Re: NOAA 11 double flare, and other obs.

JRBURCA@aol.com
Sat, 4 Oct 1997 06:57:08 -0400 (EDT)

Ed Cannon wrote:

<< Wednesday night (1 Oct. 1997 local, 2 Oct. 1997 UTC), I copied 
 NOAA 11 (88-89A, 19531) predictions from Mike's published mag. 5.5 
 predictions for Austin, since the brighter ones I generated didn't 
 have anything after 8:45 p.m. CDT (1:45 UTC).  I thought, "I won't 
 see it, but I think it does flash sometimes."
 
 So I was watching where it was supposed to be soon after exiting 
 from the shadow, and I saw what I believe was NOAA 11 flash to mag. 
 -1 for a second or so!  Then a few seconds later (5 seconds?), 
 there was another -1 flash!  I swear this is true!  It soon assumed 
 its predicted +4.n, because I couldn't see it any more from my poor 
 location.  Here's some data from my first prediction in UTC, with 
 height, shadow height, and range in km:
 
 Time.... Al Azi R.A._ Dec._ Hgt. Shd Rang Phs (QS)
 01:54:03 47 137 21:55 -03.5 0840 096 1090 039 (or 180-39 = 141)
 
 That looks suspiciously like an Iridium flare sky position to me, 
 but it wasn't one of those.  The NOAA 11 elset was 7 days old on 
 that one.  I looked for it again Thursday night but did not see it.  >> 


YES!  YES!  YES!   I saw the same thing you described but on 
Friday night local 3 Oct. 1997 (4 Oct. 1997 UTC) at approx.
03:11:30 UTC.  The really amazing thing is that I had NOT read
your post and only ACCIDENTALLY saw it.  Later, after reading your
post, I ran a pass prediction using STS Plus and it matched very
well with what I had seen.  NOAA 11 #19531 had culminated at
AZ 73.6  EL 67 at 03:13:25.  What I saw was a little NE of Jupiter
at around 03:11-12 UTC.  The program showed NOAA 11 to have
been at 03:11:30 UTC  at AZ 141 EL 40 northeast of Jupiter.  What
I saw was travelling generally south-to-north and as was NOAA 11.

I've had some experience in seeing Iridium flares so also originally 
thought that I had seen one of those.  This is how it happened:  
Having just returned from a trip, I was very busy unpacking so-to-
speak or just getting everything in order.  Tonight, I had no 
organization regarding Iridiums in pursuit of flares; no current TLE's; 
no time to deal with it; no intention of dealing with it tonight.  I went 
out to the car to take care of something and as I left the car in the 
driveway and walked towards the house, I glanced up towards Jupiter
and noticed a very bright satellite a little NE of Jupiter a little less
bright
than Jupiter.  Just as I focused on it, it dimmed for a few seconds and
then flared to that same magnitude (-2 perhaps) again for about 5 sec. 
I was amazed that I had just happened to look up in the right spot to 
see an Iridium flare.  I later tried to confirm that it was indeed an Iridium

but failed.  I obtained the latest Iridium TLE's from OIG (Oct. 2 dates) but
could not find one that fit.  Iridium 13 was in the wrong part of the sky
and going north-to-south.

Later I read Ed Cannon's post and thought it sounded very familiar.
Sure enough, I also must have seen NOAA 11 double flare and had
thought it was an Iridium flare.  It was very reminiscent of my "Iridium 9
Flare 23 Sept. 1997" report where I reported a double flare but in that
case I believe it actually was an Iridium.

Jake Rees
Burbank, Calif., USA