Meade Instruments 1697 Computer Drive System For LXD 650 and LXD 750 Mounts - Part 2 - Manual (Page 5)

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D. CNGC, IC, and UGC catalogs:
1. Press the CNGC key on the Hand Controller, then press ENTER.
2. Use the PREV and NEXT keys to cycle through the following options:
NGC New General Catalog (complete catalog).
IC Index Catalog (complete catalog).
UGC Uppsala General Catalog (complete catalog).
3. Press Enter when the desired catalog is selected. An arrow will appear to the right of the selected
catalog.
4. Press MODE to activate the curser. Using the keypad, enter the number of the desired selection
into the Hand Controler and press ENTER. The object information of the selected object then appears
on the screen.
The CDS “remembers” the database you last accessed. Each time you press the CNGC key, the same
object database will be displayed on the first line of the Keypad display. To change databases, press ENTER
to bring up the database menu.
3. The Meade CNGC* Catalog
You will notice that the Messier (M) objects, and the NGC objects have been incorporated into the Meade
Instruments CNGC listing. CNGC stands for “Computerized New General Catalog of Non-Stellar
Astronomical Objects”. The CNGC is an enhancement from the RNGC (Revised New General Catalog)
in many ways. Angular sizes are given in arc-seconds on the CNGC listing, and in a convenient scaled
format on the CDS Keypad Display.
The complete CNGC contains 7,840 objects, most of which appear in the RNGC (Revised New General
Catalog) with the same number. More than 400 objects were added to the RNGC to create the CNGC. Most
of these “should have been” in the RNGC in the sense that they are bright and large enough to have been
included.
The CNGC is enhanced from the RNGC in many ways. Angular sizes are given in arc-seconds on the
CNGC listing, and in a convenient scaled format on the CDS display. Magnitudes are given to 0.1
magnitude where possible.
The coordinates in the CNGC listing are listed for the year 2000. The CDS calculates object positions upon
power up to the current date (as shown on the time/date display). This makes the CDS pointing more
accurate. Therefore, the CNGC listing and the CDS display will not exactly agree on object positions.
Objects have been assigned a “Visual Quality Rating”, henceforth called VQ. A large number of VQs have
been obtained by direct visual observations the objects. To make the VQs as useful as possible, all
observations have been made with the same telescope and eyepiece under essentially identical observing
conditions. A higher power eyepiece was used only for very small objects. Your “Visual Quality Rating” of
a particular object will vary, largely due to sky conditions.
If the object has been rated by observation, an upper-case character (ABCDEFG) is used for the VQ on the
CNGC listing. If the object has not been observed, the VQ has been estimated by a computer program from
the object type, size, and brightness and the VQ is specified in lower-case characters (abcdefg). The VQs
for visually-rated objects are a considerably more consistent guide to observability and appearance than
either the computed VQs or an examination of the type, magnitude, and size data.
All, or very nearly all, of the objects in the CNGC are visible with the standard instrumentation and observing
conditions used to obtain the visual quality ratings. It is a good indication of what can be expected with
similar equipment by experienced deep-sky observers in excellent sky conditions. Naturally smaller
telescopes and/or less optimal observing conditions will lower the apparent quality of all objects.
* The Meade CNGC Catalog is copyright by Meade Instruments Corporation.