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magnitude.
8. FA I N T E R : You may also adjust the upper level of
brightness with the FAINTER menu file option, (you may
find few applications for limiting it to a lower value).
9. R A D I U S : The RADIUS value sets the following
boundaries regarding objects that the LX200 recognizes
in a given eyepiece while in the FIELD menu:
Which objects the LX200 recognizes
How many objects the LX200 recognizes
At power-up the RADIUS menu file option is set to 15 arc
minutes.
To calculate the true field of an eyepiece, first divide the
focal length of the telescope (e.g., 4064mm for a 16” f/10)
by the focal length of the eyepiece (the standard supplied
eyepiece is a 26mm Super Plössl, 4064 divided by 26
equals 156x magnification). Then find the apparent field
of the eyepiece (which is 52° for the 26mm Super Plössl)
and divide it by the magnification (52 divided by 156
equals 0.33°, multiplied by 60 equals 20 arc minutes).
To get the radius of the true field of view, divide the
true field by 2. In the case of the above equation, 20 arc
minutes divided by 2 equals 10 arc minutes.
Mode Two: COORDINATES/GO TO
Mode Two (COORDINATES/GO TO) lets you see where
you have pointed the LX200 in two celestial coordinate
formats, either R.A. and Dec. or altazimuth. In this mode you
can enter new R.A. and Dec. coordinates for any sky
position. Thus you can locate objects, such as comets or
asteroids, that may not appear in the LX200 library and have
your telescope slew to the new coordinates.
1.
Coordinates Menu File
At first you will see the R.A. and Dec. coordinates of where
the telescope is pointing. If you move the LX200 with the N,
S, W, or E keys, the display of coordinates immediately
updates the new position in R.A. and Dec.
You can also display computed information of the altazimuth
coordinates (ALT and AZ) by pressing the ENTER key. To
return to:the R.A. and Dec. coordinates, press the ENTER
key again.
The R.A. display consists of hours, minutes, and tenths of a
minute; the Dec. display consists of into + for North Dec. and
– for South Dec., in degrees and minutes, as shown in
Display 32:
Display 32
If you have made an ALTAZ style of alignment, the ALT and
AZ coordinate display is formatted as follows:
0° azimuth (AZ) is due South; it increases to up to 359° and
59 minutes moving clockwise, or from due South moving
We s t e r l y. Altitude (ALT) is formatted so that straight
overhead is +90° and 00 minutes, decreasing to +00°, and
00 minutes as you move the telescope level with the
horizon; then as the LX200 moves below +00.00 it will give
minus altitude readings. Display 33 shows the altazimuth
coordinate display.
Display 33
When you slew in one direction in ALTAZ, the RA and DEC
displays change at the same time. The ALT and AZ
displays change only in the direction that the telescope is
slewing.
NOTE:Only the Dec.setting circle (3, Fig.1) gives a correct
reading. The R.A. setting circle (9, Fig. 1) gives correct
readings only in the POLAR setting (see APPENDIX A).
2.
GO TO Menu Option
The GO TO menu option lets you enter new R.A. and Dec.
coordinates of any object in the sky, so that the LX200 will
slew to the new position. With this ability, your LX200
knows no bounds. You can easily find any celestial objects,
including comets and asteroids, provided that you have
accurate coordinate-reference data.
To enter a new pointing position in R.A. and Dec., press the
GO TO key. You will hear a double beep, then see a blinking
cursor over the RA coordinate numbers. Type in the new
R.A. coordinates, then press the ENTER key. The blinking
cursor is over the DEC coordinates. Enter the new Dec.
coordinates, then press the ENTER key. The LX200 slews
to the new coordinate position.
You can also slew to ALTAZ coordinates from the ALTAZ
display as described above.
If you need to enter a minus Dec. setting, do the following:
Move the blinking cursor over the + sign with the W key.
Press the NEXT key to get the – (minus) sign .
Move the blinking cursor to the first number with the E
key.
Enter the new coordinates.
If you are already at a minus (–) Dec. setting and wish to
enter a plus (+) Dec. setting, follow the same instructions
as above but press the PREV key to get the + sign .
Mode Three: CLOCK/CALENDAR
The continuously operating clock and calendar are the life
pulse of your LX200. At power-up, the telescope’s sidereal
clock automatically lets the system computer calculate
orbits of planets and precessions of stars for superior
pointing ability.
You need not re-enter local time and date need each time
you use the LX200; it has a long-life lithium battery back-up.
To set the local time and date and to enter the correct GMT
offset, see QUICK START, page 9. Use your local hour
setting appropriately in either 12-hour or 24-hour format, as
predetermined by the 12/24 HOUR TELESCOPE menu file
option.
The long-life lithium battery (Panasonic CR2032 3vDC or
Duracell DL2032B) is stored behind the power panel of the
drive base (see APPENDIX D: Behind the power panel for
RA = 02:45.9
DEC = +22'54
ALT = +72'50
AZ = 158'10
