The setting circles must be
Confused About Pointing the Telescope?
Beginners occasionally experience some confusion about how to point the telescope overhead or in other directions. In Figure 1 the telescope is pointed north as it would be during polar alignment. The counterweight shaft is oriented down- ward. But it will not look like that when the telescope is pointed in other directions. Let’s say you want to view an object that is directly overhead, at the zenith. How do you do it?
DO NOT make any adjustment to the latitude adjustment L- bolts. That will spoil the mount’s polar alignment. Remember, once the mount is polar aligned, the telescope should be moved only on the R.A. and Dec. axes. To point the scope overhead, first loosen the R.A. lock lever and rotate the tele- scope on the right ascension axis until the counterweight shaft is horizontal (parallel to the ground). Then loosen the Dec. lock lever and rotate the telescope until it is pointing straight overhead. The counterweight shaft is still horizontal. Then retighten both lock levers.
What if you need to aim the telescope directly north, but at an object that is nearer to the horizon than Polaris? You can’t do it with the counterweight down as pictured in Figure 1. Again, you have to rotate the scope in right ascension so that the counterweight shaft is positioned horizontally. Then rotate the scope in declination so it points to where you want it near the horizon.
ab
cd
Figure 14a-d. This illustration shows the telescope pointed in the four cardinal directions (a) north, (b) south, (c) east, (d) west. Note that the tripod and mount have been moved; only the telescope tube has been moved on the R.A. and Dec. axes.
To point the telescope directly south, the counterweight shaft should again be horizontal. Then you simply rotate the scope on the declination axis until it points in the south direction.
To point the telescope to the east or west, or in other direc- tions, you rotate the telescope on its right ascension and declination axes. Depending on the altitude of the object you want to observe, the counterweight shaft will be oriented somewhere between vertical and horizontal.
Figure 14 illustrates how the telescope will look when pointed at the four cardinal directions: north, south, east and west.
7. Astronomical Observing
For many users, the SkyView Pro 80mm ED EQ telescope will be a major leap into the world of amateur astronomy. This section is intended to get you ready for your voyages through the night sky.
Site Selection
Pick a location away from street lights and bright yard light- ing. Avoid viewing over rooftops and chimneys, as they often have warm air currents rising from them which distort the image seen in the eyepiece. Similarly, you should not observe through an open or closed window from indoors. Better yet, choose a site
Seeing and Transparency
Atmospheric conditions play a huge part in quality of view- ing. In conditions of good “seeing”, star twinkling is minimal and objects appear steady in the eyepiece. Seeing is best overhead, worst at the horizon. Also, seeing generally gets better after midnight, when much of the heat absorbed by the Earth during the day has radiated off into space. Typically, seeing conditions will be better at sites that have an altitude over about 3000 feet. Altitude helps because it decreases the amount of distortion causing atmosphere you are looking through.
A good way to judge if the seeing is good or not is to look at bright stars about 40° above the horizon. If the stars appear to “twinkle”, the atmosphere is significantly distorting the incom- ing light, and views at high magnifications will not appear sharp. If the stars appear steady and do not twinkle, seeing conditions are probably good and higher magnifications will be possible. Also, seeing conditions are typically poor during the day. This is because the heat from the Sun warms the air and causes turbulence.
Good “transparency” is especially important for observ- ing faint objects. It simply means the air is free of moisture, smoke, and dust. All tend to scatter light, which reduces an object’s brightness.
One good way to tell if conditions are good is by how many stars you can see with your naked eye. If you cannot see stars of magnitude 3.5 or dimmer, then conditions are poor. Magnitude is a measure of how bright a star is; the brighter a star is, the lower its magnitude will be. A good star to remem-
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