stars-- properties and life cycles Flashcards
luminosity measures the total amount of ____ it radiates per _____
energy / second
what does luminosity refer to?
the brightness of stars
our sun is assigned a luminosity of __
1
what colours can stars be?
blue / red / yellow
why is colour used?
to determine the star’s surface temperature
a blue star is _____
hotter
a red star is _____
cooler
a red star is about ____ degrees Celsius
3000
a blue star is about _____ degrees Celsius
18000
what are the 3 levels of mass?
low, intermediate (medium), high
assuming the sun has 1 solar mass, other stars range from ____ solar masses to over ____ solar masses
0.08 / 100
what does the evolution of a star depend on?
the mass it had when it originally formed
what is a red dwarf?
low mass star
what is a red giant?
a dying star that has become large in diameter and cool on the surface
what is a white dwarf?
a small, dim and hot star
what is a black dwarf?
a white dwarf that runs out of heat and energy
what is a neutron star?
a dense star that has only neutrons in its core
what is a black hole?
a region where gravitational force is so strong that nothing can escape it
what is the life cycle for a low mass star?
around 100 billion years => white dwarf => black dwarf
what is the life cycle for an intermediate mass star?
around 10 billion years => red giant => white dwarf => black dwarf
what is the life cycle for a high mass star?
around 100 million years => red supergiant => supernova
=> >40 solar mass => black hole
=> < 40 solar masses => neutron star
on the H-R diagram, where is luminosity?
the y-axis (vertical)
on the H-R diagram, where is temperature and colour?
the x-axis (horizontal)
what does the H-R diagram show?
trends in the evolution of stars
