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.
* NGC 2000 and IC databases are copyrighted by Sky Publishing Corporation and used with their
permission.
The following guide to VQs was used in the visual observing process.
Table 9a: VQ Guide
SUPER
Very bright with very interesting shape or structure.
EXECEL
Bright object with moderately interesting shape or structure
OR
Very bright object with moderately interesting shape or structure
V GOOD
Easy to see without averted vision with some interesting shape or structure.
OR
Very bright object with little or no interesting shape.
GOOD
Easy to see without averted vision with some interesting shape or structure.
OR
Bright object, but little or no interesting shape or structure.
FAIR
Easy to see without averted vision, but little or no interesting shape or structure.
POOR
Easy to see with averted vision. Often borderline visible without averted vision.
V POOR
A struggle to see with careful use of averted vison.
(none)
Not yet rated AND missing information for computer estimate.
OR
Could not see despite careful use of averted vision.
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 following is a description of the format of the optional CNGC listing for each object:
Table 10: CNGC Listings
COLUMN NAME DESCRIPTION
1 CNGC# CNGC 00001 through CNGC 7840
2 RA Right Ascension
3 DEC Declination
4 SIZE Size of object (arc-seconds)
