Leisure Time LX20 instruction manual SAO Catalog, UGC Catalog, Cngc Catalog, Object Library

APPENDIX D: LX200 64,359-

OBJECT LIBRARY

1. The LX200 64,359-Object Library

The LX200 64,359-Object Library is a collection of the most studied and fantastic objects in the sky. It includes:

•15,928 SAO (Smithsonian Astrophysical Observatory) Catalog of Stars: All stars brighter than 7th magnitude.

3 4

The following guide to VQs was used in the visual observation process:

•12,921 UGC (Uppsala General Catalog) Galaxies: Complete catalog.

•7,840 NGC (New General Catalog) objects: Complete Catalog.

•5,386 1C (Index Catalog) objects: Complete catalog.

•21,815 GCVS (General Catalog of Variable Stars) objects: Complete catalog.

•351 Alignment Stars: LX200 alignment stars.

•110 M (Messier) objects: Complete catalog.

•8 major planets from Mercury to Pluto.

This appendix has three object listings in sections 2, 3, and 4. Section 2 (page 36) is a partial list of 278 of the best NGC objects. These are most of the best objects in the sky, and as such, make good first targets. Section 3 (page 43) is a list of the 250 brightest stars and 100 double stars. The complete Messier list is shown in Section 4 (page 49).

The above databases are accessed through the M, STAR, and CNGC keys. The M key accesses the M object database only; the STAR key the SAO, STAR, GCVS, and planet databases; and the CNGC key the UGC, NGC, and 1C databases.

When the STAR or CNGC key is pressed, the display will show which database is currently active. At this point you can enter the object number for that database, or hit ENTER to bring up the menu to change databases. The LX200 will remember which database was last used.

a. SAO Catalog

The standard Star catalog used in astronomy, this catalog includes all stars brighter than 7th magnitude.

b. UGC Catalog

This catalog of galaxies includes objects as faint as 15th magnitude.

c. CNGC Catalog

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 LX200 display. Magnitudes are given to 0.1 magnitude where possible.

The coordinates in the CNGC listing are listed for the year 2000. The LX200 calculates object positions upon power up to the current date (as shown on the time/date display). This makes the LX200 pointing more accurate.

Objects have been assigned a "Visual Quality Rating" (VQ). A large number of VQs have been obtained by observing the objects. To make the VQs as useful as possible, all observations have been made with the same telescope and eyepiece under substantially identical observing conditions. Only for very small objects was a higher power eyepiece used. 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 standard instrumentation and observing conditions used to obtain the visual quality ratings. It is a good indication of what to expect with similar equipment by experienced deep-sky observers in excellent conditions. Naturally smaller telescopes and/or less optimal observing conditions will lower the apparent quality of all objects.

The following is a description of the format of the optional CNGC listing for each object:

COLUMN	NAME	DESCRIPTION
1	CNGC#	CNGC 0001 - CNGC 7840
2	RA	Right Ascension
3	DEC	Declination
4	SIZE	Size of object (arc-seconds)
5	MAG	Magnitude (-5.5 through 19.9)
6	TYPE	Type of object
7	*	* object is not in the RNGC
8	ALT CAT	Alternate catalog name & number
9	VQ	Visual Quality Rating (abcdefg ) or
		(ABCDEFG)
10	TAGS	Object Type # (0-F): S = Sky-Cat : T =
		Tirion
11	COMMENTS	Name, comments, other info