Orion SKYQUEST XT12 User Manual download pdf (Page 17)

your eyes become dark-adapted, more stars will glimmer into

view and you will be able to see fainter details in objects you

view in your telescope. Exposing your eyes to very bright day

light for extended periods of time can adversely affect your

night vision for days. So give yourself at least a little while to

get used to the dark before you begin observing.

To see what you are doing in the darkness, use a red-filtered

flashlight rather than a white light. Red light does not spoil

your eyes’ dark adaptation like white light does. A flashlight

with a red LED light is ideal, or you can cover the front of a

regular incandescent flashlight with red cellophane or paper.

Dim light is preferable to bright light. Beware, too, that nearby

porch and streetlights and automobile headlights will spoil

your night vision.

Eyepiece Selection

By using eyepieces of different focal lengths, it is possible to

attain many different magnifications with your telescope. The

telescope comes with two high-quality Sirius Plössl eyepiec

es: a 25mm focal length, which provides a magnification of

60x, and a 10mm focal length, which provides a magnification

of 150x. Other eyepieces can be used to achieve higher or

lower powers. It is quite common for an observer to own five

or more eyepieces to access a wide range of magnifications.

This allows the observer to choose the best eyepiece to use

depending on the object being viewed. At least to begin with,

the two supplied eyepieces will suffice nicely.

Whatever you choose to view, always start by inserting your

lowest-power (longest focal length) eyepiece to locate and

center the object. Low magnification yields a wide field of

view, which shows a larger area of sky in the eyepiece. This

makes acquiring and centering an object much easier. If you

try to find and center objects with high power (narrow field of

view), it’s like trying to find a needle in a haystack!

Once you’ve centered the object in the eyepiece, you can

switch to higher magnification (shorter focal length eyepiece),

if you wish. This is especially recommended for small and

bright objects like planets and double stars. The Moon also

takes higher magnifications well.

Deep-sky objects, however, typically look better at medium

or low magnifications. This is because many of them are

quite faint, yet have some extent (apparent width). Deep-sky

objects will often disappear at higher magnifications, since

greater magnification inherently yields dimmer images. This

is not the case for all deep-sky objects, however. Many galax

ies are quite small, yet are somewhat bright, so higher power

may show more detail.

The best rule of thumb with eyepiece selection is to start

with a low power, wide field, and then work your way up in

magnification. If the object looks better, try an even higher

magnification. If the object looks worse, then back off the

magnification a little by using a lower power eyepiece.

Astronomical Objects

Now that you are all setup and ready to go, one critical deci

sion must be made: what to look at?

A. The Moon

With is rocky and cratered surface, the Moon is one of the

most interesting and easy subjects to view with your tele

scope. The best time to view it is during its partial phases

when shadows fall on the craters and canyon walls to give

them definition. While the full moon may look like a tempting

target, it is not optimal for viewing! The light is too bright and

surface definition is low.

Even at partial phases the Moon is very bright. Use of an

optional Moon filter helps to dim the glare. It simply threads

onto the bottom of the eyepiece. You’ll find the Moon filter

improves viewing comfort, and helps bring out the subtle fea

tures of the lunar surface.

B. The Sun

You can change your nighttime telescope into a daytime Sun

viewer by installing an optional solar filter over the front open

ing of the telescope. The primary attraction is sunspots, which

change shape, appearance, and location daily. Sunspots are

directly related to magnetic activity in the Sun. Many observ

ers like to make drawings of sunspots to monitor how the Sun

is changing from day to day.

Important Note: Do not look at the Sun with any optical

instrument without a professionally made solar filter, or

permanent eye damage could result. Also, be sure to cover

the finder scope, or better yet, remove it altogether.

C. The Planets

The planets don’t stay put like the stars, so to find them you

should refer to Sky Calendar at our website telescope.com, or

to charts published monthly in Astronomy, Sky & Telescope,

or other astronomy magazines. Venus, Mars, Jupiter, and

Saturn are the brightest objects in the sky after the Sun and

the Moon. Your SkyQuest IntelliScope is capable of showing

you these planets in some detail. Other planets may be visible

but will likely appear starlike. Because planets are quite small

in apparent size, optional higher power eyepieces are recom

mended and often needed for detailed observations. Not all

the planets are generally visible at any one time.

JUPITER The largest planet, Jupiter, is a great subject for

observation. You can see the disk of the giant planet and

watch the ever-changing positions of its four largest moons:

Io, Callisto, Europa, and Ganymede. Higher power eyepieces

should bring out the cloud bands on the planet’s disk.

SATURN The ringed planet is a breathtaking sight. The tilt

angle of the rings varies over a period of many years; some

times they are seen edge-on, while at other times they are

broadside and look like giant “ears” on each side of Saturn’s

disk. A steady atmosphere (good seeing) is necessary for a

good view. Look closely and you may see the Cassini divi

sion, a thin, dark gap in the rings. You should also see one

or more of Saturn’s moons, which look like faint stars. The

brightest is the moon Titan.

VENUS At its brightest, Venus is the most luminous object in

1 2 ... 12 13 14 15 16 17 18 19 20

Comments to this Manuals

No comments

Orion SKYQUEST XT12 User Manual Page 17

Comments to this Manuals

Related products and manuals for Telescopes Orion SKYQUEST XT12