Re: Iridium Flare dimensions

Tony Beresford (
Wed, 13 Jan 1999 15:58:16 +1030

At 15:32 13/01/99 , you wrote:

>I have never seen this issue discussed. Do I dream again? Can the eye
>really resolve the MMA
>at the involved distances or should the Flare ALWAYS be a naked-eye
>point source? Do you dudes in Texas have weed this good?
Bob, lets take optimistic figures.
The MMA is just under 2meters long, say it is = 2.
The range to a moderate flare might be 1000 Km, say = 1,000,000 meters.
Angular size then = 2/1,000000 of radian or 412,000/1000000 arc sec
or 0.4 arcsec . the eyes resolving power at best is 60 arc sec, more
like nearer 100 for most of us.
What you saw is probably residual astigmitism  in your eyes+ glasses,
only showing under the exreme conditions of looking at at very bright
point source.
Tony Beresford