Orion ED EQ - Manual (Page 15)

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special about seeing an astronomical object in real time, with
your own eyes — “live,” if not in living color.
How to Find Deep-sky objects: Starhopping
Starhopping, as it is called by astronomers, is perhaps the
simplest way to hunt down objects to view in the night sky. It
entails first pointing the telescope at a star close to the object
you wish to observe, and then progressing 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 technique that has been
employed for hundreds of years by professional and amateur
astronomers alike. Keep in mind, as with any new task, that
starhopping may seem challenging at first, but will become
easier over time and with practice.
To starhop, 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 constel-
lations in the night sky, you will need to get 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 bright-
est deep-sky objects. These were 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 approximately 5°, so you should
choose another star that is no more that 5° 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 16). 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 starhop 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
starhopping from star to star.
8. terrestrial observing
The SkyView Pro 100mm ED optical tube can be used for
long-distance viewing over land. For this we recommend
using an optional 1.25" 45° correct-image diagonal instead
of the provided 2" 90° mirror star diagonal. The correct-image
diagonal will yield non-reversed images and provides a more
comfortable viewing angle. To install the correct-image diago-
nal, first remove the 2" diagonal from the focuser drawtube
by loosening the two thumb screws on the drawtube. Now,
place the "camera adapter" that came attached to the tele-
scope (see Figure 4) into the focuser drawtube, and secure it
with the two thumb screws on the drawtube. Now, place the
correct-image diagonal into the camera adapter, and secure
it with the thumb screw on the camera adapter. Place an eye-
piece into the diagonal, secure it with the thumb screw on the
diagonal, and you’re ready for daytime viewing.
An optional altazimuth mount or a sturdy camera tripod, as
opposed to the SkyView Pro equatorial mount, is recom-
mended for terrestrial viewing. This is because the equatorial
mount is designed for tracking the motion of stars, and is not
easy to aim at terrestrial objects.
For terrestrial viewing, it’s best to stick with low power eye-
pieces that yield a magnification of under 100x. At higher
Figure 16. Starhopping 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.