Bushnell 78-8845 Manuel d'utilisateur télécharger pdf (Page 8)

ENJOYING YOUR NEW TELESCOPE

1. First determine your targeted object. Any bright object in the night sky is a good starting point. One

of the favorite starting points in astronomy is the moon. This is an object sure to please any budding

astronomer or experienced veteran. When you have developed proficiency at this level, other objects

become good targets. Saturn, Mars, Jupiter, and Venus are good second steps to take.

2. The first thing you need to do after assembling the telescope as planned is center the desired object

in the finderscope’s cross hairs. Provided you did a reasonable job aligning the finderscope, a quick

look through the main telescope tube at low power should reveal the same image. With the lowest

power eyepiece (the one with the largest number printed on it) you should be able to focus the same

image that you saw through the finderscope. Avoid the temptation to move directly to the highest

power. The low power eyepiece will give you a wider field of view, and brighter image—thus making

it very easy to find your target object. At this point with a focused image in both scopes, you’ve

passed the first obstacle. If you don’t see an image after attempting to focus it in, you might consider

aligning your finderscope again. Once you pass this step, you’ll will enjoy the time spent ensuring a

good alignment. Every object you center in the finderscope will be easily found in the main telescope

tube, which is important for continuing your exploration of the night sky.

3. The low power eyepieces are perfect for viewing the full moon, planets, star clusters, nebulae, and

even constellations. These should build your foundation. However, for more detail, try bumping up

in magnification to higher power eyepieces on some of these objects. During calm and crisp nights,

the light/dark separation line on the moon (called the "Terminator") is marvelous at high power. You

can see mountains, ridges and craters jump out at you due to the highlights. Similarly, you can move

up to higher magnifications on the planets and nebulae. Star clusters and individual stars are best

viewed through the low power no matter what.

4. The recurring astronomical theater we call the night sky is an ever-changing billboard. In other words,

the same movie does not play all the time. Rather, the positions of the stars change not only hourly

as they seem to rise and set, but also throughout the year. As the earth orbits the sun our perspective

on the stars changes on a yearly cycle about that orbit. The reason the sky seems to move daily just

as the sun and the moon "move" across our sky is that the earth is rotating about its axis. As a result

you may notice that after a few minutes or a few seconds depending on what power you are viewing

at, the objects in your telescope will move. At higher magnifications especially, you will notice that

the moon or Jupiter will "race" right out of the field of view. To compensate, just move your telescope

to "track" it in the necessary path.

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Bushnell 78-8845 Manuel d'utilisateur Page 8