Due to bad weather conditions, the ROTSE-3a telescope at Siding Springs Observatory, Australia did not respond to GRB 100901A (Swift trigger 433065, Immler S. et al., GCN 11159). Automated re-pointing of ROTSE-3c at the H.E.S.S. site at Mt. Gamsberg, Namibia and ROTSE-3b at the McDonald Observatory, Texas observed the optical afterglow starting ~ 8.6 to 22.0 hours after the burst. The optical...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 100807A (Swift trigger 431128; Grupe et al., GCN 11067), producing images beginning 5.2 s after the GCN notice time. An automated response took the first image at 09:13:35.2 UT, 21.6 s after the burst, and during the gamma-ray emission, under fair conditions. We took 10 5-sec and 10 20-sec exposures. These unfiltered images are...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 100805A (Swift trigger 430957; Hoversten , E. A., GCN 11047), producing images beginning 6.2 s after the GCN notice time. An automated response took the first image at 04:13:39.2 UT, 50.9 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered images are calibrated relative...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 100802A (Swift trigger 430603; Troja, E., GCN 11031), producing images beginning 9.1 s after the GCN notice time. An automated response took the first image at 05:46:10.1 UT, 27.9 s after the burst, and during the gamma-ray emission, under fair conditions. We took 10 5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered images...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 100420A (Swift trigger 419932; W. H. Baumgartner et al., GCN 10628), producing images beginning 8.8 s after the GCN notice time. An automated response took the first image at 05:24:07.8 UT, 79.8 s after the burst, and during the gamma-ray emission. We took 10 5-sec, 10 20-sec and 10 60-sec exposures. These unfiltered images are...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 091208 (Swift trigger 378554; E. A. Hoversten et al, GCN 10253), producing images beginning 9.6 s after the GCN notice time. An automated response took the first image at 08:46:30.5 UT, 30.0 s after the burst. We took 10 5-sec and 42 20-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 090709 (Swift trigger 356890; Morris D. C., GCN 9625), producing images beginning 5.6 s after the GCN notice time. An automated response took the first image at 07:39:00.6 UT, 26.0 s after the burst, and during the gamma-ray emission, under good conditions. We took 10 5-sec and 50 20-sec exposures. These unfiltered images...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090708 (Swift trigger 356776; Krimm et al., GCN 9621), producing images beginning 7.4 s after the GCN notice time. An automated response took the first image at 03:39:04.5 UT, 49.2 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 10 60- sec exposures. These unfiltered images are calibrated relative...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090618 (Swift trigger 355083, Schady et al., GCN 9512). The first image was at 08:28:53.7 UT, 23.9 s after the burst (6.7 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 14.1 magnitude source with coordinates: 19:35:58.65 +78:21:24.03 (J2000), with positional uncertainty...Full Text

ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090530A (Swift trigger 353567). The first image was at 03:18:35.8 UT, 17.4 s after the burst (6.8 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: 11:57:40.5 +26:35:37.9 (J2000), with positional...Full Text

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