Astr 123 university of oregon
1 Watt is how many Joules per second?
1
This unit is the mean distance between the sun and the earth
1 AU or astronomical unit
this unit is the equivalent of 3.23 light years (ly)
1 parsec
2 new problems that occurred with the discovery of speeds distant galaxies appeared to be moving at
1. H (plank's constant) was not a constant at larger distances and 2. at larger distances Z>1 which means that these galaxies were moving faster than the speed of light, which shouldn't happen
color/light spectrum can be used mainly for two purposes, these are?
1. Identifying unknown atoms and 2. measure the doppler shift in different galaxies
What is the solar constant?
1370 W/m^2
How large is the supermassive blackhole at the center of our galaxy?
17 solar radius (17 times the size of our sun)
What is the configuration of the Helium nucleus?
2p+2n
How long will it take for the Milky Way and Andromeda to begin colliding?
3 billion years
What are the inputs and outputs of the proton proton chain?
4 hydrogen (protons) -> He + 2 positrons (e+) + 2 gamma rays + 2 neutrinos + energy
How long will it take for the sun to run out of hydrogen for pp chain reactions?
5.4 billion years
How long will it take for Andromeda and the Milky Way to form a spiracle galaxy after the collision of the galaxies begins?
7 billion years from now, or 4 billion after the start of the collision
How much landed is owned by the UO observatory for the Pine Observatory
9 Acres
About what percent of atoms in a star are hydrogen, and about what percent of mass does it take up in the star?
92% of atoms and 73% of mass
Objects orbiting around the center of the milky way obey Kepler's 3rd law. This means that?
A star that is further from the center will take more time to orbit
About how much fainter than what the eye can see can be spotted by the Robbins?
A supernova was found that is 10,000 times fainter, but newer things have been found that are 1,000,000 times fainter
How many stars are in the Andromeda galaxy?
About 1 trillion stars
Astronomers now think that there is a blackhole with more than 4 million times the mass of our sun at the center of our galaxy. Roughly how large would the event horizon of such a super massive blackhole be?
About 17 times the size of our sun
Why is hydrogen the most common element in stars?
Because it is the simplest element that has been around since the early universe
Why do supernova 1A produce about the same amount of luminosity every time
Because the amount of mass consumed is very precise
Why don't all the stars and planets collide when two galaxies merge?
Because the stars and planets are so far away from each other, they are like grapefruit in NYC meaning they can pass through with little interaction
Why are Cepheid stars good for determining distance of far away galaxies
Because their luminosity varies heavily over 4 days in the exact same pattern every time. Measuring this can give us the true luminosity and not just observed luminosity, which combined allows us to solve for distance
each atom releases different levels of energy, when electrons are dropped from higher energy levels to lower energy levels. This leads to different wavelengths being emitted. The name of the different energy/wavelengths emitted by each atom as their electrons change levels is?
Color/light spectrum
How were different atoms created?
Different actions around our universe, like supernovas, deaths of stars, the big bang, etc.
objects coming towards us and moving away from us seem to give off different wave lengths for the same distance depending on direction, this is known as?
Doppler effect
Why is the pine mountain observatory in pine mountain rather than Eugene?
Eugene is too rainy and cloudy
What is impressive about the Robbins?
Has a 14 inch mirror, and if given its location and the time it will know exactly what stars are in the sky
positron has what relationship to an electron?
It is the anti matter sibling
How do astronomers learn what elements are present in a given star?
Look at the absorption lines in its spectrum
Can we tell how big stars are from looking at them?
No
solar energy is ______ energy
Nuclear
Why don't we notice red or blue doppler shifts in every day life
Objects in everyday life do not move fast enough for us to notice these shifts, however they do in space
What is the specific process for hydrogen nuclear fusion called in our sun?
Proton proton chain or PP chain
What model is used to depict the phenomena of the universe growing and thus causing distances to become greater between galaxies
Raisins in rising bread
All distant galaxies appear to be moving away from us at a high speed, because of this they are?
Redshifted, meaning the wavelengths appear longer. Also known as Z
The very strong source of radio waves at the center of our galaxy is?
Sagittarius A
Our milky way is what type of galaxy
Spiral
Supernova 1A are known as _________ because they always produce about the same amount of luminosity
Standard candle
How was the discovery of a supermassive blackhole in the middle of the Milky Way made?
Stars were found orbiting an invisible object, using Kepler/Newtons equation ((4pi^2)/GM)a^3=T^2 they were able to find a supermassive object in an area smaller than mercury's orbit
What is located at the center of the Milky Way?
Supernova remnants (SNR) and Sagittarius A a supermassive blackhole that emits large radio waves
Which of the following objects is considered useful to astronomers as a "standard bulb" for determining distances?
Supernova type 1A
How are elliptical galaxies formed?
Tend to form from two spiracle galaxies colliding
What is the only galaxy we can see with unaided eyes besides the Milky Way?
The Andromeda galaxy
What is the name of the newest telescope at Pine Mountain?
The Robbins
What is the baseline that astronomers use to measure the parallax (the distance) of the nearest stars
The diameter of the earth's orbit around the sun
Supernova 1A or standard candles are used to determine what?
The distance of far away galaxies as we can use luminosity to determine distance
The fact that each type of atom has a unique pattern of electrons orbits helps explain why?
The fact that each type of atom shows a different absorption or emission spectrum
What was the answer to the problems
The galaxies themselves are not moving at these speeds, but are being pulled as the universe itself is expanding. Meaning V<C in its local space
Where does nuclear fusion occur?
The sun's core
When two spiracle galaxies collide what happens to their blackholes?
The two supermassive blackholes merge to form an even more supermassive blackhole
What happens when positrons and electrons collide in plasma?
They annhilate and release large amounts of energy
How do hydrogen atoms lose their electrons for the nuclear fusion process
They are heated at extreme temperatures which strips them of their electron (10 million degrees K)
True or false? Collisions and mergers between galaxies can sometimes change a galaxies type (shape)
True
Hubble's law
V=Hd, V=velocity, H=planks constant (which is the slope) and d is equal to distance
Our sun is considered to be a _____ star, which we use to make observations about other stars
Vanilla
Does this fit with Einstein's model?
Yes, the model does not preclude this and in fact it predicts it
How many stars do globular clusters have on average?
about 100,000 stars
How old are the stars in globular clusters on average?
about 11 billion years old
How far is Andromeda from the Milky Way galaxy?
about 3 Million Light Years
How many stars are in the Milky Way?
about 500 billion stars
What type of students can get involved at the Pine Mountain Observatory?
any UO students
What types of waves are affect by the Doppler effect?
any type of wave
Why does the pp chain release so much energy?
because E=mc^2 tells us small changes in mass leads to large energy releases and the mass of 4 hydrogen atoms is more than the products, on top of this there are many reactions that occur per second in sun leading to a lot of energy being released
If a galaxy would be moving towards us at a large speed it would appear
blueshifted, meaning the wavelengths appear shorter
This formula for any shift in wavelength is how you calculate the doppler effect
change in wavelength / wavelength = v/c
Pine mountain 30 miles east of Bend, in central Oregon what type of biome is this in?
desert
What is the other type of galaxy we talked about that is not elliptical or spiracle?
dwarf galaxies
What shape do orbits in space take?
ellipses, circle like shapes
Which type of galaxy contains the oldest stars?
elliptical galaxies
Which type of galaxy is observed to contain most of the older stars?
elliptical galaxies
Edwin Hubble was able to show that (with the exception of our nearest neighbors) that the further the galaxy is from us, the?
faster it is moving away from us
what does this symbol stand for?
gamma ray
What state is the sun's core in?
gaseous state
Groups of primitive stars are called?
globular clusters
What is the second most common atom in a star?
helium
What is the main ingredient in a normal star?
hydrogen
What do dwarf galaxies look like?
large magellic clouds in the sky
what does this symbol stand for?
neutrino
solar energy comes from this process
nuclear fusion
what prevents the core from collapsing on itself due to gravity?
nuclear processes, specifically nuclear fusion
What is the structure of an atom?
nucleus (neutrons + protons) + electrons
The relationship between luminosity and distance
observed brightness=L/d^2
The displacement or difference in apparent placement of an object being viewed from two different lines of sight
parallax
What color is a tracer for hydrogen?
pink
What is the gas of separated protons and electrons called?
plasma
if e- is an electron, what is a e+ particle called?
positron
When a star or galaxy is moving away from us, we observe the doppler effect by seeing the lines in its spectrum are?
redshifted
What does E=mc^2 tell us about energy?
small differences in mass can have massive energy releases
Are spiral galaxies bigger or smaller than elliptical galaxies in terms of diameter on average?
smaller
compared to the mass of our milky way galaxy, the total mass we estimate for the Andromeda galaxy is?
somewhat bigger than our galaxy
What are the two most common types of galaxies?
spiracle and elliptical
What type of galaxy is both Andromeda and the Milky Way?
spiral galaxies
Which type of galaxy contains a lot of dust and gas?
spiral galaxies
What force holds the nucleus together?
strong/nuclear force
why does nuclear fusion occur in the core?
the core is very dense (150 g/cm^3, overall solar density 1.4 g/cm^3)
Where does most of the mass in the atom come from?
the nucleus
the apparent brightness of stars in general tells us nothing about their distances; we cannot assume that the dimmer stars are further away. In order for apparent brightness of a star to be a good indicator, all stars would have to be?
the same luminosity
What are atoms natural charge?
they have no natural charge, they are neutrally charged as they have the same amount of protons and electrons
True or false, are atoms mostly empty space?
true, the nucleus of an atom is very small, the rest of area is space that an electron could potentially be in
Before you can use Hubble's law to get the distance to a galaxy what observation must you make of that galaxy?
you must make a spectrum of a galaxy and measure the red shift
