We present a study of telescopic and visual data of the Alfa Lyrid shower. Based on observations made by the members of Polish Comets and Meteors Workshop (CMW), we conclude that the shower can not be detected in visual data. On the other hand the, a clear radiant near Vega is present in telescopic observations. The coordinates of the radiant for solar longitude 112 deg. are alpha=278 deg. and delta=+38 deg. The best picture of the radiant we obtained using a geocentric velocity equal to 65 km/s and the daily drift in solar longitude equal to 1.0 deg.

The Alpha Lyrid shower was discovered in the late 50s of this century by two independent teams. The first team was a group of 44 Czechoslovakian observers led by J. Grigar, L. Kohoutek, Z. Kviz and J. Mikusek. In the period July 10-20, they noted the activity of a strong telescopic shower. The maximum was observed on July 15-16 with hourly rates around 18 using 25x100 binoculars and around 33 using 10x80 binoculars. The observations revealed two radiants, although only their right ascension could be determined precisely with one radiant at alpha=278.7 deg. and the second at alpha=300.5 deg.

The second group led by V.V. Martynenko (USSR) discovered the shower independently. The determined position of the radiant was alpha=277.5 deg. and delta=+39 deg.

In 1969 V.V. Martynenko, N.I. Bondar, N.M. Kremneva and V.V. Frolov performed another visual and telescopic study of the Alpha Lyrid shower. They estimated the activity period as July 9-19 and the position of the radiant as alpha=280.9 deg. and delta=37.8 deg. The meteors from this shower were described as being fast with average magnitude of +4.1.

Also in 1969, three radar meteors detected by Z. Sekanina from the period July 15--19 during the session of the Radio Meteor Project revealed an average radiant of alpha=286.8 deg. and delta=35.5 deg.

Due to the good weather conditions and the summer holidays, July is a good month for meteor observations in Poland. Fortunately, July is also the time in which we organize an Astronomical Camp of Comets and Meteors Workshop (CMW), which takes place at the observing station of the Warsaw University Observatory in Ostrowik. The number of participants is always around 15, so we organize two groups of four persons observing visually, one or two persons working with a few cameras pointing at different directions, and four to six persons observing telescopically 23 different fields aimed at distances from 6 to 65 degrees from the supposed radiant of the Alpha Lyrids. We use mostly 10x50, 20x60 and 7x35 binoculars. This year, we also used three 50 mm Russian refractors AT-1, which are very good for telescopic observations due to their field of view as large as 10 degrees.

Table 1 summarizes our telescopic and visual work from the period of July 9--20 of 1996--1999. The visual observations from 1999 are still under reduction and were not included in this analysis. Finally in 1996-1999, a group of 20 telescopic observers collected 209 hours of effective time with 2137 meteors observed, and a group of 33 visual observers collected 481 hours of effective time with 2115 meteors plotted onto gnomonic maps.

Table 1: Summary of visual and telescopic observations made by CMW members in the period July 9-20, 1996-1999

Year	Visual Observations			Telescopic Observations
	Teff	Observers	Meteors	Teff	Observers	Meteors
1996	86h49m	19	447	14h55m	8	68
1997	190h06m	24	1117	20h03m	10	121
1998	204h12m	24	551	57h28m	6	295
1999	?	?	?	116h35m	11	1653
Total	481h07m	33	2115	209h01m	20	2137

Visual observations

Our sample of 2115 plotted meteors was entered into the RADIANT software (Arlt, 1992). The equatorial coordinates of the meteors were obtained using the CooReader software (Samujłło and Olech, 1999). We calculated the maps of probability density using different geocentric velocities. A result of such a computation is presented in Fig. 1. This map was obtained for V=65 km/s. It is clearly visible that there is no trace of any radiant in the vicinity of alpha=278 deg. and delta=+38 deg. The clear radiant in upper-left corner of the picture is a radiant of Alpha Cygnids (see Stelmach and Olech in these Proceedings for details). Similar results were obtained for other geocentric velocities, and we conclude that there is no trace of Alpha Lyrids activity in our visual observations.

Telescopic observations

Also our sample of 2137 telescopic meteors was entered into the RADIANT software. We also calculated the density-of-probability maps using different geocentric velocities. At this time, the clear radiant near Vega was detected in all cases. The best picture of the radiant was obtained for geocentric velocity of V=65 km/s and for daily drift in ecliptical longitude of 1.0 deg (see Fig. 2). The coordinates of the radiant for the moment of maximum activity i.e. lambda=112 deg were alpha=278 deg. and delta=+38 deg, which is in excellent agreement with coordinates obtained by the discoverers of this stream.

Knowing the true coordinates of the radiant and its drift we found that there are 96 Alpha Lyrids in our sample. Table 2 presents the magnitude distribution of these events and Table 3 the velocity distribution.

Table 2: Magnitude distribution of Alpha Lyrids

0	1	2	3	4	5	6	7	8	9	mav	Tot.
0.5	1	1	1.5	1	5.5	11.5	34	28.5	11.5	7.1	96

Table 3: Velocity distribution of Alpha Lyrids. "0" refers to stationary meteors; "A" through "F" denote very slow to very fast meteors.

0	A	B	C	D	E	F	Tot.
0	2	17	34	28	14	1	96

We are going to observe this shower next year both visually and telescopically and we hope to obtain more results in the future.

Acknowledgments: This work was supported by KBN grant number 2 P03D 004 17 to A. Olech. We are also grateful to IMO for supporting our participation in the IMC.

References

Arlt R. (1992), WGN , 20 , 62.

Samujłło M., Olech A., (1999), Proceedings of the International Meteor Conference, Stara Lesna, Slovakia, 1998, 65