ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090515 (Swift trigger 352108; Beardmore et al., GCN 9356), producing images beginning 6.5 s after the GCN notice time. An automated response took the first image at 04:45:27.5 UT, 18.0 s after the burst, under fair conditions. We took 10 5-sec and 10 20-sec exposures. These unfiltered images are calibrated relative to USNO A2.0...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090418A (Swift trigger 349510; Mangano et al, GCN 9149) 19.0 s after the burst, during the gamma-ray emission, and detected the optical counterpart (Yuan et al, GCN 9150). We took 10 5-sec, 10 20-sec and 26 60-sec useful exposures before sunrise. Further analysis of single images revealed an initially rising lightcurve...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090418 (Swift trigger 349510; Mangano et al, GCN 9149) in twilight. The first image was at 11:07:59.2 UT, 19.0 s after the burst (4.2 s after the GCN notice time). The unfiltered images are calibrated relative to USNO B1.0. We detect the optical counterpart at the KAIT and UVOT position (Chornock et al. GCN 9148; Mangano...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 081024A (Swift trigger 332516; G. Stratta, GCN 8398), producing images beginning 9.1 s after the GCN notice time. An automated response took the first image at 05:53:37.2 UT, 28.4 s after the burst, under excellent conditions. We took 10 5-sec, 10 20-sec and 40 60-sec exposures. These unfiltered images are calibrated relative...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080607 (Swift trigger 313417). The first image was at 06:07:49.0 UT, 22.0 s after the burst (6.0 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 14.8 magnitude, fading source with coordinates: ...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080420 (Swift trigger 309665; Vetere, L. et al., GCN 7632) a possible short burst, producing images beginning 8.1 s after the GCN notice time. An automated response took the first image at 04:13:10.2 UT, 23.0 s after the burst, under fair conditions. These observations were affected by the Full Moon 75 degrees away. We took...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080330A (Swift trigger 308041). The first image was at 03:41:39.2 UT, 22.4 s after the burst (7.2 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a new object, not visible in the DSS (second epoch), with coordinates: ...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080320 (Swift trigger 306858), producing images beginning 6.5 s after the GCN notice time. An automated response took the first image at 04:38:10.5 UT, 32.1 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 20 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080319B (Swift trigger 306757; Racusin et al., GCN 7427) and began imaging at 06:13:11.06 UT (5.3 sec after the GCN notice time) under suboptimal conditions, because of condensation present on the CCD. Observations continued until about 5 hours after the trigger. This condensation made the analysis very difficult...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 080310 (Swift trigger 305288; Cummings et al., GCN 7382) and began imaging at UT 08:38:25.7 (5.7 sec after the GCN notice time) under cloudy conditions. The first usable image with a detection of the OT (Chornock et al. GCN 7381) starts at UT 09:03:03.4. Observations continued in fluctuating weather conditions until about...Full Text

We obtained near-infrared spectra of supernova 2008D (ATEL 1353; GCN 7160) with the NASA Infrared Telescope Facility (IRTF) and SPEX instrument. The data were taken January 14.4 UT and cover the wavelength range 0.7 to 2.5 microns. A preliminary reduction of the spectrum shows a strong absorption feature at 1.01 micron. This feature is seen in several other type Ic events (e.g. SN 1994I, Millard...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071122 (Swift trigger 297114; Stamatikos et al., GCN 7121), producing images beginning 8.5 s after the GCN notice time. An automated response took the first image at 01:24:51.5 UT, 85.9 s after the burst, under fair conditions. These observations were affected by proximity to the full moon. We took 10 5-sec, and 30 20-sec...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986, Pagani, et al.) and detected an optical counterpart as reported in GCN 6987 (Rykoff, et al.). We have improved the photometry and recalibrated the images relative to USNO-B1.0 R-band, which is significantly offset from the magnitudes in USNO-A2.0 R-band....Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986). The first image was at 04:10:14.0 UT, 80.3 s after the burst (6.0 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 19.2 magnitude, fading source with coordinates: ...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071020 (Swift trigger 294835; Holland, et al., GCN 6949) and detected the optical counterpart (Schaefer, et al., GCN 6948). During our first 80 seconds observation (starting 25.6 sec after the burst), the OT faded with a decay index of 1.52 +/- 0.03....Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071020A (Swift trigger 294835). The first image was at 07:02:52.5 UT, 25.6 s after the burst (9.5 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 13.6 magnitude, fading source with coordinates: ...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 070810A (Swift trigger 287364; Cummings, et al., GCN 6733), and detected the optical counterpart (Swan, et al., GCN 6734). The initial aperture photometry reported in GCN 6734 was biased due to contamination from the nearby star. With a reference image taken 6 days after the burst, we were able to subtract the nearby...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 070810 (Swift trigger 287364). The first image was at 02:34:02.5 UT, 1330.5 s after the burst. The unfiltered images are calibrated relative to USNO A2.0. We detect a 16.7 magnitude, fading source with coordinates: ...Full Text

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 070809 (Swift trigger 287344; Marshall, et al., GCN 6728), producing images beginning 10.2 s after the GCN notice time. An automated response took the first image at 19:22:48.2 UT, 30.9 s after the burst, under excellent conditions. We took 10 5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered images...Full Text

ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 070621 (Swift trigger 282808, Sbarufatti, et al., GCN 6560), producing images beginning 6.1 s after the GCN notice time. An automated response took the first image at 23:18:03.1 UT, 23.3 s after the burst, and during gamma-ray emission. We took 10 5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered...Full Text