Orion SIRIUS 9995 User Manual download pdf (Page 14)

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

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Orion SIRIUS 9995 User Manual Page 14

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