Download Jeopardy Questions

Astro 110
Summer 2012
Exam Review Jeopardy 2
Note: These questions might cover similar topics to questions on the exam.
These questions are not the same as questions on the exam. It is important to
understand the topics covered in class in the slides as well as the lecture
tutorials. The exam is not based on rote learning.
The Milky Way:
$100
Q: What is an open cluster?
A: These types of star clusters are young because gravity is not strong enough
to hold them together over time
$200
Q: What is the period-luminosity relationship
A: An observed relationship between the period of a Cepheid Variable star’s
variability and its luminosity. This relation enabled accurate distances to stars in
the Milky Way to be measured for the first time
$300
Q: What is the effect of dust on measuring distances?
A: This problem causes Cepheid Variable star measurements to give larger
distances than their true distance.
$400
Q: What are Population II stars and where are they located?
A: Old stars that are distributed in the halo or bulge
$500
Q: What is the main sequence turnoff?
A: This point on the HR-diagram allows astronomers to measure the age of star
clusters.
Galaxies:
$100
Q: What is the Hubble Sequence?
A: The classification of galaxies into ellipticals, spirals, and barred spirals
$200
Q: What is the evidence for dark matter in galaxies?
A: The fact that the inner and outer stars in galaxies rotate at roughly the same
speed
$300
Q: What is the Doppler effect used for?
A: We can use this effect to measure the velocities of objects, including rotation
curves in galaxies and expansion of the universe.
$400
Q: What shape of galaxy is made by stars in random, circular orbits?
A: Elliptical galaxies are shaped this way because of these two properties of their
stellar orbits.
$500
Q: In what parts of a spiral galaxy would you expect to see more O and B stars,
and are they young or old?
A: Spiral arms have many more O and B stars because they are areas of active
star formation, and they are young because O/B stars only live for short amounts
of time.
The Universe:
$100
Q: What are Type Ia supernovae?
A: Massive explosions that occur when a white dwarf enough material to
overcome the Chandrasekhar limit and collapse. They are the best distance
indicators for measuring the size of the universe.
$200
Q: What is Hubble’s Law?
A: The relationship between recessional velocity and distance for galaxies
$300
Q: What is the best evidence that supports the Big Bang theory?
A: Cosmic Microwave Background
$400
Q: How far away is a star that has a parallax angle of 10 arcseconds?
A: 0.1 parsecs
$500
Q: Name 3 pieces of evidence for dark matter
A: X-ray observations of hot gas in galaxy clusters, gravitational lensing from
galaxy clusters, flat rotation curves of spiral galaxies
Stellar Evolution:
$100
Q: What is the main sequence?
A: An area of the H-R diagram that stars sit on while they are fusing Hydrogen
into Helium in their cores.
$200
Q: How do black holes and neutron stars form?
A: When a massive star has iron at its core, and can no longer fuse atoms to
create energy, gravitational forces take over and the core collapses into either a
neutron star or a black hole, depending on if its mass can be supported by
neutron degeneracy pressure.
$300
Q: What is electron degeneracy pressure?
A: This pressure is produced when electrons are squeezed into a small space
and the electrons travel at almost the speed of light.
$400
Q: List the main phases of a star’s life if it has a mass of 4 solar masses.
A: Main Sequence, Red Giant, Planetary Nebula, White Dwarf
$500
Q: What is the difference between a nova, a core-collapse supernova, and a
Type Ia supernova?
A: Nova – Material falls on WD, fuses in small burst of energy. Type Ia
Supernova – Material falls on WD, builds up until Chandrasekhar limit, and then
everything explodes. Core-collapse Supernova – Massive star goes through
shell burning until iron, can’t support its own weight, and collapses, leaving
behind a neutron star or black hole.
Properties of Stars:
$100
Q: What is the one property of a star that determines where it lies on the main
sequence?
A: Mass
$200
Q: What is the pressure balance in a main-sequence star called?
A: Hydrostatic Equilibrium
$300
Q: What is shell burning?
A: A phase of a massive stars life where it goes through progressive steps of
fusing heavier and heavier elements at its core, while fusing lighter elements in a
shell, sort of like an onion.
$400
Q: Compare the properties of a low mass star to a high mass star in terms of
temperature, color, radius, luminosity, and lifetime.
A: Low mass stars are redder, colder, smaller, less luminous, and live longer
lives.
$500
Q: What is the main property of a star that determines it is spectral type, and
name them in order.
A: Temperature, OBAFGKM
Final Jeopardy:
Q: What are the three benefits of using telescopes to observe the night sky?
A: Larger collecting area, better angular resolution, ability to probe wavelengths
other than visible.