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(meteorobs) 1997 BR meteors

Hello,

I did not classify possible 1997 BR meteors in my previous report (see 
below), but I have just rechecked my plottings from last night (July 
18/19, 22:43-01:05 UT). There are NO slow meteors observed coming from
the RA 175, dec. 65 radiant during my observing interval.

- Marco Langbroek
  Dutch Meteor Society


---------- Doorgestuurd bericht ----------
Date: Sun, 19 Jul 1998 10:42:20 +0000 ()
From: Marco Langbroek <marcolan@stad.dsldot nl>
To: Dutch Meteor Society -- Carl Johannink <cjohannink@netsidedot de>,
    Casper ter Kuile <pegasoft@cc.ruudot nl>,
    Erwin Ballegoij <ballegoy@wxsdot nl>,
    Guus Docters van Leeuwen <guusdvl@stad.dsldot nl>,
    Hans Betlem <betlem@strw.leidenunivdot nl>,
    Jaap van 't Leven <JVTleven@interdot nldot net>,
    Jos Nijland <jnb@worldonlinedot nl>, Klaas Jobse <cyclops@zeelandnetdot nl>,
    Marc de Lignie <m.cdot delignie@wxsdot nl>, Olga van Mil <pvmilnwk@boxdot nl>,
    Peter Jenniskens <peter@max.arc.nasadot gov>, Peter Bus <epbus@wxsdot nl>,
    Reinder Bouma <rjbouma@wxsdot nl>, Robert Haas <delpsurf@pop3.cistrondot nl>,
    Eddy Echternach <zenit@astro.rugdot nl>,
    Edwin Mathlener <e.mathlener@astro.uudot nl>,
    Tim Cooper <tpcoope@mweb.co.za>,
    Robert Lunsford <lunro.imo.usa@prodigy.com>,
    George Zay <GeoZay@aol.com>, R.A.Schievink@cnt.antennadot nl,
    olech@sirius.astrouwdot edu.pl, Jurgen Rendtel <jrendtel@aipdot de>,
    Sirko Molau <molau@informatik.rwth-Aachendot de>,
    Erik Rossenberg <evanross@stad.dsldot nl>,
    NAMN Meteorobs <meteorobs@latrade.com>, dvgevers@wxsdot nl,
    hugo@astro.rugdot nl, kuiper@knmidot nl,
    Natasja de Bruijn <natasja@stad.dsldot nl>
Subject: First Perseids (LANMA July 18/19 obs.)

Hello All,

Last night has been very clear and so I enjoyed a fruitfull session on 
the July meteors. This night featured amongst others my first Perseids of 
this year. Also, this night was dedicated to the omicron (alpha) Cygnids. 
Below my observational data, and an impression.

This was the first clear moonless night since June 21. A continuous 
series of low pressure disturbances passing over last weeks temporarily 
has given way to a ridge of high pressure and warmer air. A strong breeze 
developed yesterday, and by nighttime this resulted in a very clear sky. 
In the early part of my observations I counted Lm 6.4-6.5 in Aquila and 
Draco, which is rare for my homebound location! Occasionally a small 
patchy remnant of dissolving cumuli passed over at high speed, but they 
were no serious problem. Near the end of the night, a combination of 
advancing twilight, some haze developing and fatique arrising made for a 
drop in Lm to 6.3-6.0 and a corresponding drop in meteor numbers. Venus 
rose brilliantly in the southeast. There were no frogs this time, but the 
bats were visible and audible. A very fine night!

Meteor activity was high. Some nice examples among them, but no real 
bright meteors. The brightest was a +1 omicron (alpha) Cygnid in 
northern Ophiuchus at 00:13 UT. The omicron (alpha) Cygnids were well 
recognizable. Olech et al. of the Polish Comet and Meteor Workshop recently 
got an enjoyable paper on this stream accepted by Astronomy & 
Astrophysiscs. My first encounter with 
this stream was in 1990, observing from Puimichel (S France), and it 
really is a nice stream with nice meteors. I did not know of its 
existence at that time in 1990, so they came as a surprise (I believe I 
made an report on my observation published in WGN of 1991 or 1992). My 
data from 1990 are part of Peter Jenniskens 1994 A&A curve for the stream.

This night as mentioned also saw my first Perseids of this year (3 
members). The first was a nice +2 with 0.5 s persistent train moving from 
Draco to southern Hercules at 23:22 UT. A second one, a +3 with a short 
0.25 s train appeared at 23:34 moving from Vulpecula to Ophuichus. At 
00:01 UT a +4 appeared in the same area.

A tentative calculation with my data results in an observed ZHR of 2.2 +- 
1.0 for the omicron (alpha) Cygnids and 1.8 +- 1.1 for the Perseids, 
which is in accordance with what you would expect for this date.

-Marco Langbroek
 Dutch Meteor Scoiety, the Netherlands


Obs: Marco Langbroek         LANMA
Loc: Voorschoten, The Netherlands, 52d 07' N, 4d 28' E
Date: July 18/19, 1998


UT            Teff   Lm    oCyg aCap dAqr-N dAqr-S  Per Paus  Spo
22:43-00:00   1.12   6.5    2    0    0       0      2    0    13
00:00-01:05   1.03   6.1    3    1    0       1      1    0    3

TOTAL         2.15   <6.3>  5    1    0       1      3    0    16     26


stream        +1   +2   +3   +4   +5   +6
Sporadics      0    3    3    5    4    1      <3.8>
o Cygnids      1    0    2    2    0    0      <3.0>
Perseids       0    1    1    1    0    0      <3.0>
Capricornids   0    0    1    0    0    0
d Aquarids-S   0    0    1    0    0    0