Many thanks for the responses.

I downloaded the MPCORB.DAT again tonight and it appears to have fixed the
problem with isobella as the new positions match the other ephemeris. Now
the clouds have rolled in!

Bill, I did contact you re the display problem with Vista a couple
of years ago but as there was no resolution I loaded Guide on the XP PC I
use for code development and have run it there ever since. When I upgraded
the other PC to Win 7 I ran the installed Guide version again, but the
problem remained. Youe message prompted me to load the latest version on the
Win 7 PC and it does seem to have cured the issues I was seeing with the
2008 version. Thankyou!

On Thu, Mar 24, 2011 at 2:06 PM, astronomer2002 <astronomer2002@...>wrote:

>
>
> I have used Guide 8 since it first came out and have rarely found any major
> discrepancies in the position of low numbered asteroids.
>
> However I plotted 210, isabella, and tried to find it last night. No
> asteroid down to lm 17 with ccd. Eventually I got an ephemeris from the
> minor planet centre which placed it about a degree away. I printed a chart
> of this area from Guide and lo - there it was! As it is currently mag 13.9
> it is a fairly easy target visually as well as for ccd work.
>
> I am using MPCORB database, which I also downloaded and reloaded in Guide
> last night, so I am not sure as to what is causing the discrepancy. The
> dates are correct in Guide and the epoch is 2000. I checked Ceres, just to
> see if there were any discrepancies of position between the ephemeris and
> Guide, but that one was fine.
>
> Any ideas? Am I missing an update that might cause this behaviour?
>
> I am using XP as I could never overcome the display issues and crashes on
> my Windows 7 PC when zooming in further than level 7.
>
> Many thanks for any help
>
> Ian B
>
>
>


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