Genealogy of the solar system

Séminaire IPAG de Matthieu Gounelle (MNHN), jeudi 14 mars 2013 à 11h00, IPAG seminar room

When meteorites formed, 4.5 Gyr ago, they contained short-lived radio nuclides (SLRs) such as 26Al (T1/2 = 0.64 Myr), 60Fe (T1/2 = 2.6 Myr) or 182Hf (T1/2 = 9 Myr). The origin of these radio elements and their astrophysical relevance has long been elusive. I will show that the presence of SLRs with a diversity of half-lives in the solar protoplanetary disk is nothing else but the fossilized record of sequential star formation within a hierarchical interstellar medium (ISM). This finding makes it possible to identify the genealogy of our Solar System three star generations backwards. In particular, the past presence of 26Al in meteorites shows that our Sun was born¬together with a few hundred stars ¬ in a dense collected shell situated at a distance of 5-10 pc of a parent massive star having a mass larger than 30 solar masses.