(meteorobs) Perseids from Beaver Hills Dark Sky Preserve, Alberta, Canada

[Bruce McCurdy]

Had a terrific time observing the peak of the Perseids on Sat/Sun the 11/12.
One of the best observing nights I've had in a while, despite (and in a
strange way, because of) a somewhat chaotic environment at my preferred
observing site at the Blackfoot Staging Area of BHDSP. 

 

Some of the chaos came from within, as I was in a sufficiently bipolar frame
of mind to listen to Tool's 10,000 Days on the way to the site, and to
Beethoven's Seventh on the return journey five hours later. In between times
I arrived to a fairly packed parking lot that contained a goodly number of
RASC members out for the first observing weekend of the new season and quite
a large number of curious public. Some of the latter may have learned of the
site due to a science centre staff member who shall remain nameless having
specifically named "Blackfoot" in a TV interview. (I have since spoken to
him and gently suggested he be a little less specific in future, and simply
direct folks to the DSP rather than "our" tiny little corner of it. That
parking lot isn't big enough to handle a huge influx, for one thing.)

 

Anyway, white light infractions - both incoming and outgoing -- were fairly
rampant, and will have compromised my meteor counts to some extent, due to
time lost shielding my eyes at times and inconsistent dark adaptation
generally. I really don't know how to correct for this, although that may
occur naturally in the form of reduced perception of limiting magnitude. To
my eye that started around 6.0 but gradually diminished after moonrise,
especially when the aurora that hugged the northern horizon throughout
decided to kick up its heels and dance. It didn't help transparency that it
was a very moist evening, as several observers encountered dewing problems
on their secondary mirrors; ultimately my own session ended shortly before
04:30 when some light ground fog developed that caused a halo around the
Moon and sharply curtailed the LM. 

 

In all I managed exactly four hours Teff between 05:40 and 10:23 UT
(23:40-04:23 MDT), during which time I recorded 169 meteors including 154
Perseids. Counts were pretty good right off the hop, as I enjoyed my two
best half-hour bins of the night back-to-back, as well as my highest rates
of bright ones (although no fireballs at any point). I saw 11
negative-magnitude streakers in the first 40 minutes, then just 12 more the
rest of the way. Perhaps a local anomaly, but enough to make me wonder if
the peak perhaps occurred a few hours earlier than the 12h UT projected in
the RASC Observer's Handbook. 

 

After that fine first hour of 52 Perseids, rates fell back to 30 and 31
before rebounding to 41 in the last hour after most of the white lights were
long gone. The mean magnitude was +1.90, which ranged from a high of +1.18
in the very first bin to a low of +2.56 in the very last. I looked east for
the first couple hours, then after moonrise I hid behind my car and looked
to the south, spending much of the night looking in the general direction of
Pegasus. Occasionally, though, I couldn't resist sneaking a peak at the
beautiful line-up of Pleiades-Jupiter-Moon-Venus that adorned the eastern
sky. 

 

My favourite meteor of the night was one which demonstrated impeccable
timing. I was explaining to friend how the Milky Way helps to identify
shower members due to the location of the radiant within its plane, starting
to say that "Perseids either go right along the spine of the Milky Way, or
they diverge from it. Anything that slices across is likely unrelated." Just
as the words "spine of the Milky Way" left my lips, zzzzip! a turquoise
beauty of mag -1 zipped exactly along it, leaving a one-second persistent
train as if to demonstrate!

 

There were a number of colourful meteors: among my taped notes were words
like ivory, orange, bluish-white, green, silvery-white, yellow, bronze,
blue-green and the afore-mentioned turquoise, some of them on more than one
occasion. A decent percentage displayed persistent trains, including three
that lasted in the 5-10 second range. After turning on my car FM radio in
the later part of the evening I also experienced a number of visual meteors
with simultaneous radio bursts.  

 

This was my 25th consecutive year of observing the Perseids on at least one
of the nights within 24 hours of the peak, and while it didn't approach the
400+ shower members I recorded in 1994 and 2004, it was certainly an
average-or-better show. My detailed observing log submitted to IMO is here:
http://vmo.imo.net/imozhr/obsview/view.php?id=10647

 

Bruce

***** 

 

 

 

 

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