Fermi GBM Instrument

The Fermi GBM instrument has recently observed the black hole source Cyg X-1 making a transition from a soft gamma ray state to a hard state. The result is announced in Astronomical Telegram 3802. The earlier GBM occultation result showing that the Crab Nebula gamma ray flux varies in time, together with the observations of unexpected gamma ray flaring from the Crab, is listed as Astronomy Magazine's #2 result of the year in astronomy.