RE: Unid satellite?

From: Ted Molczan (
Date: Sat Oct 09 2004 - 05:48:40 EDT

  • Next message: John Locker: "Astra and Hotbird fleet into shadow"

    LarryC wrote:
    > Hello. I am a new person in this group. I've been using the 
    > Heaven's Above website (for about 2 yrs) to monitor sat passes.
    Welcome to SeeSat-L.
    > I live in Aloha, Oregon, at 45N30, 122W50, approx.
    > On Tuesday, October 5th, I was observing the pass of 
    > LaCrosse-4, at 1219 UTC. As the sat nearly eclipsed Polaris,
    Lacrosse 4 was below your horizon at that time. Could you have miss-typed the
    [deleted details of obs of UNID object]
    > One more thing: LaCrosse-4 was blinking erratically and 
    > quickly, from what I could observe. Several times per second 
    > for less than a second, then nothing, then resume several 
    > times per second for less than a second.
    That is not characteristic behaviour of any of the Lacrosses. Normally, they are
    steady. I observed it about 3 hours earlier, and it was steady. David Brierley,
    Russell Eberst and Peter Wakelin observed it about 8 h earlier, again steady.
    Out of thousands of Lacrosse passes observed by several observers, I found three
    instances of a regular variation in brightness, all observed by Russell Eberst:
    Lacrosse 1: 1993 Oct 21
    2420 9310 0.221 1204
    8810602 184743.59 174419+391707 0.8 2.3 10 R
    8810602 184832.79 200417+354410 0.5 2.1 10 R
    Lacrosse 2: 1992 Nov 02
    2420 9211 0.221 1204
    9101701 185414.29 140918+690845 2.8 4.5 10 R
    9101701 185506.81 093205+721947 3.3 4.8 10 R
    Lacrosse 4: 2002 Feb 25
    2420 0202 0.211 1204
    0004701 185538.54 234457+463136 2.4 5.1 10 R
    0004701 185611.60 230503+592725 2.3 5.0 10 R
    Description of the above observation format:
    In each case, the period of variation was about 10 s, much slower than you
    So, if it was indeed Lacrosse 4 that you observed, then it was a very rare,
    probably unique observation; however, we need to resolve the matter of the time
    Also, can you be more precise in your description that it "nearly eclipsed
    Polaris"? For example, did it pass within 0.1 deg, or 1 deg?
    How long did you observe the blinking object, and for what fraction of that time
    did it blink?
    What was its approx minimum and maximum magnitude?
    What was its colour?
    Did you observe the blinking unaided? If not, what was the magnification and
    aperture of your optics?
    Can you provide more precise observing site coordinates?
    Once we are certain of the identity of the blinking object and the time you
    observed it, then we can try to identify the UNID object that was the subject of
    your post.
    Ted Molczan
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:

    This archive was generated by hypermail 2b29 : Sat Oct 09 2004 - 05:51:58 EDT