stars,galaxies,and the universe Flashcards
star
a large celestial body that is composed of guns and that emits light
Doppler effect
an observed change in the frequency or wave when the source or observer is moving
light year
the distance that light travels in a year.
parallax
an apparent shift in the position of an object when viewed from different
apparent magnitude
the brightness of a star as seen from the earth
absolute magnitude
the brightness that a star would have at a distance of 32.6 light years from year
main sequence
the location on the h-r diagram where most stars lie it has a diagonal pattern from the lower right to upper left
nebula
a large cloud of dust in interstellar space a region in space where stars are born
giant `
a very large and bright star whose hot core has used most of its hydrogen
white dwarf
a small hot dim star that is the left over center or an old star
nova
a star that suddenly becomes brighter
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 pulses of radio and tropical energy
black hole
an object so massive an dense that even light cant escape its gravity.
constellation
one of 88 regions into which the sky has been divided in order to describe the locations of celestial objects a group of stars recognized in a recognizable pattern
galaxy
a collection of darts dust and gas bound together by gravity
quasar
quasar-stellar radio source a very luminous object that produces energy at a high rate.
comsmology
the study of the origin properties process and evolution of the universe
big bang theory
the theory that all mater and energy in the universe was compressed into an extremely small volume that 13 to 15 billion years ago exploded and began expanding in all directions
cosmic background radiation
radiation uniformly detected from every direction in space considering a remnant of the big bang
