THE ASTRONOMER Electronic Circular No 766 1993 Aug 13 18.45UT
Ed:Guy M Hurst, 16,Westminster Close, Kempshott Rise, Basingstoke,
Hants, RG22 4PP,England. Telephone/FAX(0256)471074 Int:+44256471074
TELEX: 9312111261 Answerback: TA G TELECOM GOLD: 10074:MIK2885
GMH at UK.AC.RUTHERFORD.STARLINK.ASTROPHYSICS STARLINK: RLSAC::GMH
GMH at UK.AC.CAM.ASTRONOMY.STARLINK STARLINK: CAVAD::GMH
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PERSEIDS 1993
Alan Pickup, Edinburgh e-mails observations of the Perseids which
were made in partly cloudy skies of Scotland.
Limiting mag was about 4.5-5
Watch (UT) Cloud Meteors Comment
1993 Aug 11-12
22:10 - 22:30 4/8 to 7/8 O
22:49 - 23:15 7/8 to 2/8 1 non-Per
7 Per
23:30 - 00:02 2/8 to 7/8 10 Per Brilliant stroboscopic flash
of mag -6 or brighter from Per
about 20 deg high in N at about
23:33:20. Train lasted 6 sec.
Lit up clouds in vicinity.
Mag -3 Per two minutes later.
00:18 - 00:34 7/8 to 8/8 3 Per Mag -4 Per bolide at 00:29
(with small gaps!) low in SE.
00:48 - 01:07 8/8 - 4/8 - 8/8 9 Per
I saw 2-3 other Pers before/between/after watches, but gave up
under total cloud at 01.25.
Magnitude breakdown:
Mag: -6 -5 -4 -3 -2 -1 0 1 2 3 4
Perseids 1 0 1 2 3 0 4 4 9 4 1
non-Perseids 1
Mark Kidger, Tenerife reports results for Aug 11/12:
"I observed from 22:30-04:20UT, although heavy cloud cover did not
permit any serious observing before 00:05. It was quite obvious
though that the activity before 00:00 was not at all intense.
Uncorrected count rates for Perseids and Sporadics for 4.25 hours
of observation, with NEL=5.2 were: 140 Perseids and 31 others
(6 Cygnids, 6 Aquarids, 2 Piscid Australids and 17 Sporadics).
The highest 10 minute count rate was 14 Perseids from 03:05-03:15,
of which 6 were from magnitude 0 to -4. This translates, very
approximately, to a ZHR of 350-400, with the need to refine the
calculation somewhat to get a more exact value out. A somewhat
ill-defined peak was seen in the activity from 03:05-03:35, with
much lower rates after 03:35, about a third of the peak activity.
The rate from 01:30-03:05 was around 150-200 per hour, with
significant statistical fluctuations.Other observers agreed during
the observations that the maximum around 03:10 was quite clear.
The Perseid magnitud distribution was:
-5 -4 -3 -2 -1 0 +1 +2 +3 +4
1 4 15 16 14 13 14 12 30 17
This distribution suggests the same excess of bright Perseids, as
in previous years, although without the flux of very bright meteors
registered by some observers, especially in 1991.
A high percentage of meteors had enduring trains. The longest was a
mag -4 Perseid seen around 01:10 which left a train for some 20
seconds. No less than 4 Perseids left trains of 10 seconds or
longer and 55 (42%) of all observed Perseids had an enduring train,
as against just 1 non-Perseid (3%)."