What are Supernova Explosions? Flashcards
How does the evolution of a star depend on? (3)
- The initial mass of the star.
- The chemical composition (metallicity).
- How fast it rotates.
- The presence of a binary companion.
How does a low mass star turn into a white dwarf?
Element combine to create heavier elements which reduce to a carbon/oxygen core.
What are white dwarfs and what are they made from?
White dwarfs are the compact remnant cores of low mass stars, principally composed of the carbon/oxygen ash accumulated over the stars life.
How are white dwarfs supported against collapse?
Electron degeneracy pressure
How is the material in the density of a white dwarf said to behave?
As a degenerate gas
What is the Pauli exclusion principle?
Only two electrons, with opposite spin, can have a given energy in a given volume at any one time.
What is the Chandrasekhar mass limit?
Degeneracy pressure can support white dwarfs against self-gravity for masses up to 1.4M.
How can white dwarfs be pushed over fundamental limit in binaries?
In a single degenerate binary system, mass excretes from a large star onto the white dwarf.
In a double degenerate binary system, two white dwarfs merge.
Why is iron the heaviest element found in stars?
To make heavier elements is an endothermic process, it requires energy, rather than produces energy. Doesn’t happen in stars as there would be no energy made to give pressure against gravity.
How is a neutron star produced?
The inert iron core formed at the end of the life of a massive star will collapse. There will not be a thermonuclear runaway. Core collapse produces a compact star composed principally of neutrons and releases a flood of electron neutrinos.
What type of supernovae are observed in spiral and irregular galaxies?
Both thermonuclear and core collapse supernovae
What type of supernovae are observed in elliptical galaxies?
Just thermonuclear supernovae
