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Case-Based Study
Introduction
You may not have noticed that the sky takes on different levels of brightness and faintness until you have had to walk at night in the woods or on a street that was not lighted. Or you may have looked up into the sky and imagined how stars stay up there without falling down to earth? There are many questions that can be asked about stars that deal with their combined effort to light the galaxy.
There are many general questions that can be asked about stars. Some questions are: How do stars work? What makes them shine? Why are some stars bright and others faint? Do stars change their brightness? Are stars observable during the day? What are stars made of? Do stars move? What determines their size, temperature, and brightness? How are they born, evolve, and die?
In studying the stars, you are going to apply the laws of physics to astronomical situations. This branch of science is known as astrophysics. You will be combining the study of physics with the study of astronomy. To aid you in the study of astrophysics, you will be asked to develop cases from a progression of questions. Each question is intended to extend your knowledge of the universe. How you choose to develop each case depends upon you and your group.
Your role will be similar to that of a detective who must piece fragments of evidence into a whole picture. Like a detective, you will formulate hypotheses that relate to the scenario of the situation and then pursue various leads that fit in with the dilemma presented by the case. Detectives and scientists are primarily concerned with the causes of events and rely on observation to gather evidence. Detectives look for clues and investigate events surrounding a case; scientists use interviews and tests. Detectives and scientists form hypotheses based on their prior knowledge about the cause of the events and rule out those that are unreasonable. Both detectives and scientists tend to be extremely cautious about their conclusions for similar reasons. Their conclusions must withstand critical scrutiny of a jury of peers or a court of law. An important difference between detectives and scientists is in the way they form and use generalizations. Scientists are concerned with arriving at general statements that allow grouping of apparently dissimilar events under a single rule or generalization. Detectives are more interested in breaking down or narrowing generalizations in solving their cases rather than in establishing generalizations that might be produced from their work.
As you develop your case think about other courses that you have taken while in school (e.g., history, mathematics, literature, art, music, science, and so forth) as you seek a resolution to the case that you have selected. However, you must not rely solely on information that you have learned while a student in school. Also, think about what you already know about stars, the experiences that you have had visiting sites, reading about stars, talking with other people, and any other information that you know about that has happened outside of your formal school experience. The important point to remember is that there are multiple ways to seek resolutions to the case. There is no one right answer. You are encouraged to use your imagination and to think about innovative ways in which to resolve your selected case topic.
Your case will involve you with objects in astronomy that can only be studied by observation. This study differs from solid-state physics in which samples of materials can be studied in a controlled way in a laboratory. You will be studying stars that are presently under investigation by astronomers. In some instances, you will be the first to make computations with stars that have just been identified as variable stars. In every case, you will be studying variable stars that are currently being studied by astronomers.
As part of your case study, you will be working with astronomers at Tennessee State University who are the primary scientists who first explored the use of automatic telescopes.
Automatic Photoelectic Telescopes (APTs) are telescopes used to make photoelectric measurements. They are "automatic" in the sense that a microcomputer has taken over the role of the human in the operation of the telescope and the photometer. You will be one of six high schools in the United States who will have access to the automatic telescopes located at the Fairborn Observatory at Washington Camp, near Nogles, Arizona that houses the largest collection of automatic telescopes in the world. You will be the first to participate with the astronomers at TSU in a full scale test of the NASA Ames Research Center's Automatic Principal Astronomer software package. This new automated software package will enable future space observations to operate efficiently. You will be directly involved with the technological and scientific aspects afforded with this software program.
You are about to enter a time machine that looks back into what has already happened. What makes this interesting is that you will be looking at objects and events that are impacting our lives today, even though they have already happened. In some instances, a light that we see being emitted from the sky is reaching us from stars that are hundreds, thousands, and even millions years away. How is this possible?
Your study will engage you with diverse aspects of variable stars. A variable star is a star whose brightness is not constant. This is one of the few fields in astronomy that an amateur can contribute to the knowledge of variable stars using instruments such as binoculars and small telescopes. You will have the opportunity to report your observations to the American Association of Variable Star Observers (AAVSO) that will add important information to their data base. The observations that you will make using visual (naked eye, binoculars, small telescopes), photography, and accessing automatic telescopes, and the data you collect and analyze will make a valuable contribution to astronomers who rely on this information to learn the case history of a star or want to plan their observing programs. The study of variable stars is important, because their degree of brightness is an indicator of their stages of evolution.