Re: converting star coordinates to x,y,z

From: Brian Tung (brian_at_isi.edu)
Date: 12/09/04 

Date: Thu, 9 Dec 2004 17:18:50 +0000 (UTC)

Ioannis wrote:
> For example, what are the rectangular coordinates of Alnitak with 0,0,0
> taken at my position in Spring in Athens and at your position in Winter?

Position on the Earth is entirely negligible. The maximum difference
is, of course, twice the parallax angle, and that is at most about 1.5
arcseconds. The parallax induced by the Earth's rotation is smaller
than that by about a factor of 25,000--about 60 microarcseconds. We
don't have a snowball's chance in hell of detecting that.

I'm pretty sure the OP didn't care about that. I think he just wants
to be able to set (0, 0, 0) to whatever location in space he would like.

Brian Tung <brian@isi.edu>
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