Meteoroid stream identification: a new approach - II. Application to 865 photographic meteor orbits

The new criterion D-N for meteoroid stream identification, based on variabl es directly linked to observations, is applied to a set of 865 photographic meteor orbits and the results are compared with those obtained using the w ell-known and widely used D-SH criterion of Southworth & Hawkins, using thr esholds for meteor association computed according to Jopek & Froeschle. For 15 streams, including the Lyrids, the alpha Capricornids, the Perseids, th e Taurids, the Quadrantids, the Geminids, the Leonids, the Orionids and the southern delta Aquarids, the two searches are in very good agreement, with D-N often adding a few more members to some streams, at the same level of statistical significance as used for D-SH. The Andromedids and the a Leonid s, identified as populous streams using D-SH, are not recognized using D-N; on the other hand, using D-N five additional streams are identified, namel y the epsilon Geminids, the Monocerotids, the northern delta Aquarids and t he rather populous alpha Virginids and epsilon Piscids. In general, D-N giv es results essentially equivalent to those obtained with D-SH in many circu mstances, the most notable exception being for near-ecliptical streams, whe re the results differ markedly. We show also that the reduced distance func tion D-R can be successfully applied to search for meteor showers resulting from the same meteoroid stream; in our study the Quadrantids and the south ern and northern delta Aquarid showers have been identified as possibly bei ng originated by a single meteoroid stream.