Physics 232: Observational Astrophysics
Fall 2015

Instructor: Professor Gordon Richards  Lecture: TTh 2-3:20pm Disque 704
Office: 914 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: Joe Glaser TA e-mail:


Welcome to the home page for Physics 232: Observational Astrophysics. Watch this space for important announcements and useful hints.

Course Meetings

Lecture times: 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.


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!


This course is an introduction to the observational side of astrophysics. In this course you will 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. Do not delay in getting familiar with the telescope and getting started on your projects. Components of the course include lectures, observing nights, and analysis of observations. The amount of time spent at the telescope will vary depending on the weather.

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 (which you'll never need again), we will be using more general Python tools that have more practical applications for beyond this class.

Textbook and Reading Assignments

Required reading for the course are Birney, Gonzalez, & Oesper Observational Astronomy 2nd Ed., Cambridge and An Introduction to Astronomical Photometry Using CCDs being developed by Bill Romanishin at the University of Oklahoma. It may also be helpful to refer to Kitchin's Telescopes and Techniques: An Introduction to Practical Astronomy, 4th Ed., Springer-Verlag. 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 copies of this in Disque 808 as well, but again, they are not to leave the room. Please read the assignments before class and prepare to ask questions. See the Course Schedule below for the weekly reading assignments.

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.

We will also be making reference to

For help with operating our computer controlled telescopes and CCD camera, their manuals may come in handy.

Also helpful is Norton's Star Atlas or other star charts. Plus tons of great on-line references (for example Michael Richmond's PHYS301 class at RIT). And, of course, the material posted on the Lynch Observatory web site.

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. Don't try this at home. You may not operate the 16inch telescope by yourself; you must operate on the "buddy system."

I will hand out a list of procedures for safe telescope operation. You will be tested on these procedures. If you have any questions, ASK FOR HELP.

You must sign out the keys on a nightly basis.

You are responsible for the eyepieces, camera, and laptop computer.

There is no phone in the dome. Bring your cell phone.

Again, be sure to follow the opening/closing procedures.


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 two 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 observing projects will involve photometric observations of stars and, possibly, planets and nebulae. For the stellar observations, you will obtain digital images of a set of stars, calibrate those images using observations of standard stars, and analyze these data to produce. 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 1: creating three color mosaic images
  3. Project 2: point source photometry (of a planetary transit)

Here's a page of useful observing links.

Technical details about observing are discussed on the Observing at Drexel web page. Once you have data, you'll want to analyze it. See the Data Analysis web page for links to software and helpful hints.

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 (to be completed without any other human help).

Course Schedule (Tentative)

Please note the following schedule of readings and assignments. This schedule may be updated, so check the web page!

Week Date Topics Reading Assignments Deadlines
1 Sep 22 Lynch Observatory Tour (Start in Disque 704)
Both dome and portables
1 Sep 24 Class in Dome
1/2 @ 2pm; 1/2 @ 2:40pm
Telescope manual
2 Sep 29 Intro to Astronomy
Sky & Telescope
Birney Ch.3
HW 1 assigned
2 Oct 1 Class in Dome (w/ TA)
Learn to use CCD camera
Equinox Image Manual (pp. 6-9,17-18,23-31,35-36)
Equinox Pro Manual (for reference)
Teams formed
3 Oct 6 Detectors Birney, Ch. 8 (pp.145-148,159-162)
Romanishin, Ch. 11+12
[Kitchin, pp.1-7,15-26]
HW 1 due
3 Oct 8 Coordinates & Time Birney pp.1-10,Ch.2
Romanishin Ch.26
HW 2 assigned
4 Oct 13 Data Taking Practice
4 Oct 15 Data Reduction Birney, Ch. 9
Romanishin, Ch. 13,14,16
HW3 Assigned HW2 Due
5 Oct 20 Photometry I Birney, Ch. 5
Romanishin, Ch. 1-4
[Kitchin, pp. 276-284]
5 Oct 22 Good Weather Make-up Lecture
6 Oct 27 The Atmosphere Romanishin, Ch. 7-10
Birney, Ch. 7
HW3 Due
6 Oct 30 No Lecture
Work on Projects in Class
7 Nov 3 Photometry II Romanishin, Ch. 17-18,20,23-25
Birney, Ch. 10
HW4 Assigned
7 Nov 5 No Lecture
Work on Project 1 in Class
8 Nov 10 Observation Planning Romanishin, Ch. 24, 27
Birney, Ch. 3
8 Nov 12 No Lecture
Work on Project 1 in Class
Observer Test Deadline
9 Nov 17 Telescopes I Birney, Ch. 6
Romanishin, Ch. 5+6
[Kitchin pp.44-89]
HW 5 Assigned HW 4 Due
9 Nov 19 Telescopes II Project 1 Due
10 Nov 24 No Lecture
Work on Project 2 in Class
11 Dec 1 Spectroscopy I HW 5 Due
11 Dec 3 Spectroscopy II
Work on Project 2 in Class
Project 2 Due
12 Dec 7-11 Exam Week

Last update: 8 September 2015