Eta-Aquarids 2000 – II

The large number of observing reports coming in after the
first Shower Circular about the eta-Aquarids allowed an
update of the activity graph. The shower appears to exhibit
a period of about three days with ZHRs above 50. The data
set does not allow to conclude about the fluctuations; yet
the broad maximum and the maximum ZHR of ~60 are a clear
result of this preliminary compilation.

  
  ----------------------------------------------  
  Date Time (UT) Sol. nETA nObs ZHR +/-  
  ----------------------------------------------  
  Apr 29 1800 39.71 1 2  2.4 1.7  
  Apr 30 1740 40.67 18 4 18 4.1  
  May 01 2210 41.82 34 5 28 4.6  
  May 03 0050 42.90 33 4 36 6.1  
  May 04 0520 44.05 15 4 36 8.9  
  May 04 1820 44.58 17 5 54 13  
  May 05 0040 44.84 64 8 65 8.0  
  May 05 1330 45.35 86 6 48 5.2  
  May 06 0140 45.84 105 11 56 5.4  
  May 06 0840 46.13 35 7 35 5.9  
  May 06 1610 46.43 119 6 51 4.7  
  May 07 0630 47.01 61 8 38 4.8  
  May 08 0630 47.98 57 4 60 7.8  
  May 10 0210 49.73 23 4 24 5.0  
  May 11 0120 50.67 4 2 26 12  
  ----------------------------------------------

Solar longitudes refer to equinox J2000. Average times are given with
10-minute accuracy though often refer to many hours coverage. The
average ZHR was computed by <ZHR> = sum n / sum(Teff/C) where Teff is
the effective observing time, C is the total correction according to
limiting magnitude, possible field obstruction and radiant elevation
as sin(hR). The ZHR refers to a limiting magnitude of +6.5 and a
radiant elevation of 90 degrees. nETA is the number eta-Aquarids seen,
nObs is the number of observing periods contributing to the average;
the number of individual observers is smaller in most of the cases.

This preliminary compilation was based on the reports
of the following observers:

ATAJU Jure Atanackov (Slovenia),
BUCAN Andreas Buchmann (Switzerland),
CERJA Jakub Cerny (Czech Republic),
COOTI Tim Cooper (South Africa),
DAVMA Mark Davis (USA),
DIAAS Asdai Diaz Rodriguez (Cuba),
HOLDA David Holman (USA),
JOHCA Carl Johannink (the Netherlands),
KONKH Khalil Konsul (Jordan),
KOUWE Wen Kou (China),
LANMA Marco Langbroek (the Netherlands),
LINMI Mike Linnolt (USA),
MARAD Adam Marsh (Australia),
MARPI Pierre Martin (Canada),
MATMI Michael Matiazzo (Australia),
MCLAL Alex M’clintock (Spain),
MISKO Koen Miskotte (the Netherlands),
MOLSI Sirko Molau (Germany, from Jordan),
MOSSC Scott Moser (USA),
MOTER Erick Mota Perez (Cuba),
NATSV Sven Nather (Germany, from Morocco),
NITMI Mirko Nitschke (Germany, from Jordan),
TELKH Khaled M. Tell (Jordan) and
YOUKI Kim Youmans (USA).