Celestron 91525 Telescope User Manual


 
Celestial Observing 43
CELESTIAL OBSERVING
With your telescope set up, you are ready to use it for observing. This section
covers visual observing of both solar system and deep-sky objects.
In the night sky, the Moon is a prime target for your first look because it is
extremely bright and easy to find. Often, it is a temptation to look at the Moon
when it is full. At this time, the face we see is fully illuminated and its light can
be overpowering. In addition, little or no contrast can be seen during this
phase.
One of the best times to observe the Moon is during its partial phases (around
the time of first or third quarter). Long shadows reveal a great amount of detail
on the lunar surface. At low power you will be able to see most of the lunar
disk at one time. The optional Reducer/Corrector lens allows for breathtaking
views of the entire lunar disk when used with a low power eyepiece. Change to
higher power (magnification) to focus in on a smaller area. Keep in mind that if
you are not using the clock drive, the rotation of the Earth will cause the Moon
to drift out of your field of view. You will have to manually adjust the telescope
to keep the Moon centered. This effect is more noticeable at higher power. If
you are using the clock drive and have polar aligned, the Moon will remain
centered if using the lunar tracking rate. Consult your local newspaper or a
current astronomy magazine to find out when the Moon will be visible.
LUNAR OBSERVING HINTS
To ensure accurate tracking, be sure to select the lunar tracking rate.
Try using eyepiece filters to increase contrast and bring out more detail on
the lunar surface.
Other easy targets in the night sky include the five naked eye planets. You
can see Venus go through its lunar-like phases. Mars can reveal a host of
surface detail and one, if not both, of its polar caps. You will be able to see
the cloud belts of Jupiter and the great Red Spot (if it is visible at the time you
are observing). In addition, you will also be able to see the moons of Jupiter as
they orbit this gas giant. Saturn, with its beautiful rings, is easily visible at
moderate power. All you need to know is where to look. Most astronomy
publications tell where the planets can be found in the sky each month.
King or sidereal rates work best for tracking the planets.
Observing the Moon
Observing the Planets
Figure 6-1
This scanned drawing of
Jupiter provides a good
representation of what you
can expect to see with
moderate magnification
during good seeing conditions.