PES 105 – General Astronomy I – Exam #1 Study Guide
Fundamentals of Astronomy; History; Gravity and Motion; Light and Atoms; Telescopes
Fundamentals and History of Astronomy
What is scientific notation?
Know roughly what the speed of light is, and how a light year is defined. Know what an Astronomical Unit
represents.
What is the nearest star to the sun, and about how far away is it?
What are the steps in the scientific method used to improve scientific knowledge?
What is the ecliptic plane? What bodies move about on or near the ecliptic?
What is the term for the solar system model in which the Sun is assumed as the center of the solar system? The
model in which the Earth is the center?
What distinguished Copernicus’ model of the solar system from previously accepted models ? How was it
wrong?
Know the definitions and time of year for the Soltices and the Equinoxes.
What is the Zodiac? How does it relate to stargazing at night? At different times of year?
Upon what conditions does the location of the sunrise on the horizon depend?
What contributions did Tycho Brahe make to astronomy? What contributions did Kepler make?
What does the term “parallax” mean? What is an arc-second? A parsec?
What astronomical property did Aristarchus of Samos measure? What did Eratosthanes measure? How did they
do it?
Gravity and Motion
Understand the basic concepts of Newton’s Laws of Motion and Gravity.
What are some of the basic properties of matter? Which depends on location: mass or weight?
The Law of Gravity depends on what two quantities? How do changes in the values affect the force of gravity?
For orbits, what does the semi-major axis represent? What does eccentricity represent?
What is retrograde motion.
Where do planets move fastest: nearer the sun or farther from the Sun?
Light and Atoms
How are the properties of light (color, wavelength, frequency, energy, temperature) used in astronomy?
What is meant by wave/particle duality in dealing with light?
What are the four fundamental forces of nature?
How is the light from stars used in measuring their properties (relative motion, position, temperature,
composition)?
Know the common regions of the electro-magnetic spectrum in order of frequency, energy, and/or wavelength.
How is spectroscopy used in astronomy?
How are emission and absorption spectra different? How are they the same? How are they used to detect the
composition and amount of elements in stars?
What two properties of stars and other radiating black bodies does Wien’s Law link together?
Know the basic building blocks of atoms (protons, neutrons and electrons) and how they behave. Understand
the concept of unique, discrete electron levels. What happens when electrons change levels?
What is color, and how is it formed with emitted light? With absorbed light?
Understand the meaning and effect of the Doppler shift (red- and blue-shift) in the spectrum of a star and how it
relates to the star’s motion toward/away from us.
Telescopes
What areas of the electro-magnetic spectrum are absorbed by our atmosphere? What telescopes are useful from
the ground? From space?
What is meant by the collecting power of a telescope? By its resolving power?
What are reflecting telescopes and what are their deficiencies?
What are refracting telescopes and what are their strengths and deficiencies?
Are radio telescopes reflectors or refractors?
How does the process of interferometry help astronomers in viewing the universe?
How are the basic ways to collect light from telescopes (eye, film, CCD) similar and different?
Understand some of the problems with using telescopes, such as vibration, star tracking and light pollution
What is atmospheric scintillation?
How big can telescopes get?
Astronomical Terms
R. Gist
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Fall 2004
PES 105 – General Astronomy I – Exam #1 Study Guide
Fundamentals of Astronomy; History; Gravity and Motion; Light and Atoms; Telescopes
Know the definitions of the following terms: Syzygy, Celestial Equator, Azimuth, Elevation, Declination, Right
Ascension, Zenith, Conjunction, Synodic Period.
Sample Questions
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Chapter 1
Q: What causes the seasons?
A. The celestial sphere is tilted with respect to the equator
B. The Earth’s path is elliptical, hence closer to the Sun in the summer
C. The ecliptic is tilted with respect to the celestial equator
D. The motion of the equinoxes
E. None of the above.
Q: When would you expect to see the Moon near the North star?
A. The full Moon of the winter solstice
B. The full Moon of the summer solstice
C. Any phase around the equinoxes
D. Never.
Chapter 2
Q: The Earth’s shape is somewhat flattened, so that the diameter through the poles is shorter than the diameter
of the equator. Where would you weigh more?
A. In the poles
B. In the equator
C. My weight is the same everywhere
Q: Mars completes one orbit around the Sun in approximately two Earth years. Mars’ average distance to the
Sun is about 1.5 AU. Therefore the Mars orbital speed is lower than the Earth’s orbital speed.
A. True
B. False
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Chapter 3
Q: Which of the following lists the photons in increasing order of wavelength?
A. Microwave, Infrared, Visible light, Ultraviolet, X-rays
B. Infrared, Microwave, Visible light, Ultraviolet, X-rays
C. X-rays, Ultraviolet, Visible light, Microwave, Infrared
D. X-rays, Ultraviolet, Visible light, Infrared, Microwave
E. Ultraviolet, X-rays, Visible light, Infrared, Microwave
Q: Star X has surface temperature of 6000 K, and appears yellow. Star Y appears white. What can we
conclude about star Y?
A. Its spectrum shows strong Hydrogen emission lines
B. Its surface temperature is lower that 6000 K.
C. Its core temperature is about 12,000 K
D. Its surface temperature is higher than 6000 K
Chapter 4
Q: Large reflector telescopes have the following significant advantages over large refractors:
A. Mirrors are less expensive to fabricate than lenses
B. Mirrors weigh less than lenses of the same diameter
C. Mirrors have larger magnification
D. All of the above
E. Both A and B are significant advantages
R. Gist
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Fall 2004