Orion SIRIUS 9995 - Manual (Page 14)

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the alignment procedure must be performed again. To do
this, turn the mount’s power switch off, then on again.
two‑star alignment
Two-star alignment requires only two alignment stars but may
produce lesser pointing accuracy than the three-star align-
ment. The description below will lead you on a step-by-step
procedure on how to perform the two-star alignment.
1. From the alignment screen, select “2-Star Align” using the
scroll buttons. Press ENTER to confirm your choice.
2. The hand controller will provide a list of stars available in
your current sky for you to choose as the first alignment
star. Using the scroll buttons, choose a star you are familiar
with and press
ENTER to confirm your choice. The mount
will start slewing the telescope towards the chosen star.
When the telescope stops slewing, adjust its position with
the controller’s directional buttons until the star is centered
on the crosshairs of the finderscope. Now look in the eye-
piece and adjust the position of the telescope (again using
the directional buttons) so the chosen star is centered in
the field of view of the eyepiece. Press
ENTER to confirm
the star is centered.
3. The controller will provide a list of stars that can be used as
the second alignment star. Choose a star using the scroll
buttons and press
ENTER to confirm your choice. Repeat
the centering procedure for the second alignment star and
press
ENTER to confirm alignment.
4. Once the two alignment stars have been entered and
alignment is complete, the hand controller will display
“Alignment Successful.” Press
ENTER to access the Main
Menu. Otherwise, “Alignment Failed” will be displayed, and
the alignment procedure must be performed again. To do
this, turn the mount’s power switch off, then on again.
one‑star alignment
One-star alignment is the simplest and quickest alignment
method, as only one alignment star is required. Due to minimal
data input, however, a one-star alignment will not yield optimal
results unless polar alignment is very accurate, and any cone
error is minimized (see Appendix A). The description below will
lead you on a step-by-step procedure on how to perform the
one-star alignment.
1. From the alignment screen, select “1-Star Align” using the
scroll buttons. Press ENTER to confirm your choice.
2. The hand controller will provide a list of stars available in
your current sky for you to choose as the first alignment
star. Using the scroll buttons, choose a star you are familiar
with and press
ENTER to confirm your choice. The mount
will start slewing the telescope towards the chosen star.
When the telescope stops slewing, adjust its position with
the controller’s directional buttons until the star is centered
on the crosshairs of the finderscope. Now look in the eye-
piece and adjust the position of the telescope (again using
the directional buttons) so the chosen star is centered in
the field of view of the eyepiece. Press
ENTER to confirm
the star is centered.
3. Once the alignment star has been entered and alignment
is complete, the hand controller will display “Alignment
Successful”. Press
ENTER to access the Main Menu.
tips for choosing alignment stars
If possible, use the following tips when choosing alignment
stars for best pointing accuracy.
One-star alignment: Choose a star close to the Celestial
Equator (Dec close to 0°).
Two-star alignment: Choose two stars on the same side of the
meridian, and at least 3 hours apart in right ascension and
3° apart in declination. If you suspect your polar alignment is
poor, choose two stars that are 20° to 60° apart in declination.
Three-star alignment: For the first two stars, follow the tip above
for two-star alignment. For the third alignment star, choose a
star on the other side of the meridian. The first and third align-
ment stars should have declination coordinates between +30°
and +70° or between -30° and -70°.
Pointing accuracy Enhancement (PaE)
The three-star alignment should provide excellent pointing
accuracy for visual observation. For other applications, such as
CCD imaging, even better pointing accuracy can be obtained
in a specific region of the sky by use of the Pointing Accuracy
Enhancement (PAE) function. Perform the following procedure
to use the PAE function.
1. Choose a bright star near the area of interest in the night
sky. Consult a planisphere or software program to choose
this bright star, if necessary.
2. Find this star in the hand controller’s object database. This
is easily done by pressing the OBJECT button, which
will take you directly to the Named Star database. Press
ENTER to access the list of named stars. Use the scroll but-
tons to peruse the list, and press
ENTER to select the star.
Press ENTER again, and the LCD will ask “View Object?”
Press ENTER to issue a command to the mount to GoTo
the star. If the mount is under the control of a computer
running planetarium software, click on the star to slew the
mount to it.
3. Use the directional buttons (and RATE button) to accurate-
ly center the star in a high-powered eyepiece (10mm or
less focal length).
4. Press the ESC button, then press and hold the ESC but-
ton for 2 seconds. The hand controller LCD will read “Re-
center”, and the name of the chosen bright star will blink
three times. If the GoTo command was sent by a computer
running planetarium software, the LCD will read “Last goto
object” instead of the star’s name.
5. Make sure the chosen star is still centered in the eyepiece,
and press the ENTER button. If you don’t want to record
the star position, press the ESC button to exit the PAE
function.
After the PAE function is performed, the hand controller will
recalculate its model of the sky. The pointing accuracy in the
area of sky around the chosen bright star should now be