Re: AM-11

From: Ed Cannon (
Date: Sun Jun 04 2006 - 10:29:28 EDT

  • Next message: Ed Cannon: "Re: AM-11"

    On Saturday Jeff Umbarger wrote:
    > Saw AM-11 at 6:50:30UT at RA:15hr39min and Dec.:-5.5deg 
    > from Plano TX .... Expect to see it around 7UT tonight.
    Then early today (Sunday) he wrote:
    > Saw AM-11 at 7:02:00 UT at RA: 15hr 39min Dec: -5.5deg 
    > at about +3.0mag.  I believe this is the most distant 
    > manmade object I have ever seen with the naked eye. 
    > Just curious if others have seen naked eye objects 
    > farther?
    Last night at BCRC Mike got the telescope on this one, 
    Express AM-11 (28234, 04-015A), around 5:30 UTC I believe.  
    It was fairly bright (for a geosynch), about +9, and 
    seemed to be varying only somewhat.  There were two 
    in-plane geosats just to the east (and a bit south) of it. 
    I first saw Jeff's first Sunday-morning message above at 
    about 7:00 UTC (2:00 AM local) this morning and rushed 
    outside to try to see it.  When I was sure I saw it, the 
    time was about 7:05 UTC, and it was about +4 magnitude, 
    just south or maybe SSE of mu Ser (so roughly RA 15:50).  
    I kept watching it, and every 8 to 9 minutes there was a 
    maximum.  The brightest that I saw was +2 at about 7:19, 
    RA 16:04.  In between the maxima it got very faint (12x60), 
    maybeinvisible.  The fourth maximum at about 7:28 was +3, 
    and by 7:29 it was down to +6.  I watched for one more 
    maximum, and if there was one it wasn't much of one.
    This was about 2 miles (3km) north of BCRC, on the deck
    of the house of some friends.  
    So, with a flash period of 8 to 9 minutes, I think this 
    may be the slowest flashing geosynch we know of currently.
    This morning's episode was roughly 90 minutes later than 
    8 nights ago, so it's roughly 11-12 minutes later from 
    night to night as it drifts westward.
    Thanks, Jeff, for the heads-up as to when to look for it!  
    I'm also glad the weather was very nice.  By 7:30 UTC or 
    so, the Milky Way was faintly visible in the east.
    As to the question about most distant naked-eye object, I
    believe that ETS 6 (94-056A, 23230) may hold the record.
    I think it's been seen without magnification when it was
    at 25,000 miles (40,000 km).  A number of the flashing 
    geosynchs can be seen without magnification -- Superbird A,
    Telstar 401, Intelsat 512, TDF 1, Tele-X, ASC 1, GStar 3
    and GStar 4, Italsat 1, etc.  (There are quite a few of 
    them, but most have to be found by accident; only Superbird
    A -- 89-041A, 20040 -- has been fully predictable, for 
    years.  And it should be rising in the east any night now.)
    Now -- I tried a few hours ago, right after seeing it, to 
    send a message, but it apparently did not go through.  If
    it does after I send this one, I beg everyone's pardon for
    the approximately duplicate messages.
    Ed Cannon - Austin, Texas, USA
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