Tips on Using a Telescope

Cooling it Down

• To get the most out of a telescope, make sure the instrument is stored correctly when not in use. The ideal location is a cool, dry place where the storage temperature is the same as the viewing temperature. Doing this cuts down on the kaleidoscope effect apparent through the viewing lens as the telescope cools down to the viewing temperature. Many manufacturers have designed vents on the telescopes which helps cool them down. If a telescope is not equipped with a cooling vent, opening the reflector end to allow air in or, if this is not possible, moving the telescope broadside to the wind will help cool it down, according to Philip S. Harrington in his book, "Star Ware." Don't leave the telescope in the wind as turbulence can cause interference in the viewing tube.

The Observation Site

• The best place to put a telescope is an endlessly debated topic among astronomers. Due to an increase in light pollution, accessible places inside cities are becoming non-existent. Look for a place away from city lights, as high above sea level as possible that is also obstacle-free. Harrington recommends using national, state and local parks, with some offering special stargazing permits. Check with park officials. Other prime spots include golf courses, the desert, a hill or mountain and even your own yard.

Navigating the Night Sky

• There are several different maps available online which give guidance to the night sky depending on the time of month and year. Sky &Telescope magazine has, on its website, information on what is viewable in the night sky by week.
  There are two other ways to find objects in the night sky: star hopping and setting circles. Star hopping entails finding and centering a point in the telescope's finder and locking it into position. Locate the object to be viewed on a handheld star atlas, then turn the telescope toward it. Look for geometric shapes between fainter stars and the intended star, centering the shape in the finder. Harrington says to switch back and forth between the atlas and the telescope and hop from geometric pattern to geometric pattern, moving closer to the intended star until it is visible in the finder.
  Setting circles is more complicated and entails using the round, graduated scales found on the telescope's equatorial mounts to divide the sky into degrees. By using a calibration chart, the position of known stars can be fixed and used as a starting point for other objects in the sky. The telescope must be level and aligned and locked to the earth's polar axis--a difficult proposition if the instrument is located in the sand or on an uneven roof.