Cosmogenic radionuclides in the Antonin meteorite

Abstract

The Antonin meteorite fell on July 15, 2021 in Wielkopolska Voivodeship. Its fall was recorded by fireball camera network and the meteorite specimen was recovered soon after, during a dedicated search expedition. Main mass of Antonin was provided for scientific research relatively quickly after recovery, thanks to which the studies of cosmogenic radionuclide concentrations were carried out in the g spectrometry laboratory at the National Center for Nuclear Research in Otwock/Świerk. The analyses revealed concentration of 7Be and the traces of the cosmogenic radionuclides of 48V and 51Cr, whose half-lives are in the range of 15–28 days, clearly confirming the relationship of the specimen with the observed fireball. The relatively high concentrations of 58Co, 56Co, 46Sc, 57Co and 54Mn (half-lives of several months) also confirm the recent fall of the specimen. Additionally, collected radionuclide data allow to estimate pre-atmospheric size of the meteoroid. Distribution of 60Co and 26Al indicates a meteoroid chunk with a radius of 20–25 cm. The result of 26Al measurement suggests that the investigated meteorite fragment comes from a rather shallow depth of this meteoroid. In addition, the original mass of the meteoroid from which the Antonin meteorite originated was estimated to be less than 100 kg, most likely 70 kg