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(meteorobs) Re: Quadrantids in 2001



Joe,

Here is the IMO Shower Circular for the 2001 Quadrantids



                             -------------------------------------

                             I M O   S h o w e r   C i r c u l a r

                             -------------------------------------

                                       QUADRANTIDS 2001

                 Favorable lunar conditions accompanied the maximum of
the
                 2001 Quadrantid meteor shower. Peak activity was
expected
                 near 12h UT on January 3, corresponding to a solar
longi-
                 tude of lambda=283.16 deg.

                 Observers were satisfied by good Quadrantid rates in
the UT 
                 afternoon and evening hours of January 3, 2001. Radio
forward-
                 scatter observations as reported by Hiroshi Ogawa,
Japan, 
                 showed increased Quadratid activity until 20h UT on
January 3,
                 compared with the background activity of December
30-January 1.
                 Geometrical effects of radiant direction changes will
play 
                 a significant role though. 

                 The highest ZHR value is found for 13h30m UT on January
3
                 or a solar longitude of lambda=283.24 deg (J2000.0).
The 
                 ZHR of about 130 is a typical value for the
Quadrantids, 
                 but the number of reports for the peak period is very
small
                 whence conclusions are tentative. The peak time may
easily 
                 shift by one hour to either side once a more
comprehensive 
                 dataset is available.

                 We are very grateful to the following 23 observers who
sent
                 their reports to the Visual Commission or to the
various 
                 mailing lists in time for this first activity overview:

                 ANDBI Birger Andresen (Norway)  MEIMA Marcel Meima (UK)
                 BIVNI Nicolas Biver(USA)        NICTE Ted A. Nichols II
(USA)
                 BURWI Wlliam Burton (USA)       PUNNI Nilesh
Puntambekar (India)
                 DAVMA Mark Davis (USA)          RENJU Jurgen Rendtel
(Germany)
                 GLIGE George W. Gliba (USA)     SPAGE George
Spalding(UK)
                 GODSH Shelagh Godwin (UK)       STOWE Wes Stone (USA)
                 HALWA Wayne T. Hally (USA)      TAIRI Richard Taibi
(USA)
                 HASTA Takema Hashimoto (Japan)  TUKAR Arnold Tukkers
(the Netherlands)
                 HOSDA Dave Hostetter (USA)      UCHSH Shigeo Uchiyama
(Japan)
                 JOHCA Carl Johannink (Germany)  YOUKI Kim S. Youmans
(USA)
                 LINMI Mike Linnolt (USA)        ZHUJI Jin Zhu (China)
                 MCBAL Alastair McBeath (UK)

                 ---------------------------------------------------
                 Date   Time (UT)  Sollong nObs nIND  nQUA     ZHR
                 ---------------------------------------------------
                 Jan 02   2300     282.63   2    2     17    13 +- 9
                 Jan 03   0230     282.78   5    3     40    26 +- 4
                 Jan 03   0510     282.89  13    5    109    17 +- 3
                 Jan 03   0740     283.00   9    5     98    56 +- 6
                 Jan 03   0940     283.08  10    8    192    61 +- 4
                 Jan 03   1120     283.15   6    4     90    68 +- 7
                 Jan 03   1330     283.24   3    2     33   131 +-23
                 Jan 03   1500     283.31   4    3     53   118 +-16
                 Jan 03   1720     283.41   5    3     76    82 +- 9
                 Jan 03   1910     283.48  10    5    217    95 +- 6
                 Jan 03   2110     283.57   5    4     98    79 +- 8
                 Jan 04   0400     283.86   2    1     19    16 +- 4
                 ---------------------------------------------------

                 Solar longitudes refer to equinox J2000.0. nObs is the
number
                 of individual observing periods, nIND is the number of
individ-
                 ual observers providing them, nQUA is the number of
Quadrantids 
                 seen. The radiant position was assumed at alpha=230,
delta=+49,
                 the population index used was r=2.1. The expectation
value of the
                 ZHR,
                          ZHR = (1 + sum nQUA) / sum(Teff/C),
                 was used for the averages here, where Teff is the
effective
                 observing time and C is the total correction composed
of limiting
                 magnitude, clouds, and zenith correction. Times are
rounded to
                 the nearest 10 minutes.


                 Rainer Arlt & Vladimir Krumov, 
                 2001 January 4

                 -- 
                 Visual Commission - International Meteor Organization
-- www.imodot net



Skywayinc@aol.com wrote:
> 
>     This might seem an odd change-of-pace considering all the traffic lately
> about the Perseids and Leonids, but does anyone have any reports concerning
> the performance of the January Quadrantids earlier this year?  I was curious
> since in checking recent back issues of WGN I couldn't find any reference to
> them.  I know that this was one of the those rare years when predictions
> indicated that North America was favored + the Moon wasn't going to be a
> factor.  Did the IMO publish an "official" report?
> 
> Thanx!
> -- joe rao
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