Re: Geosat Solar Transit?

From: Tony Beresford (dberesford@adam.com.au)
Date: Sun Mar 05 2006 - 01:08:31 EST

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    At 14:21 5/03/06, Jeff Umbarger wrote:
    >Hey All,
    >     With the declination of the sun between -10 and 0
    >degrees declination for the next few weeks, would this
    >not mean that if we were monitoring the disk of the
    >sun, we would see geosats transiting the sun for the
    >northern hemisphere? At my latitude (+33.0 deg) the
    >geosats appear at around -5.25 deg declination and
    >that is where the sun will be next Tuesday. Has anyone
    >ever seen this before? That is, is worth watching for?
    Jeff,
    The problem is the extremely angular size of even the
    largest geosat solar panel span.
    A back of the envelope calculation says a 30meter span
    at 36 megameters is about a 1/4 arcsecond.
    so we are talking about a 20 inch telescope
    to resolve it theoretically. However the killer is the
    irradiance from the photosphere which will fill in
    any dark patch of airy disk size , let alone something
    much smaller.
    
    Tony Beresford
    
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