Hi Bill !

That´s a very good idea! Thank you very much.

Werner

--- In guide-user@yahoogroups.com, Bill J Gray <pluto@...> wrote:
>
> Hi Werner,
>
> Use the 'Proper Motion' button. It'll do what you're looking
for.
> The stars _will_ move, but only due to proper motion: that is,
> unless you set a really high step size, you'll never know about it.
>
> The 'RA/dec' button, in theory, animated just solar system
objects:
> at each step, the objects were 'un-drawn' at their old positions,
then
> drawn at their new positions. In practice, this didn't work very
well.
> Many things that _should_ have moved, such as the horizon, just
> stayed where they were. The 'Proper Motion' button gives all of the
> benefits, and none of the drawbacks, of the 'RA/dec' button.
>
> Incidentally, given a high step size (of a century or so), you
> can animate in 'Proper Motion' mode, and then you _will_ see the
> stars gradually crawl around the screen, and constellations deform.
> To me, it's strange that you can look at the sky as it was a few
> millennia ago and not see much difference from what it looks like
now.
>
> -- Bill
>