Large meteoroids belonging to the α-Capricornid meteoroid stream

Abstract

Several objects have been proposed as the parent body of the α-Capricornid meteoroidstream. Among them we can find the short period comets 141P/Machholz and 45P/Honda-Mrkos- Pajdusakova, but also asteroids such as (2101) Adonis, 2002 EX12(=169P/NEAT) and (9162) 1987 OA [1-5]. The debris produced by the fragmentation of the parent body give rise to an annual display of meteors from July 19 to August 18, with a maximum activity around the end of July and a ZHR of about 10 [5]. Although most of these meteors are faint, this meteoroid stream also presents a population of large (cm-sized) meteoroids that produces extraordinary bright bolides. Thus, for instance, the brightest event recorded on 2006 by the SPanish Meteor Network SPMN was associated with this meteor shower [6]. Unfortunately these events are rare, but the development of a network of meteor observing stations that can simultaneously register these fireballs is fundamental in order to fully characterize them in order to obtain precise physicochemical properties of the meteoroids, to study possible pausicity in the Earth-arriving flux, and to get more detailed radiant and orbital information. This would also provide useful data to establish which is the parent body of this stream. We present here the analysis of another very bright α-Capricornid fireball simultaneously registered from three meteor observing stations on July 31, 2011 with an absolute magnitude of - 9±1.