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Apparent Magnitudes of Satellites? Are they correct?

I have been checking some bright objects in Starry Night Pro 6 for the night sky above St Louis, USA on 22 May 2012.

2 satellites I have checked are Galaxy 19 and Chandra.  According to SNP6, Chandra was Mag -1.83 and Galaxy 19 was mag -5.72.

Surely these magnitudes can't be correct?  This would make Chandra brighter than the brightest star Sirius (mag - 1.47) and Galaxy 19 brighter than the brightest planet Venus was (mag -4.26).  SNP6 is showing Galaxy 19 at its brightest at  mag -5.74 on 19 June.


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    Keiron Smith

    Satellite magnitudes are notoriously difficult to calculate, and ours should only be used as a guide.

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    A 'guide' indicating a magnitude many times brighter than Venus for an object which is actually below naked eye visibility is useless, preposterous and unbelievable!

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