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Although overlooked by many amateur astronomers, solar
observation is both rewarding and fun. However, because the Sun
is so bright, special precautions must be taken when observing
our star so as not to damage your eyes or your telescope.
Never project an image of the Sun through the telescope.
Because of the folded optical design (on some telescopes),
tremendous heat build-up will result inside the optical tube.
This can damage the telescope and/or any accessories attached
to the telescope.
For safe solar viewing, use a solar filter that reduces the
intensity of the Sun’s light, making it safe to view. With a filter
you can see sunspots as they move across the solar disk and
faculae, which are bright patches seen near the Sun’s edge.
sOlar Observing Hints
• The best time to observe the Sun is in the early morning or
late afternoon when the air is cooler.
• To center the Sun without looking into the eyepiece, watch
the shadow of the telescope tube until it forms a
circular shadow.
• To ensure accurate tracking, be sure to select the solar
tracking rate of the optional motor drive.
Deep-sky objects are simply those objects outside the
boundaries of our solar system. They include star clusters,
planetary nebulae, diffuse nebulae, double stars and other
galaxies outside our own Milky Way. Most deep-sky objects
have a large angular size. Therefore, low-to-moderate power is
all you need to see them. Visually, they are too faint to reveal
any of the color seen in long exposure photographs. Instead,
they appear black and white. And, because of their low surface
brightness, they should be observed from a dark-sky location.
Light pollution around large urban areas washes out most
nebulae making them difficult, if not impossible, to observe.
Light Pollution Reduction filters help reduce the background sky
brightness, thus increasing contrast.
If you have a computer controlled telescope, finding deep
sky objects is relatively easy. If you have a non-computerized
telescope with an equatorial mount, the setting circles of the
telescope will help assist you in finding objects with a good star
charts or atlas.
If you have a non-computerized altazimuth telescope, there is a
way of locating deep sky objects which is called “star hopping”.
With small aperture telescopes, it will be very challenging
(but will be rewarding) to locate objects with this method. In
general, the larger the aperture the easier it is to find and see
deep-sky objects.
star HOPPing
One convenient way to find deep-sky objects is by star
hopping. Star hopping is done by using bright stars to “guide”
you to an object. For successful star hopping, it is helpful to
know the field of view of you telescope. If you’re using a 20 mm
eyepiece which also has a magnification with your telescope
of 20x and your apparent field of view of the eyepiece is 50°,
your true angular field of view is approximately 2.5º or so. If
you know an object is 3º away from your present location, then
you just need to move a little more than one field of view. You
can find out the true angular field of view by using the formula
listed in the Telescope Basics document. Listed below are
directions for locating two popular objects.
The Andromeda Galaxy, also known as M31, is an easy target.
To find M31:
1. Locate the constellation of Pegasus, a large square visible
in the fall (in the eastern sky, moving toward the point
overhead) and winter months (overhead, moving toward
the west).
2. Start at the star in the northeast corner — Alpha (α)
Andromedae.
3. Move northeast approximately 7°. There you will find two
stars of equal brightness — Delta (δ) and Pi (π) Andromedae
— about 3° apart.
4. Continue in the same direction another 8°. There you will
find two stars — Beta (β) and Mu (μ) Andromedae — also
about 3° apart.
5. Move 3° northwest — the same distance between the two
stars — to the Andromeda galaxy.
Star hopping to the Andromeda Galaxy (M31) is a snap since all
the stars needed to do so are visible to the naked eye.
Observing the sun — Careful!
Observing DeeP sky ObjeCts
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