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
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.
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
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
Introduction to Astronomical Photometry Using CCDs"
by W. Romanishin, which is also a useful reference that you should
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
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
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.
This course has several objectives:
- 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)
- to learn how to use perhaps the most versatile instrument of the
modern astronomer, the CCD camera
- to learn more about the operation of telescopes, e.g. tracking,
guiding, pointing errors, seeing, balancing, etc.
- 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.
- 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.
- 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 should be written in standard journal style and format.
Look at articles in the Astrophysical Journal for examples. Reports
- a short abstract in which the important results of
the observations and subsequent analysis are summarized.
- 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.
- an observations section in which the observations are described
and perhaps some raw data tables are given.
- 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
- 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).
- a reference section. Use the ApJ style.
We will discuss these matters in a workshop prior to the first formal
- An Introduction to CCD Observations:
Characterizing the CCD Camera
Photometry of a Mystery Star Near M32
- Color-Magnitude Diagram of an Open Star Cluster
- Measuring the Spectra of Different Stellar Types
- Surface Photometry of the Giant Elliptical M87
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.
Return to Froney Crawford's Homepage