Re: [guide-user] Jupiter and SAO79126

Bill Gray Apr 18, 2013

Hi Luc,

On 04/18/2013 03:43 AM, Luc Desamore wrote:
> Not a problem just a borderline case : there is a very close approach
> between Jupiter and SAO79126 on 2013 sept 15 at 04:27 UTC (separation
> lower than 3 arcseconds).
> In the sky view at the right position (and with a big zoom) there is
> no occultation, but the eclipse view shows a small occultation in the
> polar regions. Actually I think that there is no occultation nowhere on Earth.

Ouch. A problem due to Jupiter not being round. The eclipse/occultation
maps assume spherical objects. The actual sky view _does_ show flattened
objects, mostly noticeable only with Jupiter and Saturn. (Though Phobos and
Deimos and a few others show up as potato-like objects if you zoom in far
enough. Again, occultation charts for those objects will assume they're

I'll look into this. It's been a while since I worked on the mathematical
end of this. (Basically, Guide uses the method of Besselian elements to
compute eclipse/occultation/transit circumstances. The sources I used for
this all were thinking about essentially round objects such as the sun,
moon, Mercury and Venus. I'll probably have to derive some of the math
and see what I get, and may find that it's not really feasible at all.)

-- Bill