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(meteorobs) Re: NM 98 Delta Aqr observing



Observing in late July has had a variety of conditions, and just minimal
ideal skies.  I missed the max night of the South Delta Aquarids (July
29/30) altogether, then was too tired to go for Aug 1/2 completely clear.
From what I have seen, the late July showers continue at only half of  what
I used to see prior to 1985.  The Alpha Capricornids never did better than
2/hour, and sometimes 0/hr -- this was a borderline major shower up to 1976
before it fell off sharply.  July 30/31 within one 36-minute stretch there
were 3 bright meteors : 606 UT Alpha Cap  with 3 white bursts best at  -5m
from an orange  -1 meteor with orange train 1 second, 626 UT sporadic
blue-white  -3m with 1-second train, 642 UT South Delta Aquarid yellow  -6m
low in south too far away to show a train.  Only other bright one was July
27/28 at 554 UT, a white-blue  -3m  South Delta completely inside the Water
Jar near the radiant, so it was only 1.5 degrees long lasting 2 full seconds
with blue train for 2 more seconds.

Sporadics averaged around 5 or 6/hr, not that numerous.  These include two
Omicron Draconids, one Alpha Cygnid, and two Eridanids in the IMO-style
rates below.  The latter come from the Big Bend of Eridanus, swift, usually
trained, and with long paths due to the low radiant ESE -- I became aware of
these in 1962.  Pisces Austrinids I have never seen much from, and this year
was no exception.

No average magnitudes are given here due to the differing sky conditions.  I
will have to break them down according to what was seen in sky LM's 6.0,
6.5, and 7.0 for my long-term statistics.

From Pierre:
> Another interesting point
>is the "double" or simultaneous meteors I was seeing again last night.

I wonder whether we are using the same definition of  "simultaneous,"  for I
had no such instances at all.  The best I did was two meteors with a
3-second gap between them.  Through much of the 80's I was puzzled over the
number of simultaneous meteors being reported by Paul Jones of St.
Augustine, Florida.  We agreed that we were using the same criteria, but the
number I see is what chance would predict.  One-time-a-year  Perseid
watchers often use the phrase  "several were visible at once,"  when I
believe they mean  "several were visible in quick succession."  I have
always noted when 2 meteors were simultaneous, that is, at least a portion
of each of  them was visible at the same instant.  For simultaneous triples,
I have only 5 cases since 1960.  Remarkably, there were no such pairs during
the 1966 Leonids even as the rate reached 30/minute just before dawn in
North Florida.  That was 1 meteor every 2 seconds spaced  very evenly -- I
got all the magnitudes on paper.  Might be interesting to post the results
for that night when I get time.  The most compact group of meteors I have
ever seen came during the 1965 Leonids : 7 of them in just 4 seconds, and
these were all seen separately within a box about  30 degrees tall and only
10 degrees wide -- reminded me of a substantial six-gun shootout.  But the
total Leonid rate was only 30/hour with a Last Quarter moon near the radiant.

The report of high June Bootid rates from 1990 is not the only such report
the AMS has received over the years.  For example, during the 1975 May 30
lunar eclipse one group in Oregon reported many meteors seen "both naked-eye
and in telescopes."  I went to the Florida Keys for this event, the best
site in the U.S. for that eclipse, and saw just a tiny handful of meteors
during totality.  For the 1979 Draconids over the lower east coast of
Florida, one person and his family reported a couple hundred meteors/hour,
all going north to south, with a full moon.  I always wondered whether they
were near a bunch of high power lines, seeing reflections from passing
traffic going along the wires.  Or, in both of these cases, there may have
been a vast swarm of insects passing by well off the ground.  Some local
explanation has to be found for these strange localized reports.  No doubt
other experienced observers have some ideas in this regard.

Back to the present with the latest meteor rates.

Observing totals including time into twilight:
July 27/28, 3:04 hours, 41 meteors
July 28/29, 1:16 hours, 26 meteors
July 30/31, 4:27 hours, 79 meteors
July 31/1,   3:02 hours, 46 meteors


UT Period........Field.........Teff....  F.........LM
1998 July 27/28
522 - 626........315...+5....1.07....1.00....6.2....4 SDA...2 NDA...1 CAP
..............................................1 SIA...1 PER....4 SPOR.....13 TOT

626 - 726........330...+5....1.00....1.00....6.0....6 SDA...2 NDA...1 CAP
..............................................1 SIA.....2 SPOR.....12 TOT

726 - 826........345...+5....1.00....1.00....5.8....5 SDA...2 NDA...2 CAP
..............................................1 PER...1 PAU....5 SPOR.....16 TOT


1998 July 28/29
525 - 641........320...+5....1.27....1.00....6.5....7 SDA...5 NDA...4 PER
..............................................1 SIA...2 CAP....7 SPOR.....26 TOT


1998 July 30/31
525 - 626........315...+5....1.02....1.00....6.5....3 SDA...5 NDA...1 CAP
..............................................1 SIA...1 PER....6 SPOR....17 TOT

626-726..........330...+5....1.00....1.00....6.5....4 SDA...1 PER...2 CAP
..............................................1 PAU....6 SPOR.....14 TOT

726 - 826........345...+5....1.00....1.00....7.0....9 SDA...3 SIA...2 NDA
..............................................3 PER....3 SPOR.....20 TOT

826 - 947.............5...+5....1.35....1.00....7.2....7 SDA...6 PER...1 CAP
..............................................1 SIA....13 SPOR.....28 TOT


1998 July 31/1
624 - 726........330....+5....1.03....1.00....6.5...5 SDA...2 NDA...1 PER
..............................................2 SPOR.....10 TOT

726 - 826........345....+5....1.00....1.43....6.5....7 SDA...2 NDA...2 CAP
..............................................1 SIA...1 PER....9 SPOR.....22 TOT

826 - 926.............0....+5....1.00....1.67....7.0....5 SDA...1 NDA...1 CAP
...............................................3 PER....4 SPOR.....14 TOT


Norman