Alpha Cygnids - a possible July minor meteor shower

We present a comprehensive study of a possible \(\alpha\)-Cygnid meteor shower. Based on visual and telescopic observations made by Polish observers we estimate basic parameters of the stream. Activity of \(\alpha\)-Cygnids lasts from around June 30 to July 31 with clear maximum near July 18 (solar longitude \(\lambda_\odot=116.5^\circ\)). Maximal Zenithal Hourly Rates (ZHRs) are equal to \(3.6\pm1.2\). The structure of the radiant analyzed by {\sc radiant} software is most compact for geocentric velocity of the events equal to 41 km/s, and for the drift of the radiant (in units \(^\circ\)/day) equal to \(\Delta\alpha=+0.6\) \(\Delta\delta=+0.2\). Center of the radiant for the moment of maximum is \(\alpha=302.5^\circ\) \(\delta=+46.3^\circ\).We derive population index \(r\) equal to \(2.55\pm0.14\) from magnitude distribution of 738 possible members of the stream. Comparing the velocity distributions of 754 possible \(\alpha\)-Cygnids and 4339 sporadic events by \(\chi^2\) and Kolmogorov-Smirnov tests we conclude that both distributions are different with probability very close to 1.0. Telescopic observations strictly confirm the results obtained from visual observations. The smallest values of \(\chi^2\) parameter we obtained for the geocentric velocity equal to 40 km/s and for the drift of the radiant (in units \(^\circ\)/day) equal to \(\Delta\alpha=+0.6\) \(\Delta\delta=+0.2\). The center of the radiant for moment of maximum is \(\alpha=304.9^\circ\) \(\delta=+46.2^\circ\). In spite of making many photographic exposures we still have no photographic or video confirmation of the existence of this stream.