"We report on additional analysis of our VLT/FORS2 spectrum of the optical afterglow of GRB 091109A (Oates et al., GCN 10138, Guidorzi et al. GCN 10142, Oates GCN 10143, Afonso et al., GCN 10158 ). A careful search revealed absorption lines at 6227, 6308, and 6321 Angstroem which we identify with SiII and the CIV doublet a common redshift of z=3.076 +/- 0.002. Lyman-alpha absorption...Full Text

GROND (Greiner et al. 2008, PASP 120, 405), mounted at the 2.2m ESO/MPI telescope at La Silla Observatory (Chile), reobserved the field of GRB 091109A (Oates et al., GCN 10138) simultaneously in the g'r'i'z'JHK bands. Observations started 2009-11-20 00:42, 10.8 days after the trigger and lasted for an effective exposure of 75 min in g'r'i'z' and 60 min in JHK. At the position of the optical afterglow...Full Text

GROND (Greiner et al. 2008, PASP 120, 405), mounted at the 2.2m ESO/MPI telescope at La Silla Observatory (Chile), observed the field of GRB 091109A (Oates et al., GCN 10138) simultaneously in the g'r'i'z'JHK bands. Observations were done under clear sky conditions, starting on Nov 10 at 00:07 UTC, 19.1 h after the burst and lasted for 1.8 hours. In stacked images corresponding to a total integration...Full Text

"We have to correct the position of the object reported in our previous GCN 10139: due to a typo the R.A. position of the putative NIR afterglow of GRB 091109 reported is RA(J2000) 20:37:02.02 instead of RA(J2000) 20:37:02.2. However, we note that the correct position is still about 2" far away from the UVOT position (Oates, GCN 10143). The observed source in the REM H band early images is very...Full Text

We have analysed 7.9 ks of Swift-XRT data for GRB 091109 (Oates et al. GCN 10138), from 154 s to 18.1 ks after the BAT trigger. The data span four orbits, comprising 37 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 10140). The light curve can be modelled by a broken power-law with...Full Text

We have observed the field of GRB 091109 (Oates et al. GCN 10138) using the 0.6 Yock-Allen robotic telescope (BOOTES-3) located in Bleinheim, New Zealand. Due to bad weather conditions, observations did not start until 11:03 UT (6.1h after the burst). A combination of the first 30x60s unfiltered exposures does not show any source at the UVOT postion down to a 3-sigma limiting magnitude of R~20...Full Text

The Swift/UVOT began observerving the field of GRB 091109 156s after the BAT trigger (Oates et al., GCN 10138). We detect the optical afterglow in the white filter only, which faded rapidly. The refined UVOT position is: RA (J2000) 20:37:01.80 Dec (J2000) -44: 9:29.6 with an estimated uncertainty of 0.7 arcsec (radius, 90% confidence). This position is consistent with the XRT refined...Full Text

On 2009 November 9 at 09:26:10 UT the 2-m Faulkes Telescope South began observing GRB 091109 (Oates et al., GCN 10138) using the R and i' filters. We detect the UVOT optical afterglow candidate at a position consistent with that reported by Oates et al. (but not consistent with the object reported by REM Antonelli et al., GCN 10139), with the following magnitudes: Mid Time from GRB Total Exp...Full Text

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Using 3018 s of XRT Photon Counting mode data and 5 UVOT images for GRB 091109, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 309.25767, -44.15872 which is equivalent to: RA (J2000): 20h 37m 1.84s Dec (J2000): -44d 09' 31.4" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position...Full Text

"The robotic 60-cm REM telescope located at La Silla (Chile) observed automatically the field of the GRB 091109 (Oates et al. GCN 10138) starting about 77 s after the burst. We detect a faint object in the XRT error circle in our first H-band images at H~14.8 at coordinates: RA(J2000) 20:37:02.2; Dec(J2000) -44:09:30.4 with 1 arcsec error. This message can be cited"...Full Text

At 04:57:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 091109 (trigger=375246). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 309.265, -44.176 which is RA(J2000) = 20h 37m 04s Dec(J2000) = -44d 10' 34" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed...Full Text