Meade LXD 75-Series instruction manual Locating the Celestial Pole, One-Star Polar Alignment

Little Dipper

Polaris

Big Dipper

Cassiopeia

Fig. 42 Locating Polaris.

star, and also of the object you wish to locate, in a star atlas. Point the object at the bright star. Then loosen the R.A. setting circle lock knob (32, Fig. 1d) and turn the R.A. setting circle to read the correct R.A. coordinate of the bright star; lock the R.A. setting circle lock knob onto the object. Next, loosen the R.A. lock (33, Fig. 1d) and turn the telescope in R.A. to read the correct R.A. coordinate of the object. Tighten the R.A. lock (33, Fig. 1d). If the procedure has been followed carefully, the desired object should now be in the telescopic field of a low-power eyepiece.

If you do not immediately see the object you are seeking, try searching the adjacent sky area. Keep in mind that, with the 26mm eyepiece, the field of view of the LXD75- Series is about 0.5°. Because of its much wider field, the viewfinder may be of signif- icant assistance in locating and centering objects, after the setting circles have been used to locate the approximate position of the object.

See USING AUTOSTAR TO FIND OBJECTS NOT IN THE LIBRARIES, page 33, for infor- mation on how to manually enter coordinates into Autostar.

Locating the Celestial Pole

To get basic bearings at an observing location, take note of where the Sun rises (East) and sets (West) each day. After the site is dark, face North by pointing your left shoul- der toward where the Sun set. To precisely point at the pole, find the North Star (Polaris) by using the Big Dipper as a guide (Fig. 42).

Polar Alignment

Autostar provides several different methods of Polar Alignment: Easy, One-Star, Two- Star and Three-Star. See EASY ALIGNMENT, page 21, and THREE-STAR ALIGNMENT USING AUTOSTAR, page 52, for those procedure.

One-Star Polar Alignment

Polar One-Star Alignment requires some knowledge of the night sky. Autostar pro- vides a library of bright stars and one star from this library is chosen by the observer for alignment. Polaris is chosen by Autostar. The rest of the procedure is almost iden- tical to the EASY ALIGNMENT, page 21, except that Autostar prompts you to point the telescope at Polaris and center it in the telescope's eyepiece.

Two-Star Polar Alignment

Polar Two-Star Alignment requires some knowledge of the night sky. Autostar pro- vides a library of bright stars and two stars from this library are chosen by the observ- er for alignment. Polaris is chosen by Autostar. The rest of the procedure is almost identical to the EASY ALIGNMENT, page 21, except that Autostar prompts you to point the telescope at Polaris and center it in the telescope's eyepiece.

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