RE: Brightness of Sputnik 1 payload and rocket?

From: Ted Molczan (
Date: Mon Sep 10 2007 - 19:54:47 EDT

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    Björn Gimle wrote:
    > ... ranged in brightness between mag 0 and 4, typically mag 1 or 2.
    > > The satellite ranged between mag 4 and 7, typically mag 5 or 6.
    > >
    > > When I complete my orbital analysis of this data, I will determine 
    > > standard magnitudes. For now, I suggest std mag 1.7 for the rocket, 
    > > and 9.6 for the payload,
    > Why this 7.9 mag diff in std mag?
    > The observation range diffs are 4-3-4-4!
    > Rocket observed at long ranges also - satellite only on very 
    > favourable passes?
    Since there is some interest at this time, I have made a quick analysis of the
    payload's brightness.
    SAO reported to have processed 50 observations of Sputnik 1, and rejected 14. Of
    the 36 published, 7 were flagged as doubtful observations of the payload, and 8
    were thought to have been of a possible third piece from the launch.
    Twelve of the 36 published observations included magnitudes, six of which were
    considered to have been of the payload. They yield a standard magnitude of about
    5.7 (range 1000 km). Since the payload was a specular sphere, I assumed
    coefficient of phase to have been zero. Eventually, I will plot a scatter
    diagram of 1000 km vs. phase angle, but I doubt that much more can be learned
    from such a small data set.
    Ted Molczan
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