Re: Geosat flaring season

From: Björn Gimle (
Date: Wed Sep 12 2012 - 20:18:51 UTC

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    Yes, for many satellites in the Clarke belt (geostationary, operational)
    it's when the Sun's declination matches the the declination of the
    satellites. For your latitude this is -5.7 degrees, and occurs around
    Oct.7. The most likely satellites would be opposite to the Sun in RA, but
    the radius of the Earth's shadow is nearly eight degrees, so between +- 58
    degrees latitude this point is in shadow, and you must look a little left
    or right of this point.
    But some designs flare at 45 or 60 degrees away in RA, and some military
    satellites within +-7 degrees inclination also flare, and the season
    extends for some satellites a week or more before/after the expected date..
    You may refer to my old page and its
    spreadsheet which computes the shadow outlines,
    and to
    2012/9/12 Bob Hampton <>
    > Hello,  I am a long time satellite watcher but I have been absent from this
    > list for several years.  If I am remembering right geosat flaring season
    > (in the northern hemisphere) will begin soon i.e. shortly after Sept.
    > equinox.  I saw this a few years ago and I really was amazed - watched them
    > for several nights, lighting up one by one as they moved from Pisces into
    > Cetus.  Don't want to miss it this time.  May even want to make an event of
    > it for my astronomy club.  I'm at 36 degrees N.  Is there an easy way to
    > figure what dates to look for this?
    > Bob
    > --
    > Bob Hampton
    > President, Blue Ridge Astronomy Group
    > <828-675-4449>
    Björn Gimle, COSPAR 5919
    59.2576 N, 18.6172 E, 23 m
    Phone: +46 (0)8 571 43 312
    Mobile: +46 (0) 704 385 486
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