Onondaga Community College
SCI 103 Introductory Astronomy
12/13/04
Comprehensive Portion of the Final Exam in Introductory Astronomy
Name____________________________________
99 Points
Total
Instructor____Jaquin________________________
Class Meeting Time: MWF at 9:00
MWF at 12:30
TTH at 11:00
Records all answers, except the essay questions, on these papers by circling the correct
response or responses, drawing the appropriate lines, or filling in the blanks. The essay
questions are to be answered in the blue books that are provided.
10 Points
1. On the panels shown below, draw arrows that indicate the apparent motion of the
stars as seen by an observer near the Equator (0N latitude). The compass
direction each panel faces appears beneath each of them. Make any annotations
that you feel will clarify your response.
Polaris
East
West
1 Point
11 Points this page.
North
South
2. Which of the times below represents the time required for the stars to complete
one apparent rotation around the celestial sphere? Circle the correct response.
A. 365.25 days
C. 24 hours
B. 27.3 days
D. 23 hours 56 minutes
1 Point
3. For an observer at 43N latitude, which of the stars listed below will be above the
horizon for 12 hours?
A. Polaris near the North Celestial Pole.
B. Vega that is at 38 declination, above the celestial equator.
C. Mintaka that lies directly on the celestial equator.
D. -Sagittarius that lies -23 declination, below the celestial equator
E. All stars spend 12 hours above the horizon, even if they cannot be seen
due to daylight.
2 Point
4. The Mercator projection of the whole sky appears below. The Sun’s position on
today’s date is indicated. Which of the solid circles best represents the position of
the Sun in 3 months time? Circle the correct position.
A
B
C
D
E
Sun now.
1 Point
5. The Sun requires 365.2524 days to complete one cycle completely around the
celestial sphere. From the list below choose the best description of the path the
Sun takes around the celestial sphere.
A. The Sun moves westward along the celestial equator.
B. The Sun moves westward along the ecliptic.
C. The Sun moves eastward along the celestial equator.
D. The Sun moves eastward along the ecliptic.
1 Point
6. The Sun traverses 13 constellations as it passes around the celestial sphere. What
are these constellations called?
A. The zodiacal constellations
C. The equatorial constellations
B. The circumpolar constellations
D. The diurnal constellations
Pointsthis
thispage
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55Points
2 Points
7. The picture below represents a particular phase of the Moon. Circle the correct
name of the phase of the Moon that appears in the picture.
A. Half Moon
B. First Quarter Moon
C. Last Quarter Moon
D. Waning Gibbous Moon
E. Waxing Gibbous Moon
2 Points
8. What type of eclipse appears represented in the drawing below? Select from the
choice provided beneath the figure.
Sun
View from Earth
Moon
Earth
Note: Drawing is not to scale.
A. Total Lunar Eclipse
B. Partial Lunar Eclipse
C. Total Solar Eclipse
D. Annular Solar Eclipse
E. Partial Solar Eclipse
1 Point
9. Which of the times below represents the synodic period of the Moon, which is the
length of the lunar month?
A. 23.7 days
C. 29.5 days
B. 27.3 days
D. 31 days
3 Points
10. Which of the reasons listed below best explains why an eclipse of some sort is not
observed at every full or new moon?
A. The distance to the Moon is not constant. Some times it is closer to the
Earth (363,000 km) and sometimes it is a bit farther away from the Earth
(405,000 km). This prevents eclipses from happening at each full and new
moon.
B. The Moon travels around the celestial sphere faster that the Sun, so that it
is always ahead of the Sun. An entire year is required for the Sun to catch
up and create the appropriate geometry to cause an eclipse.
C. The Earth’s axis of rotation is tilted 23½ causing the Sun to appear to
wander from below the celestial equator to above the celestial equator
during the course of the year. Eclipses can only occur when the Sun is
crossing the celestial equator and the Moon is full or new. These two
events occur only rarely.
D. The orbit of the Moon is not flat, rather it is tilted a slight amount (about
5). This causes the Moon to be either above the ecliptic or below the
ecliptic at most full and new moons. This misalignment of the Sun, Earth,
and Moon prevents eclipses from occurring.
8 Points this page
3 Points
11. The position and phase of the Moon on a particular night is shown below. Please
sketch in the position the Moon will appear in on the next night at the same time
and sketch in the phase clearly indicating the waxing or waning trend.
Ecliptic
Looking South
2 Points
12. Which of the planets listed below appear to cycle around the zodiac every 365.25
days on average? Circle all that are appropriate.
A. Jupiter
D. Saturn
B. Mars
E. Venus
C. Mercury
2 Points
13. Which of the apparent properties listed below pertain to the Superior Planets.
Circle all those that apply.
A. Superior planets always appear close to the Sun.
B. Superior planets go retrograde.
C. Superior planets can be seen at opposition.
D. Superior planets take longer than a year to cycle through the Zodiac
E. Superior planets are brightest at maximum elongation
2 Points
14. All the objects listed below except two exhibits the occasional occurrence of
retrograde motion. Which two objects in the list below never appear to go
retrograde?
A. Mercury
D. Jupiter
B. Moon
E. Sun
C. Mars
1 Point
10 Points this page
15. Galileo is credited with which of the following discoveries that led to the rejection
of the Aristotelian/Ptolemaic Model of the Universe?
A. Galileo discovered that planets orbit in ellipses rather than in perfect
circles.
B. Galileo discovered the moons around Neptune.
C. Galileo discovered that the gravity held the planets in orbit around the
Sun.
D. Galileo discovered that Venus has phases like our Moon.
E. Galileo discovered that the Moon was made of green cheese. (O.K. so this
one is probably not the correct choice!)
1 Point
16. Johannes Kepler is credited with making the final break from Aristotle’s ideas of
planetary motion by proposing three laws of planetary motion. Which of the laws
of planetary motion listed below are NOT credited to Kepler?
A. The period of a planet’s orbit is related to the size of the orbit according to
the mathematical relationship P2=a3.
B. Planets have orbits that are inclined to the ecliptic by several degrees
depending on the size of the planet’s orbit.
C. Planets move around the Sun a variable speed; moving faster when they
are closer and slower when they are farther from the Sun.
D. Planets move on an ellipse around the Sun and the Sun is NOT at the
center of the ellipse.
1 Point
17. The statements that appear below are all related to the nature of gravity. Which of
them is NOT true?
A. The force of gravity around a star never vanishes no matter how far away
you are.
B. The force of gravity is an attractive force between any two objects with
mass.
C. The force of gravity is usually attractive, but under special conditions and
be repulsive as in escape velocity situations.
D. The gravity between two objects depends on the separation, getting weak
with greater distance between the two objects.
1 Point
18. Which of the persons listed below first successfully proposed that the Earth was a
planet, like the other planets, and was not the center of the Solar System. Rather
they proposed hat the Sun was the center of the Solar system. (Hint: He avoided
persecution by the Church in Rome by dying on the day his book “On the
Revolutions of the Spheres” was published in 1543 AD.)
A. Aristotle
D. Johannes Kepler
B. Tycho Brahe
E. Nicolaus Copernicus
C. Issac Newton
10 Points this page
8 Points
19. In the spaces listed below, write the name of the planets starting with the planet
closest to the Sun and finishing with the planet that is farthest from the Sun (most
of the time, anyway). In the second column, write the size of the planets semimajor axis (i.e. the distance the planet is from the Sun on average) in
Astronomical Units. Be as precise as you can.
Planet Name
Semi-major Axis
Closest to Sun……_________________
____________AU
_________________
____________AU
_________________
____________AU
_________________
____________AU
_________________
____________AU
_________________
____________AU
_________________
____________AU
_________________
____________AU
Farthest from Sun……_________________
____________AU
1 Points
20. Which of the values listed below best represents the mass of the largest planet in
our solar system? Circle the correct answer.
A. 1 Earth’s masses of material.
D. 1,170 Earth masses of material.
B. 95 Earth masses of material.
E. 330,000 Earth masses of
C. 318 Earth masses of material.
material.
1 Points
21. The density of a planet is an indicator of what the planet is made of. Which of the
planets below has a density of about 3.9 gm/cm3, or equivalently 3,900 kg/m3?
A. Venus
C. Jupiter
E. Pluto
B. Mars
D. Saturn
2 Points
22. Listed below are attributes of a planet or its system of natural satellites (i.e.
moons). Circle all those that pertain to Jovian type planets.
A. Heavily cratered surfaces
D. Rapid rotation
B. Few natural satellites
E. Many natural satellites
C. Deep atmospheres
F. Rings
12 Points this page
2 Points
23. Which of the statements listed below best represents the kinds of planets
astronomers have found around other stars?
A. Other solar systems appear to be like our own with terrestrial planets close
to the star and Jovian planets far from the star.
B. Other solar systems appear to be like our own with Jovian planets close to
the star and terrestrial planets far from the star.
C. Other solar systems appear to be unlike our own with terrestrial planets far
from the star.
D. Other solar systems appear to be unlike our own with Jovian planets close
to the star.
E. Other solar systems appear to be unlike our own with Jovian planets close
to the star and terrestrial planets far from the star.
The table below contains information regarding five stars. Answer the questions 23 to 26
using the information in the table. Circle the correct answer for each question.
Apparent
Absolute
Spectral Luminosity
Star Magnitude Magnitude
Type
Class
m
M
A
+1.35
-0.6
B7
V
1 Point each
B
+0.61
-5.1
B1
II
C
+13.0
+16.1
M8
V
D
-1.46
+1.4
A1
V
E
+0.96
-4.7
M1
I
24. Which star in the list is the largest in radius?
A
B
C
D
E
25. Which star is the hottest?
A
B
C
D
E
26. Which star appears the dimmest?
A
B
C
D
E
27. Which star is the most luminous?
A
B
C
D
E
28. Which star is closest?
A
B
C
D
E
29. Which value below most likely represents the mass of star A?
A. 0.1 MSun
C. 1.0 MSun
B. 0.5 MSun
D. 10 MSun
E. 100 MSun
30. Which value below most likely represents the radius of star C?
A. 0.1 RSun
C. 10 RSun
E. 1,000
B. 1.0 RSun
D. 100 RSun
RSun
31. Which value below represents the luminosity in solar units of star E?
A. .0001 LSun
C. 1 LSun
E. 10,000 LSun
B. .01 LSun
D. 100 LSun
10 Points this page
Refer to the HR diagram below to answer the following questions.
-10
a
d
-5
c
b
0
M
5
e
f
10
O
B
A
F
G
K
M
Spectral Type
2 Points
32. The above HR diagram is representative of which of the objects listed below?
A. An HII Region
D. A Globular Cluster
B. An Open Cluster
E. A sample of nearby stars
C. An OB Association
2 Points
33. What process is occurring along the portion of the evolutionary track marked “a”?
A. Core helium burning
D. Decreasing radius
B. Shell hydrogen burning
E. Planetary nebula creation
C. Decreasing surface
temperature
34. In the space below, please describe how the stars labeled f produce their energy.
8 Points
12 Points this page
Please respond to any three of the four essays below in the blue
books provided.
1. Describe the apparent motion of the Sun through the sky on both a diurnal and an
annual timescale as seen by an observer at 43N latitude. Include all relevant
timescales and angles and the difference in the apparent motion between the
summer Sun and the winter Sun. (7 pts)
2. Imagine you have been invited to attend a graduation party for the daughter of the
President of the company you are working for. The daughter has just received her
B.S. in Physics. You, the President and the daughter are standing together with
some other guests and the topic of the new Cassini mission to Saturn comes up.
One of the guests asks “Why is Saturn so much larger than the Earth? How did it
get so huge?” The daughter, who knows her physics but not her astronomy,
concedes that she does not know. The company President turns to you and
remarks, “You took an astronomy course under the world famous luminary Dr.
Jaquin. Explain to us how Saturn became so large.” Here is your opportunity to
impress the President and get that raise or wilt into the crowd and be transferred
to Austin TX never to be heard from again. Please, in an outline form, list the
points you would make that described how Saturn became so much larger
than the Earth. You do not have to write a narrative, simply a list of relevant
events, concepts or processes is sufficient. (7 points)
3. The extra-solar planetary systems thus far discovered are very different from our
own system. Briefly describe how these systems are different from our solar
system. In addition, describe the two mechanisms astronomers have invoked that
explains how these extra-solar planets came to be in the position where they are
found around their stars. (7 pts)
4. The table below summarizes the properties of a representative near-by star and a
representative bright star found in the sky. Write a narrative describing the
difference between near-by stars and bright stars generalizing from the two
particular stars given. Be complete and extend your description to include
ramifications not directly included in the two example stars (e.g. visibility, life
times, color, etc…) (7 pts)
Property
Distance
Spectral Type
Luminosity Class
Absolute Magnitude
Apparent Magnitude
21 Points this page
Bright
Star: Rigel
910 lyrs
B8
Ia
-7.1
0.12
Near-By Star:
Barnard’s Star
5.9 lyrs
M5
V
13.25
9.54