Final - 2 Flashcards
Which is of the following is NOT a property of terrestrial planets:
A) they are small
B) they are close to the sun
C) they have few moons
D) they are gaseous
they are gaseous
What is the largest mass a white dwarf can have?
A) 100M
B) 2M
C) 1.4M
D) 0.08M
1.4M
The luminosity classes of stars A,B,C,D are I, II, III, V , respectively. Which star lies on the main sequence?
D (V)
What does the Butterfly Diagram show:
A) the magnetic field strength of the sun over time
B) suns rotation over time
C) number of sunspots on the face of the sun over time
D) location of the sunspots on the face of the sun over time
location of the sunspots on the face of the sun over time
Which of the following white dwarfs has the smallest radius?
A) 1 solar mass
B) 0.8 solar mass
C) 1.3 solar mass
1.3 solar mass
At what lunar phase do Neap tides occur?
A) New
B) Half
C) Full
Half
Two stars have the same spectral type but different radii. This means:
A) they have the same composition
B) they have different temperatures
C) they have different luminosities
D) the have different colors
they have different luminosities
What’s the luminosity of a star?
A) total energy output per square meter
B) total energy output per sq. meter per unit time
C) total energy
D) total energy output/unit time
total energy output/unit time
During a stars time on the main sequence, which of the following comments is true?
A) stars core is slowly being turned into helium
B) stars core is slowly being turned into hydrogen
C) stars core stays the same
stars core is slowly being turned into helium
What is the lower mass limit for stars on the main sequence?
A) 1M
B) 0.5M
C) 0.2M
D) 0.08M
0.08M
In hydrostatic equilibrium what two forces are matched?
A) Gravity and Electromagnetism
B) Friction and Pressure
C) Gravity and Nuclear Force
D) Gravity and Pressure
Gravity and Pressure
What is a solar cycle?
A) the life history of the sun
B) life history of solar sunspot
c) the rotation of the sun
life history of solar sunspot
What is a good estimate for the temperature of the solar photosphere?
A) 5800K
B) 1000K
C) 10 million K
D) 0K
5800K
What happens in the proton-proton chain?
A) Helium breaks down to form hydrogen
B) 2 hydrogen atoms combine to form a helium atom
C) 4 hydrogen atoms combine to form a helium atom and energy
D) large atoms are broken down into smaller atoms releasing energy
4 hydrogen atoms combine to form a helium atom and energy
What was the dominant constituent of the Solar Nebula out of which the solar system was formed?
A) Rocks
B) Hydrogen and hydrogen compounds
C) Helium and helium compounds
D) Iron
Hydrogen and hydrogen compounds
Sunspots are usually…
A) much cooler than their surroundings
B) much hotter than their surroundings
C) same temperature as their surrounding
D) have a varying temperature
A) much cooler than their surroundings
Which of the following is true for stars in a globular cluster?
A) all at the same distance
B) all have the same temperature
C) all have the same mass
D) all at the same distance and have the same age
all at the same distance and have the same age
A star is moved to be three times as far away. What happens to the brightness and luminosity?
A) both stay the same
B) both decrease by factor of 3
C) luminosity stays the same, brightness decreases by a factor of 9
luminosity stays the same, brightness decreases by a factor of 9
A stars radius is doubled and its temperature is doubled. What happens to its luminosity?
A) stays the same
B) increases by a factor of 4
C) increases by a factor of 64
increases by a factor of 64
What force became distinct at time of 10^-34s?
A) Gravity
B) Strong Nuclear
C) Electromagnetic
Strong Nuclear
Why must a high mass star be hot at the center?
A) higher temps create higher pressure to combat lower gravity
B) high mass stars can have low temps at the core
C) higher temps create higher pressures to combat higher gravity
C) higher temps create higher pressures to combat higher gravity
Which of the following is NOT true for upper main sequence stars?
A) burn hydrogen to helium via CNO cycle
B) radiative cores and convective envelopes
C) have higher masses
radiative cores and convective envelopes
The time the sun spends on the main sequence is 10 billion years. How much time does a star with 10 times the solar mass and 50 times the solar luminosity spend on the main sequence?
A) same time
B) 5 billion years
C) 2 billion year
2 billion year
What is the minimum mass a star can have?
A) 0.001 solar masses
B) 0.08 solar masses
C) 0.1 solar masses
0.08 solar masses
How do low mass stars end their life?
A) Red Giants
B) White Dwarfs
C) Black Hole
White Dwarfs
What is happening in the sub-giant phase?
A) hydrogen shell burning starts
B) helium core burning starts
C) carbon core burning starts
hydrogen shell burning starts
What shape are planetary orbits?
A) circles
B) ellipses
C) spirals
ellipses
What is the eccentricity of a circle?
A) 10
B) 1
C) infinity
D) 0
0
With Hubble’s law, if I triple the distance of the galaxy, what happens to its recession velocity?
A) stays the same
B) doubles
C) triples
triples
What spectral type and luminosity class is the sun?
A) A1 I
B) B6 III
C) G2 V
G2 V
A star has a parallax of 0.001 seconds of arc. How far away is it?
A) 1000 parsecs
B) 1000 AU
C) 1000 light years
1000 parsecs
Which of the following stars, given their spectral types is the reddest
A) 01
B) G2
C) M3
D) B5
C) M3
What is a circumpolar star?
A) stays close to the north pole star
B) always stays above the horizon
C) always stays at the same latitude
always stays above the horizon
If I double the mass of earth and double its radius, what happens to its escape velocity?
A) stays the same
B) goes up by a factor of 4
C) goes up by a factor of 2
stays the same
When the moon appears to completely cover the sun (solar eclipse), the moon must be at which phase?
A) New
B) Full
C) First Quarter
New
Which of the following is an absolute quantity?
A) luminosity of the sun
B) speed of light
C) laws of physics
D) both speed of light and laws of physics
both speed of light and laws of physics
What is a rough estimate for the gravitational mass of the Milky Way?
A) a billion solar masses
B) 10^10 solar masses
C) 10^11 solar masses
10^11 solar masses
If the Earth’s orbit around the Sun were changed to be a perfect circle about the Sun so that the Earth’s distance to the Sun never changed, but its tilt was the same, how would this affect seasons on Earth?
A) There would be no seasons
B) Difference between seasons much more noticeable
C) Experience seasons in the same way we do now
C) Experience seasons in the same way we do now
When did the big bang occur?
A) 12 billion years ago
B) 13.8 billion years ago
C) 12 million years ago
13.8 billion years ago
Jim and John are twins. Jim stays on Earth and John goes away on a spaceship flying at 0.5c. When John returns, 10 years have passed by for Jim. How much time has passed by for John?
A) 4.33 years
B) 8.66 years
C) 10 years
8.66 years
Put the following stellar spectral types in temperature order starting with the hottest: I: M2, II: B7 Ill: 03
IV: 05
A) III, IV, II, I
B) IV, III, I, II
C) I, II, IV, III
A) III, IV, II, I
Put the following stars (III,Ill<IV) apparent magnitude in order of how bright they appear in the sky starting with the faintest: I: 0, II:3, III:2, IV:-1
A) III,II,I,IV
B) II, III, I, IV
C) I, II, III, IV
B) II, III, I, IV
