(meteorobs) 2005 Lyrids from Edmonton

Bruce McCurdy bmccurdy at telusplanet.net
Fri Apr 22 19:34:42 EDT 2005


    It seems the Lyrids never fail to disappoint :), but every year I want to take another crack at them, no doubt because they fill a huge gap on the northern calendar between the Quadrantids and the Perseids. Tried again last night, despite a big bright Moon and thin cirrus which laid the darkness to waste. The peak was, however, favourable to North America, variously listed at 10h UT (Observer's Handbook), 1030 UT (Lunsford) or 0630 UT (Kronk). And there was a prediction of a possible outburst.   

    I headed out to a spot just north of the city where eventually I could just make out the 5.0 mag star in the bowl of the Little Dipper. It was a pleasant spring night, and by the time I set up around 3 a.m. MDT it was my old friends the summer constellations which were rising to prominence in the east and northeast. I was facing that way by default, hiding in the shade of my car and looking in the general direction of my shadow throughout.  I also had the car radio tuned to a distant station for radio bursts, and of course my Northern Claw Radiometeor Detector was ticking away automatically at home.    

    The first meteor of the night was perhaps the most interesting, I was just doing my scan of the Little Dipper when a zeroeth mag meteor almost split Polaris, right in my direct vision. There was an exactly simultaneous radio burst which "sounded" like what I saw, same "light curve", same duration. Fortunately, I had my microcassette recorder on at that moment as I was doing my limiting magnitude estimate and it caught the burst. I also have my own reaction to the meteor, my voice also resembling the radio burst but a few tenths of a second later. I figure if I can make a wave file out of that tape I should obtain a very good estimate of my personal reaction time (useful for timed measurements such as occultations). 

    Under the conditions I don't think my visual counts have much scientific value, but it's safe to say there was no outburst around the time of the peak. My observing window was from 9-11 UT, during which time I saw a handful of sporadics and only five Lyrids. Surprisingly and FWIW, four of the five occurred in a single ten-minute bin, from 1020-1030 UT. 

    My other observation of interest came during my one active bin. First of all an airplane flew over whose fuselage? contrail?? caused an extended medium-level radio burst. (Alister Ling and I unambiguously made this connection with three different airplanes that caused minute-long bursts during a shower last year, confirming a long-held suspicion about why the Northern Claw records more *long* bursts during the day, despite many fewer underdense bursts.) As this gradually gained in volume, a brilliant meteor flashed down below Vega towards the eastern horizon, causing a meteoric increase in the volume over and above that caused by the plane. Seconds later, a second nice meteor flashed near the zenith with similar effect to the radio reception. I wish I had my tape recorder running during this time, it was a textbook example of the differences between a real meteor and a spurious signal.  

    After the little burst the Lyrids died to nothing again, the sporadics continued to dribble in at a low rate, and I suspect my eyes began to glaze over because a couple of times I caught myself not reacting to a faint meteor for a couple of seconds. I don't usually have that problem during the more active showers, I think it has something to do with lowered expectations.  I'll monitor for that again during the rumoured shower known as the eta Aquarids. :)    

    Bruce

      


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