astronomy test 2 Flashcards
explain nuclear fusion
where L nuclei (deuterium and tritium) combine to make a heavier atom (helium)
what two elements make up a star
hydrogen and helium
what is the difference between stars that are plants and stars the are galaxies
planets - shine by reflected light, small, move
galaxies - shine by light they create, very large, stationary
what is the explosion called at the end of a stars life
supernova
what instrument is used to obtain characteristics about a star
telescope/spectroscope
give 2 reason why the sun is important
light, keeps earth in orb it (gravity )
warmth (maintains constant temperature range)
what protects the earth from charged particles released from the earth
magnetosphere
what part of the sun do these charged particles come from
solar flare
what is parsec used to mesure
distance between galaxies
what are ly used
distance within galaxies
when are AU used
within solar systems
what is an AU
AU = 150 000 000 km therefore the sun are earth are One AU apart
what is the name given to the study of the nature, origin and evolution of the universe
Big Bang theory
how do we know our galaxy is expanding
outer planets are “red shifted”
what are the three types of galaxies
elliptical - football shaped, old stars little gases
spiral - pinwheel shaped, young star, lots of gases
irregular - undefined shape, mix of old and new stars, gases
the brightness of a star as if it were located 33 ly from Earth
absolute
indicates a star’s surface temperature
colour
determines the length and magnitude stages of a star’s life cycle
mass
the total amount of energy produced by a star
luminosity
what does if mean if a star is red shifted
it is moving away
what is the difference between a meteor and a comet
meteor - rocket with dust
comet - icy with dust
meteor, meteorite and meteoroid
meteor - shooting stars
meteorite - rocky fragments the hit the earth
meteoroid - a small asteroid
where is the Kuiper belt found
outside the solar system
