The Perseids
Finally, we beat our Meteor Jinx! Previous BAS attempts at serious meteor
observing have been thwarted by the weather. This one initially looked like it
was going the same way - it was fairly cloudy when we rolled up to Cliddesden
about 9PM, but there were one or two "mugholes" showing so, with the unbridled
optimism that you need for astronomy in this country, we decided it was a go!
We drove our various wagons onto the school-field and unpacked a vast amount of
kit. Vast amount of kit, I hear you ask? For meteor observing? Well, you know
how we like to go hi-tech when we can :) Bob, Dave and I brought our StellaCams,
two of which were mounted on Bob's neat little EM-2 mount so we could try to
capture some tracked images of the Perseids. Andria brought her LX90 along and
the plan was to use my StellaCam on that to show some good deep-sky views for
any visitors that might turn up. Sod, however, had different ideas and
unfortunately the monitor that we were going to use for
LX90-viewing died a death, reason as yet unknown.
The meteor cameras fared better - we were able to record from Bob's onto a
camcorder and from Dave's onto a laptop, until inverter power for the laptop ran
out, when we switched to a second, standby, camcorder. Regular boy-scouts we are
:) Results have yet to be analysed, but we certainly caught some meteors. At the
same time as we were recording at Cliddesden, Nick was recording from his back
garden in Aldermaston with a rather fast, rather good lens (better than our £5
Ebay specials!) - his results can be seen here :
http://www.trutek-uk.com/ Once we're
processed all our tapes it will be interesting, if we can tie the two sets
together, to look to see if any parallactic shift is evident. If it is, we might
be able to figure out the height of some of the brighter meteors.
Enough of the techy stuff. How did the evening go? Very well in fact! Over a
dozen people turned up, which was pretty good considering the early cloud-cover
and forecasts of rain for Saturday. I "counted" Andria, Bob, Dave SW, Dave W,
John S, John M, Lesley, Malcolm (and possibly Malcolm's Dad, whose name I still
don't know, sorry :), Michelle, Richard and Julie, and six visitors (who went
away with a copy of our natty, new program card). Maybe there were more,
apologies if I missed you - there were various bodies lying around on the ground
in the dark, meteor-watching (I expect), and I really didn't like to stroll over
and say "who are you?" :)
The clouds started to thin around 11PM, by midnight we down to 20% cloud-cover
and by half-past midnight it was clear. Yippee, we won one! The Perseids put on
a good show, as they usually do, and by 12:30AM they were coming thick and fast.
Especially fast - short bright streaks were the most obvious feature of the
Perseids, but sporadics (meteors not associated with any particular radiant)
were also abroad. Some of these were travelling the "wrong way", i.e. west to
east, the same way as the Earth and as these have to run to catch us up, rather
than smacking into us head-first, they took longer to pass over. Some of the
best ones we saw were sporadics, great "slow" bright streaks cutting across the
sky, leading to various "oohs" and "aahs"! Several left bright trains and
various people noticed colours in the trains.
We kept at it until just after 4AM, when, finally, the clouds came back and
covered the sky in just a few minutes. End of session! How many did we bag?
Well, the group I was with (me, Andria, Bob, Dave SW and John H) spotted 174,
not bad we felt, especially as Bob and Dave had cameras (and a telescope) to
tend to and John had to leave before the end. Of these we counted 130 as
Perseids and 44 as "sporadics", though some of the latter may well have been
from the other minor showers active at this time. If it hadn't been for the
school "insecurity" lights and the massive light dome of Basingstoke to the
north we could well have picked up more.
Andria very selflessly logged away and missed seeing quite a few of the meteors
as a result, so hats off to her! If anybody has a spare Dictaphone they'd like
to donate to the club, we could put it to good use next time allowing our
recorder to observe as well as log!
Using these hard-won records I've produced three graphs showing the number of
meteors we saw (in five-minute slots) and their magnitude and constellation
distribution. If you look at the graphs (with the eye-of-faith) you can see that
there is a slow increase in numbers as the night wore on and the radiant got
higher, that we saw more medium-bright meteors than very faint ones or very
bright ones and that Pegasus was the place to be looking. Well, whooooeeey,
rocket-science!
I hope all who came had a good time. We plan, if there's enough interest,
to have an observing evening on the second Friday of every month. The first one
is on the 9th of September. All levels will be catered for, so please come
along. If there's any particular thing you'd like to see, just grab me at a
meeting and ask, or email me (shawbrendan@hotmail.com)!
We should have enough expertise and kit to show you almost anything up there.
Maybe even a few more meteors :)
Brendan
