Observations from NASA's Rossi X-ray Timing Explorer (RXTE) have revealed that the youngest known pulsing neutron star has thrown a temper tantrum. The collapsed star occasionally unleashes powerful bursts of X-rays, which are forcing astronomers to rethink the life cycle of neutron stars. "We are watching one type of neutron star literally change into another right before our very eyes. This is a long-sought missing link between different types of pulsars," says Fotis Gavriil of NASA's Goddard Space Flight Center in Greenbelt, Md. Gavriil is lead author of a paper in the February 21 issue of Sciencexpress. McGill's Vicky Kaspi is a co-author of the paper, as well as Marjorie Gonzalez, who worked on the paper at McGill but is now based at the University of British Columbia.