Pair of Colliding Stars Spill Radioactive Molecules into Space

Astronomers have made the first definitive detection of a radioactive molecule in interstellar space: a form, or isotopologue of aluminum monofluoride. The new data reveal that this radioactive isotopologue was created by the collision of two stars, a tremendously rare cosmic event that was witnessed on Earth as a “new star,” or nova, in the year 1670.