Astronomy 102 Final Exam Study Guide
| 100% Correct Answers | Verified |
Latest 2024 Version
Which layer of the sun does nuclear fusion take place? - ✔✔Core
Which layer of the sun is between the photosphere and the radiation zone? - ✔✔Convection zone
What two forces in the sun balance to determine the physical size of the sun? - ✔✔Gravity and Radiation
pressure
How does the density of the sun change as the distance from the center of the sun increases? -
✔✔decreases
How does the temperature of the sun change as the distance from the center of the sun increases? -
✔✔decreases
How does energy transfer through the convection zone of the sun? - ✔✔Hotter material rises to the
surface while cooler material sinks towards the center to get reheated
Convection on the surface of the sun makes the surface to appear... - ✔✔granulated
As distance is increased from the surface to the sun what is the order of the layers of atmosphere? -
✔✔Photosphere, chromosphere, transition zone, corona
What is not a characteristic of sun spots? - ✔✔They are always prominent on the surface of the sun
The magnetic field lines of the sun are always constant? T/F - ✔✔False
What causes the magnetic field lines of the sun to distort? - ✔✔Differential rotation of the surface of the
sun
,How often do sun spots peak in their natural cycle? - ✔✔11 years
How often does the magnetic poles of the sun flip? - ✔✔11 years
During a nuclear fusion reaction a small amount of mass seems to disappear. What happens? - ✔✔Mass
is converted into energy
What fundamental force has to be overcome in order for 2 protons to fuse together? -
✔✔Electromagnetism
Once the nucleus is formed in an atom what force holds the nucleus together? - ✔✔Strong nuclear force
In the sun there are a few different fusion reactions that happen in succession. In the first two protons
fuse together. What is the outcome? - ✔✔a) a neutrino is ejected
b) H^2 (Deuteron) is produced
c) A positron is ejected
**d) All of the above
What immediately follows the creation of the positron? - ✔✔It reacts with an electron with both
electron and positron being annihilated and energy is produced
The resulting h^2 (Deuteron) from the first nuclear reaction eventually does what? - ✔✔Fuses with
another proton to form Helium-3
In the last nuclear reaction in the chain of events that goes on in the sun two helium-3 nuclei fuse to
form helium-4. The original two helium-3 nuclei have 4 protons total. The final helium-4 nucleus has 2
protons total. What happens to the other 2 protons? - ✔✔The 2 protons are ejected
When measuring the distance to a star, what limits our ability when using the stellar parallax method? -
✔✔Parallax decreases as distance increases
, When measuring the relative speed of a star we measure the radial velocity by observing what? -
✔✔The Doppler Shift of the star
When measuring the transverse velocity of a star we measure what? - ✔✔The motion of the star across
the sky
Which star would appear brighter? - ✔✔Alpha Centauri
Why does the apparent brightness of a star diminish with the distance squared? - ✔✔Light spreads out
both vertically and horizontally
By measuring the intensity of two distinct colors of light from a star one can extrapolate what? - ✔✔the
black body curve of the star
How can we easily determine the surface temp of a star? - ✔✔From the peak color of the black body
curve
As long as a star is close enough we can measure its distance via stellar parallax. Once this distance is
known we can determine what other property by observing the stars apparent brightness? -
✔✔Luminosity
If luminosity versus surface temp is plotted for a set of stars then what do we call this plot? - ✔✔HR
Diagram
If luminosity vs surface temp is plotted for a set of stars then what correlation do 90% of the stars have?
- ✔✔Main sequence
The size or radius of a star can be determined by observing what two properties of the star? -
✔✔Luminosity and temp
By knowing how luminosity and surface temp correlate on a HR Diagrams what can we determine about
a star - ✔✔its distance
| 100% Correct Answers | Verified |
Latest 2024 Version
Which layer of the sun does nuclear fusion take place? - ✔✔Core
Which layer of the sun is between the photosphere and the radiation zone? - ✔✔Convection zone
What two forces in the sun balance to determine the physical size of the sun? - ✔✔Gravity and Radiation
pressure
How does the density of the sun change as the distance from the center of the sun increases? -
✔✔decreases
How does the temperature of the sun change as the distance from the center of the sun increases? -
✔✔decreases
How does energy transfer through the convection zone of the sun? - ✔✔Hotter material rises to the
surface while cooler material sinks towards the center to get reheated
Convection on the surface of the sun makes the surface to appear... - ✔✔granulated
As distance is increased from the surface to the sun what is the order of the layers of atmosphere? -
✔✔Photosphere, chromosphere, transition zone, corona
What is not a characteristic of sun spots? - ✔✔They are always prominent on the surface of the sun
The magnetic field lines of the sun are always constant? T/F - ✔✔False
What causes the magnetic field lines of the sun to distort? - ✔✔Differential rotation of the surface of the
sun
,How often do sun spots peak in their natural cycle? - ✔✔11 years
How often does the magnetic poles of the sun flip? - ✔✔11 years
During a nuclear fusion reaction a small amount of mass seems to disappear. What happens? - ✔✔Mass
is converted into energy
What fundamental force has to be overcome in order for 2 protons to fuse together? -
✔✔Electromagnetism
Once the nucleus is formed in an atom what force holds the nucleus together? - ✔✔Strong nuclear force
In the sun there are a few different fusion reactions that happen in succession. In the first two protons
fuse together. What is the outcome? - ✔✔a) a neutrino is ejected
b) H^2 (Deuteron) is produced
c) A positron is ejected
**d) All of the above
What immediately follows the creation of the positron? - ✔✔It reacts with an electron with both
electron and positron being annihilated and energy is produced
The resulting h^2 (Deuteron) from the first nuclear reaction eventually does what? - ✔✔Fuses with
another proton to form Helium-3
In the last nuclear reaction in the chain of events that goes on in the sun two helium-3 nuclei fuse to
form helium-4. The original two helium-3 nuclei have 4 protons total. The final helium-4 nucleus has 2
protons total. What happens to the other 2 protons? - ✔✔The 2 protons are ejected
When measuring the distance to a star, what limits our ability when using the stellar parallax method? -
✔✔Parallax decreases as distance increases
, When measuring the relative speed of a star we measure the radial velocity by observing what? -
✔✔The Doppler Shift of the star
When measuring the transverse velocity of a star we measure what? - ✔✔The motion of the star across
the sky
Which star would appear brighter? - ✔✔Alpha Centauri
Why does the apparent brightness of a star diminish with the distance squared? - ✔✔Light spreads out
both vertically and horizontally
By measuring the intensity of two distinct colors of light from a star one can extrapolate what? - ✔✔the
black body curve of the star
How can we easily determine the surface temp of a star? - ✔✔From the peak color of the black body
curve
As long as a star is close enough we can measure its distance via stellar parallax. Once this distance is
known we can determine what other property by observing the stars apparent brightness? -
✔✔Luminosity
If luminosity versus surface temp is plotted for a set of stars then what do we call this plot? - ✔✔HR
Diagram
If luminosity vs surface temp is plotted for a set of stars then what correlation do 90% of the stars have?
- ✔✔Main sequence
The size or radius of a star can be determined by observing what two properties of the star? -
✔✔Luminosity and temp
By knowing how luminosity and surface temp correlate on a HR Diagrams what can we determine about
a star - ✔✔its distance
