Astronomy 110 Laboratory: Student Guide

Fall 2007 Astronomy 110L Thurs. 6:00 - 9:00 pm


Our motivation in developing this class came from our students. Over the years, many Astronomy 110 students have said they wanted to study and observe the night sky. This astronomy laboratory was developed to give students some practical knowledge of the stars and some real, `hands-on' observing experience. We assume that you are truly motivated and interested, and that you are willing to invest some time in learning the stars and the use of telescopes. These are not terribly difficult subjects, and anyone can learn something about them. Nonetheless, you will need commitment to do well in this class. Although we have asked you to buy a book to serve as a guide to the night sky, this subject can't be learned from a book or lectures. The point of this course is to see for yourself.

When studying astronomy in this way, some patience is necessary. For example, the weather may be bad when we go out to observe. Even when circumstances seem good, the things we are trying to see may be hard to find, indistinct, or just plain invisible; the best course of action may be to keep on looking, find something else to look at, wait until conditions improve, or try again another night. Finally, observing the universe makes new demands on your visual abilities; you will have to learn new ways to use your eyes, and that will take time.

I can help you in this process, but I can't work miracles. If you get frustrated, you will have to find your own motivation to keep on looking - because if you don't look, you won't see anything! How you find your motivation is your business. Your motives are part of your personality, and I can't change your personality any more than I can tell you what foods to eat, what music to enjoy, or what kind of friends to make. If you understand that your motivation is your responsibility, I welcome you to this class and to the study of astronomy.

We have detected two trends in student behavior: (1) some students want to take Astr 110 Lab without taking Astr 110. And we noticed, from the results of quizzes, that students that had taken Astr 110 did not perform better than those who had not. For those reasons I decided to try a new approach, making an Astr 110 Lab which is self-contained and does not require any previous exposure to Astr 110. We will study the results of this 2007 experiment, guided both by our evaluation of the results of the course, and by the comments voluntarily provided by the students.


Working in pairs or groups is quite common in science labs, and this lab is no exception. Teamwork can be quite effective; it's often possible to figure things out faster if you work with another person, and some experiments are much easier with two pairs of hands. We have designed many of these projects for teams of two to four people.

When making measurements, we strongly urge you to make the observation yourself, individually, so that you get the educational value and experience of using the equipment and "seeing for yourself". Then, after all the group members have tried, you can compare your results as a "sanity check". If your results differ just a bit, then keep your own results. Most scientific measurements are affected by random errors (to be discussed in class) so you should NOT change your results to match your friend's results. Of course, if your results differ wildly, then you should try to figure out what went wrong.

In a real team, everybody is actively involved and contributes to the group effort. To insure that everybody is involved, we require you to use your own words in writing your observing log and lab reports. This is very important - expressing yourself with your own words will help you to understand the material. It's pretty obvious when people copy from each other, and we will not give credit if people turn in identical work! On the other hand, we will give you credit if you use your own words - because that shows that you understand what you have been doing.


As already emphasized, the point of this course is to observe as much as we can. We will try to observe every night the weather seems reasonably good, and meet indoors only when bad weather rules out any kind of observation.

Unfortunately, the UH campus is not a good place for observations; there are too many lights, and Manoa is often cloudy. Therefore, we will be making field trips to observe. Most of our observing session will be in Kapiolani park. As an observing site, Kapiolani park is not ideal, but it is better than campus and it's easy to get there. We will also arrange several trips to really dark sites where we can observe fainter stars.


Astronomy is a very safe activity. Unlike some science labs, we have little need for hazardous materials or equipment (you might burn your fingers on a hot light-bulb, but only if you grab it at the wrong time). We will be working outdoors at night, but we are a large group and there is safety in numbers. Still, people sometimes feel nervous being outside at night in a fairly dark place; if you feel threatened, please let us know.

There is one safety rule which must be emphasized, even though it may not seem all that relevant to this class: NEVER LOOK AT THE SUN THROUGH ANY TELESCOPE OR BINOCULARS unless you are using a professionally-designed solar filter! It's important that the filter cover the entire aperture of the telescope or binoculars and that it is securely attached so it can never fall off by accident. The telescopes we use in this class can take all the sunlight falling on an eight-inch circle and concentrate it into a spot half an inch in diameter. That concentrated light is about 250 times brighter than normal sunlight; it can permanently destroy your vision in much less time than it takes you to blink your eye.

For legal reasons, we do require you to sign a release form before the first field trip. This is the same form used for field trips in other classes at UH.


We will be observing outside at night for several hours at a time, and you should plan to dress appropriately. It can get a little cool in the evenings, and clothes which were comfortable in mid-afternoon will not keep you warm enough at night. Wear loose-fitting clothes you can move around in easily, and bring a sweater or jacket. We may have to wait out the occasional shower, so bring a poncho or umbrella.

Low blood sugar makes it harder to see faint stars; you may want to bring a snack along when we are observing.

Nicotine impairs your night vision, and you should avoid smoking before or during the class (or at any other time, if you want to live to see the next return of Halley's comet). If you must light up, wait until we take a break, and move well away from the telescopes and from anyone who might not like the smell of cigarette smoke.


We will provide all the key equipment for this class, including telescopes, binoculars, and other optical aids. Detailed instructions will be given in class; this is just a summary.

  1. 8-inch Dobsonian Reflecting Telescopes.

    These are robust and simple to operate, yet quite powerful when used properly. We have one scope for every four students in this lab.

  2. 10 × 50 Binoculars.

    Binoculars are useful for star-gazing; they help to bridge the gap between naked-eye and telescopic views. We have one pair of binoculars for every student.

  3. Red Observing Flashlights.

    Red light enables you to see your notes and sketches without ruining the dark adaptation of your eyes. We have one flashlight for every student.

  4. Refracting Telescope Kits.

    These simple kits will help you understand the operating principles of larger telescopes. We have one kit for every student.

  5. Spectroscope Kits.

    A spectroscope is a device which separates light by color (technically, by the wave-length of the photons). We have one kit for every student.

  6. Cross-staff.

    A cross-staff is a simple device for measuring angles - for example, the angle between two stars. We have one for every student.

You will need to buy a few items for this class. Most are available at the UH bookstore or your local shopping center:

  1. A bound notebook to use as an observing log.
  2. A ring binder for handouts and other course material.
  3. Blank, unlined paper for sketching; pages should be 8.5×11 inches. If you buy a pad of blank paper, be sure the individual pages are easy to remove.
  4. A clip-board, useful in making drawings while observing.
  5. Pens, pencils (colors optional), pencil sharpener, eraser, etc.
  6. A ruler marked in centimeters. Should be at least 30 cm long.
  7. A calculator - ideally, one which can handle scientific notation for very large and very small numbers. Advanced math functions will not be necessary.
  8. A straw beach-mat or blanket - convenient when viewing constellations directly overhead.


In the website of this course you will find information about most of the projects we will undertake. You are supposed to read the information. It will help you to get a better idea of what we plan to do. We will not produce handouts with this information, unless you report that you cannot make your own printouts. Because we can't predict the weather a week in advance, we will often announce two projects for the next meeting: one dealing with some kind of observation, and another involving indoor lab work in case of bad weather. You are expected to read the available information about these projects in advance. It will save us all a lot of time. If we wind up observing, we will generally recycle the indoor project for the following week. If we have to work indoors, we may or may not be able to recycle the observing project; some observations can only be made at specific times.


As part of this class, you should keep a log of your observations and experiments in your lab notebook. Doing so helps you remember what you have seen and done. Your log does not have to be very elaborate, but it should be reasonably accurate and complete. We will not inspect your observing log, and it will not impact your grade, so you might be tempted to do nothing about it. That is your decision, but it would be a mistake. If you do not write down things, you will soon forget everything. You will have trouble completing your reports, and later on you will forget everything you saw and learned in this course. It's your choice.

To insure accuracy and avoid the temptation to alter previous entries, you should use only pens, and not pencils, when logging your observations. Never erase what you have written; instead, cross it out with a single line. Neatness is not so important as long as your writing can be read and the order in which you have written things down is clear.

Begin your notes on each observing session or lab on a fresh page. Start by writing down the place, date, time, and weather conditions on the upper right of the page. Also note if the Moon is up, since moonlight has a big influence on the visibility of faint stars. Make a note if conditions change while you are observing.

Write a brief entry in your log for each observation you make. Include the subject of your observation, the equipment you used, and a few descriptive words to help remember what you saw. If you were using a telescope, note which eyepieces you used. A small sketch of your observations can be included right next to the log entry; if you make a more detailed drawing on loose paper, make a note of it in your observing log.


Drawing astronomical objects is a very good way to improve your observational skills. When you make a drawing you concentrate on what you are seeing; as a result, you will see things you might not have noticed, and remember more of what you have seen. Artistic ability can help, but the point is not to produce beautiful pictures, so don't worry if your sketches are not artistically satisfying. The main point is to make a serious effort to represent what you see on paper. If you try, you may be surprised at how much you can actually show in a drawing. On the other hand, if you have no artistic inclinations, we will not force you to draw anything. Your grade will depend only on the result of the quizzes and our evaluation of your project reports.

Rough sketches can be included in your observing log, but there are several reasons to use a separate pad of blank paper for more detailed drawings. First, the lined paper in your log book tends to confuse your eye; blank paper simplifies the process of comparing your drawing to your subject. Second, you can - and should - use the entire page, instead of cramping your drawing into a corner of the log book. Third, you can - and should! - use pencils instead of pens, and you can also erase as needed, since the goal is the final drawing, not the stages you went through in producing it.

On each drawing you make, you should note the name of the object, the date and time, and any equipment you used. Don't forget to list each drawing in your observing log.


A second component of your work is writing up the observations and experiments you have performed. This allows you summarize your work and draw conclusions from your observations. Detailed instructions will be provided with each assignment, but in general we expect you to follow the traditional format for lab reports, which includes an introductory section, a description of the equipment used, a summary of your results, and a discussion of your conclusions.


Instead of a final exam, we will have a short quiz almost every week. The quiz may be given indoors at the start of class, or outdoors during an observing session; you should be ready for either one, since we won't know ahead of time if we will be observing or working inside. The quiz will test you on the reading assignment or on the activities of the previous weeks. You can probably do well on the quizzes without extra study, but it is important to do all the assigned reading, and a good idea to briefly review last week's work before coming to class.

Each indoor quiz will have one question requiring a short written answer. The quiz will start at 6:05 pm, and end by 6:15 pm. We will close the door when the quiz starts and ask anyone who comes late to wait outside until the quiz is over; this is to spare people taking the quiz the distraction of late arrivals. Because of organization limitations, quizzes may not be made-up for any reason.

Outdoor quizzes will be given one-on-one during an observing session. They will test practical observing skills and familiarity with the night sky; for example, we may ask you to point to a constellation we studied the week before, or focus a telescope on a particular star.

Before setting your final grade, we will drop your two lowest quiz grades; thus you can miss two quizzes without directly affecting your final grade. This should not be taken as encouragement to skip any quizzes! If you decide to skip a quiz, you risk missing an opportunity to do well on what may turn out to be an easy question. To increase your chances of a good final grade, you should make a point of showing up in time for all quizzes!


Unlike some classes, this class is not graded on a curve. Curves predetermine the percentages of students getting As, Bs, Cs, and Ds; that seems unfair, and may discourage people from trying to do better. You will get written comments and letter grades (including plus and minus grades, when appropriate) on your quizzes, and on each report or drawing you turn in. We will provide as much feedback as possible so you will know how you are doing in this class.

Your final grade will depend on the lab reports and drawings you hand in, and the quizzes you take in class. In case of doubt we will consider your attendance record. Lab reports count for 70%, and quizzes for 30% of the total grade. Your final grade will be lowered by one-third of a letter for every two lab sessions you have missed without a valid excuse (for example, if you total grade was an "A-", but you missed two sessions, your final grade would be a "B+"). Valid excuses include serious illness, family emergencies, and the like; we can make allowances for sports or cultural activities if you bring a note from your coach or instructor beforehand.


As a university student, you may be going through a time of rapid change. Perhaps you are living away from home for the first time. You have new freedoms - the freedom to decide your own hours, chose your associates, set your own priorities. With those freedoms come some new responsibilities.

Attendance is one of your responsibilities. We will take attendance each time the class meets. You can miss one lab without penalty; if you miss two or more without a valid excuse, your final grade will suffer, and you may fail the class.

Your responsibilities do not end when you come to class. I don't expect you to pay full attention every moment, but if your attention wanders then you must make an effort to focus again. I can't direct the focus of your mind - you are the only person who can do that. We will take 15 minute breaks at suitable points through each class; please limit social activities and discussions unrelated to astronomy to the breaks.

You are also responsible for handling the equipment with care. Telescopes and accessories are expensive, and we can't afford many replacements or repairs. Accidents can be forgiven, but carelessness is another matter; anyone who recklessly or deliberately damages equipment will automatically fail the course.

We will automatically fail anyone who is drunk or intoxicated in class.

It is your responsibility to know and follow the rules for the labs, reports, and quizzes. These rules are designed to make sure that everyone gets full credit for their work. Someone who tries to gain credit without doing the work, or tries to prevent other people from getting credit for the work they have done, is cheating. Any action which gives someone an unfair advantage cheats everyone else. Treat other students as you'd like them to treat you.

Roberto H. Méndez (

Last modified: August 23, 2007