1. INTRODUCTION

At 08:57:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071118 (trigger=296856). Swift slewed immediately to the burst. The XRT found a fading source in the BAT error circle. The UVOT found a faint source in the XRT error circle, not seen in later exposures. The best position is the UVOT position

RA = 19 58 51.8 Dec = +70 07 29.2

with an uncertainty of 0.6 arcsec (radius, 90% confidence).

2) BAT OBSERVATION AND ANALYSIS

Using the data set from T-239 to T+303 s, the BAT ground-calculated position is RA, Dec = 299.839, 70.130 deg, which is

RA (J2000) = 19h 59m 21.4s Dec (J2000) = +70d 07' 47"

with an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a broad single peak starting at ~T-25 s, peaking at ~T+55 sec, and ending at ~T+110 s. T90 (15-350 keV) is 71 ± 20 s (estimated error including systematics).

The time-averaged spectrum from T+4.5 to T+81.2 s is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.63 ± 0.29. The fluence in the 15-150 keV band is 5.0 ± 1.0 x 10-7 erg/cm2. The 1-s econd peak photon flux measured from T+80.26 s in the 15-150 keV band is 0.3 ± 0.1 ph/cm2/s. All the quoted errors are at the 90% confidence level.

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We have imaged the field of GRB 071118 (Cummings et al., GCN 7106) with the automated Palomar 60-inch telescope beginning at 01:49 UT on 19 November. We do not detect any source at the location of the optical afterglow (de Pasquale et al., GCN 7116). Using the USNO-B1 catalog as a reference, we calculate upper limits of R > 22.5, i' > 22.5 at this epoch. ...Full Text

We performed optical imaging observations (g', Rc and Ic) of the field of GRB 071118 (Cummings et al., GCN 7106; Markwardt et al. GCN 7109) with 50cm MITSuME telescope at Okayama Astrophysical Observatory from UT 9:00:31 (194 sec after the trigger) to UT 13:03 on November 18 2007....Full Text

We have observed the field of GRB 071118 (Cummings et al. GCN 7106) with the 1.5m telescope at Sierra Nevada Observatory in Granada (Spain) starting at 18:00 UT (~9 hours after the burst). We detect the afterglow reported by UVOT (De Pasquale et al. GCN 7116) in a 18x300s exposure I-band image (with mean date Nov 18.8038 UT) as a faint object of I~21.7. It is however not detected in a V band...Full Text

The Swift/UVOT began observing the field of GRB 071118 (Cummings et al, GCN 7106) 123s after the BAT trigger....Full Text

We have analysed the first 4 orbits of Swift-XRT data obtained for GRB 071118 (trigger number 296856, Cummings et al., GCN 7106). The data consist of 122 s in Windowed Timing (WT) mode, starting 128 s after the BAT trigger and 8.8 ks in Photon Counting (PC) mode. Using 1298 s of overlapping XRT Photon Counting mode and UVOT V-band data, we find an astrometrically corrected X-ray position (using...Full Text

Using the data set from T-239 to T+303 sec from the recent telemetry downlink, we report further analysis of BAT GRB 071118 (trigger #296856) (Cummings, et al., GCN 7106). The BAT ground-calculated position is RA, Dec = 299.839, 70.130 deg, which is ...Full Text

At 08:57:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071118 (trigger=296856). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 299.817, +70.093 which is ...Full Text