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WorksheetsAstro 150 S 2024 Final Review 2/2 May 3, 2024
Total questions: 20
Worksheet time: 12mins
What happens immediately after a solar-mass main sequence star stops burning hydrogen fuel in its core?
Helium fuses in the core
Helium flash
Hydrogen fuses in shells around the core
The core compresses
Supernova explosions will result in... (multiple correct answers)
White dwarfs
Neutron stars
Black holes
Complete destruction of the star
Which of these is NOT a way we can detect black holes?
Direct imaging
Radiation from accretion disks
Iron K α spectral line
Watching objects disappear into them
From the point of view of an astronaut falling into a black hole, how is time passing for things far away from the black hole?
Time is flowing the same
Time is speeding up
Time is slowing down
It depends on the black hole mass
What makes the 21 cm line?
A certain hydrogen spectral line
A certain helium spectral line
Hydrogen electrons flipping spin
Helium electrons flipping spin
Why does the Milky Way's rotation curve look like this?
The stars orbit according to Kepler's laws
There is a lot of dark matter in our Galaxy
Gravitational interactions between stars speed up orbits
This actually ISN'T the rotation curve we observe
What type of galaxy is the Milky Way?
An elliptical
A spiral
A barred spiral
An irregular
Where do giant elliptical galaxies come from?
Spiral galaxies using up all their material
They form from enormous gas clouds
Ordinary ellipticals stripping matter from passing galaxies
Spiral galaxies merging together
Why do galaxies collide, but stars don't?
Gravitational interaction swings stars away from each other
There is a lot of space between the stars compared to their size
Most stars get flung away from each other during galactic collisions
They do, they just become black holes and disappear on collision
What differentiates the different types of AGN?
Their inclination toward us
Their distance away from us
Their age
Their mass
If we measure an object's brightness, what quantity must we determine to figure out the object's distance?
Luminosity
Mass
Temperature
Radius
True or False: Since our Universe is expanding, every galaxy is moving away from us.
True
False
Why are standard candles so important in astronomy?
They are all at the same distance from us.
They have the same luminosity.
They have the same brightness.
They are used as tools to measure their intrinsic luminosity.
If Galaxy #1 is twice as far away from us as Galaxy #2, how much faster or slower is Galaxy #1 moving away from us compared with Galaxy #2?
2 times slower
4 times slower
2 times faster
4 times faster.
If the Hubble constant is 70km/s/Mpc, what is the radial velocity of a galaxy at a distance of 100 Mpc away from us?
7 km/s
70 km/s
700 km/s
7,000 km/s
Cosmic Microwave Background (CMB) is the microwave blackbody radiation at T ~ 3 K. What is the true about the CMB at the actual time of the event?
The radiation was cooler than the current one.
The radiation was still in the microwave part of the EM spectrum.
The radiation was hotter and at the shorter wavelength than the current one.
It was completely identical as now.
True or False: We can see the Universe before the CMB using electromagnetic wave
True
False
Rank the composition of the universe in order from the least to the most abundant (ordinary matter refers to gas and stars that emit light).
dark energy, dark matter, ordinary matter
dark mater, dark energy, ordinary matter
ordinary matter, dark matter, dark energy
ordinary matter = dark matter = dark energy
We have detected ~ 5,600 exoplanets so far. What is the most common type of planet in the galaxy and what is special about our own Solar System?
Planets between Earth and Neptune size are most common, but our solar system doesn't have such planets.
Jupiter-sized planets are most common, and our Solar system is nothing special because we have Jupiter.
Planets between Earth and Neptune size are most common, and our solar system has those planets, too.
Earth-sized planets are most common, and our Solar system is special because we have just one Earth.
True or False: Only the sun-like stars have a habitable zone
True
False
