12
13
3.4), which is the star in the “Big Dipper” connecting the handle to the “dip-
per”. If you cannot see Megrez, then you have fog, haze, clouds, smog, or
other conditions that are hindering your viewing. (See Figure 10)
Magnification limits
Every telescope has a useful magnification limit of about 2X per millimeter of
aperture. This comes to 152X for the FunScope. Some telescope manufactur-
ers will use misleading claims of excess magnification, such as “See distant
galaxies at 640X!”. While such magnifications are technically possible, the
actual image at that magnification would be an indistinct blur.
Moderate magnifications are what give the best views. It is better to view a
small, but bright and detailed image than a dim, unclear, oversized image.
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
Magnification limits
Every telescope has a useful magnification limit of about 2X per millimeter of
aperture. This comes to 226X for the StarBlast. Some telescope manufacturers will
use misleading claims of excess magnification, such as “See distant galaxies at
640X!”. While such magnifications are technically possible, the actual image at that
magnification would be
an indistinct blur.
Moderate magnifications
are what give the best
views. It is better to
view a small, but bright
and detailed image
than a dim, unclear,
oversized image.
tant 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.
To find deep sky objects in the sky, it is best to consult a star chart or
Planisphere. These guides will help you locate the brightest and best deep-sky
objects for viewing with your FunScope.
You can also try low-power scanning of the Milky Way. Use the 20mm eyepiece
and just cruise through the “star clouds” of our galaxy. You’ll be amazed at the
rich fields of stars and objects you’ll see! The Milky Way is best observed on
summer and winter evenings.
Viewing Hints
Amateur astronomy can be an entertaining and educational activity for the
entire family. Astronomy is also a serious scientific pursuit. As with any sci-
ence you will achieve the best results by following some basic guidelines.
These recommendations will assist you in getting the most out of your new
telescope. This is just a sample of suggested techniques; for more helpful tips
please visit the
Learning Center
at
oriontelescopes.com
.
“seeing” and transparency
Atmospheric conditions vary significantly from night to night. “Seeing” refers
to the steadiness of the Earth’s atmosphere at a given time. In conditions of
poor seeing, atmospheric turbulence causes objects viewed through the tele-
scope to “boil”. If, when you look up at the sky with your naked eyes, the stars
are twinkling noticeably, the seeing is bad and you will be limited to viewing
with low powers (bad seeing affects images at high powers more severely).
Planetary observing may also be poor.
In conditions of good seeing, star twinkling is minimal and images appear
steady in the eyepiece. Seeing is best overhead, worst at the horizon. Also,
seeing generally gets better after midnight, when much of the heat absorbed
by the Earth during the day has radiated off into space.
Especially important for observing faint objects is good “transparency” – air
free of moisture, smoke, and dust. All tend to scatter light, which reduces an
object’s brightness. Transparency is judged by the magnitude of the faintest
stars you can see with the unaided eye (6th magnitude or fainter is desirable).
If you cannot see stars of
magnitude
3.5 or dimmer then conditions are poor.
Magnitude is a measure of how bright a star is – the brighter a star is, the
lower its magnitude will be. A good star to remember for this is Megrez (mag.
Figure 10:
Megrez connects
the Big Dipper’s handle to its
“pan”. It is a good guide to how
conditions are. If you can not
see Megrez (a 3.4 mag star) then
conditions are poor.