Astronomy 104: Astronomy Laboratory

Spring 2020, David Kaplan (UWM Dept. of Physics)

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Instructor: Prof. David Kaplan [he/him/his]
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Acknowledgement of Student Responsibilities:

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How To Do Well In Astronomy 104

This course consists of 13 laboratory exercises, described below. Students must perform the exercises during their scheduled sections. Each assignment will be graded. The final grade for the class will be the average of the top 12 of the 13 grades, so the lowest grade will be dropped.

Attendance is required. Absences will only be allowed with the advance permission of the instructor (Prof. Kaplan) - not the teaching assistants. If you miss a lab due to medical reasons please provide the instructor with appropriate documentation (a Doctor's note). The last full week of the lab (April 28-30) is a makeup date, used if any exercises have been missed with excused absences. You cannot just miss a lab and show up: permission is necessary.
It is usually possible to accommodate students who have to switch their lab to a different day of the week (for example due to a religious observance). Please let the instructor know in advance if this is required.

To request an approved absence, please fill out an Absence Request Form

Astronomy 103 or a comparable Astronomy Survey course (Astronomy 300 or 400 is acceptable).

Please bring a scientific calculator with you to each lab.

The required textbook is:
Pearson Custom Library: Astronomy
Astronomy 104: Astronomy Laboratory
ISBN: 9781323342596
Price: $27.18

Note that this is a custom-printed book for this course, so you cannot get a used copy or a copy from elsewhere. Many of the exercises will be found within this book, and you will fill them in and then hand the material in to the teaching assistants.
The textbook from Astronomy 103 (Astronomy, by Fraknoi, Morrison, and Wolff) is recommended: it will help to put the exercises into context, and each lab refers to a particular section (or sections) of the book. Please bring your textbook to the lab sessions if you have it. This book is free, so you can just download a PDF if needed.

University Policies: For information on university policies such as religious observances, incompletes, discriminatory conduct, and so forth, see: No weapons are permitted in any building on the UWM campus.


Section in your textbook

Lab 1: Week of January 21, 2020 Planetary Motion and the Night Sky (book)
Chapter 2

You will infer the structure of the Solar System based on simple observations you can make with the naked eye.

Note: do not do Retrograde Motion.

Lab 2: Week of January 28, 2020 Retrograde Motion and the Shape of Mars' Orbit Section 1.1/1.3

You will discover how the puzzling "retrograde," or backward apparent motion of the planet Mars occurs.
Based on data from Tycho Brahe, you will plot the orbit of Mars and see how different shapes (circle, ellipse) fit the data.

Lab 3: Week of February 4, 2020 Orbital Motion of a Planet (Computer) Section 3.1

Moving on to the planets of our solar system, often the brightest objects after the Moon in our night sky, you will learn two ways to determine the length of a year on Earth and decide which is a better method. You will determine the maximum elongation of Venus, as well as the size of its orbit and the length of its year. You will then use this information to verify one of Kepler’s laws for the motion of planets.
Lab 4: Week of February 11, 2020 Gravity and Orbital Motion (book, Computer) Sections 3.1, 3.3

You will use a gravity simulator to investigate orbital motion and Kepler's Laws. The simulator is at:
Note: do not do Orbit Shape: Kepler's First Law.

Lab 5: Week of February 18, 2020 Phases of the Moon (book)
Section 4.5

Long an object of mystery to ancient cultures, you will learn about the geometrical relationship of the Earth/Moon/Sun system. You will discover the different phases of the moon and what process creates them. You will also learn about eclipses. 
Note: do not do Why don't lunar and solar eclipses occur during every cycle of phases? or Can you see the Moon during the day?.

Lab 6: Week of February 25, 2020 Spectral Analysis
Section 5.3

How do we tell what distant objects in the sky are composed of? We will explore one method, called spectroscopy. You will observe several unknown emission spectra using spectrographs. After sketching the spectra, you will try to identify the unknown elements by comparing your spectra with the spectra of several common elements 
Lab 7: Week of March 3, 2020
Colors of Stars (book, Computer) Sections 17.2, 17.3
You will investigate what the color of a star reveals about its physical properties. The simulator is at:, and the image of Omega Centauri is at:
Lab 8: Week of March 10, 2020
HR Diagram (computer) Section 18.4

What are other stars like in the Milky Way? We will use surface temperature, luminosity and peak wavelength to map out the variety of stars found in the night sky, recreating the H-R Diagram: one of the fundamental relations for all astronomers. Also see:
Week of March 17, 2020: No Lab (Spring Break)

Lab 9: Week of March 24, 2020
Nuclear Fusion and Energy in Stars (book) Section 16.2

You will explore the creation of heavy elements and release of energy through nuclear fusion in stars.
Note: do not do the questions involving clay or marbles.
Note: do not do the question As helium builds up....
Lab 10: Week of March 31, 2020 Gravity and Black Holes (book)
Chapter 24

You will investigate some of the exotic phenomena that result from the enormous gravity in the vicinity of a black hole.
Note: see Lab 9 Question 2 for a modification of Section 2, Question 2.

Lab 11: Week of April 7, 2020 Solar Energy and the Habitable Zone
Chapter 7.2

We explore the object at the center of our solar system, the Sun. We learn about the energy it provides to the planets, how the Sun’s energy interacts with atmospheres and determine the Solar System’s Habitable Zone: the zone where life is most likely to exist. 

Lab 12: Week of April 14, 2020 Radial Velocity and Exoplanets (book)
Section 21.4

You will investigate the indirect detection of exoplanets using the observed reflex motion of stars. You will again use the simulator:
Lab 13: Week of April 21, 2020 Hubble Law (Computer) Section 26.5

You will calculate the age and size of the Universe using software to measure how far away galaxies are and how quickly they are moving away from the Sun.
Week of April 28, 2020 Makeup

If you have missed any exercises with an excused absence, this will be an opportunity to do a makeup.













Software for some exercises is based on Project CLEA