Tuesday, 1 August 2006

Lacrosse 5: now you see it, now you don't....

Phillip Masding had predicted a possible Lacrosse 5 (2005-016A) flare for me for last night at 21:50:22 UTC:

Flare Results for Flight Mode YVV Panel Angle 33°
12. SAR MA 2.97104043228698 at 31/07/2006 21:51:22 Alt=74.2391395227923

However: it did not flare, but disappeared again instead....

I picked Lacrosse 5 up at about 21:50:00 UTC near Bootes/CrB. It was mag. +2.5 brightening to +2.0 in the next half minute or so.

Somewhere around 21:50:45 I started to look at my clock to trigger the camera countdown at 21:51:07 UTC. When I looked up again at 21:51:09 or so, it already was gone. It did not re-appear.

The photograph (21:51:18.1 to 21:51:28.8 UTC) shows no trail at all, meaning that at that time it must have been fainter than +3.5. Would it have been as bright as it was a 21:50:00 to 21:50:45 it would be visible on the image, and certainly if it subsequently would have flared.

There was some thin cirrus in the sky, but the area where it should have flared was clear and faint stars are visible on the image.

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