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The 86-92 J saga

As mentioned in my review of the year 1994 the 86-92 J object showed some strange behavior on or about july 18th. In figure 1 all my observations in 1994 and the 3 from MM in the recent observation department in Flash 88, december 1994, are plot- ted. After I had made the graphics I came across an obs by TC on june 11. He observed the satellite with a period of 6.48 s. This well fitts the regr-line asuming it is a half period.

In figure 1A some corrections are added. The observations on day 0 and 6 were erased because the satellite was still accel- lerating. The obs on day 166 was probably wrong.

The jump between day 198 and 202 stays prominent in both figu- res. Something happend.

In figure 2 more corrections were made. The obs between day 150 and 198 were doubled and the obs on day 330 was halved. Recalculation gives a good fitting regr-line. But this is a bit to much manupilating the obs. Then the above mentioned obs by TC was a quarter period?

Zooming in on figure 1 gives us figure 3 where the obs marked with a dot in figure 1 were erased. Now the regr-line fitts well.

Zooming in on the right part of figure 1 gives figure 4. Because of the low number of obs some care had to be taken. But the distribution in time makes up for it. The regr-line fitts excellent.

Conclusion

On or about july 18 the rocket-stage suddenly slows down in rotationperiod. I observed 86-92 J on july 18 and saw it almost S, mag 7. My last two obs this year on 86-92 J were four days later when I saw it at 26.5 seconds. This didn't ring any bells as it looked like double period. The remarks in flash 88 about MM's latest obs of 86-92 J made me take a closer look at this satellite. The results are the figures with this article.

Remarks

It is a pity no more obs around and after day 200 were made. We almost missed a nice phenomena. What caused this has still to be determined, possibly a hit by a meteorite. The sudden venting of remaining fuel, the leak caused by a meteorite, is also possible. The two branches of the graph fit well and further observa- tions must make clear of the above can be maintained.

Leo Barhorst



Next: Jonathan's Space Report Up: Flash 90 Previous: Determining the orientation


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