Has 1992- 30 J been accelerating and is now back on "normal" behavior?? The latest observations of 1992- 30 J prompted me to do a kind of search in the TLE's to see if a MM-jump did occur that could explain the sudden accelerating of the period. I used the recently obtained TLE-Archive on CD-ROM from Allen Thomson to do the search. What a wealth of info! In 1999 I made the last observations of 1992- 30 J (21984) in april: 92- 30 J 99-02-13 19:43:21 LB 171.4 0.5 2 85.7 AA, mag 4->7 92- 30 J 99-02-14 03:55:30 LB 177.8 0.5 2 88.9 AA, mag 4->inv 92- 30 J 99-04-01 21:35:22 LB 173.2 0.5 2 86.6 AA, mag 4->inv 92- 30 J 99-04-12 20:53:17 LB 90.3 0.5 2 45.2 AA, mag 5->inv It was in a slow tumble; the last obs being seen as half period. There are no indications in the TLE's that a MM-jump occured in april 1999. More than a year later I decided to take a look againand to my sur- prise it was flashing much quicker. Following it over the next days showes clearly an acceleration. 92- 30 J 00-05-05 23:29:30 LB 81.8 0.5 7 11.7 AA, 6->i 92- 30 J 00-05-06 01:28:05 LB 104.3 0.5 9 11.6 AA, 5->i 92- 30 J 00-05-12 22:30:33 LB 84.1 0.5 10 8.4 AA, 5->i 92- 30 J 00-05-13 22:02:10 LB 81.9 0.5 10 8.2 AA, 5->i 92- 30 J 00-05-20 21:01:01 LB 73.3 0.2 10 7.33 FF, 5->i When plotted with Satflash it seems that the minimum has already occurred between May 13 and 20 as the slope of the trendline is decreasing. With more observations in the next days it can be told for sure; or that the miniumum is still to come. Looking at the TLE's in the TLE-Archive on CD-rom the Mean Motion (MM) shows a gradual increase during 1999 and the first part of 2000. On 2000 day 00002 it was 12.22109247; reaching a maximum of 12.22109850 on day 32. Further fluctuating slightly and going up again on day 56, reaching 12.22109817 on day 72. Then the rate increases more rapidly, see table below. Day 2000 MM 00081 12.22110242 00104 12.22111413 00106 12.22112359 00108 12.22121737 00110 12.22130153 00111 12.22131354 00114 12.22133697 00115 12.22134587 00117 12.22138570 00118 12.22139123 00119 12.22139428 From OIG I still had the following data: 00126 12.22140293 00132 12.22134898 00137 12.22131393 00138 12.22130708 00139 12.22130608 00141 12.22130909 So it seems that around day 107 something happend to 1992- 30 J; and also around day 116, but smaller. From the latest elsets it seems to go up again till day 139 and then MM is increasing again. Perhaps Kurt Jonckheere can find some time to do a MM analyses, as he used to do in the past. I've requested historical TLE's from OIG for the period April 1st till present. Concluding: 1992- 30 j is an object to be watching closely and observe on every oppurtunity. More accelerations are possible. Greetings and clear, dark skies Leo Barhorst 52.767 N 5.09 E 2 m ASL ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
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