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light-years are a measure of ... distance
A light year is a measure of how far _ can travel in __. light... one year
We use the method of __ to determine how far away stars are from Earth. parallax
If a star moves a lot in the sky from winter to summer, it is ___ than other stars that did not move much. closer
All stars are huge spheres of .. gases
Stars release huge amounts of ... energy
A stars __ reveals its temperature color
What is fusion? When two atoms are smashed together to form a new kind of atom
What is the "fuel" of a star? hydrogen
We classify stars according to their __, __ and __ size, temperature, luminosity (and color)
What class of star is our suN? G
How bright a star looks from Earth depends on a) distance from Earthb) absolute magnitude (how bright it really is)
What is absolute magnitude? How bright a star really is, compared to other stars
What is apparent magnitude? How bright a star appears from Earth
In main sequence stars, the ___ a star the hotter, brighter, and faster it burns. bigger
What are the classes of stars in order of hottest to coldest? O B A F G K M
In stars, the gas ___ undergoes fusion to become ___. 2 atoms of hydrogen.... 1 atom helium
Our sun is a __ sized star. Medium
When our sun nears the end of its life, it will form a __ but not a __ or a __. white dwarf.... not a black hole or neutron star
What color are class K stars? orange
What color are class O stars? Blue/White
What color are class B stars? Blue/White
What color are class M stars? red
What color are class A stars? White
What color are class G stars? yellow
What color are class F stars? pale yellow
Our solar system is a ___ system. single star system
What is an eclipsing binary? When two stars in a binary system are moving past each other, and one appears to eclipse the other.
What 2 kinds of evidence do we have that a star is a binary system, even if we can't see the 2nd star? a) wobble b) eclipsing
How many galaxies are in our universe? 40 billion is the best estimate we have now
In a binary system, when one star's gravity affects the other and makes it move back and forth, this is called... wobble
How many stars are in a galaxy? billions, if not trillions
What is the name of our galaxy? The milky way
What shape is the milky way galaxy? spiral
What is the nearest galaxy to the milky way? What is its shape? Andromeda, it's spiral shaped
What is the next nearest star to our sun? Alpha Centauri <- this is not on your test
What is a "falling star" really? meteor
What is an asteroid? a huge rock in space
What is a meteoroid? a small rock in space
What is a meteor? A meteoroid that has entered Earth's atmosphere
A red giant will form either a ___ in large stars or a ___ in massive stars. neutron star, black hole
Small and medium stars will form a __ at the end of their life cycle, which will form a ___ when it runs out of energy. White dwarf ... black dwarf
What is a star explosion called? Supernova
What is a comet? A huge chunk of ice and dirt that revolves around the sun like the planets do
What is a meteorite? a space rock on Earth's surface
All stars start out as a ... nebula
When the gases in a nebula stick together due to gravity, they form a... protostar
A protostar does not become a real star until ___ starts. fusion
One possible theory of what happens to our universe when it finishes expanding, is that it will ___. This is called the ___. contract..... "big crunch"
A black hole has such strong ___ that it pulls in everything, even light. gravity
How old is our sun? 4.6 billion years
How old is the universe? 10-15 billion years
Our universe is constantly ___ and has been ever since the big bang occured ___ years ago. expanding, 10-15 billion years
What is the most universally accepted theory of how the universe began? the big bang theory
What was Edwin Hubble's theory? That the galaxies that are farther away from the Milky Way, are moving away faster than close galaxies
The name for a galaxy with a black hole at its center is quasar
The name for a neutron star that gives off radio waves is pulsar
What star is even more dense than white dwarfs? neutron stars
Only the most massive stars become __ when they die. black holes
What happens after a star is a giant or supergiant, depends on the star's ___. mass
What is the next closest galaxy to ours? Andromeda
What shape is the Andromeda galaxy? spiral
What shape is the milky way galaxy? spiral
What are the 3 shapes of galaxies? spiral, elliptical, irregular
Galaxies with very little dust in them, do not... make new stars
How many stars are in a galaxy? billions, if not trillions
What is the name of our galaxy? The milky way
What are the hottest and brightest stars called? blue giants
What are the cool, bright stars called that are the end of a star's life cycle? red giants or red supergiants
What are small, white, dim stars called? White dwarfs
A star spends most of its lifetime as a __ star. main sequence
List the planets in our solar system from closest to the sun to the farthest: mercury, venus, earth, mars, jupiter, saturn, uranus, neptune
How can we remember the order of the planets? My very educated mother just served us nachos.
Created by: jmclaren