The light elements enlighten lightening from our young sun

Our Sun is a typical G2V type star that has lived almost half (4.56Ga) of its main-sequence life time. Sun like stars during their pre-main sequence stage has been observed to be highly active. Understanding the activity of the early Sun during the pre-main sequence stage is a key towards understanding the origin and early evolution of the Solar system. Although synthesis of the light elements by 'nu' process during the death of a massive star had been suggested, the idea of irradiation from the early Sun as the progenitor of short-lived now-extinct radionuclide (SLN) ¹⁰Be was favoured for the measured excesses in the daughter product isotope, ¹⁰B, in the first forming Solar system solid. A later theoretical analysis showed a plausible pathway of trapping by solar nebula of ¹⁰Be that was produced in the interstellar medium. A follow up study suggested plausible presence of another short-lived now extinct radionuclide ⁷Be along with ¹'⁰Be in the same calcium, aluminum,-rich inclusion (CAI). However, the isotopic (Li-Be-B) records in the CAI that showed clear evidence of post magmatic alterations in the form of secondary minerals and disturbed isotopic records of other isotope systematics (Mg, Sr) along with a more robust cosmogenic correction method of the obtained isotopic data suggested lack of a robust linear correlation between lithium isotope and Be/Li ratio. In a recent theoretical study, it was shown that the nucleosynthetic yield from a weakly exploding, low mass (~8 solar mass) supernova can account for the observed abundance of ¹⁰Be in calcium, aluminum-rich inclusions found in meteorites. Hence, reinstating a stellar source for ¹⁰Be and thereby weakening the assertion of irradiation from early Sun as a source of SLNs. (author)