Early 18th century cosmic ray flux inferred from 44Ti in Agen meteorite

Taricco, C., Sinha, N., Bhandari, N. et al.

Astrophys Space Sci (2016) 361: 338. doi:10.1007/s10509-016-2909-7
First Online: 26 September 2016
DOI: 10.1007/s10509-016-2909-7


“We report the measurement of radioactivity of cosmogenic 44Ti in Agen meteorite, a H5 chondrite that fell in 1814. The 44Ti activity in meteorites is related to centennial-scale changes in cosmic ray intensity caused by heliospheric magnetic field modulation in the interplanetary space between heliocentric distances of 1 and 3 AU. The measured low 44Ti activity in Agen suggests a strong modulation of galactic cosmic rays at the turn of the 18th century, resulting in a low cosmic ray flux and is consistent with the linearly decreasing trend of GCR flux, modulated by the Gleissberg solar cycle during the past 250 years, as previously suggested by us.”