Celestron 91519 Instruction Manual page 30

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Once completed, press the Align button and use the Up/
Down buttons on the hand controller to select Polar Align
from the list
Align Mount – After performing a two star alignment with one
calibration star and slewing your telescope to any bright star
in the telescope's database, select the "Align Mount" option
The telescope will then slew away from and then back to the
same star
1 The hand control will ask you to re-center the star in the
finderscope and press ENTER
2 The hand control will ask you to accurately center the star
in your eyepiece and press ALIGN. The telescope will
then "sync" on this star and slew to the position that the
star should be if it were accurately polar aligned
note: For the most accurate alignment, it is best to use a
reticle eyepiece or a high power eyepiece to precisely center
the star in the field of view
3 Use the mount's latitude and azimuth adjustments to
place the star in the center of the eyepiece Do not use
the direction buttons on the hand control to position the
star Once the star is centered in the eyepiece, press
ENTER; the polar axis should now be pointed towards
the North Celestial Pole
updating your Star alignment
After polar alignment, it is a good idea to check the pointing
accuracy of the telescope to see how much it may have been
affected by moving the mount Since the polar alignment
process requires you to "sync" the telescope on a bright
star before you begin, it will be necessary to undo the sync
before re-aligning To undo the sync:
• Press the Align button and use the Up/Down buttons on
the hand controller to select Undo Sync from the list, and
press Enter The message Complete will display on the
LCD.
To re-align your telescope:
1 Slew the telescope to one of the original alignment stars
or another bright star if the original alignment stars are
no longer in a convenient location Press the Align button
and use the Up/Down buttons on the hand controller to
select Alignment Stars from the list
2 The hand control will ask you which of the original
alignment stars you wish to replace. Use the Up/Down
buttons to select the desired star and press Enter
3 Once again, center the star in the finderscope and
press Enter
4 Center the star in the eyepiece and Press Align
5 Repeat the process on a second alignment star
For additional all-sky pointing accuracy, it is a good idea to
align on at least one additional calibration star located on
the opposite side of the Meridian To add calibration stars:
30 I
1 Slew the telescope to a bright star on the opposite side
of the Meridian from your two alignment stars
2. Press the Align button and use the Up/Down buttons on
the hand controller to select Calib Stars from the list, and
press Enter
3 Align the star in the finderscope and then in the eyepiece
as you did with the alignment stars
Display align – the user can now display the polar
alignment error in the RA and DEC axes These values show
how close the mount is pointed at the celestial pole base on
how accurately the user centered the alignment star with the
hand control and with the mount adjustment To display the
alignment error:
• Press the Align button and use the Up/Down buttons on
the hand controller to select Display Align from the list,
and press Enter
Pointing at Polaris
This method of Polar aligning utilizes Polaris as a guidepost
to the celestial pole Since Polaris is less than a degree from
the celestial pole, you can simply point the polar axis of your
telescope at Polaris Although this is by no means perfect
alignment, it does get you within one degree and is suitable
for visual observing and short exposure piggyback photography
This must be done in the dark when Polaris is visible and can
be done using the hole in the polar axis or with the help of
the optional polar axis finderscope
1 Set up the telescope so the polar axis is pointing towards
north
2 Remove the polar finderscope cover and the polar axis
cover from both sides of the mount The polar finderscope
cover unthreads from the rear of the mount, and the polar
axis cover presses into the front of the mount
3. Loosen the DEC clutch knob and move the telescope so
the tube is perpendicular to the polar axis (i e , the tube
should be pointing either due west or east)
4. Look through the hole located underneath the polar
finderscope cover (or through the eyepiece if using the
optional polar axis finderscope) You should be able to
see the sky from the hole under the polar axis cover
5. Adjust the mount in altitude and/or azimuth until Polaris
is visible through the polar axis hole Center Polaris as
accurately as possible
Like the Display Align method, this gets you close to the
pole but not directly on it For help in identifying and locating
Polaris, read the section below
Finding the north celestial Pole
In each hemisphere, there is a point in the sky around which
all the other stars appear to rotate These points are called
the celestial poles and are named for the hemisphere in
which they reside For example, in the northern hemisphere
all stars move around the north celestial pole When the
telescope's polar axis is pointed at the celestial pole, it is
parallel to the Earth's rotational axis

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