The parent bodies of the Quadrantid meteoroid stream
Astronomical Institute, Slovak Academy of Sciences, 05960 Tatranská Lomnica, Slovakia e-mail: [zkanuch;ne]@ta3.sk
Accepted: 5 April 2007
Aims.We attempt to prove or disprove the comet 96P/Machholz and asteroid 2003 EH1 as the parents of the Quadrantids. These two bodies have been regarded as the most probable candidates. Moreover, we investigate a possibility of an existence of their common progenitor, in the past.
Methods.For the moments of several perihelion passages of each parent-body candidate under consideration, we model the theoretical streams around the orbit of the candidate and, via a numerical integration, monitor the dynamical evolution of these streams. The perturbations by eight major planets are taken into account. For the end of the evolution, corresponding with the present, we construct the distributions of orbital elements of that part of a given stream, in which the particles approach the Earth's orbit. These distributions are compared with the corresponding orbital elements of the photographically detected Quadrantids.
Results.It is proved that at least one of 96P and 2003 EH1 is the parent body of the Quadrantid meteor stream. Due to an uncertainty in the orbit determination and unknown non-gravitational effects, it is impossible to decide which one of these two bodies is the dominant parent or whether both these bodies have significantly released the meteoroids into the stream. A large population of the Quadrantid stream had to be released from a parent (or parents) at least few millenia ago. If the Earth is also impacted with younger, several-century-old particles, these originate from the asteroid 2003 EH1. However, this young population can represent only a fraction of the entire Quadrantid-shower population. We also demonstrate some possibilities allowing an existence of a progenitor and its splitting to 96P and 2003 EH1. However, we suggest that, within a solely dynamical study, it is impossible to prove that the splitting event did actually happen. Neither of the other candidates considered, comet C/1939 B1 and asteroid 5496, associates any Earth-impacting meteor stream.
Key words: meteors, meteoroids
© ESO, 2007