Horizontal branch stars fuse helium, and helium fusion makes less energy than hydrogen fusion. So then, why does a horizontal branch star have a higher luminosity than a main sequence star?

• Helium fusion happens faster

• The helium fusing core is much larger than the hydrogen fusing core was

• The star is fusing hydrogen and helium in the core

• The star is fusing hydrogen in shells and helium in the core

Tags

NGSS.HS-ESS1-1

NGSS.HS-ESS1-3

A question to give you a sense of how much of a star's mass is in the core--what birth mass of a star corresponds to a core mass of 1.4 solar masses?

• 1.4 solar masses

• 2 solar masses

• 8 solar masses

• 16 solar masses

What keeps a white dwarf from collapsing?

• Carbon's resistance to compression

• Electrons that have the same properties as other electrons

• Neutrons that have the same properties as other neutrons

• Oxygen's resistance to compression

What happens if a white dwarf becomes more massive than 1.4 solar masses?

• CRUNCH!

• Dude, chill. It just gets more massive.

• BOOM!

Tags

NGSS.HS-PS1-8

What happens when the core bounces before a supernova?

• Trapped neutrinos escape

• A shockwave blasts through the star

• A black hole is formed

• The star "gurgles" before exploding

Which is better at resisting collapse?

• Neutron degeneracy pressure

• Electron degeneracy pressure

• They are equivalent, just present in different environments

How do neutron stars become mostly neutrons?

• The MS lifetime of the star made neutron-rich elements

• Neutrons are captured from the supernova remnant

• Extreme pressures merge electrons and protons

• The protons are annihilated in the supernova

Tags

NGSS.HS-PS1-8

Which of the following can be an origin of heavy elements? Remember, in astronomy terms, "heavy elements" is anything more massive than helium.

• Big Bang Fusion

• Exploding White Dwarfs

• Cosmic Ray Fission

• Merging Neutron Stars

Tags

NGSS.HS-ESS1-3

Which two forces are primarily responsible for the formation of the heaviest elements (bottom two rows on the periodic table)?

• Exploding white dwarfs

• Dying low mass stars

• Exploding massive stars

• Merging neutron stars

Tags

NGSS.HS-ESS1-3

Why doesn't a white dwarf collapse?

• The magnetic fields holds the star together

• The star is so small gravity doesn't have any force to collapse the star

• Hydrostatic Equillibrium

• Electron Degeneracy Pressure

Tags

NGSS.HS-ESS1-3