Chapter 1: Introduction
The spectrometer is the astronomer’s scalpel to the universe. Within an object’s spectrum are clues to its chemical composition, temperature, movement, age, and just about any other physical property it may have. A majority of what astronomers know about the universe has come from spectroscopic measurements. The spectrometer is perhaps the astronomer’s most important tool.
Amateurs were the first to attach a spectrometer to a telescope, but shortly after that, professionals adopted the idea and have dominated the field since. Most objects of astronomical interest are dim to begin with and separating their light into individual wavelengths makes them even harder to detect. Because of this, spectrometry was productive only when done with large professional telescopes. However, the recent CCD revolution has made spectrometry once again accessible to the amateur. The sensitivity of CCDs makes it possible to take a professional-level spectrum with an amateur level scope.
With funding from the American Astronomical Society (AAS), the Wheaton College Astronomy Department was able to purchase the new Self Guided Spectrometer (SGS), a self-contained spectrometer produced by the Santa Barbara Instrument Group. The department’s goal, and my original goal for this thesis, is to use this spectrometer to analyze supernovas. I soon found that before we could begin such an undertaking, we needed more preparation than originally thought. Because the return of amateur spectrometry is still in its early stages, there are few resources available, which makes this preparation doubly difficult.
Finding adequate software to process and analyzing spectra was difficult, and learning how to use the software, even more so. Although manuals for the spectrometer and software packages are available, there were still unanswered questions and difficulties. The learning curve to do astronomical spectrometry was greater than I had anticipated. I felt that with the limited resources available, it would be difficult for a student to become familiar with the equipment and the methods, and then use them to complete a research project within an academic year. This motivated me to write a guide to astronomical spectrometry that is specific to the equipment and software available to us.
In this guide I focus on the problems and questions I encountered. I have some of my own solutions, but in no way should they be regarded as the only solutions possible. My hope is that future students can use my thesis as a means of quickly familiarizing themselves with the equipment and software. This should allow students to complete independent projects within the academic year or even a semester.