Binary Millisecond Pulsar Discovery via Gamma-Ray Pulsations
  Millisecond pulsars, old neutron stars spun-up by accreting matter from a
companion star, can reach high rotation rates of hundreds of revolutions per
second. Until now, all such "recycled" rotation-powered pulsars have been
detected by their spin-modulated radio emission. In a computing-intensive blind
search of gamma-ray data from the Fermi Large Area Telescope (with partial
constraints from optical data), we detected a 2.5-millisecond pulsar, PSR
J1311-3430. This unambiguously explains a formerly unidentified gamma-ray
source that had been a decade-long enigma, confirming previous conjectures. The
pulsar is in a circular orbit with an orbital period of only 93 minutes, the
shortest of any spin-powered pulsar binary ever found.
