This file contains both bursts: GRB 050117A annd GRB 050117B Eventually, the Swift-BAT team retracted the 'B' burst -- it is not a burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2951 SUBJECT: GRB050117: Swift XRT Position DATE: 05/01/17 13:42:00 GMT FROM: David Burrows at PSU/Swift D. N. Burrows, J. E. Hill, G. Chincarini, J. Nousek, N. Gehrels, and P. Schady report on behalf of the Swift XRT team: The Swift XRT reported a prompt position for GRB050117. The burst was discovered by the BAT and the Swift spacecraft performed a prompt slew. The XRT found a bright source in the field and imaged it at IMG_START_DATE: 13387 TJD; 17 DOY; 05/01/17 IMG_START_TIME: 46548.64 SOD {12:55:48.64} UT The XRT position is GRB_RA: 358.4644d {+23h 53m 51s} (J2000), 358.5274d {+23h 54m 07s} (current), 357.8439d {+23h 51m 23s} (1950) GRB_DEC: +65.9418d {+65d 56' 30"} (J2000), +65.9699d {+65d 58' 12"} (current), +65.6635d {+65d 39' 49"} (1950) The XRT positions are not yet fully calibrated, and we estimate an uncertainty of 30 arcseconds in these coordinates. The XRT prompt image confirms that a point source is located at this position. A check of SIMBAD shows no bright X-ray sources in this location. Further information, including an XRT lightcurve and spectrum, will be available in a few hours. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2952 SUBJECT: GRB050117: Swift-BAT detection of a long multi-peaked burst DATE: 05/01/17 14:57:54 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC), S. Barthelmy, L. Barbier (GSFC), A. Blustin (MSSL), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), J. Kennea (PSU) H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (LANL), T. McMahon (Langston U.), D. Palmer (LANL), A. Parsons (GSFC), G. Sato (ISAS), P. Schady (MSSL), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift-BAT team: At 12:52:36 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050117. The spacecraft autonomously slewed to the burst for the first time with a real GRB. The BAT on-board calculated location is RA,Dec 358.427,+65.945 (J2000) with an uncertainty of 4 arcmin (radius, 3-sigma, including a systematic uncertainty). This is within 55 arcsec of the XRT position (Burrows et al., GCN Circ 2951). This burst occurred while Swift was near the SAA. The lightcurve is multi-peaked with a duration of ~200 sec. We note that the XRT was on target during the later portion of the gamma-ray phase of the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2953 SUBJECT: MASTER:GRB050117 SWIFT DATE: 05/01/17 15:33:32 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, A.Krylov, V.Kornilov, G.Borisov, D.Kuvshinov, A.Belinski, M.Kuznetsov, S.Potanin, G.Antipov, E.Gorbovskoy, N.Tyurina Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow After SWIFT alert (GCN 2951) MASTER robotic telescope (http://observ.pereplet.ru) had imaging the corresponding area of the sky. We have unfiltered images of the error box (45s exposition, 6 square degrees field) started at 17 Jan 2005 14:58:40 UT (after 2 hours GRB time). The limiting magnitude on the first image was about 17.0. There is no OT within the SWIFT error circle. JPG-images are available at http://observ.pereplet.ru/images/SRG1806-20/050117/ Observations are continued. This message may be cited. This work is partly supported by RFFI 04-02-16411. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2954 SUBJECT: GRB050117: MASTER optical observations DATE: 05/01/17 17:43:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, A.Krylov, V.Kornilov, G.Borisov, D.Kuvshinov, A.Belinski, M.Kuznetsov, S.Potanin, G.Antipov, E.Gorbovskoy, N.Tyurina Sternberg Astronomical Institute, Moscow After SWIFT alert (GCN 2951) MASTER robotic telescope (http://observ.pereplet.ru) had imaging the corresponding area of the sky under the bad weather conditions. We have 50 unfiltered images of the error box (45s exposition, 6 square degrees field) started at 17 Jan 2005 14:58:40 UT (2 hours after GRB time). The limiting magnitude on the summ of the best 10 images was about 19.0. There is no OT within the 0'5 SWIFT error circle. The central part of the JPG-images are available at http://observ.pereplet.ru/images/SRG1806-20/050117/summ10.jpg This message may be cited. This work is partly supported by RFFI 04-02-16411. Mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2955 SUBJECT: GRB050117: Refined XRT position DATE: 05/01/17 18:09:23 GMT FROM: David Burrows at PSU/Swift J. E. Hill, J. A. Kennea, D. C. Morris, D. N. Burrows (PSU), A. A. Wells, J. P. Osborne (U. Leicester), G. Tagliaferri (OAB), M. Ivanushkina, S. Hunsberger, J. A. Nousek, P. Roming (PSU), P. Schady (MSSL), S. Barthelmy, F. Marshall and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: We have derived a refined Swift XRT position for GRB050117, based on preliminary alignment corrections to the raw position reported in Burrows et al. (GCN 2951). The refined XRT position is: RA(J2000) = 358.47067 = 23h 53m 53.0s Dec(J2000) = +65.93882 = +65:56:20 The estimated uncertainty in this position is 15 arcseconds (radius). This is the first time that the Swift observatory has executed a prompt slew to a GRB, and the XRT position was measured 192 seconds after the burst occurred. Because the burst was quite long, the first XRT data were collected before the burst ended, a first for a focussed X-ray GRB/afterglow observation. We note that the XRT in-flight calibration program has not yet begun because the Swift observatory is still in its commissioning phase. The burst occurred at 12:52:36 UT (Sakamoto et al., GCN 2952) just before Swift entered the South Atlantic Anomaly (SAA) and while the burst location was within the Swift Earth limb constraint. The Swift spacecraft began slewing to the burst at 12:54:38 UT, while in the SAA. The XRT imaged the source immediately after the slew ended, at 12:55:48.64 UT. The source was very bright, resulting in a successful centroid on the first 0.1s Image Mode exposure. The XRT then collected a partial Photodiode Mode frame and stopped data collection because it was in the SAA. Although we have not yet calibrated fluxes measured in XRT's Image Mode, the X-ray source intensity in the Image Mode frame appears to be comparable to Cyg X-2, which puts it at roughly 1/2 Crab (based on RXTE ASM data on Cyg X-2 and the Crab). The source is located just outside the zero-visibility region around the Swift orbit pole and has only short periods of visibility on each orbit. Most of these visible periods occur while Swift is in the SAA, which limits the amount of time when the source can be viewed by the XRT. Automated observations will proceed for the rest of 2005 Jan 17 when the source is visible. We expect to obtain a total observing time of about 15 minutes, spread out between 12:55 UT and 19:29 UT. Because of orbital precession, the source will not be visible again by the Swift XRT until 2005 Jan 21. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2956 SUBJECT: GRB 050117: Optical observation DATE: 05/01/17 18:43:54 GMT FROM: Ken ichi Torii at RIKEN K. Torii (Osaka University) reports: The error region of SWIFT GRB 050117 (Burrows, et al. GCN 2951; Sakamoto, et al. GCN 2952) was observed with the 14-inch ART at Osaka University. The observation started at 2005 January 17, 14:05 UT and a sequence of 60-s exposures in B, V, Rc, and Ic was repeated. We note that Galactic extinction is severe in the burst direction (E(B-V) = 1.7 or A_R = 4.6 according to Schlegel, et al. 1998) and compared our stacked Ic-band frame (60-s x 10 frames, mean epoch 14:38 UT) with the USNO-A2.0 (R) magnitude. As a result of the preliminary analysis, no new source brighter than about 17.5 mag is identified within the refined XRT error region (Hill, et al. GCN 2955). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2957 SUBJECT: GRB 050117, I-band observations DATE: 05/01/17 21:39:08 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia A. de Ugarte Postigo, A. Sota, M. Jelínek, J. Gorosabel, A. J. Castro-Tirado (IAA-CSIC, Granada) and J. M. Castro Cerón (U. Copenhagen) report: The refined SWIFT/XRT error box (Hill et al. GCN 2955) for GRB 050117 (Sakamoto et al. GCN 2952) has been observed with the 1.5 m telescope at the Observatorio de Sierra Nevada in Granada, southern Spain. I-band (6 x 300 s) images were acquired starting on 17 Jan, 18:30 UT (i.e. about 5.6 hr after the GRB trigger). No new sources within the error box are found when comparing with the DSS-2 plates down to I = 20.5 . Near-IR images -specially in the K-band- would be required in order to indentify the afterglow at these wavelengths, as there is severe extinction in the line of sight (A_I = 3.40; A_K = 0.65). This has been also pointed out by Torii (GCN 2956). This message can be quoted. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2958 SUBJECT: GRB050117: optical observation DATE: 05/01/17 22:59:47 GMT FROM: Alexei Pozanenko at IKI, Moscow R. Karimov, M. Ibrahimov, B. Kahharov, I. Asfandiyarov, D. Sharapov (UBAI), A.Pozanenko (IKI), V.Rumyantsev (CrAO), G.Beskin (SAO) report: We observed error box of Swift GRB050117 (Burrows, et al. GCN 2951; Sakamoto, et al. GCN 2952) with 1.5m telescope of Mt.Maidanak high-altitude observatory. R-band images (5 x 300 s, 4 x 240 s exposures) were taken between 15:48 and 17:21 (UT) Jan. 17. In comparison with DSS2 (red plate) no new source down to R=20 was found in a stacked image within refined XRT error box (Hill, et al. GCN 2955). More detailed analysis is in a progress. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2959 SUBJECT: GRB050117b: Swift-BAT detection of a weak burst DATE: 05/01/18 00:29:22 GMT FROM: David Palmer at LANL D. Palmer (LANL), S. Barthelmy, L. Barbier (GSFC), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC), G. Sato (ISAS), P. Schady (MSSL), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift-BAT team: At 20:03:35 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050117b. The BAT on-board calculated location is RA,Dec 243.380,-70.358 (J2000) with an uncertainty of 10 arcmin (radius, 3-sigma, including a large systematic uncertainty). This is 44 deg off the BAT boresight. This burst occurred with a steeply decreasing background event rate while Swift was exiting the SAA. This weak burst is at the BAT detection threshold. The duration is ~2 sec. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2960 SUBJECT: GRB050117: Palomar WIRC Ks-band observations DATE: 05/01/18 07:53:11 GMT FROM: Derek Fox at CIT Derek B. Fox and S. Bradley Cenko (Caltech), with Eric J. Murphy (Yale) report on behalf of a larger collaboration: "We have imaged the XRT localization region (Hill et al., GCN 2955) of GRB050117 (Burrows et al., GCN 2951; Sakamoto et al., GCN 2952) with the Hale Telescope + WIRC camera at Palomar Observatory, in the Ks-band, from 03:15 to 03:47 UT on Jan 18, with mean epoch 14.7 hours after the burst. Comparison of our individual images to the 2MASS Atlas reveals four 2MASS catalog objects, and no new sources to the Ks~16 mag depth of that survey, within the XRT localization region. Further analysis of these images is ongoing." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2962 SUBJECT: GRB050117a: Refined analysis DATE: 05/01/18 23:38:44 GMT FROM: Scott Barthelmy at NASA/GSFC S. Barthelmy, L. Barbier (GSFC), J. Cummings (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (LANL), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC), G. Sato (ISAS), P. Schady (MSSL), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift-BAT team: Further analysis of Swift-BAT GRB050117a (Sakamoto et al., GCN Circ 2952) yields the fluence to be 7x10^-6 erg/cm2 in the 15-350 keV band and a peak flux of 0.88 +/- 0.06 ph/cm2/sec (also 15-350 keV) in a 5-sec wide window bracketing the highest peak (starting at T+85 sec) in the multi-peak lightcurve. We note that the ~200-sec duration quoted in Circ 2952 was an eye-ball fit for the the total duration. The proper T90 time is 169 sec (15-350 keV). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2963 SUBJECT: GRB050117a: Radio Observations DATE: 05/01/19 02:43:21 GMT FROM: Dale A. Frail at NRAO Dale A. Frail reports on behalf of a larger collaboration: "On January 19.08 UT the VLA was used to observe a region toward the refined XRT position (GCN#2955) of the Swift burst, GRB 050117A (GCN #2952 and 2962). At a frequency of 8.46 GHz no emission was detected above a 4-sigma level of 130 microJy within the 30-arcsec diameter error circle." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2980 SUBJECT: GRB 050117a: Radio Observations DATE: 05/01/25 21:12:48 GMT FROM: Alicia Soderberg at Caltech A. M. Soderberg (Caltech) and D. A. Frail (NRAO) report on behalf of a larger collaboration: "On 2005 January 24.14 UT we carried out follow-up observations with the VLA centered on the refined XRT position (GCN#2955) of the Swift burst, GRB 050117A (GCN #2952 and 2962). At a frequency of 8.46 GHz no emission was detected above a 2-sigma level of 56 microJy within the 30-arcsec (diameter) error circle. No further observations are planned." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6013 SUBJECT: Further Retractions of previous Swift-BAT triggers DATE: 07/01/12 14:50:25 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC) on behalf of the Swift-BAT Team This adds to and amends GCN Circ 5987 (Barthelmy) to complete the corrections to the trigger type identifications for previous Swift-BAT triggers. The table below contains the Trigger Number, the Trigger Date and Time, and a Comment about what we are currently classifying the trigger. TRIGNUM DATE TIME DESCRIPTION 102899 05 Jan 17 20:03:36 We originally issued GCN Circ 2959 which called it GRB 050117B, but we now classify this as an SAA-induced noise event. 131395 05 Jun 02 10:41:45 This was classified in GCN Circ 5987 as "S/C drifting in Sun_Reference Safe_Hold mode", but we now believe the s/c attitude was correctly known thus making the identification SGR1806-20 solid; and further, there is temporal coincidence with a HETE detection (K.Hurley, private communication). 158539 05 Oct 06 13:52:40 This was originally classified as EXO 0748-676 in the real-time Notices, but we now classify this as a chance coincidence of noise in the rate and image domains with the location of EXO 0748-676. 213190 06 Jun 02 23:54:34 This was called "GRB060602B (or possibly an XRB)" in GCN Circ 5208, but we now believe this to be an x-ray burster source with a high confidence level.