Tuesday 21 March 2006

Clear skies, nice Lacrosse 5 pass

After a few grey days, this monday turned into a very clear day. Bright blue skies in the daytime, good dark sky in th evning. I had only one good pass this evening, but a nice one: Lacrosse 5 (2005- 016A, #28646), one of my regular targets lately, made a near-zenith pass at 19:38 UTC.

Lacrosse 5 was bright and steady, appearing in the west-northwest, crossing over Cassiopeia and climbing towards the zenith and Ursa Major, at magnitude +2.0 to +1.5. No "disappearance tricks" this time.

I obtained a series of 3 images during this pas, hence 3 trails to measure and 6 positions in total. Relative to Mike McCants' elset 06074.84503776, I get the following residues:

xtrk dltaT dlpos
(deg) (sec) (deg)
0.02 0.24 0.086
0.00 0.31 0.114
0.01 0.22 0.120
0.02 0.18 0.105
0.01 0.02 0.013*
0.01 -0.08 0.045*

The last two (marked by an asterisk) deviate from the rest of the set by some 0.2 seconds in delta T. This means I might have been a tad slow in pressing the shutter release button for the last image.

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