science chapter 2 Flashcards
(20 cards)
spectrum
the band of color produced when white light passes through a prsim
apperent magnitude
the brightness of a star as seen from the Earth
absoulte magnitude
the brightness that a star would have at a distance of 32.6 light-years from Earth
light-year
the distance that light travels in one year; about 9.5 trillion kilometers
parallx
an apperent shift in the position of an object when viewed from different locations
red giant
a large, reddish star late in its life cycle
white dwarf
a small, hot, dim star that is the leftover center of an old star
H-R diagram
Hertzprung-Russel diagram, a graph that shows the realtionship between a star’s surface tempature and absolute magnitude
main sequnce
the location on the H-R diagram where most stars lie
supernova
a gigantic explosion in which a massive star collapses and throws its layers into space
neutron star
a star that has colapsed under gravity to the poinyt that the electrons and protons have smashed together to form neutrons
pulsar
a rapidly spinning neutron star that emits rapid pulses of raido and optical energy
black hole
an object so massive and dense that even light cannot escape its gravity
galaxy
a collection of stars, dust, and gas bound together by gravity
nebula
a large cloud of dust and gas in innerstelar space; a region in space where stars are born or where stars explode at the end of their lives.
globular cluster
a tight group of stars that looks like a ball contains up to 1 million stars
open cluster
a group of stars that are close toether relitave to surrounding stars
quasar
a very luminous, starlike object that genartes energy at a high rate; qusars are thought to be the most distant objects in the universe
cosmology
the study of the origin, properties, processes, and evloution of the universe
big bang theory
the theory that states the universe began with a trmoundus explosion 13.7 billion years ago
