Orion 9877 manual telescope, Tips on observing with your

Tips on observing with your

telescope...

ith the telescope assembled, balanced Wand polar-aligned as described previously, you are ready to begin observations. Decide on an easy to find object such as the Moon, if visible, or a bright star to become accustomed to the functions and operations of the telescope. For the best results during observa-

tions, follow the suggestions given as follows:-

●To centre an object in the main telescope, loosen the telescope's R.A. and DEC locks. The telescope can now turn freely on its axes. Use the aligned viewfinder's crosshairs and re-tighten the R.A. and DEC. locks.

●If you have purchased an assortment of eyepieces, always start an observation with a low power eyepiece (e.g. a 20mm or 25mm eyepiece). Get the object well centered in the field of view and sharply focused. Then try the next step up in magnification. If the image starts to become fuzzy as you increase magnification, then back down to a lower power as the atmospheric steadiness is not sufficient to support high powers at the time you are observing. Keep in mind that a bright, clearly resolved but smaller image will show far more detail than a dimmer, poorly resolved larger image. Eyepieces of 20mm and 25mm focal length provide a wide field of view, ideal for general astronomical observing of star fields, clusters of stars, nebulae and galaxies. They are probably the best eyepieces to use in the initial finding and centring of any object.

●Once centered, the object can be focused by turning one of the knobs of the focusing mechanism. You will notice that the astronomical

object in the field of view will begin to slowly move across the eyepiece field. This motion is caused by the rotation of the Earth on its axis, although the planets and stars are for practical purposes fixed in their positions in the sky. The platform on which the telescope is sitting (the Earth) rotates once every 24 hours under these objects. To keep astronomical objects in the field of view of the polar aligned telescope, simply turn the R.A. slow motion control. These objects will appear to move through the field more rapidly at higher powers.

Note: The Declination slow motion control is only used for centring purposes, not for tracking.

●Avoid touching the eyepiece while looking through the telescope. Vibrations resulting from such contact will cause the image to move.

●You should allow a few minutes for your eyes to become dark adapted before attempting any serious astronomical observations. Use a red filtered flashlight to protect your night vision when reading star maps or inspecting the components of the telescope.

●Avoid setting up the telescope inside a room and observing through an open window (or worse still, a closed window). Images viewed in such a manner may appeared blurred or dis- torted due to a temperature difference between the inside and the outside air.

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