Re: Magnitude estimates on Heavens-Above

From: Jonathan T Wojack (tlj18@juno.com)
Date: Mon Apr 23 2001 - 13:16:28 PDT

  • Next message: Allen Thomson: "Re: Magnitude estimates on Heavens-Above"

    > I too have noticed discrepencies and mentioned them on this list. 
    > Since I am often doing visual photometry on variable stars on the
    > same night I have a pretty good idea what a given magnitude looks
    > like. While I would expect variations of 1-2 mag. just due to
    > presentation of a satellite, still on several I have noted 4 mags. 
    
    Personally, I've never had any trouble with the magnitude estimates from
    Heavens-Above.com.  90%+ are within a magnitude of reality.  I mean, you
    could be observing flares.  As I recall, it is very difficult to predict
    when a satellite will produce a flare.  Unless you know the orientation
    of the satellite at nearly any moment in time, and know in immense detail
    what the satellites' reflecting surfaces are like, you can't predict
    them.  For instance, you might see a ISS flare - but you'll never be able
    to predict them accurately.  The orientation of the ISS might be fairly
    well-known (it certainly isn't spinning!), but its surfaces aren't.  And
    by time you would get a "surface map", it'd be out of date!
    
    ------------------------------
    Jonathan T. Wojack                 tlj18@juno.com
    39.706d N   75.683d W            
    
    4 hours behind UT (-4)
    
    ________________________________________________________________
    GET INTERNET ACCESS FROM JUNO!
    Juno offers FREE or PREMIUM Internet access for less!
    Join Juno today!  For your FREE software, visit:
    http://dl.www.juno.com/get/tagj.
    
    -----------------------------------------------------------------
    Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
    in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
    http://www2.satellite.eu.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Mon Apr 23 2001 - 13:18:18 PDT