Re: flare droughts

Bjoern Gimle (
Fri, 20 Feb 1998 07:07:13 +0100

> wrote:
>I have noticed this too - maybe the area on the earth's surface that gets
>more flares in a given month migrates around the planet, much like the
>past c.15 days.  I am wondering if, assuming the planes stay fixed
>relative to the sun (and from here the background constellations), not

They don't - they move (.3 deg/d?) and Earth adds 1 deg, and the sun
"wanders" north (and south). 

>degree) I would also expect such a two month periodicity would be smoothed
>out by "noise" and not be so obvious.

There is a three day periodicity in pass times, but since the planes,
and Sun declination, has changed considerably, this is one noise.

I have tried to find location-relative periodicities, but they were on
the order of months, so Sun has moved a lot more.

I have also run a prediction for two different locations, four years for
a few satellites, and one year for a complete 66-sat config, and found
only random fluctuations, except the shift day/night flares, and a
latitude factor of 1/cos and a little more.

I sent these to Don Baker of Iridium Corp., and I could post them on
my web site.

On the other hand, you can imagine that there are only random variations,
if you map the tracks around you (with my still incomplete but working
irid_map beta, or simply manual plotting of iridflar data)

Use a 3-line verbose output, 15-degree off-specular, and mag.limit 5.0/5.0
(or even 5 degree, 3.0/3.0 if you think this leniency proves nothing)
and you'll see from the Max.Mag.column and track plots, that someone
in your neighbourhood gets the monsters !

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