Meade LX90 instruction manual Star Charts

1.Obtain a rough polar alignment as described earlier. Place the illuminated reticle eyepiece (or eyepiece/Barlow combination) into the eyepiece holder of the telescope.

2.Point the telescope, with the motor drive running, at a moderately bright star near where the meridian (the North-South line passing through your local zenith) and the celestial equator intersect. For best results, the star should be located within ±30 minutes in R.A. of the meridian and within ±5° of the celestial equator (see “CELESTIAL COORDINATES,” page 47). Pointing the telescope at a star that is straight up, with the Declination set to 0°, will point the telescope in the right direction.

3.Note the extent of the star’s drift in Declination (disregard drift in Right Ascension):

a.If the star drifts South (or down), the telescope’s polar axis is pointing too far East.

b.If the star drifts North (or up), the telescope’s polar axis is pointing too far West.

4.Move the wedge in azimuth (horizontally) to effect the appropriate change in polar alignment. Reposition the telescope’s East-West polar axis orientation until there is no further North-South drift by the star. Track the star for a period of time to be certain that its Declination drift has ceased.

5.Next, point the telescope at another moderately bright star near the Eastern horizon, but still near the celestial equator. For best results, the star should be about 20° or 30° above the Eastern horizon and within ± 5° of the celestial equator.

6.Again note the extent of the star’s drift in Declination:

a.If the star drifts South, (or down) the telescope’s polar axis is pointing too low.

b.If the star drifts North, (or up) the telescope’s polar axis is pointing too high.

7.Use the altitude adjust control on the wedge to make appropriate changes in altitude, based on your observations above. Again, track the star for a period of time to be certain that Declination drift has ceased.

The above procedure results in very accurate polar alignment, and minimizes the need for tracking corrections during astrophotography.

LX90 TIPS

Star Charts

Even with the Autostar 30,000 object library, star charts and planispheres are still useful for a variety of reasons. In particular, they are a great aid in plan- ning a night of celestial viewing.

A wide variety of star charts are available in books, in magazines, on the inter- net and on CD Roms. Meade offers Epoch 2000sk™ and other star locator software. Contact your Meade dealer or Meade's Customer Service depart- ment for more information.

Astronomy and Sky and Telescope magazines print star charts each month for up-to-the-minute maps of the heavens.

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