flashcards
absolute magnitude
a brightness scale used to measure of how bright a star would be if it were seen from a standard distance
galaxy
a large collection of stars, dust, and gas bound together by gravity
apparent magnitude
the brightness of a star as seen from earth
HR diagram
hertzsprung russell diagram, a graph that shows the relationship between a star’s surface temperature and absolute magnitude
light year
the distance that light travels through space in one year
luminosity
the actuakl brightness of an object such as a star
main sequnce
the religion on the Hr diagram where stars spend most of their lives
nebula
a large cloud of dust and gas in interstellar space; a religion in space where stars are born
neutron star
the core of a supernova that has collapsed under gravity to the point that the electrons and protons have smashed together to form neutrons
planet
a relatively large spherical body that orbits a star
pulsar
a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation
revolution
the motion of a body that travels around another body in space; one trip along an orbit
rotation
the spin of a body in its axis
solar system
the collection of large and small bodies that orbit our central star, the sun
star
a large celestial body that is composted of gas and that emits light; the sun is a typical star
