NOAA 11 -- another double flare to -1

Ed Cannon (
Thu, 19 Mar 1998 04:14:35 -0600

Beautiful night over central Texas!  One-power observing.

I noticed in Mike's published mag. 5.5 predictions for
Austin that NOAA 11 (19531, 88-89A) was going to be about 
where it was (northbound from the SE) last October when I 
(and Jake Rees a couple of nights later) saw it do a 
double flare.  The prediction I had this time was at alt. 
46, az. 134.  (I found out it went near Alphard [alpha 
Hydrae] when I looked up the mag. +2 star it passed.)

So I looked for it and was *not* disappointed.  It 
displayed two maxima to at least -1 (with Sirius, for 
comparison, not too far away) that lasted a few seconds 
each.  The maxima were separated by approx. 10 to 15 
seconds, and between them it was faint-to-invisible.  I 
recorded 2:14:27 and 2:14:42 UTC (19 March) for the
flares, but I may have waited a couple of seconds later 
on the second one.  After the second one, it remained 
faintly visible for perhaps 15-20 seconds.  

NOAA H) is currently (or was until quite recently) 
stabilized and at least partly operational, or on standby 
status: (w/ picture) (See July 16.)

so perhaps these events are predictable.  The problem is,
looking at that picture of NOAA 11, it's hard to see how it
could do *double* flares....

TRMM/ETS7 Rk (25065, 97-74C) seems possibly to have slowed 
to a period of about 30 seconds.  Very bright maxima.

Cosmos 1867 (18187, 87-60A) looked like it would have been 
very interesting with magnification; it was flashing with 
what appeared to be multiple flashes (almost like sparkles?) 
at each maximum.

Astex (05560, 71-89A) brightened to about +1.5 as it
approached and reached culmination and then quickly dimmed 
to its predicted +3.n magnitude.

There was a pretty nice Lacrosse 3 pass.

I tried to some extent to see Superbird A flashes but really
didn't know when to expect them.

Ed Cannon
Austin, Texas (UT campus) 30.286N, 97.729W, 150m