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Observational Flashes

Observational Flashes is open to short observational contributions by all observers. English language texts are preferred, but short (!) Dutch, French and German language items will be translated if received. Observational flashes are sometimes edited by BDP, so any language errors are his responsibility.

Mike McCants, Austin, Texas

I observed 90- 40 D on Feb 5 with a period of 12.05 s (at mag 9 to 10). Range gradually increasing from 6000 to 7000 miles. "Double maximum". Each maximum was a smooth rise and fall. The maxima were separated by about 4.5 seconds. The minimum between the maxima was only about 1/2 to 3/4 of a magnitude less than the maxima.

The day before I saw 93- 15 B with 15.58 seconds (mag 4 to 8). Sharp flashes to about magnitude 4 at a range of about 3000 miles. 85- 94 G seems to go down. I saw it with 35.5 seconds at mag 7.5 to 8.5 on Feb 4. It was difficult to measure.

And, of course, I have been continuing to watch 65 8A decrease its period. I saw it on Feb 2. The first and third maxima show sharp flashes. They are separated by 4.93 seconds. So in some sense the period should be 9.86. But that would not be consistent with my previous observations (of the 1/2 period). The maximum between these two was a "slow" maximum, but had the same brightness as the other two.

79- 30 B is still going down. It was 4.44 on Feb 6. The same goes for 94- 24 B (13.72 on Feb 6), 88- 50 A (3.37 on Feb 6) and 92- 8 B (19.0 on Feb 6 and 18.0 on Feb 7, going down fast!). It looks like 86- 37 B has accelerated. I saw it with 9.34 seconds on Feb 18. I saw 94- 85 B on Feb 24. I have only seen this object at full phase. It seemed "steady" except that it seemed to dim a little bit every 1/2 second. But it wasn't reliable enough for me to try to count.

87- 74 G (the 'other' G object) had a period of 9.63 on Feb 24. Primary max was followed by a deep minimum, a secondary maximum, a shallow minimum, then the primary maximum.

My program that looks for objects with large changes in mean motion 'kicks out' (over the last two months) the following objects :

77 57B ??, 84 109B, 85 90B ?, 86 37B, 88 39B ??, 89 26B ??, 89 42B, 89 86A, 90 4B, 90 36B, 91 19B (very likely), 91 42B, 93 36B (very likely), 94 24B, 94 29B, 94 83B

One ? means doubtful, two ? means very doubtful. Objects with big changes in mean motion frequently undergo an acceleration simultaneously!

On Feb 10 87- 49 B showed only very small magnitude fluctuations at a full phase. I made several timings and they all showed differences of 12, 24, or 36 seconds. So I think the period is 12.

Russell Eberst, Edinburgh, Scotland

Early on the morning of February 18, I will make my 150,000th observation. My 100,000 was made on 1984 October 9, so the last 50,000 has taken 10 years 4 months 9 days.

compiled by BDP

Next: Patterns in tracks Up: Flash 91 Previous: Introduction to Artificial