Orion SPACEPROBE 130ST EQ - Manual (Page 14)

D. The Stars
Stars will appear like twinkling points of light. Even power-
ful telescopes cannot magnify stars to appear as more
than a point of light. You can, however, enjoy the different
colors of the stars and locate many pretty double and mul-
tiple stars. The famous “Double-Double” in the constellation
Lyra and the gorgeous two-color double star Albireo in
Cygnus are favorites. Defocusing a star slightly can help
bring out its color.
E. Deep-Sky Objects
Under dark skies, you can observe a wealth of fascinating
deep-sky objects, including gaseous nebulas, open and
globular star clusters, and a variety of different types of gal-
axies. Most deep-sky objects are very faint, so it is important
that you find an observing site well away from light pollution.
Take plenty of time to let your eyes adjust to the darkness.
Do not expect these subjects to appear like the photographs
you see in books and magazines; most will look like dim gray
smudges. Our eyes are not sensitive enough to see color in
deep-sky objects except in a few of the brightest ones. But
as you become more experienced and your observing skills
get sharper, you will be able to ferret out more and more
subtle details and structure.
How to Find Deep-Sky Objects: Star Hopping
Star hopping, as it is called by astronomers, is perhaps the
simplest way to hunt down deep-sky objects to view in the
night sky. It entails first pointing the telescope at a bright star
close to the object you wish to observe, and then progress-
ing to other stars closer and closer to the object until it is in
the field of view of the eyepiece. It is a very intuitive tech-
nique that has been employed for hundreds of years by pro-
fessional and amateur astronomers alike. Keep in mind, as
with any new task, that star hopping may seem challenging
at first, but will become easier over time and with practice.
To star hop, only a minimal amount of additional equipment
is necessary. A star chart or atlas that shows stars to at least
magnitude 5 is required. Select one that shows the positions
of many deep-sky objects, so you will have a lot of options
to choose from. If you do not know the positions of the con-
stellations in the night sky, you will need a planisphere to
identify them.
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
brightest 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 cur-
rently centered 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 pos-
sible. Move the telescope slightly, until the telescope is cen-
tered 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 13). 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.
8. 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 changes in temperature and humidity. Do not store the
14
Figure 13. Star hopping is a good way to locate hard-to-find
objects. Refer to a star chart to map a route to the object that uses
bright stars as guideposts. Center the first star you’ve chosen
in the finder scope and telescope eyepiece (1). Now move the
scope carefully in the direction of the next bright star (2), until it
is centered. Repeat (3 and 4). The last hop (5) should place the
desired object in the eyepiece.