Re: Iridium flare was slow

From: Harald Edens (
Date: Sun Jan 13 2002 - 03:46:05 EST

  • Next message: Leo Barhorst: "Obs Jan 13 morning"

    Hello Tom, others, 
    First, I'd like to quickly indroduce myself to this group.  I'm a graduate 
    student in physics, interested in weather and astronomy.  I'm an occasional 
    satellite observer, mostly Iridium flares.  My location is The Netherlands, 
    I asked myself that question by Tom a while ago.  The Iridiums move slower 
    because you look down their track (most of their velocity is away or towards 
    you if you see an Iridium low in the south or north, and the satellite does 
    not have much of a tangential speed w.r.t. you).
    I had an interesting observation, be it maybe hallucination but I am not sure.
    I went out for a -8 flare 35d altitude, 155d azimuth.  I saw it coming and 
    it created a corona in a cirrostratus veil.  What was interesting is that it
    slowly lit up, obtained maximal brightness (which I estimated only -5 or so, 
    so I thought it was due to the clouds).  Then I saw (I think) a red flare, very 
    quickly (1/2th second or so) followed by more brightening and then the -8 flare.  
    Has anybody seen a similar event?  it was Iridium 18 and its path of max. flaring
    lay 1.5 km to the east of me.  Maybe it was just a twinkling, and I saw only the
    red part of the spectrum, like the twinkling Sirius does when it is low... but 
    at 35 degrees altitude?  The weather was fair (save for cirrus).
    Harald Edens
    NL, Wijdenes
    52d 37' 49.0" N
    05d 09' 25.5" E
    ----- Original Message ----- 
    From: "Tom Wagner" <>
    To: "SeeSat" <>
    Sent: Sunday, January 13, 2002 7:54 AM
    Subject: Iridium flare was slow
    > Tonight I saw a -2 iridium flare that was about 30 degrees above the SSE
    > horizon. It was one that was pretty late as far as iridium flares go. It
    > seemed to brighten more slowly that what I am used to seeing. It also barely
    > moved.
    > Being quite ignorant of the geometry of these occurrences, can someone tell
    > me if there are times when one can expect the flare to be more gradual and
    > expect the satellite to move more slowly. Like, are the later ones more apt
    > to be this way?
    > Thanks.
    > Tom
    > Iowa
    > USA
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