Re: Confirmation of 92-86C, and observations

Bjoern Gimle (b_gimle@algonet.se)
Mon, 10 Aug 1998 10:21:33 +0200

I made two errors in my estimate of the effect of Pierre's 0.000015 =
ndot2:

I used a value ten times the actual difference.
I converted one minute to fraction of days, not orbits.
The error, in fraction of orbits, is squared age of elset in days,
times delta ndot2, which means it takes 54 days for 0.000002 to
build up to one minute.

I observed 92 86C 100 seconds before prediction using Mike's 86C - 13.
It was 0.2 degrees lower than predicted in Sagitta (50 deg. S)
but 0.1 above at the last point. I was steady at magn +2 for the
minute I followed it from culmination.

I note that Mike's three elsets show progressive changes with ndot2 in
Epoch, B*, RAAN, AOP, MA and MM as can be expected, but the middle
i and e appear rounded. Nevertheless I used the middle elset, and
adjusted MM and B* to agree with Pierre's ndot2 and my observations
(ELCOR format):
    1
   59.22371 -18.22857      44.    Bj=F6rn Gimle
92 86C - 15 USA 89 rk                            7256 x 368
1 22519U 9208603  98216.18566278  .00001500  00000-0  30500-3 0    06
2 22519  56.9260 235.2590 3380000  51.9560 308.0440  8.43995000    02
1 98 08 09 21 26 46.2   19 41.9  +16.92   1950 1
1 98 08 09 21 26 53.6   20 03.3  +18.51   1950 1
1 98 08 09 21 27 28.3   21 45.95 +23.08   1950 1

Searching in twilight for USA 129 I noticed rapid double flashes,
about 9 seconds between the pairs, along the predicted track.
First pair mag.-1, second +0 (no pos.), last (fourth?) +3
Probable identification MOS 1=20
MOS 1            2.4  1.5  1.3  6.9 d
1 17527U 87018A   98211.18340086 -.00000043 +00000-0 +00000-0 0 07027
2 17527 098.8336 262.8395 0019583 350.1011 009.9760 14.00506641583186
1 98 08 09 20 08 27.0   14 40.8  +15.4    1950 .1
1 98 08 09 20 08 56.1   14 13.8  +20.4    1950 .1

Timed NOSS 2-3 rk one degree above eps Peg:
1 98 08 09 20 29 38.8   21 45.0  +10.8    1950 .4