(meteorobs) IMO Shower Circ.: Quadrantids 2006

[Rainer Arlt]

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     I M O   S h o w e r   C i r c u l a r
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     QUADRANTIDS 2006, visual observations

Visual observations of the 2006 Quadrantids received 
by the IMO before January 8 were used to provide a 
rough estimate of the 2006 activity of the meteor shower. 
A total of 303 Quadrantids seen during 34 hours of 
effective observing time were reported by 21 observers.

The maximum of the shower was lower than usual, with
a ZHR of about 85 near January 3, 23h-24h or a solar 
longitude of 283.39 degrees (J2000.0). The expected
maximum would have occurred at 18h20 UT on January 3.
Only a single observer from Japan was able to report
his data for that time (first line in below table) 
with a ZHR clearly below 100, too.

The number of individual observing periods is very small.
The shape of the activity profile depends on the sampling
of these data. The below table is not 'hand-picked' but
still it is a selected one out of three different compu-
ter-generated  samplings. The selection is arbitrary;
we can find out what happened only more additional data.

If you have not yet sent your report, please do so.


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Jan (UT)   Solarlong  Nint NQUA      ZHR          lm
-----------------------------------------------------
03 19h00   283.1864    1    12    60.6 +- 16.8   5.40
03 20h10   283.2356    3     9    36.9 +- 11.7   5.42
03 22h00   283.3137    9    25    54.6 +- 10.7   5.62
03 23h00   283.3609   11    71    67.2 +-  7.9   5.56
03 23h40   283.3898    3    24    85.4 +- 17.1   5.74
04 02h30   283.5075    4     6    42.3 +- 16.0   4.72
04 03h10   283.5374    3    15    36.6 +-  9.2   5.33
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We are grateful to
  Pierre Bader (Germany), 
  Rohit Belapurkar (India), 
  Sushrut Bhanushali (India), 
  Charuta Deshpande (India), 
  William Godley (USA), 
  Lew Gramer (USA), 
  Shy Halatzi (Israel), 
  Manali Kulkarni (India), 
  Omkar Kulkarni (India), 
  Rhishikesh Kulkarni (India), 
  Jens Lacorne (France), 
  Alastair McBeath (UK), 
  Tushar Purohit (India), 
  Pulin Raje (India), 
  Aaditya Ramdas (India), 
  Trupti Ranka (India), 
  Jurgen Rendtel (Germany), 
  Rahul Sangole (India), 
  Amit Shukrun (Israel), 
  Shigeo Uchiyama (Japan), and
  Michel Vandeputte (Belgium) 
for their quick submission of the observing reports.

The Zenithal Hourly Rates (ZHR) were computed with an
assumed population index of r=2, and a simple radiant
elevation correction, 1/sin(hR). Solar longitudes
refer to equinox J2000.0.

Rainer Arlt, 2006 Jan 8, 14h UT

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