The 2006 Orionid outburst imaged by all-sky CCD cameras from Spain: meteoroid spatial fluxes and orbital elements

Abstract

By using high-resolution low-scan-rate all-sky CCD cameras, the SPanish Meteor Network (SPMN) detected an outburst of Orionid meteors associated with comet 1P/Halley on 2006 October 20–21. This detection was made possible due to the operational concept of the SPMN that involves continuous monitoring of meteor activity throughout the year. Accurate heliocentric orbits have been obtained for three meteors imaged simultaneously from two stations during the outburst. Additional astrometry of 33 single-station meteors indicates that the activity was produced from a conspicuous geocentric radiant located at α = 92.◦ 2 ± 0.◦ 5 and δ = +15.◦ 4 ± 0.◦ 6 which is similar to the radiant observed during the 1993 Orionid outburst despite the fact that the last one peaked on a different date. The radiant position obtained by the SPMN is consistent with that derived from digital pictures taken a few hours before from Ankara (Turkey). The extent of the outburst (a background of bright meteors was observed over several days), its absence in other years, and the orbital period of the three Orionid orbits suggest that the outburst could be produced by meteoroids trapped in resonances with Jupiter but additional data are required. The SPMN’s continuous coverage of meteor activity allowed the identification of the main sources of meteors during 2006 October: mostly due to the Orionid stream, the two branches of the Taurid stream associated with comet 2P/Encke, and the δ Aurigids. Surprisingly, once a detailed analysis of the double-station video meteors was completed, some additional minor stream activity was discovered, that is, the ν Aurigids. In consequence, we also present two accurate orbits of this unexpected, but previously identified, minor shower.