(meteorobs) Re: Request for comments: "Hot Falling Stars of Summer"


In regard to your statement,

>Many people may be unnecessarily discouraged from meteors this Summer, since
>the Perseids - that ancient shower of mid-August which never fails to produce
>high rates - ...

I really hesitate to accept it at face value with the less-than-thrilling
rates that I usually see in excellent skies.  The Perseids are a reasonably
good shower with occasional better displays.  Definitely not a  "reliable"
shower, in the sense of  "best of the year",  which I so often read about in
popular literature.  If  "high rates"  means 30 to 40/hour, then, yes, we
are all right; this is a good display for casual watchers.  The public isn't
going to see 100/hour very often, even from dark skies.  Joan has been with
me for 3 Perseid maxes in the 1990's (but not last year)  and wasn't
impressed with any of them after seeing the Geminids.

The latest WGN has the 1997 Perseid peak over North America, in agreement
with what I saw.  It was a very good shower, peaking at 68/hour in sky LM7.3
with the radiant 58 degrees high from SW Florida.  This time I was
impressed, and the first for me since 1989.  Correcting my peak rate to a
radiant located at the zenith, I would have seen 80/hr.  68 /  sin 58o = 80.
I would have seen about 86% of those meteors in sky LM6.5, borrowing my own
correction factor determined from observed sporadic meteors empirically,
hence a zenithal rate corrected downward to a LM6.5 sky would be  on the
order of  86% of 80, or 69.  A lack of faint meteors kept the peak from
being  stronger.

My long-term baseline for an average Perseid shower,  back to 1964,  is
40/hr observed at the max.  The popular quoted peak rate before 1977 was
usually 50.   The years 1969, 1977,1978, 1981, 1989,and 1997 were the good
years.  The 1990's have all been below my average until 1997.  None of the
recent outbursts have occurred when I was watching.