unit 6 vocab Flashcards
A brightness scale is used to measure how bright a star would be if it were seen from a standard distance.
Absolute Magnitude
The brightness of a star as seen from Earth.
Apparent Magnitude
A large collection of stars, dust, and gas bound together by gravity.
Galaxy
Hertzsprung-Russell diagram, a graph that shows the relationship between a star’s surface temperature and absolute magnitude.
H-R Diagram
the distance that light travels through space in one year; about 9.46 trillion kilometers.
light-year
the actual brightness of an object such as a star.
luminosity
the region on the H-R diagram where stars spend most of their lives; it has a diagonal pattern.
main sequence
a large cloud of dust and gas in interstellar space; a region in space where stars are born.
nebula
the core of a supernova that has collapsed due to gravity to the point that electrons and protons smash together to from neutrons.
neutron star
a large spherical object that orbits around a star.
planet
a magnetized rotating neutron star that emits a beam of electromagnetic radiation.
pulsar
the motion of a body that travels around another body in space; one trip along an orbit
revolution
the spin of a body on it’s axis
rotation
the collection of large and small bodies that orbit our central star; the sun.
solar system
a large celestial body that is composed of gas and that emits light; the sun is a typical star
star
the distance between two adjacent troughs or crests of a wave
wavelength
a gigantic explosion in which a massive star throws its outer layers into space but maintains it’s core.
supernova
space and all the matter and energy in it
universe
the hot, dense, dim core of matter that remains from the collapse of a low matter star.
white dwarf
a galaxy shaped like a pinwheel, with a bulge in the center and spiral arms extending outward
spiral galaxy
a spherical or elongated galaxy with a bright center with very little dust and gas
elliptical galaxy
a galaxy with irregular shape that does not fit into any other category
irregular galaxy
all of the different wavelengths and frequencies of electromagnetic radiation, from radio waves to gamma rays.
electromagnetic spectrum
the theory that all matter and energy in the universe was compressed into an extremely small point that exploded 13 to 15 billion years ago to all directions
big bang theory
