https://phys.org/news/2018-07-pair-colliding-stars-radioactive-molecules.html > This is the first molecule bearing an unstable radioisotope definitively detected outside of our solar system. Unstable isotopes have an excess of nuclear energy and eventually decay into a stable, less-radioactive form. In this case, the 26-aluminum (26Al) decays to 26-magnesium (26Mg). > "The first solid detection of this kind of radioactive molecule is an important milestone in our exploration of the cool molecular universe," said Tomasz Kamiński, an astronomer with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and lead author on a paper appearing in Nature Astronomy.