A lower initial abundance of 41Ca: implications for the origins of short-lived radionuclides

The initial abundances and distributions of short-lived radionuclides (half-lives < 5 Myr, SLRs) are important for understanding the solar system formation. Among these SLRs whose former presence 4.5 billion years ago has been inferred through studies of meteoritic components, 41Ca plays a crucial role in constraining the immediate astrophysical environment and the formation timescale of the nascent solar system due to its short half-life. However, there have only been very limited data for 41Ca since the discovery in 1994 because of the challenging mass spectrometry. In this talk, I will introduce how the initial abundance of 41Ca was revised by using a state-of-the-art ion microprobe, and what the new data implied in terms of the origin(s) of SLRs.