The 'silent world' of Comet 15P/Finlay

Comet 15P/Finlay is unusual in that, contrary to ab initio expectations, it demonstrates no apparent linkage to any known meteor shower. Using data co ntained within the Electronic Atlas of Dynamical Evolutions of Short-Period Comets, we evaluate theoretical shower radiants for Comet 15P/Finlay, but find no evidence to link it to any meteoric anomalies in recorded antiquity . This result, however, must be tempered by the fact that any Comet 15P/Fin lay-derived meteoroids will have a low, 16 km s(-1), encounter velocity wit h Earth's atmosphere. Typically, therefore, one would expect mostly faint m eteors to be produced during an encounter with a Comet 15P/Finlay-derived m eteoroid stream. We have conducted a D-criterion survey of meteoroid orbits derived from three southern hemisphere meteor radar surveys conducted duri ng the 1960s, and again we find no evidence for any Comet 15P/Finlay-relate d activity. Numerical calculations following the orbital evolution of hypot hetical meteoroids ejected from the comet, at each perihelion epoch since 1 886, indicate that Jovian perturbations effectively 'drive' the meteoroids to orbits with nodal points beyond the Earth's orbit. The numerical calcula tions indicate that, even if Comet 15P/Finlay had been a copious emitter of meteoroids during the past 100 years, virtually none of them would have ev olved into orbits capable of being sampled by the Earth. There are good obs ervational data, however, to suggest that Comet 15P/Finlay is becoming a tr ansitional comet-asteroid object, and that it has probably not been an effi cient producer of meteoroids during the past several hundreds of years.