them now show that the rule holds up across a sweeping range of white dwarf masses.
What is a white dwarf?
White dwarfs are the superhot stripped-down cores of dead stars. Scientists had predicted that these stars should do something really weird. Now, telescope observations show this really does happen: White dwarfs shrink as they gain mass.
