eta-Aquarids 2003

New moon on 1 May provided favourable observing conditions for the Eta-Aquarids this year. By 8 May, 19 observers reported 322 Eta Aquarids in 71.02 h net observing time. In general, rather low activity was recorded (ZHRs~30) with an extended 4-day plateau and no apparent maximum.

  
  --------------------------------------------------------------------  
  Date	UT	sollong	n_ind	n_obs	nETA	ZHR	+/-  
  --------------------------------------------------------------------  
  03 May	0050	42.16	 7	 7	19	26.2	6.4  
  04 May	0330	43.24	 6	11	38	26.4	4.4  
  05 May	0150	44.14	11	17	70	32.2	3.8  
  05 May	1810	44.80	 2	 3	16	12.3	3.0  
  06 May	0130	45.10	 8	13	61	36.6	4.6  
  06 May	1810	45.77	 3	 3	26	20.4	3.9  
  07 May	0120	46.06	 8	13	67	31.3	3.8  
  07 May	2000	46.81	 1	 2	 9	21.8	6.9  
  08 May	0140	47.04	 4	 4	16	27.1	6.6  
  --------------------------------------------------------------------  
  

Solar longitudes refer to equinox J2000.0. n_ind is the number
of individual observers, n_obs is the number of individual
observing periods, nETA is the number of Eta-Aquarids observed.
The radiant position was assumed at alpha=338deg, delta=-1deg,
the population index used was r=2.4. The expectation value of
the ZHR,

ZHR = (1 + sum nLYR) / 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 and cloud coverage. Error bars are derived as err=sqrt(1+sum nLYR).

We are very grateful to the following observers for their efforts,
impressions and quick reporting of data:

Alexandre Amorim (Brazil),
Jure Atanackov (Slovenia),
Ana Bankovic (Serbia),
Aleksandra Dimitrievska (Serbia),
Petros Georgopulos (Greece),
Daniel Gruen (Germany),
Shy Halatzi (Israel),
Carl Johannink (The Netherlands),
Anna Levina (Israel),
Irena Lisovski (Israel),
Bert Matous (USA),
Ian Musgrave (Australia),
Bojana Obradovic (Serbia),
Peta O`Donohue (Australia),
Branislav Savic (Serbia),
Juan Martin Semegone (Argentina),
Ana Sovilj (Serbia),
Oliver Wusk (Australia) and
Kim S. Youmans (USA).