(IAAC) Revised NGC / IC

Hi Lew,
Brian Skiff was questioning where the "revised" NGC info comes from - that 
used by Chris Marriott in SkyMap Pro. It is from a database completed a year 
or so ago by Wolfgang Steinicke, one of the team members of the NGC / IC 
Project out in Arizona. Their website homepage can be found at:
This project is immense in its scale, and is quite a service to amateurs, in 
particular. Many errors in older catalogs have been corrected, and the guys 
are building a handy photo archive of images of all the NGC and IC objects - 
about 30% complete at this point, I would guess. There are links at the home 
page to the members individual databases and observations. Steve Gottlieb's 
files are especially impressive, as they contain observational records made 
with 8", 13" and 17.5" scopes. The project site is well worth exploring - I 
hope that the their efforts aren't overlapping too much with those of IAAC, 
Surface brightness is indeed a good yardstick to guide visual observers 
hunting down galaxies and larger planetaries. But even there, there is 
considerable disagreement among the various catalogs. Brian is correct, 
though. If you set yourself a threshold for a particular scope - say a 
surface brightness of 12.5 for an 8" scope, or 13.5 for a 16" scope, you will 
screen out a lot of objects that aren't worth chasing down. But again, this 
is a purely subjective technique, and the catalogs are only a rough guide to 
what an amateur can expect.
Good luck if you can get out there tonight! I'll be down at FDO for as long 
as the conditions permit.
Doug Stewart
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