the way stars appear to move each night when you look at them from the same place on earth
What is west?
Comets, asteroids, stars, planets, rings, galaxies, other material structure seen or detected in space
What is a celestial body?
a natural luminous body visible in the sky especially at night
What are stars?
relative brightness of something
What is luminosity?
define light year
a unit of length in astronomy equal to the distance light travels in a year
define constellation
What is a group of stars that form a pattern?
Define solar system
the sun together with the group of celestial bodies that are held by its attraction and revolve around it
any of a very large group of stars and associated matter that are found throughout the universe
What is a galaxy?
2 ways to describe the earth's location in our universe
What is 3rd planet from the sun in the Milky Way Galaxy?
Define solar flare
an explosive eruption of waves and particles into space
the entire celestial cosmos
What is the universe?
a star of very great intrinsic luminosity and enormous size
What is a super giant?
define Milky Way
broad luminous irregular band of light that stretches completely around the celestial sphere
The earth goes around the sun and the sun goes around ___________________________
What is the center of the Milky Way?
star of great luminosity and large mass
What is a giant?
5.88 trillion miles
What is a light year?
The difference in apparent magnitude and absolute magnitude
Apparent magnitude is the luminosity of a celestial body as viewed from earth while absolute magnitude is the luminosity viewed from earth (apparent magnitude) but from a distance of 10 par secs.
the role temperature plays in location and brightness of stars
the sun is the star closest to earth so it looks bigger and brighter and gives off more heat than other stars
The two gases that make up stars
What is hydrogen and helium?
Why does the Milky Way look creamy?
Because what we see is a myriad of faint lights
Two ways stars are alike?
What is (1)they are all made of gases, especially helium and hydrogen and (2) they all give off light and heat?
small whitish star of low intrinsic brightness with a mass about equal to the sun but a density many times larger
What is a white dwarf?
A two dimensional graph where absolute magnitudes of stars are plotted against their spectral types or luminosity plotted against temperature.
What is a Hertzsprung-Russel Diagram?
the percent of the stars in the universe that are main sequence stars
What is 90%?
stars that fuse hydrogen atoms to form helium atoms in the core
What are main sequence stars?