Vocab
What is a light year?
The distance light can travel in one year
What are the 4 stages of a stars life?
1. protostar
2. main sequence star
3. red giant
4. white dwarf
How are stars classified?
by how hot they are
What all is found in a galaxy?
stars, dust, gas, nebulas, open clusters, and quasars
Explain the theory of the Big Bang
the universe began with a tremendous explosion. all contents of the universe were gathered together under extreme pressure, temperature, and density in a tiny spot
What is the H-R diagram?
a graph showing the relationship between a star's surface temperature and its absolute magnitude
what is the difference in a star life cycle of a large star vs an average star
Large stars eventually become supernovas and black holes.
how are stars identified?
by their colors
What are the three types of galaxies?
Spiral, elliptical, and irregular
What is the explanation for the radiation found coming from all directions in space?
it is leftover gas from Big Bang
What is a neutron star that is spinning?
a pulsar
Stars spend most of their time in which stage?
main sequence
What color stars are the hottest and coolest?
blue- hottest
red- coolest
What galaxy is earth located in and what type of galaxy is it?
Milky way and spiral
How is a black hole formed?
leftovers of a supernova are so massive they collapse to form it
what is a galaxy?
a large group of gas, dust, and millions of stars
What happens to supernovas?
a huge explosion and the star might die
What are stars made of?
hydrogen, helium, and other gases.
how is a nebula different from a galaxy?
how does a star's temperature change as it ages?
it gets cooler
what is the study of origin, properties, and evolution of the universe
cosmology
What is a neutron Star?
the center of a collapsed star (extremely dense)
on the H-R diagram what is bottom to top and left to right?
hot (blue)on left-- cool (red) on the right
Bright on the top and dim on the bottom
what causes a main sequence star to become a red giant?
the main sequence star uses up all its hydrogen it can no longer give off engery. the star then expands and cools forming a red giant.
How do scientists estimate how many stars a galaxy has?
by measuring the size and brightness of the galaxy