Astronomy Flashcards
Galaxy
Is a collection, of stars gas, dust and planets
Our galaxy
Barred spiral, Milky Way centre is a black hole 100,000 light years, 46 billion stars,
Star clusters
Groups of stars, fairly close with gravitational pull between them, too small to be a galaxy
Constellations
Groups of stars that are related bc/ of the view from earth, can change over thousands of years
Scientific notation
Nx10^x, decimals move over the number
light
particle called a photon that travels as a wave, wavelegnth is the measurement from crest to crest
visible light spectrum
380nanometers to 750 nm
radiation
energy that spreads out as it moves
electromagnetic spectrum
all types of em radiation
absorption spectrum
specturm em radiation through a substance, made when atoms absorb energy, dark lines or gaps
emission spectrum
spectrum of em radiation emitted, made when atoms emit energy, shows coloured lines on a black background
lightyear
how far light can travel in a year
birth of stars
nebula-cloud gas dust, mostly H & He when it reaches a certain density gravity pulls the gas to gether creating a lump in the nebula called a protostar. when gravity and temp create nuclear fusion gravity pushes in heat pushes out, stabilizing.
nuclear fusion
when two hydrogen hit eachother making helium, causing a release of energy
the mass of the star determines
the colour, the lifespan, the brightness, size
Hertzberg russel diagram shows..
evolution of stars. main sequence is 90% of stars diagonal, goes from the top right to bottom left, hot and bright cool and dim
medium sized star life cycle
stellar nursery, planetary nebula, red giant most of the H is He so core contracts pushes out and cools down , white dwarf outer layer cools, black dwarf (cooled down)
massive life cycle
burn faster, red supergiants, supernovas, neutron stars iron core spinning around radiwaves
supernova
converts hydrogen to helium, until it becomes iron then it stops, gravity pulls in tries to implode iron stops, creates big explosion
supermassive star life cycle
red supergiant, super nova, black hole
black hole
what’s left behind after the supernova, so much gravity doesn’t let light escape surrounded by radiation emitting celestial objects
what is spaghettification
after you pass the event horizon When falling towards a black hole, for example, an object is stretched in the direction of the black hole
HR diagram
white dwarfs-cool dim
giants-cool mid luminosity
super giants-cool and bright
big bang theory (doppler effect)
when something is moving away from us the wavelegnths legnthen making them shift to the red side of the spectrum. This shows that the planets and stars are moving away showing that the universe is still expanding
what is the big bang
the whole universe was in a hot dense state, then nearly fourteen billion years ago expansion, after expansion known as time zero
Big bang (cosmic background radiation)
the big bang released lots of energy and the universe is still glowing from this extra energy, radiotelescopes show us this
Converting units to and from km
to unit (ly or AU) /
from unit (ly or AU) x
Planets
Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus, Neptune
Planet requirements
orbit a star, enough gravity to become a sphere, cleared objects from orbit
Terrestrial planets
rocky surface, smaller, closely spaced, close to sun. Mercury, Venus earth and mars
gas planets
gasses (H & He), larger, further apart, further from the sun, Jupiter saturn uranus and neptune
why is pluto a dwarf planet
it does not have a clear neighbourhood around the orbit
Sun age
5 billion, 5 billion years left
sun distance from the earth
1 AU, 1.5*10^8
Sun composition
73% hydrogen, 25% helium, 2% other
sun gravity
huge mass creates gravity pull so strong keeps planets in orbit
sun size
14,000,000 km diameter, 1 million earths can fit inside
sun energy generation
gravity pulls mass together creates heat & termperature, hydrogen atoms move violently and fuse creating helium atoms create energy
Solar flares
erupt sending streams of high energy subatomic particles into space
prominences
streams fo glowing gas arch into space and return to the sun
solar wind
stream of charged particles into space, northern lights
magnetosphere
earths magnetic field protects us from the deadly particles of the solar winds,
layers of the sun
core, radiation zone, convection zone,
Atmosphere: photosphere, cronosphere, corona
core
center of the sun
radiation zone
energy transferred by EM radiation
convection zone
outermost area of the sun’s interior
photosphere
gives off the most light
cronosphere
reddish tint
corona
halo around during solar eclipse
