GS428A (very fast moving object)
Picked up on two frames exposed for a NEOCP object this very fast
moving object has not been able to be identified with a known artificial
satellite (though it is very likely to be one, see below)
The two frames were exposed unbinned, the full field being 25'x25'
and pixel scale 1.5"/pixel.
2004 Feb 08 01:40:55-01:41:25
2004 Feb 08 01:42:10-01:42:40
and astrometry for the start and end positions for each trail is as
GS428A C2004 02 08.07008107 48 19.71 +56 39
GS428A C2004 02 08.07042807 48 47.01 +56 35 31.7 J95
GS428A C2004 02 08.07094907 49 27.93 +56 30 06.4 J95
GS428A C2004 02 08.07129607 49 54.24 +56 26 36.0 J95
Clouds stopped follow up immediately after the trails had been
recognised and searches two hours later when the clouds started to break
failed to recover the object. Gary Hug also performed searches for the
object but also failed to find it.
On close examination the trails are not continuous, but made up of
discreet points. The object appears to have been varying in brightness
with a period of about five seconds, with four or five flashes per period.
Travelling at 10.3"/second, these flashes must have lasted no more than 0.5
seconds, quite likely shorter to not appear elongated.
Measuring the brighter flashes gives a magnitude of about +16.0, but
because these flashes are about 100 times shorter than the stars were
exposed for indicates that these flashes may have been up to five
magnitudes brighter, or approximately mag +11 or 12. Images taken in later
days with short exposures of 1 second have confirmed that the flashes
reach at least mag +12.
Below are enlargements of the two trails and intensity profiles showing
the change in brightness.
Movement is top right to bottom left in the images and left to right in
the line profiles.