Meade LX90GPS Telescope User Manual


 
18
Astronomical Observing
Used as an astronomical instr
ument, your telescope has many optical and electromechanical
capabilities. It is in astronomical applications where the high level of optical performance is
readily visible.The range of observable astronomical objects is, with minor qualification, limited
only b
y the observer’s motivation.
To Track an Object Automatically
As the Earth rotates beneath the night sky, the stars appear to move from East to West. The
speed at which the stars move is called the sidereal rate.You can setup your telescope to move
at the sidereal rate so that it automatically tracks the stars and other objects in the night sky. If
the telescope is not tracking an astronomical object, the object will drift out of the eyepiece field
of view. The tracking function automatically keeps an object more or less centered in the
telescope’s eyepiece.
To automatically track objects, you must initialize AutoStar, and then select "Targets:
Astronomical" from the AutoStar Setup menu. You must also learn how the AutoStar keypad
operates in order to move through the AutoStar menus.
Moving Through AutoStar’s Menus
The AutoStar database is organized in levels for quick and easy navigation.
Press ENTER to go deeper into AutoStar's menu levels.
Press MODE to move back toward the top menu level.
Press the Scroll keys to move up and down through the options available for each
level.
Press the Arrow keys to enter characters and digits.
The Arrow keys are also used to move the telescope.
Automatic Alignment Feature (Auto Align
)
AutoStar offers four methods of altazimuth (alt/az) alignment; this section describes how to ini-
tialize and align your telescope using Automatic Alignment. (For a description of the other
alt/az alignment methods, see pages 38 and 39. For information about equatorial (polar) align-
ment, see
APPENDIX A, page 50.)
To prepare your telescope for Automatic Alignment:
1. Tighten the R.A. and Dec. locks (9 and 6, Fig. 1).
2. Verify that AutoStar is properly connected to your telescope.See
HOW TO ASSEMBLE YOUR
TELESCOPE
,
page 13.
3. Flip the telescope power switch to the ON position.
When you slide the On/Off switch to “On” on your telescope’s computer control panel, a version
screen briefly appears, followed by “Welcome to AutoStar.”
4. “Press 0 to align or Mode for Menu.” displays. Press “0” to begin Automatic Alignment. (If you
wish to choose a manual alignment method, keep pressing Mode to go through the menus to
find other alignments.)
Note: A
utoStar initializ
es the Smar
t Drive if "On" has been previously performed PEC
training and you have "parked" the telescope. If you have parked it, AutoStar will
remember its position on the worm gear. If you do not park the scope and turn it off, it
will not remember its position. See
PARK, page 28 and PEC TRAINING, page 54.
5. "Automatic Alignment" displays. The system now performs the following routines (press
any AutoStar key to abort Automatic Alignment; see
IMPORTANT NOTE, at the left) :
Caution: As the telescope performs the following operations, it will swing and rotate.
Keep a safe distance from the telescope.
The telescope now finds the level and tilt posi-
tion of the telescope
, and also detects where tr
ue Nor
th is
.
It ma
y not actually le
v
el or tilt
the telescope or point to Nor
th—it is just detecting these positions
. This make take a
minute or two.
a. Detects “level” of the base of the telescope; finds tilt and tip. To detect level,
AutoStar must calculate "level" at three compass points. See
FINDING TRUE LEVEL in
on page 21.
Impor
tant Note:
Press any key on the
A
utoStar handbo
x to
abor
t the GPS fix.
Press MODE repeat-
edly until "Select Item"
displays and use the
AutoStar menu options
to choose a manual
alignment or to find an
AutoStar option, such
as "Brightness."
Definition:
Initialization
is a pro-
cedure that ensures
that A
utoStar operates
correctly
.When you
first use AutoStar, it
doesn't yet know
where the observation
location site is or the
time or date of the
observation session.
During the
automatic
alignment procedure,
the system calculates
these parameters
automatically.
AutoStar uses this
information to precise-
ly calculate the loca-
tion of celestial objects
(such as stars and
planets) and to move
your telescope cor-
rectly for various oper-
ations.