What is a star left at the core of a planetary nebula called?

What is a star left at the core of a planetary nebula called?

The exposed core of a Red Giant that is left behind after the formation of a planetary nebula is known as a white dwarf. In a white dwarf, the force of gravity compressing the star is balanced by a electron degeneracy pressure.

What causes a Stars core to expand?

Hydrogen is still available outside the core, so hydrogen fusion continues in a shell surrounding the core. The increasingly hot core also pushes the outer layers of the star outward, causing them to expand and cool, transforming the star into a red giant.

What happens to the core of a star as it expands into a red giant?

The core of a red giant is contracting, but the outer layers are expanding as a result of hydrogen fusion in a shell outside the core. The star gets larger, redder, and more luminous as it expands and cools.

Which of the following describes what is left over after a medium sized star casts off its outer layers?

Once a medium size star (such as our Sun) has reached the red giant phase, its outer layers continue to expand, the core contracts inward, and helium atoms in the core fuse together to form carbon. The star will now begin to shed its outer layers as a diffuse cloud called a planetary nebula.

What is it called when a star begins to run out of fuel and grows larger?

The star begins to run out of fuel and expands into a red giant or red super giant. Hydrogen atoms are fused together generating an enormous amount of energy igniting the star causing it to shine.

What is the difference between a massive star and an average star?

The average star, like our own, turns into a white dwarf. A massive star becomes either a neutron star or black hole.

What is the last element that the star makes before it dies and goes supernova?

Figure 1: Structure of an Old Massive Star. The fusion of silicon into iron turns out to be the last step in the sequence of nonexplosive element production. Up to this point, each fusion reaction has produced energy because the nucleus of each fusion product has been a bit more stable than the nuclei that formed it.

What happens to a star after hydrogen stops fusing in the core?

Once a star has exhausted its supply of hydrogen in its core, leaving nothing but helium, the outward force created by fusion starts to decrease and the star can no longer maintain equilibrium. The force of gravity becomes greater than the force from internal pressure and the star begins to collapse.

What is the remnant after a high mass star dies?

High-mass stars die explosively as type II supernovae leaving cores of reduced mass, neutron stars or stellar black holes, and remnants of expanding gas and dust called a supernova remnants.

What happens when the core of a star expands?

As the core contracts, it heats up. This heats the upper layers, causing them to expand. As the outer layers expand, the radius of the star will increase and it will become a red giant. The radius of the red giant sun will be just beyond Earth’s orbit.

What happens when a star reaches the red giant phase?

Once a medium size star (such as our Sun) has reached the red giant phase, its outer layers continue to expand, the core contracts inward, and helium atoms in the core fuse together to form carbon. This fusion releases energy and the star gets a temporary reprieve.

What happens to a low mass star when it dies?

THE DEATH OF A LOW OR MEDIUM MASS STAR After a low or medium mass or star has become a red giant the outer parts grow bigger and drift into space, forming a cloud of gas called a planetary nebula. The blue-white hot core of the star that is left behind cools and becomes a white dwarf.

What happens to the core of a black dwarf star?

The Fate of Sun-Sized Stars: Black Dwarfs Once a medium size star (such as our Sun) has reached the red giant phase, its outer layers continue to expand, the core contracts inward, and helium atoms in the core fuse together to form carbon. This fusion releases energy and the star gets a temporary reprieve.