Orion 9829 instruction manual Using the Polar Axis Finder Scope, Tracking Celestial Objects

Figure 8. The optical tube must be at a 90° angle to the right ascension axis in order to view through the polar axis finder

The polar axis finder scope is now ready to be used. When not in use, replace the plastic protective cover to prevent the polar finder from getting bumped, which could knock it out of alignment.

Using the Polar Axis Finder Scope

The reticle of the polar axis finder scope for the SkyView Pro has a tiny star map printed on it that makes precise polar alignment quick and easy. To align the mount using the polar axis finder scope, follow these instructions:

1.Approximately polar-align the mount as outlined in the previous procedure.

2.Loosen the Dec. lock lever and rotate the optical tube on the declination axis so that the tube is at a 90° to the right ascension axis (Figure 8). Tighten the Dec. lock lever.

3.Remove the cap on the front opening of the mount (Figure 4). Focus the polar finder by rotating its eyepiece. Now, sight Polaris in the polar axis finder scope. If you have fol- lowed the approximate polar alignment procedure accu- rately, Polaris will probably be within the field of view. If not, move the tripod left-to-right, and adjust the latitude up-and down until Polaris is somewhere within the field of view of the polar axis finder scope.

4.Shine a red flashlight down the front end of the polar find- er to illuminate the reticle within the field of view. Make sure the flashlight shines in at an angle, so as not to block the polar finder’s field of view. It may be helpful to have a friend hold the flashlight while you look through the polar finder. Note the constellation Cassiopeia and the Big Dipper in the reticle. They do not appear in scale, but they

indicate the general positions of Cassiopeia and the Big Dipper relative to the north celestial pole (which is indicat- ed by the cross at the center of the reticle). Rotate the ret- icle so the constellations depicted match their current ori- entation in they sky when viewed with the naked eye. To do this, release the R.A. lock lever and rotate the main tel- escope around the R.A. axis until the reticle is oriented with sky. For larger optical tubes, you may need to remove the tube from the mount to prevent it from bumping into the mount. Once the reticle is correctly oriented, use the right ascension lock lever to secure the mount’s position.

5.Now use the azimuth adjustment knobs (Figure 2) and the latitude adjustment L-bolts (Figure 4) on the mount to position the star Polaris inside the tiny circle marked “Polaris” on the finder’s reticle. You must first loosen the knob underneath the equatorial mount on the center sup- port shaft to use the azimuth adjustment knobs. Once Polaris is properly positioned within the reticle, you are precisely polar aligned.

If you do not have a clear view of Polaris from your observing site, you will not be able to use the polar-axis finder to pre- cisely polar align the telescope.

Note: From this point on in your observing session, you should not make any further adjustments in the azimuth or the latitude of the mount, nor should you move the tri- pod. Doing so will undo the polar alignment. The tele- scope should be moved only about its right ascension and declination axes.

Use of the Right Ascension and Declination Slow-Motion Control Knobs

The right ascension (R.A.) and declination (Dec.) slow-motion control knobs allow fine adjustment of the telescope’s position to center objects within the field of view. Before you can use the knobs, you must manually “slew” the mount to point the telescope in the vicinity of the desired target. Do this by loos- ening the R.A. and Dec. lock levers and moving the telescope about the mount’s right ascension and declination axes. Once the telescope is pointed close to the object to be viewed, retighten both lock levers.

Note: If you have an optional motor drive attached you will need to loosen the manual clutch on the R.A. (and Dec. for dual-axis drives) gear shaft before using the slow-motion control knob.

The object should now be visible somewhere in the tele- scope’s finder scope. If it isn’t, use the slow-motion knobs to scan the surrounding area of sky. When the object is visible in the finder scope, use the slow-motion knobs to center it. Now, look in the telescope’s eyepiece. If the finder scope is proper- ly aligned, the object should be visible somewhere in the field of view. Once the object is visible in the eyepiece, use the slow-motion knobs to center it in the field of view.

Tracking Celestial Objects

When you observe a celestial object through the telescope, you’ll see it drift slowly across the field of view. To keep it in

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