Levenhuk Skyline PRO 127 MAK Telescope - Manual (Page 16)

When observing through a telescope, astronomical objects appear to move slowly through the
telescope's field of view. When the mount is correctly polar aligned, you only need to turn the
R.A. slow-motion control to follow or track objects as they move through the field. A R.A. motor
drive can be added to automatically track celestial objects by counteracting the rotation of Earth.
The rotation speed of the R.A. drive matches the rotation rate of Earth for stars to appear
stationary in the telescope eyepiece. Different tracking speeds are also available in some models.
A second drive can be added to give Dec. control which is very useful for astrophotography.
The quickest way to find objects is to learn the constellations and use the finderscope, but if the
object is too faint you may want to use setting circles on an equatorial mount. Setting circles
allow you to locate celestial objects whose celestial coordinates have been determined from star
charts. Your telescope must be Polar aligned and the R.A. setting circle must be calibrated before
using the setting circles. The Dec. setting circle was calibrated at the factory and no additional
calibration is required for it.
The telescope's R.A. setting circle is scaled in hours, from 1 to 24, with small lines in between
representing 10 minute increments. The upper set of numbers applies to observations in the
Northern Hemisphere, while the numbers below them apply to observations in the Southern
Hemisphere.
Loosen the Dec. lock knob and rotate the telescope tube until the pointer on the setting circle
reads 90°. Retighten the Dec. lock knob. Loosen the azimuth lock knob and move the mount so
that the R.A. axis points roughly at Polaris. Use the two azimuth adjustment knobs above the "N"
to make fine adjustments in azimuth if needed. For more accurate alignment, look through the
finderscope and center the Polaris on the crosshairs using the azimuth and latitude adjustment
knobs.
After a while you will notice your target drifting slowly North or South depending on the direction
of the pole relative to Polaris. To keep the target in the center of the view, turn only the R.A.
slow-motion control.
After your telescope is polar aligned, no further adjustments in the azimuth and latitude of the
mount should be made in the observing session, nor should you move the tripod. Only movements
in R.A. and DEC axis should be made in order to keep an object in the field.
In the Southern Hemisphere you must align the mount to the SCP by locating its position with star
patterns, without the convenience of a nearby bright star. The closest star is the faint 5.5-mag.
Sigma Octantis which is about one degree away. Two sets of pointers which help to locate the SCP
are α and β Crucis (in the Southern Cross) and a pointer running at a right angle to a line
connecting α and β Centauri.
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Tracking celestial objects
Setting (calibrating) the R.A. setting circle
In order to set your Right Ascension circle you must first find a star in your field of view with
known coordinates. A good one would be the 0.0 magnitude star Vega in the Constellation Lyra.
From a star chart we know the R.A. coordinate of Vega is 18h 36m.
Loosen the R.A. and DEC. lock knobs on the mount and adjust the telescope so that Vega is
centered in the field of view of the eyepiece. Tighten the R.A. and DEC. lock knobs to lock the
mount in place. Now rotate the R.A. setting circle until it reads 18h36m. You are now ready to use
the setting circles to find objects in the sky.