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 ------------------------------------------------------------------- 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%)."