Re: Primary and Secondary Flashes

Bjoern Gimle (
Sun, 3 Oct 1999 10:16:13 +0200

>In the case of Superbird A (and many other objects such as Spot 3) the
>flashes are originating from different surfaces of the object.  With
>Superbird A you begin to see flashes spaced 23 seconds apart.  Then another
>surface begins to flash (the other side of the solar panels??) and you're
>getting flashes every 11.5 seconds.  The additional, secondary flash is
>clearly dimmer that the original flash.  After a few minutes the secondary
>flash is too dim to be observed and a few minutes later Superbird a stops
>flashing entirely.
>for info on flashing satellites.
I haven't seen it myself yet, but from all accounts the secondary flashes
become brighter, and the primary fainter.
Then the primary flashes more or less disappear, and you have again a 23
second period.
But the latter series is shifted 11.5 seconds wrt. the first,
and the transition, "phase shift", is important for the
determination of the rotational axis.