Celestron G-9.25 - Nighttime Observing

Telescope Basics • 23
Nighttime Observing
Looking at objects in the sky is quite different than looking at objects on Earth. For
one, many objects seen in the daytime are easy to see with the naked eye and can be
located by using landmarks. In addition, objects on the ground are stationary, at
least for the most part. In the night sky you will see a tremendous amount of stars
through the telescope that are not visible to the naked eye. One way to find objects
(at least initially) is by using other stars to guide you there. This method of finding
objects, known as star hopping, is very accurate. Yet it requires a fair amount of time
to learn the stars well enough to guide you to other objects. In addition, the stars will
appear to drift out of the field of view. This is due to the Earth’s rotation. In fact,
anything in the sky, day or night, will drift out unless the telescope has been polar-
aligned and the optional motor drive is running. There is more on this in the section
on “Polar Alignment.”
1. Orient the telescope so that the equatorial mount is pointing north, as close to
true north as possible. You can use a landmark that you know faces north to get
you in the general direction.
2. Adjust the mount until the latitude indicator points to the latitude of your
observing site.
3. Insert the eyepiece (low power) into the telescope to give you the widest field
possible.
4. You are now ready to observe.
5. Release the right ascension and declination clamps and point the telescope at the
desired target. The Moon or one of the brighter planets is an ideal first target.
6. Locate the object in the finder.
7. Lock the R.A. and DEC clamps to hold the telescope in place.
8. Center the object in the finder using the slow motion knobs.
9. Turn the focus knob until the image is sharp.
10. Take your time and study your subject. If looking at the Moon, look for small
details in the craters.
That’s all there is to using your Celestron telescope. However, don’t limit your view
of an object to a single eyepiece. After a few minutes, try using a different optional
eyepiece, a more powerful one. This gives you an idea of how the field of view
changes.