Decay of 96- 54 B = Centaur r
Alan Pickup (alan@wingar.demon.co.uk)
Sat, 15 Mar 1997 22:02:47 +0000
Having been away all day, I've only been able to tackle this interesting
object in the past couple of hours.
The latest OIG elsets for this are:
Centaur r 5328 x 100 km
1 24316U 96054B 97074.30063786 .00112179 -19108-4 52326-5 0 764
2 24316 25.2175 88.8864 2875202 267.1283 60.2174 10.01432485 8957
Centaur r 5113 x 89 km
1 24316U 96054B 97074.40033338 .06214934 -19855-4 17384-3 0 776
2 24316 25.2021 88.8220 2797505 267.4663 60.6065 10.20464813 8962
Centaur r 4921 x 98 km
1 24316U 96054B 97074.49817405 .41398097 -20345-4 16972-2 0 803
2 24316 25.2441 88.3375 2713684 268.4328 60.7912 10.36194582 8972
Centaur r 4763 x 95 km
1 24316U 96054B 97074.59427556 .89217835 -20851-4 32485-2 0 821
2 24316 25.2404 88.0107 2649911 269.3199 60.7725 10.50377322 8982
Centaur r 4567 x 91 km
1 24316U 96054B 97074.68878157 .93592373 -21413-4 26958-2 0 841
2 24316 25.2373 87.7052 2570129 269.7091 61.5176 10.68568484 8991
I've done my best to fit SatEvo evolutions through these and earlier
elsets. As well as varying the start mean motion and ndot/2 terms to get
a decent fit through the equator crossings derived from the published
elsets, I have also adjusted the start eccentricity and mean anomaly to
keep the perigee height reasonable (~96 km) and the initial equator
crossing at the "correct" time.
I've tried two fits:
The first ("9057") evolution is based on an initial elset at 97073.07.
This gives a mean residual of 7 seconds for the "best" 11 elsets since
that time. By "best" I mean that I ignore duplicate elsets by taking
only the last-issued elset on each rev. The worst residual is 20s. The
indicated decay is at March 16.79.
The second ("9075") evolution is based on a more recent start elset at
97074.19. It has a mean residual of 6s and a worst residual of 16s (at
97074.59) over the 6 best elsets in the meantime. The indicated decay is
also at March 16.79.
The following predicted elsets are based on the latter "9075" evolution:
Centaur r 4287 x 96 km
1 24316U 96054B 97074.78112098 1.19870882 26472+0 40780-2 0 90752
2 24316 25.1978 87.3264 2445147 269.7730 62.4686 10.94452785 9007
Centaur r 4057 x 96 km
1 24316U 96054B 97074.87173013 1.27628928 31034+0 41595-2 0 90752
2 24316 25.1901 86.9914 2342379 270.3457 63.0875 11.16859791 9018
Centaur r 3824 x 96 km
1 24316U 96054B 97074.96050803 1.36602040 36982+0 42557-2 0 90756
2 24316 25.1820 86.6507 2235632 270.9283 63.7396 11.40294761 9022
Centaur r 3588 x 96 km
1 24316U 96054B 97075.04744537 1.47122456 43950+0 43704-2 0 90758
2 24316 25.1754 86.3038 2124191 271.5215 64.4314 11.64932512 9031
Centaur r 3347 x 96 km
1 24316U 96054B 97075.13252487 1.59649519 53627+0 45093-2 0 90758
2 24316 25.1665 85.9501 2007140 272.1263 65.1699 11.90996746 9049
Centaur r 3102 x 96 km
1 24316U 96054B 97075.21572079 1.72739012 57608+0 46203-2 0 90759
2 24316 25.1590 85.5893 1884024 272.7434 65.9619 12.18620779 9057
Centaur r 2851 x 96 km
1 24316U 96054B 97075.29701079 1.88696806 73248+0 47585-2 0 90753
2 24316 25.1511 85.2206 1754328 273.3741 66.8122 12.47948876 9069
Centaur r 2592 x 96 km
1 24316U 96054B 97075.37636466 2.08968729 97109+0 49408-2 0 90756
2 24316 25.1426 84.8433 1616227 274.0195 67.7395 12.79429764 9075
Centaur r 2322 x 96 km
1 24316U 96054B 97075.45373227 2.35817499 13664+1 51860-2 0 90755
2 24316 25.1334 84.4565 1467046 274.6814 68.7715 13.13726521 9080
Centaur r 2035 x 96 km
1 24316U 96054B 97075.52903443 2.73505003 21075+1 55164-2 0 90755
2 24316 25.1232 84.0587 1302626 275.3620 69.9523 13.51889795 9098
Centaur r 1721 x 96 km
1 24316U 96054B 97075.60214633 3.31688700 34958+1 60332-2 0 90758
2 24316 25.1141 83.6481 1115364 276.0647 71.3648 13.95767956 9102
Centaur r 1363 x 96 km
1 24316U 96054B 97075.67285905 4.27096725 59768+1 67359-2 0 90753
2 24316 25.1033 83.2216 0891230 276.7947 73.1581 14.48908945 9117
Centaur r 923 x 96 km
1 24316U 96054B 97075.74082789 6.45542366 21636+2 80150-2 0 90753
2 24316 25.0893 82.7738 0600541 277.5613 75.6612 15.18845524 9129
Good luck to anyone who tries to spot this.
Alan
--
Alan Pickup | COSPAR site 2707: 55d53m48.7s N 3d11m51.2s W 156m asl
Edinburgh | Home: alan@wingar.demon.co.uk +44 (0)131 477 9144
Scotland | Royal Observatory: A.Pickup@roe.ac.uk +44 (0)131 668 8224