Astronomy 102 Lab

The Observing Log

• Format
• What Goes In The Observing Log
• Examples of Log Entries
• How to Make the Best Use of Your Time
• Observations and the Honor Code

Astronomy stands apart form the other physical sciences in that the evidence (or data) is obtained mainly by observations rather than by experimentation. In the same vein, the introductory astronomy lab is different from other science labs you may take at Vanderbilt: it is based mostly on observations of the sky, most of them done at night. The purpose of the Astronomy 102 labs is to become familiar with the night sky, to learn how to use a telescope, to help you develop skills in scientific observations, and to directly experience simple astronomical phenomena. During the semester, you will compile your naked eye and telescope observations in an observing log, a diary of sorts. Keeping a log brings continuity to your lab work, which is not neatly parceled into weekly, independent experiments, but much more flexible in nature. It will also allow you to see your skills in visual observations improve during the semester.

See the Lab Grading page for information about how and when your observing log will be graded.

Format

Use a 3-ring binder (1.5" thick will do) with pockets inside the covers.  Use dividers to present each lab in a separate section.  Use pencils rather than a pens. Since the log will be handwritten outdoors and at night, please make an effort to write legibly, don't be messy and maintain a decent level of organization. A log which we can't make sense of will get a poor grade.

What Goes In The Observing Log

Initially, you will spend a fair amount of time learning how to use the telescope and you will not be very effective in making observations. Your logbook entries should include the difficulties you encounter and your personal impressions as you first use the telescope and look at celestial bodies. Most of the entries in your log should be observations (what you see), both with the telescope and with the unaided eye. A variety of projects (observing the moon, planets, constellations, double stars, the sun, sunsets, spectra of stars, etc.) are described below. Everything you observe is to go in your log, in the form of sketches/drawings, notes, comments, measurements, etc., as appropriate for each type of object and project. The key is to pay attention to what you see! Your personal impressions about what you see and comments about the lab activities are also an important part log.

Examples of Log Entries

8/12/2000, 9:35pm CDT on Branscomb Quad (naked eye observation). The night is cloudless but hazy. Bright first quarter moon lights up the sky and only the brightest stars are visible. I spotted the Summer Triangle (Vega, Altair & Deneb) easily. The triangle is very large and overhead and it points "downward" (i.e. towards the South). Vega is the brightest star of the three and shines with a bluish-white light. It twinkles a lot. Using these three bright stars, I spotted several constellations: Cygnus, Aquila, Hercules. Constellations are sketched below. I couldn't see any of the stars in Lyra, except for Vega (haze + moon + light pollution?). I should try again on a better night.

[Your sketch here]

9/22/00, 8:23pm CDT on Library lawn. Lab night. The night is quite clear with a few scattered clouds. It is rather windy and the telescope shakes quite a bit. Observation of Jupiter with the telescope. With the 25mm eyepiece, Jupiter is a bright little ball with two gray bands straddling the equator. Three bright "stars" are located more or less in a line about the planet (see sketch below) and there are several fainter stars in the field. If these three stars are moons of Jupiter, I wonder where the 4th bright moon is (to figure out later). The view is much bigger with the 10mm eyepiece and more details can be seen on the surface. The image is somewhat blurry, however and details come and go. Our plan: make a sketch of the planet now [You will find templates for the planets in Appendix A3], go observe something else and come back for another sketch at the end of the lab period to see how much the planet has rotated in the meantime. Sketching is hard! Details are difficult to see. The sketch below is the most I could see with certainty. [Make a sketch of the planet. An example is given in the Jupiter lab ]. There is an interesting oval shape, like an "eye". TA says it is the famous Red Spot. Cool! Clouds moved in before my lab partner could sketch the planet again, so we can't figure out the rotation. Bummer.

[Your sketch here]

Note

Examples of sketches of planets, phases of the moon, constellations, etc. will be available in a binder at the observing facility. Templates with the correct outline of planets (and rings for Saturn) as well as for drawing the phase of the Moon will be provided by the TAs. Always use templates for these observations!

How to Make the Best Use of Your Time

The flexibility in the astronomy lab is intended to make up for cloudy lab nights when it is not possible to observe and also allow you some choice in the kind of objects you observe. If you have a productive, clear lab night, then you are not expected to do more observing on your own time. On a week when your lab night is clouded out, you should go out and make naked eye observations on your own time, scheduled as you please. Do not sit idle during labs if you have completed what the TA's had prepared for that evening. Use the telescope to look at other things, or spend time learning the constellations and star names, or make naked eye observations of the moon, etc. Put everything down in your log. Remember, the lab period is scheduled class time and it is 3 hours per week. Use it wisely. Should a long spell of cloudy weather mess with our plans, indoor lab activities will be assigned. In Nashville, we get the most clear night in September and October. The weather worsens rapidly in November. Do not postpone your observing activities until you can't conduct them because of bad weather!

Observations and the Honor Code

When using a telescope, you will be working with a lab partner. At other times, observing with a partner is appropriate and even encouraged. However, in all cases, the observations you report in your log book and the words must be your own. In some instances where frequent or extensive observations are required (observation of the orbit of the Moon and the Moon lab, for example), you can combine your observations with those of one partner to get a more complete picture. In this case, you must explicitly state who did what observations (give the name of your partner) and present your partner's observations as photocopies (not hand-drawn reproduction).  Failure to do so will be considered plagiarism, a violation of Vanderbilt's honor code.

It is understood that all observations you report in your log are to be made by actually looking at the sky. WARNING: Reporting "fake observations" is not recommended as it would constitute a violation of Vanderbilt's honor code. While you might get away with it, be advised that your professor has a lot of experience with this type of observations and will not be fooled easily. You should be aware that several students have been caught in the past. If you have any doubt about what is appropriate, ask the teaching staff.