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a star is - the brighter a star is, the lower its magnitude will
be. A good star to remember for this is Megrez (mag. 3.4),
which is the star in the "Big Dipper" connecting the handle to
the "dipper" (Figure 8). If you cannot see Megrez, then you
have fog, haze, clouds, smog, or other conditions (such as
light pollution) which are hindering your viewing.
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2.4
1. 7
1. 9
Figure 8.
Megrez connects the Big Dipper's handle to it's "pan".
If you can not see Megrez (a 3.4 mag star) then viewing conditions
are poor.
light Pollution
Most of us live where city lights interfere with our
view of the heavens. As our metropolitan areas have
become more developed, the scourge of light pollution
has spread, washing out many stars and nonstellar
celestial objects from our sight. Faint deep sky objects
become difficult or impossible to see through the murk
of light pollution. Even bright nebulas like the Orion and
Lagoon Nebulas lose much of their delicate detail. The
Moon and planets are not affected; they require steady
air more than dark skies, so they remain good targets
for city-dwelling observers.
The International Dark-Sky Association is waging the
fight against light pollution. The IDSA was founded in
1988 with the mission of educating the public about
the adverse impact that light pollution has on the night
sky and astronomy. Through educational and scien-
tific means, the nonprofit IDA works to raise awareness
about the problem and about measures that can be
taken to solve it.
Do you need help dealing with local officials to con-
trol street or building lighting in your area? The IDA's
extensive support materials can show you how. Help
preserve dark skies, join the IDA today! For information,
write to IDA, 3225 N. First Ave., Tucson, AZ 85719-2103
or visit their website: www.darksky.org.
The best way to avoid immediate problems with light
pollution, however, is to take your telescope to where
there are dark skies. You will be amazed at how many
stars you can see when you get away from the city
lights
1. 9
2.
3.4
2. 5
tracking Celestial objects
The Earth is constantly rotating about its polar axis, com-
pleting one full rotation every 24 hours; this is what defines
a "day". We do not feel the Earth rotating, but we see it at
night from the apparent movement of stars from east to
west.
When you observe any astronomical object, you are watch-
ing a moving target. This means the telescope's position
must be continuously adjusted over time to keep an object
in the field of view. This is easy to do with the StarBlast 6
because of its smooth motions on both axes. As the object
moves off towards the edge of the field of view, just lightly
nudge the telescope to re-center it.
Objects appear to move across the field of view faster at
higher magnifications. This is because the field of view
becomes narrower.
Eyepiece Selection
By using eyepieces of different focal lengths, it is possible
to attain many magnifications or powers with the StarBlast
6. Your telescope comes with two Sirius Plössl eyepieces
(Figure 9): a 25mm, which gives a magnification of 30x, and
a 10mm, which gives a magnification of 75x. Other eyepiec-
es can be used to achieve higher or lower powers. It is quite
common for an observer to own many eyepieces to access
a wide range of magnifications.
25mm eyepiece
Figure 9.
The 25mm and 10mm Sirius Plössl eyepieces.
10mm eyepiece
7
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