Galaxies and stuff Flashcards
galaxy
a collection of stars,dust,and gas bound together by gravity
spectrum
the band of color produced when white light passes through a prism
apparent magnitude
the brightness of a star as seen from Earth
absolute magnitude
the brightness that a star would have at a distance of 32.6 light years away from Earth
light year
the distance that light travels in one year about 9.5 trillion kilometers
parallax
an apparent 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 leftover from the center of an old star
H-R diagrahm
A graph that shows the relationship between a stars surface temperature and absolute nagnitude
main seqence
the location on the H-R diagram where most stars lie
nebula
a large cloud of gads and dust in interstellar space; a region in space where stars are born or where stars explode at the end of their lives
solar nebula
the cloud of gas and dust that formed our solar system
cosmology
the study of the origin,properties,process, and evolution of the universe
big bang theory
the theory that states the universe began with a tremendous explosion 13.7 billion years ago
globular cluster
a tight group of stars that looks like a ball and contains up to 1 million stars
open cluster
a group of stars that are close together relative to surrounding stars
quasar
a very luminous star like object that generates energy at a high rate; quasars are thought to be the most distant objects in the univerwse
black hole
an object so massive and dense that even light cannot escape its gravity
neutron star
a star that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons
pulsar
a rapidly spinning neutron star that emits rapid pulses of radio and optical energy
