Final - 1 Flashcards
What is the end point in the life of an upper main sequence star?
A) White Dwarf
B) Planetary Nebula
C) Supernova
D) Red Giant
Supernova
In terms of solar masses, what is the maximum possible mass for a neutron star?
A) 1
B) 2
C) 3
D) 1.4
3
What is the Schwarzschild radius of an object?
(A) The distance from an object at which the escape velocity is zero m/s
(B) The distance from an object at which the escape velocity is c m/s
(C) The distance from an object at which the escape velocity is infinity m/s ) 1 light year from a black hole
The distance from an object at which the escape velocity is c m/s
What is a pulsar?
A) A rotating neutron star
B) A rotating white dwarf
C) A rotating star
D) A rotating black hole
A rotating neutron star
Why do low mass stars not progress beyond having Carbon in their cores?
A) They are not hot enough
B) They are not bright enough
C) They are not massive enough
D) They do go beyond Carbon burning
They are not massive enough
If the density of matter in the Universe was less than a certain critical value, then:
A) the Universe would keep on expanding forever
B) the Universe would start to contract at some point
C) the Universe would explode
the Universe would keep on expanding forever
Whats a rough estimate for the age of the Universe?
A) 1 billion years
B) 5 billion years
C) 7 billion years
D) 12 billion years
12 billion years
What is the mass-to-light ratio for the Milky Way?
A) 1
B) 10
C) 100
D) 0.1
10
What is a good estimate for the diameter of the Milky Way Galaxy?
A) 1 light year
B) 1000 light years
C) 10,000 light years
D) 100,000 light years
100,000 light years
What type of stars are found in elliptical galaxies?
A) Pop I
B) Pop II
C) Pop I and Pop II
D) Pop I and Il and III
Pop II
Which of the following types of proto-galactic gas cloud is most favorable for forming a spiral galaxy?
A) High Angular Momentum and low density
B) High Angular Momentum and high density
C) Low Angular Momentum and high density
D) Low Angular momentum and low density
High Angular Momentum and low density
What is a good estimate of the metallicity of pop Il stars?
A) 0%
B) 2%
C) 0.2%
D) 10%
0.2%
What is the maximum possible mass for a white dwarf?
A) 1 solar mass
B) 1.4 solar masses
1.4 solar masses
What force separates out at the Planck time?
A) Gravity
B) Strong Force
C) Weak Nuclear
Gravity
What is the progenitor of a type 1 supernova?
A) Red Giant Star
B) White dwarf and red giant binary star
C) Neutron Star and red giant binary star
White dwarf and red giant binary star
Which of the following best describes what happens during the Sub-Giant phase?
A) Helium burning in the core
B) Helium burning in a shell around the core
C) Hydrogen burning a shell around the core
Hydrogen burning a shell around the core
Which stellar evolution stage occurs after the horizontal branch but before the Planetary Nebula stage for low mass stars?
A) Asymptotic Giant Branch
B) White Dwarf Stage
C) Red Giant Stage
Asymptotic Giant Branch
What is the altitude of your zenith?
A) 0 degrees
B) 30 degrees
C) 90 degrees
90 degrees
True/False - A mass varies according to your location in the Universe
False
What is retrograde motion?
A) planets rise in the east and set in the west
B) planets deviate from their usual motion around the eastward and move westward relative to the distant stars for a short while
B) planets deviate from their usual motion around the eastward and move westward relative to the distant stars for a short while
After a star leaves the main sequence, how long does it have left in its active life?
A) 1 billion years
B) 10 billion years
C) 1 million years
1 billion years
Which of the following does NOT occur in high mass stellar evolution?
A) Helium Flash
B) Expansion of the outer envelope
C) Contraction of the core
Helium Flash
Which of the following spectral types is the bluest?
A) M3
B) G2
C) G1
G1
A star’s radius is tripled and its temperature is doubled. What happens to its luminosity?
A) Stays the same
B) Goes up by a factor of 144
C) Goes up by a factor of 64
Goes up by a factor of 144
What is the acceleration due to gravity (g) on Earth? The units are m/s2.
A) 9.8
B) 10
C) 12.1
9.8
What happened at the surface of last scattering?
A) Helium atoms form
B) Protons, Electrons and Neutrons form
C) Hydrogen atoms form
Hydrogen atoms form
When did the CMB form?
A) t=0.001s
B) t=1000 years
C) t=300,000 - 500,000 years
t=300,000 - 500,000 years
What determines the curvature of spacetime?
A) temperature
B) location
C) mass
mass
Which of the following needs the highest temperature for the process of nuclear fusion to occur?
A) hydrogen
B) helium
C) carbon
Carbon
If a star’s temperature is doubled but it’s radius is kept constant, what happens to the luminosity?
A) stays the same
B) doubles
C) goes up by a factor of 16
goes up by a factor of 16
Which of the following is NOT a stage of upper main sequence evolution?
A) Red Giant Phase
B) Core Helium Burning
C) Helium Flash
Helium Flash
Which of the following is NOT a feature of lower main sequence stellar evolution?
A) Blue Loops
B) Sub-Giant Phase
c) Red-Giant Phase
Blue Loops
What is the most important thing determining what will happen to a star during its life?
A) Mass
B) Temperature
C) Composition
D) Luminosity
Mass
How does a 7 solar mass star end its life?
A) Black Hole
B) Neutron Star
C) Brown Dwarf
Neutron Star
Absolute magnitude is a measure of a stars…
A) Age
B) Temperature
C) Luminosity
Luminosity
Apparent magnitude is a measure of a star’s…
A) Temperature
B) Distance
C) Distance and Luminosity
Distance and Luminosity
What is the end point in the life of a 1 solar mass star?
A) White Dwarf
B) Black Hole
C) Neutron Star
White Dwarf
What is a worldline?
A) a path on the spacetime diagram
B) a path on the HR diagram
C) the way the luminosity of a star varies during its life
a path on the spacetime diagram
What is the end point in the life of a 3 solar mass star?
A) White Dwarf
B) Black Hole
C) Neutron Star
Neutron Star
Roughly how many minutes does it take light to reach the earth from the sun?
A) 60
B) 8
C) 1
8
What is the zero-point of latitude?
A) the Earth’s equator
B) the North Pole
C) the South Pole
the Earth’s equator
If an object starts from rest and the acceleration is g, what is the velocity of the object after 3 seconds?
A) g
B) 2g
C) 3g
3g
How many years does the Sun take to complete the Solar cycle?
A) 1 year
B) 5 years
C) 10 years
D) 11 years
11 years
Which of the following best expresses what happens if the Sun were to contract slightly:
A) It would keep on contracting
B) The temperature at the core increases which makes the nuclear fusion reactions produce energy at a faster rate which creates greater pressure to halt the contraction
C) The temperature at the core decreases which makes he nuclear fusion reactions produce enery at a slower rate which reduces pressure to halt the contraction
The temperature at the core increases which makes the nuclear fusion reactions produce energy at a faster rate which creates greater pressure to halt the contraction
If the distance doubles to a star, what happens to its luminosity and brightness?
A) both stay the same
B) brightness stays the same and luminosity decreases by a factor of 4
C) luminosity stays the same and brightness decreases by a factor of 4
luminosity stays the same and brightness decreases by a factor of 4
If I triple the distance to a star, what happens to the brightness?
A) stays the same
B) goes down by a factor of 9
C) goes down by a factor of 3
D) goes up by a factor of 9
goes down by a factor of 9
Which luminosity class is on the main sequence?
A) V
B) I
C) II
D) III
V
A star in the bottom right of the HR diagram is
A) hot and bright
B) cool and bright
C) cool and dim
D) hot and dim
cool and dim
What happens in the horizontal branch phase?
A) hydrogen shell burning
B) Helium core burning, maybe some hydrogen shell burning
C) carbon core burning
Helium core burning, maybe some hydrogen shell burning
What happens in the Planetary Nebula Stage?
A) Multiple shell burning
B) outer envelope of the star is blown off
C) carbon shell burning
B) outer envelope of the star is blown off
