Re: TDF-1 Naked-eye Geosat Flasher

Ron Lee (
Wed, 18 Aug 1999 23:36:53 -0600

>4:38UT - some flashes already visible from 1 set of panels (period
>approx 28 seconds).
>4:47:30UT - Second set of flashes becoming visible. 1st set near maximum
>4:52 UT - BOTH sets near SAME brightness (3rd mag.)
>4:56 UT - 1st set becoming invisible.
>4:59 UT - Last flash visible.

The above is Rick's obs on 18 Aug UT I believe.  I am including it since it
appears close to what I observed on 19 Aug 99 UT.  From Falcon, CO (USA),
I first noticed a flash at about 4:53 UT.  Equal brightness flashes around
5:06-5:07 UT then I quit looking when the flashes became faint about 5:13 UT.

The time from first flash (in 7x50 binocs to mid point and to the end is
roughly the same as Rick's Obs.  Once he posts his time for 19 Aug, we can get
a general idea of the time shift with longitude difference (I am at 104.56 W,
38.94 N).  Assuming his mid point is around 5:03 UT on 19 Aug, I am 3-4 
minutes later.

I did notice double flashes near the mid-point.   I need to review the tape
recording to get a better handle of the process as I saw it.  I also ran out
of tape before the end since I did not know when it would start.  I assumed
it would be later but started early just in case.

Regardless, flashes last about 20 minutes in binoculars and knowing it is
as you view it from more easterly locations may allow others to find it.
Providing a consistent mid point will allow someone like Rob Matson to
determine a pointing angle and then to predict future flashes like he did
for Superbird-A.

Ron Lee