Astronomy 101 exam 1 study guide.
This guide summarizes the vocabulary and concepts that you should review to prepare
for the first midterm exam. You will be asked some questions that require visualization of
concepts, and you will be asked to do some simple calculations. It is helpful to review
the homework and PRS in-class questions - these provide examples of the types of
calculations you might be asked to perform on the exam. The PRS questions are posted
on the course web page (www.astro.umass.edu/~tripp/a101fall08). Good luck!
Part 1: perspective on the size, age, and surprising nature of the universe
Basic vocabulary
1. Astronomical objects: solar system, galaxy, local group, star clusters (open and
globular), observable universe
2. Measurement units. Examples: light year, "AU" (astronomical unit)
3. Basic math: scientific notation, powers of 10
Concepts
1. Calculations with scientific notation and powers of 10
2. Converting units of measurement (e.g., converting from miles to kilometers)
3. Some basic aspects of the Solar System
The classification of planets: terrestrial vs. jovian gas giants
The reason that Pluto was booted
4. The size of the universe
Relative size of the Sun, planets, and Solar System
Distances between stars and the size of the galaxy
Size of the universe
5. The age of the universe and the scale of time
6. The way that astronomers can look back in time and study the ancient universe
7. Creation of elements by nuclear fusion reactions deep inside stars
Our astronomical origins!
8. The expanding universe
9. The discoveries made by Edwin Hubble and Albert Einstein
The "Hubble Law"
The relation between the Hubble constant and the "age" of the universe
Gravitational lensing
10. Basic motions of the earth: rotation, orbit around the Sun
11. Basic motions of the Sun within the Galaxy
Part 2: mapping the sky
Basic vocabulary
1. Angles: angular diameter, linear diameter, & distance; degrees, arcmin, arcsec
2. The celestial sphere: north & south celestial poles, celestial equator, ecliptic,
ecliptic plane, Polaris, circumpolar, right ascension, declination, the spring
equinox (also known as the "vernal" equinox)
3. The local sky: zenith, horizon, meridian, altitude, nadir, latitude, longitude
4. Phases of the Moon: waxing, waning, crescent, first quarter, third quarter,
gibbous, new, full, dark side, rotation & orbital period
5. Seasons on Earth: Winter & Summer Solstice, Spring & Fall Equinox
6. Eclipses: lunar eclipse, solar eclipse, partial eclipse, annular eclipse, umbra,
penumbra, nodes, saros cycle
7. Planets: planet names, retrograde motion
8. Parallax (in general) and stellar parallax
Concepts
1. The nature of the Milky Way
Our galaxy is shaped like a disk
We're located in the outer region of that disk
What we see depends on which way we look
with respect to this disk of stars
The current model of our galaxy
2. Constellations & the need to work with angles in astronomy
3. Calculations using angles: linear distance vs. angular diameter vs. distance
Measuring angles in radians instead of degrees
4. Mapping the sky using the celestial sphere & local sky
5. Navigation using the stars and Polaris
6. Diurnal (daily) motion and its impact on observing the sky
7. Annual motion and its impact on observing the sky
8. The nature and cause of seasons on Earth
9. The nature and cause of the phases of the Moon
10. The nature and cause of eclipses
- Solar vs. lunar eclipses
- The effects of refraction and light scattering on lunar eclipses
- Reason for partial and annular eclipses
- The reasons that predicting eclipses is so difficult
11. Retrograde motion
12. The connections between astronomical cycles and the basic cycles of our lives
Part 3: perspective from the history of astronomy
Vocabulary/History
1. Tools/sites of ancient astronomers, e.g., Stonehenge, the Anasazi Sun Dagger
2. Important Greek astronomers: Aristotle, Eratosthenes, Aristarchus, Claudius
Ptolemy
3. Important astronomers of the "Copernican Revolution": Copernicus (duh),
Brahe, Kepler, Galileo
4. The scientific method: hypothesis, model, theory, Occam's razor, hypothesisdriven vs. discovery-driven science
Concepts
1. Accomplishments of ancient astronomers
2. Accomplishments (and failures) of Greek astronomers
3. Accomplishments (and failures) of Copernican Revolution astronomers
4. The Ptolemaic model and epicycles
5. Kepler's Laws
6. Galileo's observations
7. The hallmarks of good science vs. pseudoscience