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Re: (meteorobs) Eclipse and meteors!
We got the eclipse in clear sky from Lehigh Acres, Florida. Sky went from
LM4.5 to 7.0, watching from Robert Riefer's house in a remote part of
Lehigh. Very few people any more can have that kind of sky right over their
house. I would call the eclipsed moon average brightness this time, Danjon
2. Brightest in several eclipses since the volcanic action of a few years
ago, but not as bright as eclipses in the 70's. Color was rather muted
also, more gray than copper. I saw the 1968 eclipse with Spica 2o away;
moon slightly closer to Saturn this round. We used Robert's f/5 12.5"
reflector a little. I did have a full view of the sky most of the time, but
saw only 2 meteors. No official recording.
Sky LM alone during totality won't be usable to determine how bright the
eclipsed moon is. That also depends on your local weather and city lights.
I was a bit astonished that the discussion of meeting for the 97 Geminids
went on for so long before the moon phase was considered. Even Bob's first
mention of the full moon didn't stop it in its tracks!
Let's name 8 moon phases:
new moon
waxing crescent
first quarter
waxing gibbous
full moon
waning gibbous
last quarter
waning crescent
From year to year on the same date the moon will advance about 3 phases.
Three years later on the same date the moon advances just one phase. And 19
years later the phase is almost exactly the same. Meteor observers will
remember very well what the moon was doing at a major-shower max, so they
can tell what will be going on at the next 2 or 3 also. If your experience
and memory get long enough, the 19-year cycle becomes handy. I saw the 1978
Geminids at full moon from Miami with a rate of 15/hour, sky LM4.5. So 1997
will be the same. By 1998 I will complete my second complete long cycle of
meteor observing, having started in 1960.
I used the earliest IMO shower list for September observing. Was unfamiliar
with Sigma Orionids, and didn't see much. Kappa Aquarids in 1995 impressed
me greatly due to slow speed and noticeable numbers.. These can indeed be
separated from the sporadic background confidently at 1/hour or less. For
certain, the Sigma's can't be. The speed difference needs to be considered
for accepting the presence of a minor shower or not. 3/hr, especially a ZHR
3, is too much for some. A rate that high is blatantly obvious at my
perception level, which is flat normal. But it would not impress someone
with high perception.
From Cook's "Working List of Meteor Streams" (1973), which the AMS has been
using, we have the slowest shower, the Camelopardalids. Mar 14 to Apr 7, no
definite max, 118.7,+68.3, velocity 6.8 km/s; daily motion +1.35,+0.51. But
with no max date, how to find the radiant? Maybe use the midpoint date of
Mar 26. In any event, what is the chance of seeing a sporadic crawl out of
Camelopardalis at that time of year? I have several of these, never more
than 1 in a year. Spectacular every time, even if not very bright.
Norman
nmcleod@peganetdot com
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