Physics 232: Observational Astrophysics
Fall 2017

Instructor: Professor Gordon Richards  Lecture: TTh 2-3:20pm Disque 704
Office: 812 Disque Hall Phone: 215-895-2713
e-mail: (subj: PHYS232) Office Hours: WF 3:30-4:30pm
Text: "Observational Astronomy" (2nd Ed.) by Birney, Gonzalez, & Oesper and Bill Romanishin's "Book"
TA: Rob Stone TA e-mail:


This web page is the syllabus. If you're reading a printed copy, you can find the web page at You should check this for updates!

Course Meetings

Lecture: Tuesdays and Thursdays from 2-3:20pm in Disque 704. Some days we will instead meet in the Lynch Observatory on the roof of Curtis. After Week 2, lecture may occasionally be canceled if the night looks to be clear, so that you have time to work on your observing projects instead.

Observing: There is a nighttime component to this class. It is listed as meeting 4 hours per week, not because we will, but because you are expected to spend at least 10 hours at night working at the observatory during the quarter (in addition to the ~3 hours of lecture each week).


This course is an introduction to the observational side of astrophysics. Components of the course include lectures, observing nights, and analysis of observations. Weather will play a significant role in determining when your observing nights are. In this course you will specifically learn how telescopes and astronomical detectors work and you will make your own observations, using telescopes on the Drexel Campus. Available telescopes include a Meade 16 inch (in the dome of the Joseph Lynch Observatory on the roof of Curtis Hall), a 10 inch Dobsonian, a Meade 8 inch Schmidt-Cassegrain, and a computer-controlled Celestron 5 inch. You will do both visual observing (through the telescope eyepiece) and digital imaging using a CCD camera. You will analyze the CCD data to quantify your measurements.

Observing (at night!) is a significant required component of this course. For astronomers, long hours under the night sky are fun. If it will be difficult for you to be on campus at night, you should not take this class. There will be only a few clear nights during the quarter and you must use them whenever they arise. So, do not delay in getting familiar with the telescope and getting started on your projects.

Observing sessions will be scheduled when the skies are clear enough to observe (see ``Observing'' below). The teaching assistant will be available for help during the observing sessions.

After you obtain an ample set of observations, you will analyze these measurements and write up reports on your results.


By the end of this course, you will be familiar with


We will assume familiarity with Freshman-level physics and calculus. Physics 111 or 113 and Math 121 are prerequisites. Students should also be comfortable using the linux operating system, such as implemented on the Department of Physics computing cluster. Knowledge of Python will be a huge plus; if you aren't comfortable with it, you might want to learn the basics on your own using a site like Rather than using professional astronomy software, we will be using general tools that have more practical applications for beyond this class.


Please read the assignments before class and prepare to ask questions. See the Course Schedule below for the weekly reading assignments.

The primary reading for the course comes from Birney, Gonzalez, & Oesper Observational Astronomy 2nd Ed., Cambridge.

I will also frequently make use of An Introduction to Astronomical Photometry Using CCDs that was being developed by Bill Romanishin at the University of Oklahoma. I don't think that he still intends to publish it, but it is a good reference.

There is also a new book by Mark Gallaway, An Introduction to Observational Astrophysics 1st Ed., Springer-Verlag, which has some nice project descriptions, but the first edition is filled with grammatical errors, so we aren't going to use it as the primary textbook.

The historical book used for this class, which may be helpful to refer to, is Kitchin's Telescopes and Techniques: An Introduction to Practical Astronomy, 4th Ed., Springer-Verlag. It was more relevant before the era of CCDs, but is still an excellent resource.

I have placed copies of the Birney and Kitchin books in the Astro common area in Disque 808. You may use them there, but they are not to leave the room.

You are also encouraged to purchase a recent copy of Sky & Telescope magazine. There are recent copies of this in Disque 808 as well, but again, they are not to leave the room.


You will need to become intimately familiar with the manuals for the big telescope, the main CCD camera, and the telescope/camera control software, and the focuser:

For data processing, we will be making use of the AstroPy libraries, which are included in the Anaconda Python distribution. If you would prefer to use your laptop instead of the computers in Disque 704, you should make sure that these are installed.

Outline of Lectures

Following is an outline of the topics covered, not necessarily in this order. The Course Schedule below details when we will cover these topics and the assigned readings. Some of these topics will be covered in parallel, so that you will learn some background and some practical topics each week.


Operating heavy equipment in the dark on a rooftop is dangerous. Observing in the dome requires you to stand on a ladder in the dark, while electrical cables dangle from the telescope and the roof. You are responsible for the safety of yourselves, the eyepieces, camera, and laptop computer. Carefully following the the opening/closing procedures will help keep all of these safe.

As such, you may not operate the 16inch telescope by yourself. You must operate on the "buddy system", and, since there is no phone in the dome, bring your cell phone.

You must sign out the keys on a nightly basis, log your observations, and send e-mail to report when you have left the observatory.


Grades will be based on the following weighting of different components of the course:
Observer's test: 20-25%
Observing projects: 25-40%
Homework: 20-25%
Final Exam: 20-25%

The following sections of the syllabus describe each of these components.


To fulfill the significant ``lab'' component of this course, you must successfully pass the ``observer's test'' and complete three observational projects in the ten weeks of this course. Be warned: weather is fickle, so don't plan to leave your observing until late in the term. We will keep track of when conditions are/are not suitable for observing. A safe plan would be to attempt observations on every clear night until you complete the projects.

In the observer's test, you must demonstrate a basic knowledge of the night sky and that you understand how to operate the telescope and camera. This test includes opening the dome, setting up the telescope, checking that the telescope correctly points and tracks, obtain the target, take an image with the camera, and transfer the data back to a computer in the department for analysis. Knowledge of telescope safety and common sense will be tested. You will have to show that you understand how to open/close up the telescope.

The first observing project can be done in Disque and will help you to get familiar with the CCD camera in relative comfort rather than trying to learn on-the-fly in the cold, dark dome.

The other observing projects will involve learning how to make three-color images and how to perform detailed photometric measurements (that would allow you to discover new planets!). For each project, you will submit a written report that details both your observations and your analysis.

Observing teams:
For the sake of safety and huddling together for warmth when it gets cold, you will work in teams of 3 (with one group of 4). Organize yourselves into groups by the end of week two and let me know what you have decided. I will assign students to groups after that.

Observing projects:

  1. Observer's Test
  2. Project 0: getting to know your CCD camera
  3. Project 1: creating three color mosaic images
  4. Project 2: point source photometry (of a planetary transit)

Homework Assignments

There will be 4-5 homework sets, which will test your knowledge of properties of celestial objects and principles of observation. Solutions to the homework will be handed out in class on the due date (and/or posted on the web page), thus late homework will not be accepted. There will be no ``dropped homeworks.'' Please strive to present your answers in an organized fashion; the clarity of your solutions will count toward your grade.

Science is a collaborative enterprise and you are encouraged to discuss the homework problems. But you and you alone are responsible for the work that you turn in. Please write up your own solutions to the problems. Serious breaches of this policy will result in homework scores being divided by the number of ``participants.''


There will be no midterm exam. There will be a take-home Final Exam (due no later than Monday 11 December and to be completed without any other human help).

Course Schedule (Tentative)

Please note the following schedule of readings and assignments. This schedule will be updated each week depending on weather. Specifically, if there is a clear night during the week, I may cancel lecture to allow you to get work done for other classes and have time to get up to the observatory at night.

Week Date Topics Reading Assignments Deadlines
1 Sept. 26 Intro to Astronomy
Sky & Telescope
Birney Ch.3
Gallaway Ch. 6
HW 1 assigned Start forming groups
1 Sept. 28 Lynch Observatory Tour (Start in Disque 704)
Walk through telescope use, both dome and portables
2 Sep 28 Detectors Birney, Ch. 8 (pp.145-148,159-162), Ch. 9
Romanishin, Ch. 11+12
Gallaway, Ch. 7
[Kitchin, pp.1-7,15-26]
2 Oct 5 Class in Dome
1/2 @ 2pm; 1/2 @ 2:40pm
Telescope manual
Print/read/highlight HW 1 due
3 Oct 10 Learn to use the CCD camera (in lab) SBIG STL-1001E Camera
The SkyX (Professional)
HW 2 assigned
3 Oct 12 Data Taking Practice (in class with TA)
4 Oct 17 Coordinates & Time Birney pp.1-10,Ch.2
Romanishin Ch.26
Gallaway, Ch. 4
4 Oct 19 Finish Project 0 in Class HW2 Due (Project 0)
4 Oct 24 Data Reduction Birney, Ch. 9
Romanishin, Ch. 13,14,16
Gallaway, Ch.7+8+9
HW3 Assigned
5 Oct 26 Photometry I Birney, Ch. 5
Romanishin, Ch. 1-4,23
Gallaway, Ch2
[Kitchin, pp. 276-284]
Observer Test Deadline
6 Oct 31 The Atmosphere Romanishin, Ch. 7-10,19
Birney, Ch. 7
Gallaway, Ch. 10
HW3 Due
6 Nov 2 No Lecture
Work on Projects in Class
7 Nov 7 Photometry II Romanishin, Ch. 17-18,20,23-25
Birney, Ch. 10
Gallaway, Ch. 10,11
HW4 Assigned
7 Nov 9 No Lecture
Work on Project 1 in Class
8 Nov 14 Observation Planning Romanishin, Ch. 24, 27
Birney, Ch. 3
8 Nov 16 No Lecture
Work on Project 1 in Class with TA
9 Nov 21 Telescopes I Birney, Ch. 6
Romanishin, Ch. 5+6
Gallaway, Ch. 3
[Kitchin pp.44-89]
HW 5 Assigned HW 4 Due
10 Nov 28 Telescopes II Project 1 Due
10 Nov 30 No Lecture
Work on Project 2 in Class
11 Dec 5 Spectroscopy I HW 5 Due
11 Dec 7 Spectroscopy II
Work on Project 2 in Class
Project 2 Due
12 Dec 7-11 Exam Week

Last update: 24 September 2017