Perseid magnitudes

R.B. Minton (rbminton@sembilan.UCHSC.edu)
Fri, 30 Aug 1996 07:28:30 -0600

Hi:  Thanks for the interesting question regarding a lower limit for Perseid
meteor magnitudes.  During the 1993 Perseid shower (I believe it was either 1
day before or 1 day after max), I put my image tube on the 16" Dob and aimed 
it at the radiant.  In this setup, it has a 1/2 degree field and goes to 13th
magnitude.  During 30 minutes I got no meteors.  This is not a very long sample
time, but it was long enough to give me the impression that the really small
meteors (perhaps approaching the size of dust) were not there.  Perhaps sunlite
sweeps them out of the stream.  As I recall, something the size of a few 
microns can be swept out this way.  Do you or anyone else know how large a 
meteor it takes to be 12th magnitude (given a perseid velocity head-on)?
  
I too noticed a lot of the brighter ones were paired.  It got to be such a 
pronounced correlation, that I was very tempted to aim my video camera at the
old location of the 1st one in hopes of catching the 2nd one - but I decided
it would screw-up my normal count statistics.
  
The brightest one I saw was a pair seperated by 1 minute.  It traveled about
horizontal, right to left, about 30 deg high, to the left of Polaris.  The 
first one was mag -1 and left a beautifull blue-green train for 5 seconds.  It
was as dazzling as a neon tube.  The second was mag 1 and left a 1 sec train -
in the exact same location.
  
Regards.
 

R. B. Minton
-104.7932, +40.0876, 4525 ft.