Re: Possible bright USA 112 flash

From: Tony Beresford (
Date: Sat Apr 22 2000 - 22:58:13 PDT

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    At 13:45 23/04/00 , Mark Hanning-Lee wrote:
    >I forgot to check this for some days, but just ran a check against
    >mccants.tle with a mag 15 limit and a very high perigee / range. To my
    >surprise 23609 USA 112 is a good match, az 34 deg el 14 deg. If anyone's
    >interested I can send the Skymap .cfg file that I used.
    >Leo Barhorst's recent posting marks USA 112 as (Trumpet 2?).
    It is guessed that its a Trumpet satellite rather than an SDS(comsat)
    satellite because of the higher perigee. Trumpet satellites are suppossed to be
    listening for radio transmissions and its supposed to have a large dish
    or phased array. The orbit is a 12 hour synchronous orbit like the
    Molniya commsats. It passes overhead here once a day, currently in shadow
    around midnight. Its a companion to USA103 , whose ascending node differs 
    by 120 degrees. 
    >I'm surprised that a sat could flash 11 mag brighter than predicted, but
    >I guess some high-orbit (near GEO) sats can flash real bright.
    Why not, Irdiums change by 13 magnitudes if you are in the center of a
    sun glint. Both USA103 and USA112 were first detected by Rob McNaught
    as they sun glinted to a brightness brighter than mag -2 while in
    the field of view of his all-sky camera network doing fireball patrol
    work. A member of my local Astro Society who lives about 80Km
    south of my location saw USA 103 flare up to mag -1.5 a couple of months
    ago. Some 2-4 square meters of mirror surface is enough.
    Tony Beresford
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