Re: (meteorobs) Iridium flares and meteor photography

    I've been watching Iridium Flares since mid-April using predictions
from www2.gsoc.dlrdot de/satvis .  I have found that the timings are very
precise, in fact you could set your watch by them to WWV accuracy.  This
is of course dependent on the precision with which your site coordinates
are known.  I have seen several web links to sites that supposedly give
the Lat/Long for any site on Earth, but they usually give one coordinate
for an entire city, which is not accurate enough.  You have to get out a
good map, ruler, and calculator and do it yourself.
    The predicted sky location is also very accurate, and known flares
could be avoided by meteor photographers by choosing a different area of
the sky to monitor.
    Also, Iridium flares are symmetrical so there should be a gradually
brightening/dimming trail on both sides of the maximum flare, not just
before the flare, as most often occurs with photographed meteor trails.
They should be easy to distinguish from meteor trails on photographs.
    Lastly, if this isn't heresy, I'd like to suggest that Iridium
flares make a useful training tool for visual meteor observers.  Meteor
magnitude estimates brighter than -4 are usually not much more than
guesses since we have nothing in the sky to compare the meteor with.
These predicted flares allow anyone with clear or partially clear skies
to step outside at the right time and see a magnitude sample as bright
as -7.  I've seen enough of them that I'm beginning to develop a
magnitude memory for brighter than -4 events.

David Holman