(meteorobs) Re: Setting Sun's Magnitude

[JBortle at aol.com]

Considering that typical atmospheric extinction amounts to something like 5 
magnitudes at an elevation of around 1-2 degrees above the true horizon, then   
-20 is a very acceptable value for "the setting Sun." 

However, and I don't know how many times I've said this to various observers 
over the years, in the case of extremely bright meteors an individual viewing 
the event under a moonless nighttime sky will be so unprepared and overwhelmed 
by the sudden appearance of a truly bright object (in excess of say -7 or -8) 
that it would be expected for them to wildly overestimate its brilliance. A 
meteor truly equal to the full moon in brilliance (and naturally subtending a 
much smaller apparent diameter) seen in a dark sky likely could not be looked 
at directly by a dark adapted observer. In the case of the nighttime appearance 
of a fireball of -20 , it would unquestionably blind the observer for several 
minutes. Even the resulting brilliance of the surrounding sky during such an 
event would undoubtedly force you to cover your eyes.

J.Bortle