astronamy pt3 Flashcards
(34 cards)
geocentric model
the idea that the earth was at the center of the solar system
also earth was thought to be stationary because they couldn’t feel it move
heliocentric model
the idea that the sun was at the center of the universe
Nickolas Cupernicus
supported by astronomy
order of planets
mercury, Venus, Earth, mars, Jupiter, Saturn, Uranus, Neptune
Kuiper belt
disk shaped regions beyond Neptune commets asteroids lot a lot of ice bodies
Oort Cloud
cloud with ice bodies surround the sun
retrograde motion
apparent motion of a planet in a direction opposite that the other bodies in the system are going in
an illusion created by the look of the skies
all the other planets are going faster so it looks like it’s going backwards
if the motion is normal and not retrograde it is called prograde
AU
astronomical unit is the distance from the earth to the sun= 1 AU
To find another planets Au you just take their distance to the sun and divide it by 1 AU (149.6 million km)
light years
the distance light travels in a year
can measure other distances in space
parsec
3.26 light years
scientific notation
a way to write high numbers by writing a number between 1-9 then writing 10 exposent the times you want to times the number by 10
the HR diagram
a tool to show different relationships between stars
it measures luminosity and temperature
at different ages/stages at the same time
each star is a dot
y axis= luminosity
x axis= surface temp, right- lower temperature
used to show the elevation of stars and investigate their properties
main sequence star on the HR diagram
a star with a predictable relationship between brightness and temperature
would mean that if its hotter than its brighter
or cooler then its dimmer
throught the middle of the HR
giants
cool but very luminous
very large
has the same energy as the main sequance but are bigger
just above the main sequance the the right
super giants
very luminous more than giants
very large
top right corner
white dwarfs
very hot but dim so very small
bottom left corner or HR
star evolution
stars spend 90% of their lives in the main sequence burning helium and hydrogen
then then become giants or super giants when they finish burning hydrogen and begin burning just helium
white dwarfs is the last step for low intermediate mass stars
stellar spectra
the use of a spectroscope to look at the light energy of a star to determine it’s composition
can find out what elements are in it and what their temperatures are
spectroscope
split’s light energy into a pattern of colors (visible light) for observation
each element shows a recognizable pattern of lines
physical property
the big bang
approx 13.7 billion years ago there was a single atom (singularity)
and all matter and space created in an instant from the singularity
it keeps growing
energy converted into matter in clumps created protons neutrons electrons and atoms
the process of the big bang
atoms formed creating hydrogen and icetopes
the universe was 75% hydrogen and 25% helium (like now)
years later
stars and galaxies formed
our solar system was formed approx 4.6 billion years ago
misconceptions of the big bang
there was no explosion- only an expansion
there was nothing before the singularity
the singularity was not a burning flame
expansion started at time 0
how does Hubble’s law prove the big bang
he proved that the galaxies are always expanding and red shift
how does background radiation prove the big bang
people noticed that were was radiation static that was spread across space
believed to be left over from the big bang
hubble’s law
Hubble proved a expanding universe by noticing that other galaxies are red shifted proving that they are going away from us
he also noticed that the further away the galaxy the faster is is moving away
proving the expanding universe
