"We have performed spectral analysis of GRB 080916C (GCN 8245, 8246). The time averaged spectrum, from 8 keV up to 30 MeV, of the main emission up to 66 seconds after the burst is best fit by a Band function with Epeak = 424 +/- 24 keV, alpha = -0.91 +/- 0.02, and beta = -2.08 +/- 0.06. The fluence (8 keV - 30 MeV) is 1.9e-4 erg/cm^2. These spectral analysis results are preliminary; the final results...Full Text

We have imaged the field of GRB 080916C (van der Horst, GCN 8245) based on the localization by Fermi/LAT (Tajima et al, GCN 8246) in J, H, and Ks with the Simultaneous three-color InfraRed Imager for Unbiased Survey (SIRIUS) on the Nagoya-SAAO 1.4m telescope (IRSF) starting at 2:53 on September 17 UT for 50 min. The optical afterglow candidate suggested by Clemens et al. (GCN 8257, GCN 8272)...Full Text

We observed the field of GRB 080916C for a second time with GROND at 08:04 UT on September 19th, 2008, 3.3 d after the GBM trigger with 54 min of effective exposures. Observations were performed at an average seeing of 1.7" and at an average airmass of 1.7. We do not detect the afterglow candidate first reported by Clemens et al. (GCN 8257) with the following 5-sigma upper limits: z' > 22...Full Text

We observed the field of GRB 080916C for a second time with GROND at 08:04 UT on September 19th, 2008, 3.3 d after the GBM trigger with 54 min of effective exposures. Observations were performed at an average seeing of 1.7" and at an average airmass of 1.7. We do not detect the afterglow candidate first reported by Clemens et al. (GCN 8257) with the following 5-sigma upper limits: z' > 22...Full Text

The Swift/UVOT began observations of the field of GRB 080916C 17.0 hours after the Fermi GBM dectection (Goldstein & van der Horst, GCN 8245). No afterglow is detected within the XRT error circle (Evans, et al., GCN 8255) in any of the observed UVOT filters. UVOT magnitude 3-sigma upper limits are reported in the following table: Filter T_start T_stop Exp(s) Mag (3-sigma upper limit) ------------------------------------------------------------- v...Full Text

The Swift XRT started observing the field of the FERMI GRB 080916C (Goldstein et al., GCN 8245) at 2008-09-16 17:11:28 UT, about 17 hours after the trigger. We confirm that the X-ray source reported by Kennea (GCN 8253) is the afterglow of the GRB. Using 2614 s of XRT Photon Counting mode data and 2 UVOT images, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment...Full Text

The long GRB 080916ó (Fermi GBM trigger 243216766/080916.009; Goldstein and van der Horst, GCN 8245; Tajima et al., GCN 8246; Hurley et al., GCN 8251) triggered Konus-Wind at T0=764.632 s UT (00:12:44.632). The burst light curve shows the main part with a duration of ~70 s followed by a weak tail seen at least till ~T0+200 s. As observed by Konus-Wind the burst had a fluence of (1.24 +/-...Full Text

GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile) observed the field of GRB 080916C, which triggered Fermi GBM (Goldstein et al., GCN 8245) and for which significant correlated emission was detected by the Fermi LAT (Tajima et al., GCN 8246). The field was followed up by Swift XRT (Kennea et al., GCN 8253). Observations started...Full Text

Using 1310 s of XRT Photon Counting mode data and 1 UVOT images, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching to the USNO-B1 catalogue): RA, Dec = 119.84706, -56.63788 which is equivalent to: RA (J2000): 07 59 23.29 Dec (J2000): -56 38 16.4 with an uncertainty of 2.1 arcsec (90% confidence). This position may be improved as more data are received...Full Text

At 17:08 UT, September 16tHETE 2008 Swift began TOO observations of the Fermi GBM and LAT detected GRB 080916C (GCN 8245,8246). Preliminary analysis of downlinked data from this observation reveals a single point source detected in the field of view at RA, Dec = 119.8459, -56.63891 which is equivalent to: RA (J2000): 07h 59m 23.0s Dec (J2000): -56d 38' 20.1" with an estimated uncertainty...Full Text

GRB 080916C (Goldstein and van der Horst, GCN 8245; Tajima et al., GCN 8246) was also observed by AGILE (MCAL, SuperAGILE, and ACS - but not localized), RHESSI, INTEGRAL (SPI-ACS), Konus-Wind, and MESSENGER. A preliminary triangulation gives a long, narrow error box centered at RA, Dec = 119.830, -56.790 degrees (0.2 degrees from the center of the LAT error circle), whose corners are: RA(2000)...Full Text

We report a detection by the Fermi Large Area Telescope (LAT) of emission from the long GRB 080916C, which was triggered by the Fermi Gamma-ray Burst Monitor (GBM) at 00:12:45 UT on September 16tHETE 2008 (GCN 8245). The angle of the GBM best position (RA, Dec=121.8,-61.3) with respect to the LAT boresight was 52 degrees at the time of the trigger, which is close the edge of our field of view...Full Text

"At 00:12:45 UT on 16 September 2008, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located the bright GRB 080916C (trigger 243216766 / 080916.009). The on-ground calculated location, using the GBM trigger data, is RA = 121.8, Dec = -61.3 (J2000 degrees, equivalent to J2000 8h 07m, -61d 18'), with a statistical uncertainty of less than 1 degree (radius, 1-sigma containment) and an additional...Full Text