Iridium Double-Flare Advisory

From: Gerhard HOLTKAMP (
Date: Sun Feb 19 2006 - 16:12:42 EST

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    Observers in mid-latitudes (North) and a few folks South might be able to see 
    a few Iridium double flares over the next few days when a right MMA (antenna) 
    flare gets paired with a solar panel flare.
    Candiates for double flares on the Northern Hemisphere are those flares 
    happening over the next few days in the early evening South-East sky between 
    Saturn and Procyon. For observers between 46 and 47 deg. latitude the MMA and 
    solar panel flares almost coincide so you probably see a single flare at a 
    somewhat higher magnitude. Further toward the North the solar panel flare 
    trails the MMA flare by a few seconds. (12 sec at 50 deg., 20 sec at 52 deg. 
    - this varies slightly throughout the week). Further to the South the solar 
    panel flare comes first (10 sec at 44 deg., 28 sec at 40 deg.).  
    The geographic line of maximum flare for the solar panel flare 
    lies East of the one for the MMA flare so the chances of actually seeing a 
    double flare are probably best if you are somewhat to the East of the maximum 
    MMA flare line. If you see a flare or what it actually is you see will thus 
    depend on your very location at the time. It may be a proper double flare 
    with equal peaks or different peaks or a single brighter flare or even kind 
    of a plateau for a few seconds - or nothing out of the ordinary. So it's best 
    to just look out for those flares over the next few days and expect some 
    surprises one way or the other.
    A few Iridium double flares are also in store for the Southern Hemiphere over 
    the next few days but - sorry - it's an early morning affair for you in the 
    North-West sky between Corvus and Leo. The spacing between the right MMA and 
    the solar panel flare is larger than for those Northern flares (45 sec at 34 
    deg. South, 60 sec at -38 deg, 70 sec at -40 deg.). 
    At my very own location (49.88 North, 8.66 East) my calculations tell me to 
    expect three double flares (22-FEB with mag -3.2/-2.4, 23-FEB mag -3.2/-1.0 
    and 26-FEB mag 0/-3.8) but what I'm most likely going to see will be clouds!
    Gerhard HOLTKAMP
    Darmstadt, Germany
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