[Andrew C]

Hi again Alistair,

I have modified and attached the second spreadsheet tonight to allow the LAT and LONG and TIMEZONE to be changed at will, so that you can try it out. It was previously loaded with my local data as absolute values so I had to make some adjustments.

The way to use it is to open the 'interesting objects' sheet, set your LAT and LONG (replacing the Alice Springs ones in red in rows 2 & 3), and read off the row number for one or two objects of interest (e.g. beta centauri is 129). Then switch to the 'alt az calculation' sheet, and plug in the row numbers for the object(s) inthe blue cell(s) in rows 17 (& 60). Then set your CURRENT TIMEZONE in red in row 25. The date and current local time are both automatic, but you can change the date manually if you want to calculate for other than the current day. Make sure your computer is showing the correct local time to match these settings by the way.

You should then be able to read off the true ALT and true AZ from rows 47/58 and 88/99. If you subsequently hit the F9 key these will recalculate each time.

The 'angular difference' sheet shows the sky separation angle between the two objects.

Once LAT, LONG and TIMEZONE are set, you only need to change the object numbers for new object calculations.

You can add your own objects to the list to customise it.

Please let me know how it goes.

Cheers

Andrew