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7. astronomical Viewing
How to Find Interesting celestial objects
You need to use a star chart or atlas to help find objects so you won’t be disap-
pointed at what you see. Except for the moon and bright planets, it’s pretty
time-consuming to hunt down impressive nebulas and star clusters by trial-and-
error. You should have specific targets in mind before you begin looking through
the eyepiece.
Don’t spend a lot of money on a fancy, expensive star atlas until you have seen
all the brightest objects listed in a basic atlas. The Edmund Mag 6 Star Atlas is
highly recommended for all levels. A Planisphere will help you learn the constel-
lations visible at a given time of night and any particular date. Use a red-light
flashlight to preserve your night-adapted vision.
You can locate Saturn, Jupiter, Venus, Mars, and the other planets by referring to
the charts published in Astronomy or Sky & Telescope magazines each month.
These objects are fun to follow across the skies as the months go by.
Unless you know exactly where to look, you'll need a star atlas to locate celestial
objects. Don’t expect to find anything interesting without one! The universe is vast,
and it will take a LONG time to find interesting subjects if you just scan
at random!
the Moon
Night viewing of the moon and its surface detail is one of the easiest and most
interesting ways to first use your telescope. The best time to observe is when the
moon is not full, as the shadows on the surface reveal more detail. You may want
to try using more powerful optional eyepieces for observing the details of the
moon’s surface.
the Planets
Planets are the brightest objects beside the sun and the moon. While the posi-
tions of the stars remain fixed relative to each other, the positions of each planet
are constantly changing. Don’t be disappointed that you can’t tour all the visible
planets when your first get your telescope . . . you must limit yourself to planets
which happen to be well placed for observing at the moment.
Some daily newspapers, the magazines Sky & Telescope and Astronomy, or
Abrams Planetarium Sky Calendar will tell you the location of planets and the
times they are visible. Your SkyView 4.5 is capable of showing you the planets
Venus, Mars, Jupiter and Saturn in some detail. Other planets may be visible but
will likely appear star-like. Since planets are quite small, optional higher power
eyepieces are recommended and often needed for detailed observations.
JUPITER The largest planet, Jupiter, is a great subject for the SkyView 4.5. You
can see the disc of the giant planet, and watch the ever-changing positions of four
of its largest moons – Io, Callisto, Europa, and Ganymede. Higher-power eye-
pieces should bring out the cloud bands and perhaps even the Great Red Spot
(which has faded to yellow in recent years).
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Unstable atmosphere or atmospheric distortions (dust in the air, air currents, etc.)
will show up at higher magnifications. With an out-of-focus star image, any move-
ment across the “disc” will be a result of an unstable atmosphere. Make sure you
are not looking over buildings or any other source of heat: that will also cause the
image to become distorted.
If the movement is on one side of the disc, or there is a distinct slow moving bump
or spike in one section, this is an indication of tube currents. To solve this problem,
let the telescope cool down longer, or store cold (outside garage or storage facil-
ity) to minimize the temperature change needed to reach equilibrium.
Do You Wear Eyeglasses?
Keep your glasses on to begin with. Just look though the eyepiece and adjust the
focus knob for the best image. Many people prefer to remove their glasses and
just re-focus the telescope (especially with higher power eyepieces).
Preserve Your night Vision
Don’t expect to walk directly from a normally-lit house into a back yard, and imme-
diately see faint nebulas, galaxies, or star clusters. Your eyes take about 30
minutes to reach perhaps 80% of their full dark-adapted sensitivity. Many observ-
ers notice improvements after several hours of total darkness. Very bright daylight
for extended times can affect your night vision for days. So please, give yourself
at least a little while to get used to the dark. (Nearby porch and street lights seri-
ously affect night vision, as do automobile headlights.)
Eyepiece selection
Always start up with your lowest-power, widest-field eyepiece. Of the telescope’s
standard eyepieces, the 25mm Kellner provides 36.4x magnification, which is
moderately low and provides very bright images of deep space objects; the 9mm
provides 101x. Many other eyepieces are available for more detailed close-up
viewing and for even lower power, wider field viewing. Most amateur astronomers
will end up with a selection of three to six eyepieces, making it possible to choose
the right magnification, brightness, and contrast for each object and for different
observing conditions.
Switch up to higher magnification eyepieces only after you’ve located a small
object. Most viewers use the lowest-power eyepiece all the time! Keep in mind that
higher powers will always be fainter and less sharp (this is a fundamental law of
optics). Naturally, higher magnifications are desirable for viewing many celestial
objects; we simply want to emphasize to the beginner that the low magnification
eyepiece is definitely the one to use when searching for an object and for extend-
ed viewing.
Exotic, extra-heavy eyepieces may cause enough imbalance on the tube that you
will need to adjust the counterweight for optimum tube balance.