Re: Blue ISS

=?ISO-8859-1?Q?Bj=F6rn_Gimle?= (
Fri, 26 Feb 1999 11:37:47 +0330 (GMT+03:30)

On 26 Jan 1999 wrote:

> I believe it is superfluous to mention that an
> object was seen in this or that constellation.
> One would have to reconstruct the local sky in order
> to appreciate these indications. Since nobody will do that 
> (for lack of time) it would be better not to mention the
> constellations where an object was seen because this is
> far too denpendent on the observer's location.
> However, what could be interesting is a mention of azimuth
> and elevation where certain effects like flashes,
> flares, dimming etc. occurred. This permits at least a
> quick mental evaluation of the phase angle.

I disagree with most of this, except for operational, Earth-
attitude-controlled satellites (and the final remark on UT)

If you want to identify an UNID observation, a sky map
reference is faster to evaluate than heaps of coordinates.
(Which you probably have to sketch/graph/rerun anyway)

If an object is spinning, its spin axis, the orbit's
orientation and the Sun-satellite line is changing very
slowly compared to the 2-600 degrees/hour of Observer-
Satellite. The flashes will trace roughly conical sections
on the sky, and if an observer finds a predicted pass
through a constellation where a flash has occurred a few
days ago, the odds are for a flash. This is demonstrated
by many past observations, like "Ursa Major flasher" and

And most observers do not use instruments with setting
circles for finding and reporting satellites, so they depend
on stellar references anyway.


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