We conducted a deep optical imaging integration on the field of GRB 100205A (Racusin et al., GCN 10361) using LRIS on the Keck I 10m telescope starting at 09:48 UT on 2010 Feb 7. We integrated for a total exposure time of 4000 seconds in g-band and 3770 seconds in R-band simultaneously under clear skies but variable and generally poor seeing conditions (1.5 arcsec average). The mid-point of...Full Text

We observed the GRB 100205A (GCN 10361 Racusin et al.) with J and K-band using KASINICS instrument on the 1.8m telescope at the Bohyunsan Optical Astronomy Observatory (BOAO), Korea, starting from 2010-02-05, 17:28:13 UT. We also observed the GRB with z and Y filters using the LOAO 1-m telescope, starting from 2010-02-05, 10:37:51 UT. We do not detect the afterglow at the reported...Full Text

We observed the field of GRB 100205A (Swift trigger #411248; Racusin et al., GCN 10361) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at LaSilla Observatory (Chile). Due to cloud coverage, observations started only on 05 Feb. 2010 at 06:37:58 UT, 2.3 h after the burst, and were severely affected by passing cirrus. In stacked...Full Text

"We have imaged the field of GRB 100205A (Racusin et al. GCN 10361) using CFHT. The observation was started at 7:11UT on Feb. 6 (about 26.9 hr after the burst). The z'-band stacked image shows no source at the position of the NIR afterglow (Tanvir et al. GCN 10366) down to z'~24.5." ...Full Text

We have calibrated the JHK photometry for the candidate Gemini-N + NIRI afterglow (Tanvir et al., GCN 10366) of GRB 100205A (Racusin et al., GCN 10361) against two 2MASS stars in the field. Converted to AB magnitudes we find: J_AB > 23.37 mag (1-sigma UL) H_AB = 23:54 +- 0.22 mag K_AB = 21.91 +- 0.20 mag Thus, based on our photometry we measure a red K-H color, K_AB - H_AB = 1.6...Full Text

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The Swift/UVOT began settled observations of the field of GRB 100205A 177s after the BAT trigger (Racusin et al., GCN 10361). We do not detect any source at the enhanced Swift XRT position (Racusin et al., GCN 10361) nor at the position of the Gemini-North K-band detection (Tanvir et al., GCN 10366). UVOT magnitude 3-sigma upper limits are reported in the following table: Filter T_start T_stop...Full Text

We have analysed 1.5 ks of XRT data for GRB 100205A (trigger=411248, Racusin et al. GCN 10361), from 157 s to 4.95 ks after the BAT trigger. The data comprise 11 s of Windowed Timing (WT) mode settling data and the remainder is in Photon Counting (PC) mode. At this point Swift coverage of the source stopped due to thermal constraints, but further observations are now underway. The enhanced...Full Text

Using 1394 s of XRT Photon Counting mode data and 2 UVOT images for GRB 100205A, 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 = 141.38751, +31.74050 which is equivalent to: RA (J2000): 09h 25m 33.00s Dec (J2000): +31d 44' 25.8" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This...Full Text

We observed the field of GRB 100205A (Racusin et al. GCN 10361) with Gemini-North/NIRI, beginning at 06:55 UT (approx 2.6 hr post burst). In a deep K-band integration we detect a point source within the enhanced XRT error circle, at position (accuracy ~0.5 arcsec): RA(2000) = 09 25 33.02 dec(2000)= +31 44 25.0 The approximate magnitude (calibrated against two faint 2MASS stars in the field) is...Full Text

We have imaged the field of GRB 100205A (Racusin et al., GCN 10361) with the Gemini Multi-Object Spectrograph (GMOS) on the 8 m Gemini South telescope beginning at 05:48 UT on 05 February 2010 (~ 40 minutes after the burst trigger time). Observations were conducted in the r' filter for a total of 600 seconds. We find no new point sources at the location of the X-ray afterglow (Racusin et al....Full Text

We observed the field of GRB 100205A (Racusin et al., GCN 10361) with the 0.6m Super-LOTIS telescope located at KPNO under poor conditions. Observations began 110 seconds after the trigger and continued for 7 minutes before we were forced to close due to humidity. In 270 seconds of stacked V-band exposures, we detect no new sources in the XRT error circle down to a limiting magnitude V > 18...Full Text

We observed the field of GRB 100205A (Racusin et al., GCN 10361) with the NOT equipped with ALFOSC. Observations were carried out in the R and I bands, starting at 4:58 and 5:16 UT, that is 39 and 58 min after the GRB, respectively. Within the XRT error circle, we do not detect any new source down to limiting magnitudes R > 23.7 and I > 23.2 (assuming R=17.3 and I = 16.8 for the object...Full Text

At 04:18:43 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100205A (trigger=411248). Swift slewed immediately to the burst. The BAT on-board calculated location is RA 141.406d, Dec +31.739d, which is RA(J2000) = 09h 25m 37s Dec(J2000) = +31d 44' 22" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed...Full Text