Universe Flashcards
a brightness scale used to measure how bright a star would be if it were seen from a standard distance.
absolute magnitude
the brightness of a star 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 about 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 the star 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 under the gravity to the point that the electrons and protons have smashed together to form neutrons
Neutron star
a relatively large spherical body that orbits a star.
planet
A highly 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 its 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 its core remains
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-mass star.
white dwarf
A galaxy shaped like a pinwheel, with a bulge in the center and spiral arms extending outwards.
Spiral galaxy
A sphere or elongated galaxy with a bright center and very little gas and dust
elliptical galaxy
a galaxy with a weird shape that doesn’t fit into any other category.
irregular galaxy
all the different wavelengths and frequencies of electromagnetic radiation, from radio waves to gamma rays.
electromagnetic spectrum
The theory that the matter and energy of the universe was comprised into a small volume and then exploding and made the universe.
big bang theory
CMB; the electromagnetic radiation left over from the formation of the universe.
cosmic microwave background
a phenomenon which occurs when a star or galaxy is moving away from the earth.
red shift
an observed change in frequency or wavelength when the source is moving with respect to the observer.
doppler effect
a tool used to collect light from stars and separate the colors in the light.
spectroscope
