(meteorobs) Perseids active in Alberta

[Bruce McCurdy]

Second attempt; after staying up an extra hour until 7 a.m. to send the
following quickly, I stupidly sent it to the old meteorobs address. Some
things just aren't meant to be timely, I guess.

*******

 Here's a very preliminary Perseid report from Edmonton, Canada. Some 25
observers gathered at our dark site at Blackfoot Reserve, ~53.5° N., 113° W.
Cirrus clouds and mild aurora interfered to some extent, with a limiting
magnitude of ~5.5 for the first three hours gradually declining to 5.0.
Nonetheless, we had a *surprisingly* strong showing, especially earlier in
the evening before the putative peak. With the radiant still rising the
counts nevertheless flattened out, in large part due to gradually
deteriorating sky conditions. However, there weren't so many faint meteors
in the earlier hours to explain the drop-off; my impression (and that of
others in our circle) was that the peak may well have occurred closer to 8h
UT.

I recorded on microcassette the personal counts of several observers in our
circle, however on the ride home I mentally transcribed only my own results
from my taped notes. (There are limits to concentration at 5:30 a.m.) I
personally observed for 5 hours between 05:35 and 10:35 UT, with no breaks
for a Teff of 300 minutes. My hourly counts (Perseids only):

                              #       ~LM
05:35-06:35         66         5.5
06:35-07:35         78         5.6
07:35-08:35         79         5.3
08:35-09:35         55         5.1
09:35-10:35         56         4.9

Total                  334

I have not yet calculated ZHRs but I would imagine they will prove quite
exceptionally high given the mediocre LM. I am quite shocked, I have
observed the Perseids at night of maximum for 17 consecutive years, and this
was my second highest gross total, behind only the 361 Perseids I recorded
in 6+ hours in 1994 under pristine mag 6.5 skies at the Mount Kobau Star
Party, less than two years after the passage of Comet Swift-Tuttle. (I have
never been completely skunked in all those years, although I have seen as
few as 4 on the most weather-challenged night.)

A significant percentage of meteors were mag 0 or brighter, although very
few qualified as fireballs. The best one occurred behind my head but I saw
the flash as it lit up the sky like lightning. It was estimated by those who
saw it as being in the mag -5 to -6 range. This seemed consistent with the
volume of the roar, a secondary magnitude estimation method I have developed
after years of observing in a group and always seeming to miss the best
ones!

All of us saw a very beautiful golden sporadic which took a good 6-8 seconds
to slowly cruise from near Polaris to beta Andromedae. Another sporadic went
directly *towards* the radiant point, prompting one member of our group
(Dave Robinson) to call it a "Perverseid". :)

Among a relative handful of sporadics I identified two or three kappa
Cygnids, and two delta Aquarids.

I returned home to find that my radio detector also had a good night, with
counts clearly quite a bit higher than the previous few nights. However,
that count, plus the transcription of my tape for the others in our group,
will have to wait for a few hours of shut-eye.

regards, Bruce