Reply to : Arild Noland

>> Agreed. On my future online resource I would like to include the

ability to filter the data for such things as magnitude, separation, mag
difference etc. Even it is very hard to tell beforehand how difficult a
pair may be, the limiting resolving power and magnitude of your
telescope/sky do filter out a tremendous lot of the WDS. I tried this now
on an old import I had of WDS. There's a total of 63,069 systems in the
database, filtering for my 4" with minimum sep of 1.1", primary brighter
than 10 and secondary brighter than 12.7, leaves some 4,574 systems, about
7 % of the total. Obviously a lot of these systems will be next to
impossible given too huge mag difference, but ut gives an idea. <<

I wrote a program in Visual Basic to search on primary mag. / mag.
difference / RA / Dec. / discoverer code / etc. using the WDS, but it
doesn't include constellation names, so I switched to the SAC Double Star
Database, which is only about 10,000 entries, and includes constellation
names, and map numbers for Sky Atlas and Uranometria.

Richard.


E-mail from: Richard Mallett, 14-Sep-2002