14
Start by choosing bright objects to view. The brightness of
an object is measured by its visual magnitude; the brighter
an object, the lower its magnitude. Choose an object with a
visual magnitude of 9 or lower. Many beginners start with the
Messier objects, which represent some of the best and bright-
est deep-sky objects, first catalogued about 200 years ago by
the French astronomer Charles Messier.
Determine in which constellation the object lies. Now, find the
constellation in the sky. If you do not recognize the constella-
tions on sight, consult a planisphere. The planisphere gives an
all-sky view and shows which constellations are visible on a
given night at a given time.
Now, look at your star chart and find the brightest star in the
constellation that is near the object you are trying to find. Using
the finder scope, point the telescope at this star and center it
on the crosshairs. Next, look again at the star chart and find
another suitably bright star near the bright star currently cen-
tered in the finder. Keep in mind that the field of view of the
finder scope is about 7°, so you should choose another star
that is no more that 7° from the first star, if possible. Move the
telescope slightly, until the telescope is centered on the new
star.
Continue using stars as guideposts in this way until you are
at the approximate position of the object you are trying to find
(
Figure 19
). Look in the telescope’s eyepiece, and the object
should be somewhere within the field of view. If it’s not, sweep
the telescope carefully around the immediate vicinity until the
object is found.
If you have trouble finding the object, start the star hop again
from the brightest star near the object you wish to view. This
time, be sure the stars indicated on the star chart are in fact
the stars you are centering in the eyepiece. Remember, the
finder scope (and main telescope eyepiece, for that matter)
gives an inverted image, so you must keep this in mind when
star hopping from star to star.
XI. Care and Maintenance
If you give your telescope reasonable care, it will last a lifetime.
Store it in a clean, dry, dust-free place, safe from rapid chang-
es in temperature and humidity. Do not store the telescope
outdoors, although storage in a garage or shed is OK. Small
components like eyepieces and other accessories should be
kept in a protective box or storage case. Keep the caps on the
front of the telescope and on the focuser drawtube when it is
not in use.
Your SpaceProbe 130ST EQ telescope requires very little
mechanical maintenance. The optical tube is steel and has a
smooth painted finish that is fairly scratch-resistant. If a scratch
does appear on the tube, it will not harm the telescope. If you
wish, you may apply some auto touch-up paint to the scratch.
Smudges on the tube can be wiped off with a soft cloth and a
household cleaner.
Cleaning Lenses
Any quality optical lens cleaning tissue and optical lens clean-
ing fluid specifically designed for multi-coated optics can be
used to clean the exposed lenses of your eyepieces or find-
er scope. Never use regular glass cleaner or cleaning fluid
designed for eyeglasses. Before cleaning with fluid and tissue,
however, blow any loose particles off the lens with a blower
bulb or compressed air. Then apply some cleaning fluid to a
tissue, never directly on the optics. Wipe the lens gently in a
circular motion, then remove any excess fluid with a fresh lens
tissue. Oily fingerprints and smudges may be removed using
this method. Use caution; rubbing too hard may scratch the
lens. On larger lenses, clean only a small area at a time, using
a fresh lens tissue on each area. Never reuse tissues.
Cleaning Mirrors
You should not have to clean your telescope’s mirrors very
often; normally once every year or so. Covering your telescope
when it is not in use will prevent dust from accumulating on
the mirrors. Improper cleaning can scratch mirror coatings, so
the fewer times you have to clean the mirrors, the better. Small
specks of dust or flecks of paint have virtually no effect on the
visual performance of the telescope.
The large primary mirror and the elliptical secondary mirror of
your telescope are front-surface aluminized and over-coated
with hard silicon dioxide, which prevents the aluminum from
oxidizing. These coatings normally last through many, many
years of use before requiring re-coating (which is easily done).
To clean the secondary mirror, remove the mirror in its hold-
er from the 4-vaned spider in the tube. Do this by grasping
the secondary mirror holder with your fingertips while turning
the central bolt on the spider’s central hub counterclockwise.
Handle the mirror holder only; do not touch the mirror surface.
Then follow the same procedure described below for cleaning
the primary mirror. The secondary mirror is glued into its hold-
er, and should not be removed from the holder for cleaning.
To clean the primary mirror, carefully remove the mirror cell
from the telescope. Do this by first removing the four screws
that connect the mirror cell to the tube. These screws are locat-
ed on the outside of the tube, just above the mirror cell casting.
Next, remove the primary mirror from the mirror cell; you will
need to remove the three mirror clips to do this. Completely
unthread the two Phillips head screws on each clip, and care-
fully lift the mirror from its cell. Be careful not to touch the front
surface of the mirror with your fingers. Set the mirror with the
aluminized face up on a clean, soft towel. Fill a clean sink,
free of abrasive cleanser, with room-temperature water, a few
drops of liquid dishwashing detergent, and if possible, a cap-
full of rubbing alcohol. Submerge the mirror (aluminized face
up) in the water and let it soak for several minutes (or hours if
it’s a very dirty mirror). Wipe the mirror under water with clean
cotton balls, using extremely light pressure and stroking in
straight lines across the surface. Use one ball for each wipe
across the mirror. Then rinse the mirror under a stream of luke-
warm water. Any particles on the surface can be swabbed gen-
tly with a series of clean cotton balls, each used just one time.
Dry the mirror in a stream of air (a “blower bulb” works great),
or remove any stray drops of water with the corner of a paper
towel. Water will run off a clean surface. Cover the mirror sur-
face with tissue, and leave the entire assembly in a warm area
until it is completely dry before reassembling the telescope.
