1. Test Your Eyesight

Here is a diagram of the Pleiades star cluster, in the constellation Taurus, the Bull. The magnitudes of the stars are indicated with the decimal point missing. Thus, 59 = 5.9. Make a copy of this diagram with a pencil and paper. (This will help you learn the stars.) Some night, when this constellation is up, find out how faint you can see. Do it again when the moon is shining and see what the effect is. Or, do it just after you come outside and before your eyes are dark adapted. Then wait a quarter-hour and do it again. Repeat after another quarter-hour. How long does it take for you to become fully dark-adapted?

2. Star Time

The constellations move westward in the sky each night. Also, if you observe them carefully at the same time each night, you will notice that they move westward with the passing weeks. This means that, to catch the constellations at the same part of the sky, you would have to go out a little earlier each night.

Here is a task for you. Select an observing spot where you have a good view southward and have some markers, such as trees, telephone poles, or houses to determine the location of the stars. Make a drawing of the location of some prominent stars at a convenient time one night about an hour or two after dark. Then go back a week later and try to determine the exact time when the stars are in the same position as they were before. From this, you can calculate how many minutes earlier the stars are each night. It may not be accurate with only one week's observation, so try it again after another week or two.

When you have an answer, send me an e-mail message

3. Finding North

North and south are defined as the direction of the point about which the stars seem to rotate. How many different ways can you think of to determine north (if you are in the northern hemisphere) or south (if you are in the southern hemisphere)? For example you might suggest taking a long time exposure of the stars and finding the circular star trails with the North (or south) at the center of the circles.

Don't forget, you can also use the sun during the day time.

Send me your list by e-mail , with a good description of each method, and I will post them on the Web Page.

4. Apparent size of the moon

Here is one that requires some geometry. If you had a one-foot ruler, how many feet away from your eye would it have to be to just reach across the face of the moon? What about the sun? What if you only had a yard stick. How many yards away would it have to be to just reach across the moon?

Send me your result by e-mail , with a good description of your method.

5. Build a Giant Sundial

You can build a giant-sized sundial that will tell time to withing five or ten minutes. Just find a flat aread of ground and plant a tall stick on the south side -- or the north side if you live south of the equator. Then follow the progress of the tip of the shadow. Put a small marker in the ground every half hour with a label on it. (Tongue depressors would be good, or popsicle sticks.) Another way is to put a small mirror on a window sill of a south facing window and mark the ceiling where the spot of light falls, using removable sticky dots.

One of the interesting things to watch is how the position of the shadow changes with the seasons. So, after you have made a complete set of hour or half-hour markers, leave them in place for a few months and then come back and do it again. What do you expect to find? How does this agree with what you actually find?

6. Variable Stars

Here is a more ambitious set of projects. The following diagrams show the locations in their constellations of some naked-eye stars whose brightnesses vary significantly. Your first task is to locate several of these stars in the sky by comparing these diagrams with a chart of the constellations. (See a current issue of Sky & Telescope Magazine if you need a constellation map.) Then watch them carefully for a month or two, making an estimate of their brightness by comparison with other stars in the neighborhood. (For example, you can note that Beta Lyrae is just as bright as the star next to it in Lyra, and then becomes as faint as the star across from it.)

These stars have very different behaviors and the lengths of the cycle of variation are also very different, If you are patient, the variations will reveal themselves. Keep a diary. Let me know by e-mail when you have some results or if you want more information about making the observations. Another good source of information that can be contacted on the Web is the AAVSO (see STAR FINDER Resources). By joining the AAVSO you can get access to finder charts and instruction books.

[ ]

Beta Lyrae is near Vega and it is an eclipsing binary star.

[ ]
Beta Persei (Algol) is also an eclipsing binary and it was probably known the the ancients.

[ ]

Eta Aquilae is a pulsating star whose brightness changes are rather smoothe.

[ ]

R Leonis is a red star that will disappear completely from sight.

[ ]

Chi Cephei is a red star, and behaves somewhat like R Leonis.

[ ]

Delta Cephei is like Eta Aquilae.

Diagrams from Patrick Moore, The Pocket Guide to Astronomy.

7. Astrophotography of Constellations

Fun with a Tripod and Camera:
Here is a site that gives an introduction to the simplest method using a small camera and a tripod. If you make unguided exposures short enough (1 minute or less) you don't need to worry about the motion of the stars. It's amazing how much you can do with the simplest approach if you have a good lens and fast film.

Building a simple guider Astronomy Magazine Website has useful lists of sources of equipment. It also has a very nice article on astrophotography and advice on building a simple "barn door" star tracker

[Top]