Physico-chemical properties of meteoroids from the alpha-capricornid stream

Abstract

Several objects have been proposed as the parent body of the α-Capricornid meteoroid stream. Among these 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]. This stream produces an annual display of meteors from about July 19 to August 18, peaking around the end of July [5]. Although most of these meteors are faint, this meteoroid stream also presents a population of large (cm-sized) meteoroids that give rise to very bright bolides. Thus, for instance, the brightest event recorded in 2006 by the SPanish Meteor Network SPMN was associated with this meteor shower [6]. Unfortunately these events are rare, but a continuous monitoring of the night sky is fundamental in order to register these fireballs. In this way, we can study the physico-chemical properties of these meteoroids and also obtain precise orbital information to establish which is the parent body of this stream. We present here the analysis of four α-Capricornid fireballs registered in July 2012 in the framework of our continuous fireball monitoring and spectroscopic campaigns.