Re: Scope control, coordinate systems

Bill J Gray Oct 20 10:31 AM

Ben Davies wrote:

> But, if I choose 'epcoh of d' and then try to use the menu
> option GOTO | coordinates Enter RA/Dec, the dialog box lists the
> epoch as D2000.0 and refuses to go there - "Not a valid epoch".

Um. I see your point... at present, there's no way to enter
coordinates as simply "epoch of date".

The closest you can get is this. Go into the Time dialog,
click on Time Format, and select the time to be shown in years,
with, say, five decimal places. The time will then be shown
in the legend in that form. Right now, it would be something
in the ballpark of 2003.801.

Go back to the Enter RA/Dec dialog, and specify an epoch
of J2003.801.

A small problem: this will allow you to enter _mean_
coordinates for J2003.801, not _apparent_ ones (the latter
have been adjusted for nutation and aberration). It'll get
you within about 30" or so, but not closer.

-- Bill