Superbird, further report.

Malcolm Purves (malcolmp@ukonline.co.uk)
Thu, 02 Sep 1999 03:24:58 +0000

At 11:48 01/09/99 -0700, Matson, Robert wrote:
>Excellent job, Malcolm!
>
>Based on your description, it sounds like you acquired Superbird
>pretty close to its peak, but missed the ramp-up prior.

Yes, it would seem so, but I am rather astonished as to how
I could have missed it ! I had eta just outside fov to the right
theta at top, and zeta-chi was a bit further out of fov to the
left. So apart from scans to the left to view zeta-chi and to
the right to check on below eta, I had the right area in view
most of the time between 0310 and that first flash.
Astounded I am! Fatigue I expect, as I had allowed myself too
long an 'uncertainty' period prior to the prediction. But
at least the more experienced chappies can now take over without
suffering too much 'binocular elbow' through waiting too long !

I am also astonished because I *did* pick up two serendipitious
satellite intruders during the watch! One was well before the
first flash and entered the field from the top right and exited
bottom left, just about occulting tau on its way through.
The second one was a few minutes after the last flash ( while
I was still checking the field for further Superbird activity).
This last one entered from the bottom (south) of the field and
climbed rapidly vertically a fraction to the right of zeta-chi.
I didnt take time out to time them, as that was not the business
at  hand ! I didn't want to miss any of the main event!
However, this evening/night is cloudy and I have been learning
more how to drive Skymap. If I am driving this thing correctly it
turns out that the first intruder was Cosmos 1048 r at 03:24/03:25
and the second one was Cosmos 1515 r at 3:42/3:43. ** tles below
So that neatly brackets what I was seeing. Quite exciting really,
I wonder what is the probability of getting 3 sats all in the
same field of view of 10x50s in a 20 minute period ? 

In the excitement of it all I clean forgot to watch for Mir !

>assume you were seeing flashes once very 11.5 seconds or so
>initially, but only once every 23 seconds toward the end.

No,not quite.
By counting in my head " a thousandandone thousandandtwo"  etc
I had 11 to 13 each time.
Apart from some 'lost' time in the middle ( when I tried,
unsuccesfully, to time the flashes by my clock ) they were all
about that same period apart.
Eventually, on one occasion, when I counted to 20 and there was
 no flash I looked away to the clock and noted the time as a
possible end point. So I may have missed a last flash at 23 but
only the one because I continued to watch the area for several
minutes afterwards , even after the Cosmos 1515r event.
After seeing nothing more I 'upgraded' my possible end timing
to an actual end :-!) went indoors, typed up my prelim. and
went to bed !

**
Cosmos 1048 r    7.4  2.4  0.0  5.5 v 10.5       803 x 753 km
1 11112U 78105B   99244.04567628  .00000391  00000-0  14776-3 0  6744
2 11112  74.0286 221.4928 0035412 156.7764 203.4999 14.34147950 86822
Cosmos 1515 r    7.4  2.4  0.0  5.5 v 6.48       646 x 621 km
1 14552U 83122B   99243.87621735  .00000800  00000-0  10582-3 0  2742
2 14552  82.5234  24.9341 0017914 299.0801  60.8618 14.78689345846728
**

It is now 03:15 local, the clouds have got thicker, to the extent that
I can not see to the end of my garden, so I think early to bed is
indicated as there is not going to be any viewing of Superbird or
anything else tonight :-!(

Malcolm.