As White Dwarfs Cool Which of the Following Occurs

White dwarfs cool down very slowly because a their interiors are poor conductors b they have large surface areas c their degenerate electrons cannot move around d their dense atmospheres have high opacity e they have very low mass densities. White dwarfs are the end states of stars less than around 6 times the mass of the Sun.


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The layers of the star loosen up and the star becomes a white dwarf.

. Question Correct Mark 100 out of 100 Flag question Question text The majority of stars are small cool type-M stars called Select one. For example a star like the Sun will loose. Most stars become white dwarfs.

Stars like our sun fuse hydrogen in their cores into helium. A white dwarf with a mass of 059 times that of the Sun that has a helium atmosphere and a surface temperature of 8000K will take about 15 billion years to cool down to 7140K. Rank the stages in the order they occur.

White dwarfs must still have some nuclear fuel or they would not be visible. All novae are thought to involve a a. Because a white dwarf have no source of energy of its own the only heat it produces is a remnant from its helium-fusing days.

Black dwarf giant main-sequence planetary nebula supernova white dwarf. The adiabatic pulsation properties. White dwarfs are stars that have burned up all of the hydrogen they once used as nuclear fuel.

Examples of White Dwarfs. If you watched someone fall towards a black hole youd see the light from them get blueshifted to ultraviolet and X-ray wavelengths. Cooling down another 500K will take about 03 billion years while cooling down to 6000K and then another 500K will take 04 billion and 11 billion.

Hydrogen burns up in the stars core and the core begins to freeze. Some stellar cores are too massive to become white dwarfs. Stars with main sequence masses less than about 5 solid masses cannot ignite the helium fusion required to become white dwarfs and a white dwarf cannot support its own weight by its degenerate pressure if its mass is greater than 14 solar masses.

Some giant stars will lose mass into space and form planetary nebulae. The coolest pulsating white dwarfs are the ZZ Ceti stars and the hottest correspond to the pulsating PG1159 stars. Some giant stars will lose mass into space and form planetary nebulae Some stellar cores are too massive to become white dwarfs Red dwarfs will live for a very long time and Most stars become white dwarfs.

Based on the deaths of lower-main-sequence stars select all of the correct statements from the following list. Though the white dwarf Sirius B is smaller than Earth it is quite dense. They are extremely dense because the matter that forms the white dwarfs is degenerate.

Even a teaspoonful of its material can outweigh the heaviest object on Earth. White dwarfs stars are typically found in binary systems as in the case for the white dwarf companion Sirius B which accompanies Sirius A the brightest star in the night sky. White dwarfs cool down very slowly because a their interiors are poor conductors b they have large surface areas c their degenerate electrons cannot move around D their dense atmospheres have high opacity e they have very low mass densities.

The minimum mass of a white dwarf is about 14 solar masses. Which of the following statements about white dwarfs is NOT correct. Equal amounts of normal perfect and degenerate gases.

Red dwarfs become red giants. The sun will become a giant star that fuses carbon. All white dwarfs have masses in a small range from about 5 to almost 14 M.

We also find that most DQ white dwarfs transform into DQpec when their photospheric densities exceed 015gcm3 015 gcm 3. However we identify stars for which the DQDQpec transition occurs at lower photospheric densities possibly due to the presence of a strong magnetic field. The size of a white dwarf star as compared to Earth.

Once this occurs and nuclear fusion is stable at the. The following example illustrates the point. Leave out any stages that will not occur in the evolution of a star of similar mass to the sun.

Which of the following statements about white dwarfs is NOT correct. The white dwarfs are the endpoints of small to mid-sized stars. The white dwarf is the core of the star that is left after episodes of mass loss causes the star to eject its outer layers which continue expanding out into space to form a planetary nebulae.

The layers of the star expand and a chemical reaction causes a supernova. Consider the following possible stages in the evolution of a star like our sun. One cubic inch of its material would weigh 136 metric tons 15.

The following table includes some known white dwarf examples and their proximity to. After billions of years it is predicted that white dwarfs cool to become black dwarfs lifeless stellar husks although the age of the universe 137 billion years has not been sufficient for this to occur yet. In a galaxy like the Milky Way the formation of new stars generally occurs in the spiral arms of the galaxys disk.

A white dwarf will cool to be com e a black dwarf in several a. Hydrogen burns up in the stars core and the core begins to cool. White dwarfs are com posed mostly of a.

Mass has no effect on the life cycle of a star.


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