TITLE: GCN CIRCULAR NUMBER: 8580 SUBJECT: SGR 1806-20: Fermi GBM detection. DATE: 08/11/29 17:52:19 GMT FROM: Valerie Connaughton at MSFC Valerie Connaughton (UAH) and Chryssa Kouveliotou (NASA/MSFC) report on behalf of the Fermi GBM Team: "At 00:38:12.71 UT on 29 November 2008, the Fermi Gamma-Ray Burst Monitor triggered on a short, soft event (trigger 249611893 / 081129027). The GBM on-ground location is consistent with the Soft Gamma Repeater SGR 1806-20. A preliminary estimate of the duration (128 ms) and count spectrum of the event reinforce its association with the repeater source. This is the second recent Fermi GBM-triggered event from SGR 1806-20, the first having occurred on 06 November 2008 (GCN 8497, McBreen and Kouveliotou). The angle from the Fermi LAT boresight is 118 degrees. Detailed timing and spectral analysis are in progress."