Astronomy 313: Observational Optical Astronomy
Department of Astronomy, Haverford College
Fall 2003 - Spring 2004

Welcome

Welcome to the 2003-2004 edition of Astronomy 313: Observational Optical Astronomy, taught by Froney Crawford.

Instructor Contact Information

Instructor: Fronefield Crawford
Office: Koshland INSC Link 106
Phone: (610) 896-2973
Email: fcrawfor@haverford.edu
Fall 2003 Office Hours: Tue 10:00-12:00 noon, Wed 2:00-4:00 p.m.
Spring 2004 Office Hours: Mon 2:00-4:00 p.m., Wed 2:00-4:00 p.m.

Come see me anytime.

Course Description

Astronomy 313 is a one unit course which lasts the entire academic year, i.e., you must register for both semesters to get credit for the course. The course will consist of five observing projects which involve using the CCD camera on the 16" Schmidt-Cassegrain telescope located in the large dome of the Strawbridge Observatory. Data from these observations will be analyzed with the software package IRAF on the workstation located in the computer room of the Observatory. [To access that room after hours, you will need an OB3 key. For those of you who do not already possess this key, obtain a key request form from the instructor and take it to Security as soon as possible.] The results of two or three of the projects will be presented as formal reports and the results of the others as brief, descriptive reports.

The course will be very informal. After the initial instructional observing sessions, each observing team (consisting of two or three students) will have the responsibility for scheduling observations. The regularly scheduled "class time" (Mon 7:30-10:00 p.m.) will serve three purposes. For the first few weeks of the fall semester, this time will be used for workshops on a variety of topics; e.g., an introduction to CCD cameras, an introduction to the IRAF software package, operating the 16" Schmidt-Cassegrain telescope, analyzing astronomical data, etc. In addition, we will meet occasionally during this time throughout the year to discuss the details of individual projects and reports. Finally, this time slot will give assurance that there is at least one night a week when members of the observing teams do not have scheduling conflicts (in the past, scheduling has been a big problem).

Textbook

The textbook for the course is Handbook of CCD Astronomy by Steve B. Howell. This little book serves both as an introduction to charge-coupled devices (CCDs) and to their use for astronomical observations. CCDs have arguably revolutionized observational optical astronomy and so understanding how they work is essential for a course on this topic.

At our first meeting, I will also hand out a copy of "An Introduction to Astronomical Photometry Using CCDs" by W. Romanishin, which is also a useful reference that you should use.

Prerequisites

The primary prerequisite for this course is Astro 205/206; therefore, it is expected that all students will have a working familiarity with the 12" Schmidt-Cassegrain telescope located in the small dome in the Strawbridge Observatory. It is anticipated that some students will also have some familiarity with the UNIX computer operating system, the IRAF software package, and/or general CCD camera operation. However, students unfamiliar with these systems will be quickly brought up to speed and will then be able to direct most of their efforts to the observing projects. The primary purpose of the first two projects is to learn CCD camera operations and basic photometric techniques.

The Schmidt-Cassegrain is a fairly complicated and delicate instrument, and it is quite susceptible to damage from misuse. It is imperative that you be thoroughly checked out by your instructor before using the telescope. Two trained observers must be present during any observing run.

Course Goals

This course has several objectives:
1. to provide the opportunity for students to learn about particular astronomical phenomena firsthand through observing specific objects. In this respect, students should spend some time reading about the theory of the astronomical objects being observed (see the discussion below about report format)
2. to learn how to use perhaps the most versatile instrument of the modern astronomer, the CCD camera
3. to learn more about the operation of telescopes, e.g. tracking, guiding, pointing errors, seeing, balancing, etc.
4. to learn more about planning observing runs, e.g. how to anticipate good weather patterns, how to determine which observations need "dark time" and which can get by with "bright time", etc.
5. to learn the details of modern astronomical data processing, including the IRAF package and such procedures as flatfielding, scattered light correction, aperture photometry, surface photometry, spectral analysis, etc.
6. to learn the fine art of scientific collaboration. Students will work in teams of two or three and will be required to change partners during the year.

Formal Reports

Formal reports should be written in standard journal style and format. Look at articles in the Astrophysical Journal for examples. Reports should include:
1. a short abstract in which the important results of the observations and subsequent analysis are summarized.
2. an introduction of approximately one page in which the observations are placed in an astrophysical context. It is in this section that one may wish to review current scientific understanding of the object or the results of previous observations.
3. an observations section in which the observations are described and perhaps some raw data tables are given.
4. an analysis section which describes the reduction of the data. This needn't be in great detail. Caution -- never put simple arithmetic calculations in this section; just let the reader know how the analysis is being done. Tables, graphs, and images are appropriate in this section. Note -- items 3 and 4 are often intermingled.
5. a discussion and/or conclusions section which gives a clear presentation of the important results and, if appropriate, comments on the significance of them. If you want to wax philosophical, this is the place to do it (in moderation).
6. a reference section. Use the ApJ style.

We will discuss these matters in a workshop prior to the first formal report.

Tentative Projects

1. An Introduction to CCD Observations: Characterizing the CCD Camera
2. BVRI Photometry of a Mystery Star Near M32
3. Color-Magnitude Diagram of an Open Star Cluster
4. Measuring the Spectra of Different Stellar Types
5. Surface Photometry of the Giant Elliptical M87

Final Remarks

The responsibility for planning and making the observations and analyzing the data is the student's alone. The instructor is only there to give assistance. The student is even responsible (to a degree) for weather conditions. One of the important aspects of being a good astronomer is seeing to it that the appropriate observations are made. If these observations are not given very high priority in your evening affairs, the weather will ultimately beat you. The telescope/CCD/computer system is a complicated one, and problems will invariably arise. In some ways this is a good thing. Research rarely proceeds smoothly. The way in which one solves unexpected problems in large measure determines one's worth as a scientist.