Orion starBlast 4.5 EQ User manual

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343 S. Fifth Avenue Ann Arbor, Michigan aadl.org
ORION STARBLAST 4.5” TELESCOPE
INSTRUCTION MANUAL
WARNING: Never look directly at the Sun through your telescope or its nder scope –
even for an instant – as permanent eye damage could result. Do not point the telescope
at the Sun, as parts will melt! Children should use this telescope only with adult supervision.
ANN ARBOR DISTRICT LIBRARY
Sponsored in part by the University Lowbrow Astronomers, a non-prot educational organization
promoting public awareness of astronomy. They hold public sky watches, demonstrations,
presentations, and discussions, all free of charge. For a calendar of events, including information
about the open houses at the Peach Mountain Observatory, visit www.umich.edu/~lowbrows/
The Club is providing AADL with ongoing help in education and maintenance of the telescopes.
We hope you enjoy using it.

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Telescope Parts
1. Eyepiece
2. EZ Finder
3. Optical tube
4. Focuser
5. Tube Clamp
6. Altitude Clamp
7. Mirror Assembly (Please don’t touch)
8. Support
9. Handle
10. Feet
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Focuser Details
11. Focus Knobs
12. Eyepiece Securing Thumb Screws
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Getting Started
Please read the instructions and practice with the telescope inside before you take it out in the dark.
When setting up the telescope, put it on something solid, like a picnic table or a wooden box. The tele-
scope must be on something solid because any vibration or movement will be magnied when looking
through it.
This is a “Push-to” telescope. Once you nd what you are looking for, you can either watch the object
move through your “eld of view” (what you see through the eyepiece) and then reposition the tele-
scope, or keep pushing the scope to hold the object in the center of the eyepiece. Objects appear to
move across the eld of view faster at higher magnications. This is because the eld of view becomes
narrower. You may nd it helps to hold one hand near the carrying handle to steady it while moving
and aiming the telescope.
Like all Newtonian reector telescopes, the image in the eyepiece is upside-down. Turning the eyepiece
won’t help. When looking at star charts or Moon maps, you will have to keep this in mind.
NOTE: The Moon map on page 8 has been ipped to match what you see in the eyepiece.
Do You Wear Eyeglasses?
If you wear eyeglasses, you will probably be able to observe with your glasses off by just refocusing
the telescope to your unaided vision. If your eyes are astigmatic, images will probably appear best
with glasses on. This is because a telescope’s focuser can accommodate for nearsightedness or
farsightedness, but not astigmatism.

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Focusing the Telescope
Always start by using your lowest-power (turn the body of the Zoom so the pointer is at “24”) to locate
and center the object. Low magnication shows a larger area of sky in the eyepiece, making nding and
centering an object much easier.
With the eyepiece adjusted for low power (24 mm), aim the telescope in the general direction of an
object at least 1/4-mile away. Use a steeple, telephone pole, or a chimney. Slowly rotate the focus knob
until the object comes into sharp focus. Go a little bit beyond sharp focus until the image starts to blur
again, then reverse the rotation of the knob, just to make sure you’ve hit the exact focus point.
Once you’ve centered an object in the eyepiece, you can switch to a higher magnication by twisting
the Zoom‘s barrel, if you wish. This is recommended for small and bright objects, like planets and
double stars. The Moon also takes higher magnications well. You may have to refocus a little after
changing power.
If you nd that it’s awkward to put your eye up to the eyepiece, you can rotate the tube by loosening
the knob on the tube clamp and moving the optical tube until the focuser is in a convenient position.
Be sure to tighten it again!
You may nd that the optical tube is either too hard to move or does not stay in place. Use the altitude
adjustment tension knob (it holds the telescope to the upright part of the base) to nd the right level
of tension.

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Operating the EZ Finder
A “nder scope” helps you nd things. It’s like a sight on a rie. The EZ Finder works by projecting a
tiny red dot onto a lens mounted in the front of the unit, so that when you look through the lens, the
red dot will appear to oat in space. Turn the power knob clockwise until you hear a “click” indicating
that power is on.
With your eye positioned at a comfortable distance, look through the back of the EZ Finder with both
eyes open to see the red dot. The intensity of the dot can be adjusted by turning the power knob. Use
the dimmest possible setting that allows you to see the dot without difculty. At the end of your ob-
serving session, be sure to turn the power knob counterclockwise until it clicks off.
Aligning the EZ Finder
When the EZ Finder is properly aligned with the telescope, an object that is centered on the EZ Finder’s
red dot should also appear in the center of the eld of view of the telescope’s eyepiece. Alignment of
the EZ Finder is easiest during daylight. Aim the telescope at a distant object at least 1/4 mile away,
such as the top of a telephone pole or chimney and center it in the telescope’s eyepiece. Now, turn the
EZ Finder on and look through it. The object will appear in the eld of view near the red dot. If the red
dot is centered on the object in the eyepiece, you’re done!

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If not:
Without moving the telescope, use the EZ Finder’s left/right (azimuth) and up/down (altitude) adjust-
ment knobs to position the red dot on the object in the eyepiece.
When the red dot is centered on the distant object, make sure that the object is still centered in the
telescope’s eld of view. If not, re-center it and adjust the Finder’s alignment again. When the object
is centered in the eyepiece and on the red dot, the Finder is properly aligned with the telescope. This
doesn’t need to be exact, but the closer it is, the easier it will be to nd things in the eyepiece!
The nder scope has a battery pack attached to the telescope, instead of the stock “button” battery.
To change batteries, just slide the cover off the pack, and replace the two AAA batteries.
Fog on the mirrors and eyepieces:
One of the odd things that happens when stargazing is that dew forms on pretty much everything
(and everyone). The big mirror is tucked safely down at the bottom of the telescope, and so it does
not get much dew on it. Eyepieces, however, often have dew form on them, making them useless
until they warm up and dry out. As it warms up, the fog should disappear. Please don’t wipe the lens
with a tissue or cloth. The eyepiece has special coatings on it that could be damaged if you do. There is
a Lens Pen in the accessory pack. Use the brush to remove any dust, then use the “cup” (under the cap)
to clean the lens. This will not work for dew. Please do not ever touch the lens.

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Images will be much better if you set up the telescope outside fteen or more minutes before you start
observing. This allows the optics to cool down to air temperature, reducing image-degrading air
currents inside the telescope’s open tube.
Setting Magnications
This eyepiece chart shows what magnication you will have for
each setting of the Zoom eyepiece. The “True Field” describes
the width of the image in the eyepiece. A full Moon is 30 minutes
of arc (or ½ of a degree) wide, so you could t about four
full Moons in the eld of view when using the 18mm setting.
Change the Zoom setting until your target ts the eyepiece the
way you like. You will have to tweak the focus.
What to Expect
Depending upon what is in the sky, planets will look small, but you might be able to see cloud bands on
Jupiter or the rings of Saturn. Craters on the Moon will be clear and numerous, the waxing and waning
of Venus should be visible, and many bright deep-sky objects will ll the eyepiece. Don’t expect to see
color as you do in NASA photos as our eyes are not sensitive enough to see color in deep-sky objects,
except in a few of the brightest ones. Remember that you are seeing these objects using your own
eyes! Each session with your telescope will be a learning experience. Each time you work with the
telescope, it will get easier to use, and stellar objects will become easier to nd.

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Objects to Observe:
The Moon is one of the easiest and most
interesting targets to view with your telescope.
Lunar craters, “seas”, and even mountain ranges
can all be clearly seen from a distance of 238,000
miles away! With its ever-changing phases,
you’ll get a new view of the Moon every night
it’s up.
Make sure to observe the Moon when it
is well above the horizon to get the sharpest
images. The best time to observe is during a
partial phase, that is, when the Moon is not full.
During partial phases, shadows are cast on the
surface which reveal more detail, especially
right along the border between the dark and
light portions of the disk (called the “terminator”).
Use the Moon Map here to nd the major craters
and features.

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The Planets do not stay at “xed” locations like the stars do. To nd them, you should refer to the
Sky Calendar (telescope.com), or to charts published monthly in Astronomy, Sky & Telescope, or other
astronomy magazines and web sites. Venus, Jupiter, and Saturn are the brightest objects in the sky after
the Sun and the Moon.
Stars: Even powerful telescopes cannot magnify a star to appear as more than a point of light. You
can, however, enjoy the different colors of the stars and locate many pretty double and multiple stars.
Look at the middle star in the handle of the Big Dipper, Mizar. It is really two stars very close together.
Being able to see the two stars separate is called “Star Splitting.”
The gorgeous two-color double star, Albireo, in Cygnus is a favorite. Defocusing a star slightly can help
bring out its color.
Deep-Sky Objects: Under dark skies, you can see lots of fascinating deep-sky objects, including
nebulas, star clusters, and a variety of different types of galaxies.
Most deep-sky objects are very faint, so it is important that you nd an observing site well away from
light pollution. Take plenty of time to let your eyes adjust to the dark. Do not expect these subjects to
appear like the photographs you see in books and magazines; many will look like dim gray smudges.
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.