What describes a white dwarf?

What describes a white dwarf?

A white dwarf is what stars like the Sun become after they have exhausted their nuclear fuel. Near the end of its nuclear burning stage, this type of star expels most of its outer material, creating a planetary nebula.

What are white dwarfs mainly made of?

What are they made of? Because white dwarfs are the remnant cores of normal stars, they are primarily made of the “waste” products of the nuclear fusion reactions that made them shine before they turned into white dwarfs. These “waste” products are primarily carbon and oxygen, with traces of other elements.

Are white dwarfs warm?

A white dwarf is very hot when it forms, but because it has no source of energy, it will gradually cool as it radiates its energy away. This means that its radiation, which initially has a high color temperature, will lessen and redden with time.

What is an example of a white dwarf star?

Theoretically, white dwarfs cannot exceed 1.4 solar masses, some examples of white dwarf stars are Sirius B, Procyon B, or Van Maanen. The nearest known white dwarf to us is Sirius B, at a distance of 8.6 light-years away.

What are the characteristics of a dwarf star?

THE characteristics of a red dwarf star are: low luminosity (say, not more than one tenth that of the sun), small mass (say, not more than three quarters that of the sun) and high density (perhaps 30–100 times the density of the sun).

Which characteristics best describe white dwarfs as compared to giants?

Which characteristics best describe white dwarfs as compared to giants ? White dwarfs are warmer and dimmer than Giants.

Do white dwarfs glow?

The infant white dwarf is incredibly hot and bathes the surrounding space in a glow of ultraviolet light and X-rays. Some of this radiation is intercepted by the outflows of gas that have left the confines of the now dead star. The gas responds by fluorescing with a rainbow of colors called a planetary nebula.

How strong is a white dwarf?

According to NASA, the gravity on the surface of a white dwarf is 350,000 times that of gravity on Earth.

How long do white dwarfs live?

NASA estimates that the sun will stay a white dwarf for around 10 billion years. However, other estimates suggest stars can stay in this phase for 1015, or a quadrillion, years. Either way, the time required to reach this stage is longer than the current age of the universe, so none of these exotic objects exist—yet.

Are white dwarfs bright or dim?

White dwarfs are hot (10,000K), dim stars. This at first seems like a contradiction all by itself, since hot things are usually quite bright. However, white dwarfs are also very small…

How fast do white dwarfs cool?

A white dwarf takes about 4 billion years to cool to 6,000 K, so we can conclude that the cluster is around 4 billion years old.

Why do white dwarfs take so long to cool?

Since white dwarfs are very small (similar in size to the Earth), they are very inefficient radiators and consequently cool very slowly. Furthermore, as a white dwarf cools its surface temperature decreases which further slows the rate of cooling. This means that white dwarfs will stay warm for many billions of years.

How do you tell if a star is a white dwarf?

White dwarfs typically have a radius just . 01 times that of our own sun, but their mass is about the same. Stars like our sun fuse hydrogen in their cores into helium. White dwarfs are stars that have burned up all of the hydrogen they once used as nuclear fuel.

How white dwarf is formed?

The vast majority of white dwarfs are formed after a dying star has shed its outer layers to form a planetary nebula, leaving behind an approximately Earth-sized inner core that is the white dwarf. Other white dwarfs in binary systems may explode as novae but then not go on to form a neutron star or a black hole.

Is a white dwarf the hottest star?

New observations of a white dwarf reveal that it is a scorcher, at roughly 250,000 degrees Celsius (482,000 Fahrenheit) — about 2.5 times hotter than a typical star remnant that is just beginning to cool.

What is White described as?

White is the lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully reflect and scatter all the visible wavelengths of light.

What is a white dwarf quizlet?

What is a white dwarf? -A white dwarf is the core left over from a low-mass star, supported against the crush of gravity by electron degeneracy pressure. A white dwarf typically has the mass of the Sun compressed into a size no larger than earth.

Which best describes white dwarf supernovae?

Based on the curves shown here, which of the following statements best describes how we can distinguish a massive star supernova from a white dwarf supernova? A white dwarf supernova is brighter at its peak and over a few months fades more steadily than a massive star supernova.

Is a white dwarf big or small?

A low or medium mass star (with mass less than about 8 times the mass of our Sun) will become a white dwarf. A typical white dwarf is about as massive as the Sun, yet only slightly bigger than the Earth. This makes white dwarfs one of the densest forms of matter, surpassed only by neutron stars and black holes.