This file contain Circulars on both the "A" and "B" bursts: //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3580 SUBJECT: GRB 050713A: ROTSE-III Optical Limits DATE: 05/07/13 05:16:29 GMT FROM: Sarah Yost at U.Michigan S.A. Yost, E.S. Rykoff, W. Rujopakarn (U Mich), K. Alatalo (Berkeley), B. Schaefer (Louisiana State) report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 050713A (Swift trigger 145675), producing images beginning 10.7 s after the GCN notice time. An automated response took the first image at 04:29:24.8 UT, 22.4 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and 10 60-sec eposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma error circle or at the XRT position, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 16.2-17.7; we set the following limit, noting it is adversely affected by the glare from the nearby bright star SAO 10034 (V=6.6), 67" from the XRT position. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 04:29:24.8 4:30:46.8 82 17.7 22.4 Y //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3581 SUBJECT: GRB 050713: Swift detection of Bright Burst DATE: 05/07/13 05:31:34 GMT FROM: Abe Falcone at PSU/Swift A. Falcone (PSU), D. Palmer (LANL), A. Blustin (MSSL), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), H. Krimm (GSFC/USRA), D. Burrows, D. Morris, C. Gronwall (PSU), C. Markwardt (GSFC/UMD), K. Page (Leicester), N. Gehrels (GSFC) At 04:29:02.39 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050713 (trigger=145675). The spacecraft slewed immediately and was on target at approximately 70 seconds. The flight-determined location is RA,Dec 320.536,+77.072 {+21h 22m 09s, +77d 04' 20"} (J2000) with an uncertainty of 3 arcmin (radius, stat+sys). This is a bright burst with a peak count rate of 6000 cts/sec in the 15-350 keV band. The brightest part of the burst duration is ~20 seconds, followed by smaller peaks at T+50, T+65 and T+105 seconds. The spacecraft slewed immediately and the XRT began observing the burst at 04:30:14.9 UT (72.6 s after the BAT trigger). XRT found a very bright, uncataloged, fading X-ray source at: RA: +21h 22m 09.6s (J2000), DEC: +77d 04' 30.3" (J2000). This position is 11 arcseconds from the BAT position. The estimated uncertainty is 6 arcseconds radius (90% containment). The Swift Ultra Violet/Optical Telescope (UVOT) observations began at 04:30:17.7 UT, 75 seconds after the BAT trigger. The first data taken after the spacecraft settled was a 100 sec exposure using the V filter with the midpoint of the observation at 125 sec after the BAT trigger. Based on comparisons to the DSS and USNO, we detect no new source at the XRT position. The 3-sigma upper limit in the V-filter is approximately 17.81 mag. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3582 SUBJECT: GRB050713: possible I-band afterglow DATE: 05/07/13 06:44:19 GMT FROM: Daniele Malesani at SISSA-ISAS,Trieste,Italy D. Malesani (SISSA), P. D'Avanzo (INAF-OAB), E. Palazzi (INAF/IASF, Bo), G.L. Israel (INAF, OARm), G. Chincarini (Univ. Milano-Bicocca), L. Stella (INAF, OARm), M. Pedani (INAF, TNG) report on behalf on a larger collaboration: We observed the field of GRB 050713 (Falcone et al., GCN 3581) with the Italian TNG telescope, located at the Canary Islands. The object was observed after twilight, with a seeing of ~1.4", starting at 5.274 UT (0.8 h after the GRB). A 2-minutes exposure was acquired in the I filter. Inside the XRT error circle, we detect one source at the coordinates (J2000): alpha = 21:22:09.6, delta = +77:04:29 with an uncertainty of ~1". We note two further objects lying just outside the nominal XRT error circle: 1: alpha = 21:22:11.8, delta = +77:04:27 2: alpha = 21:22:08.4, delta = +77:04:39 All these object are fainter than the DSS limit, so we cannot confirm if any of them is related to the GRB. Further analysis is in progress. A finding chart can be found here: http://www.sissa.it/~malesani/GRB/050713/GRB050713_finder.jpg This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3583 SUBJECT: GRB 050713: ARC NIR Detections and Identification of Fading DATE: 05/07/13 07:24:05 GMT FROM: Daniel E. Reichart at U.North Carolina F. Hearty (Colorado), G. Stringfellow (Colorado), D. Q. Lamb (Chicago), D. G. York (Chicago), G. Wallerstein (Washington), V. Woolf (Washington), S. Anderson (Washington), J. Dembicky (APO), J. Barentine (APO), R. McMillan (APO), B. Ketzeback (APO), and D. Reichart (North Carolina) report on behalf of the ARC GRB team of the FUN GRB collaboration: We began observations of the localization of GRB 050713 (Falcone et al., GCN 3525) with NIC-FPS on the 3.5m ARC at APO beginning 53 min after the burst. We detect all three of the candidates identified by Malesani et al. (GCN 3582) in J,H,Ks in 80-sec integrations, and identify their first candidate as fading. NIC-FPS is currently in its commissioning phase. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3584 SUBJECT: GRB 050713, R-band observations at NOT DATE: 05/07/13 08:02:26 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia S. Guziy, A. J. Castro-Tirado, A. de Ugarte Postigo, J. Gorosabel (IAA-CSIC Granada), J. de León Cruz (IAC Tenerife), O. Bogdanov (Nikolaev State Univ.) and M. Jelínek (IAA-CSIC), report: "Following the detection of GRB 050713 by Swift (Falcone et al. GCNC 3581), we obtained R-band images at the 2.5m Nordic Optical Telescope (+ ALFOSC) starting on June 13.295 UT (about 47 min after the burst onset). We confirm the presence of an optical source fainter than the DSS-2 limiting magnitude within the reported Swift/XRT error box, at RA(2000) = 21 22 09.53, Dec(2000) = +77 04 29.5 (+/- 0.4"), consistent with the position reported by Malesani et al. (GCNC 3582). Further observations are needed in order to confirm if this is the optical afterglow to GRB 050713. " This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3586 SUBJECT: GRB 050713 : Planned XMM-Newton observation DATE: 05/07/13 08:51:52 GMT FROM: Norbert Schartel at XMM-Newton/ESA XMM-Newton will observe GRB 050713 at location (RA=21h 22m 09.6s, DEC=+77d 04' 30.3", J2000), starting at 09:41:00 UT, on July 13, 2005, for an exposure of 33000 seconds. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3588 SUBJECT: GRB050713: Liverpool Telescope prompt observations DATE: 05/07/13 10:07:09 GMT FROM: Alessandro Monfardini at JMU/Liverpool Robotic Tele A. Monfardini, A. Gomboc, C. Guidorzi, C.G. Mundell, R.J. Smith, I. A. Steele, C.J. Mottram, D. Carter, M.F. Bode (Liverpool JMU) report: "The 2-m Liverpool Telescope followed up robotically the GRB050713 detected by SWIFT (GCN 3581). Three prompt images (2-4 minutes) have been acquired. No later time observations have been acquired. We clearly detect the first object suggested by Malesani (GCN 3582) at: RA = 21:22:09.6, DEC = +77:04:29 (1 arcsec error) At a mean epoch of 3 minutes after the reported GRB time we preliminarly estimate a magnitude of r'=19.2 with large errors due to comparison with USNOB1.0 and magnitude conversion. Further analysis is ongoing. The afterglow is detected on individual images. This message can be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3590 SUBJECT: GRB 050713B DATE: 05/07/13 13:09:51 GMT FROM: Simon Vaughan at Leicester U/BA S. Vaughan (Leicester), A. Falcone (PSU), D. Palmer (LANL), A. Blustin (MSSL), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), H. Krimm (GSFC/USRA), D. Burrows, D. Morris, C. Gronwall (PSU), C. Markwardt (GSFC/UMD), K. Page, M. Goad (Leicester), S Rosen (MSSL), N. Gehrels (GSFC) At 12:07:17.62 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050713B (trigger=145754). The spacecraft slewed immediately. The flight-determined location is RA,Dec 307.843,+60.920 {20h 31m 22s,+60d 55' 12"} (J2000) with an uncertainty of 3 arcmin (radius, 90% c.l. stat+sys). The burst lightcurve has 1 (maybe 2) peaks within ~30 sec duration. It is riding on top of two long bumps which are believed to be background, but without the full Malindi data, we can not determine if the bumps are background or burst-related. The peak rate (without bumps) is ~1000 cnts/sec in the 15-350 keV band. The spacecraft slewed immediately and the XRT began observing the burst at 12:09:33 UT (136 s after the BAT trigger). XRT found a bright, uncataloged, fading X-ray source at: RA: +20h 31m 15.5s (J2000), DEC: +60d 56' 38.4" (J2000). This position is 100 arcseconds from the BAT position. The estimated uncertainty is 6 arcseconds radius (90% containment). The Swift Ultra Violet/Optical Telescope (UVOT) observations began at 12:09:33 UT, 136 seconds after the BAT trigger. The first data taken after the spacecraft settled was a 100 sec exposure using the V filter with the midpoint of the observation at 186 sec after the BAT trigger. Based on comparisons to the DSS, we detect no new source at the XRT position. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3591 SUBJECT: RBO RI observations of GRB 050713A DATE: 05/07/13 14:15:41 GMT FROM: Ron Canterna at U of Wyoming C. Rodgers, E. Hausel, and R. Canterna report on behalf of the Red Buttes Observatory GRB Team as part of the FUN GRB Collaboration. We responded to GRB 050713A (Swift trigger 145675; 4:29 UT) at 04:54 UT with a series of 5 minute R and I exposures centered on the location of the original Swift-BAT GRB position under excellent conditions. We did not observe the afterglow candidate (Malesani GCN 3582) brighter than the following magnitude limits: UT Time Since Filter Limiting Start GRB Magnitude 04:56 0:27 R 19.4 05:01 0:31 I 18.2 06:02 1:33 R 19.4 06:08 1:38 I 18.7 10 sigma limiting magnitudes were derived from the USNO-B1.0 catalogue //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3592 SUBJECT: GRB050713B: Faulkes North Telescope observation DATE: 05/07/13 14:30:59 GMT FROM: Cristiano Guidorzi at ARI,Liverpool JMU C. Guidorzi, R.J. Smith, C.G. Mundell, A. Monfardini, A. Gomboc, I. A. Steele, C.J. Mottram, D. Carter, M.F. Bode (Liverpool JMU), P. O'Brien, N. Bannister, E. Rol (Leicester), on behalf of the RoboNet-1.0 collaboration report: "The 2-m Faulkes North Telescope followed up robotically the GRB050713B detected by SWIFT (Vaughan et al., GCN 3590) 3.3 min after the GRB trigger time. The automatic "detection mode" procedure didn't detect any obvious candidate to about R=18.2 from 3 10-s images (mean epoch of 3.8 min after the GRB), with FOV of 4.6'x4.6' centred on the BAT in-flight location. The above limit is also confirmed by visual inspection of the images. The limiting magnitude is automatically calculated with respect to the USNOB1.0 'R2' values of the field objects. Further observations are ongoing. This message can be cited" //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3593 SUBJECT: GRB 050713b : Lulin R-band observations DATE: 05/07/13 14:46:06 GMT FROM: Yuji Urata at RIKEN Z.Y. lin(NCU), K.Y. Huang, W.H. Ip (NCU), Y. Urata(RIKEN), Y. Qiu (BAO), Y.Q. Lou (THCA) on behalf of EAFON report: " We have performed R-band imaging for the entire error region of GRB 050713b (Vaughan et al. GCN 3590) from 24 min after the burst with Lulin 1-m telescope. No source was detected at position of the fading X-ray source during our observation with following limiting magnitude derived from the USNO-B1.0 catalogue. UT Exposure Filter Limiting Start Time Magnitude 12:31 300 s R 21.2 12:37 300 s R 21.6 12:43 300 s R 21.3 12:49 300 s R 21.6 12:54 300 s R 21.6 This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3594 SUBJECT: GRB 050713A XMM-Newton observation DATE: 05/07/13 15:02:03 GMT FROM: Norbert Schartel at XMM-Newton/ESA N. Loiseau, P. Munuera, R. Gonzalez-Riestra, M. Santos-Lleo, P. Calderon, and M. Sierra-Gonzalez report: Quick-Look-Analysis of the XMM-Newton observation of the GRB 050713A field based on the EPIC PN exposure started at 10:54:50 UT, shows the presence of a source with coodinates coincident with SWIFT/XRT coordinates (Falcone et al., GCN Circ. 3581). The average EPIC PN source count rate for the first 3ks was estimated to be 1.0 [counts/sec] GRB 050713A is also detected with the RGS spectrometer. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3595 SUBJECT: GRB 050713A : Lulin R-band observation DATE: 05/07/13 16:04:27 GMT FROM: Yuji Urata at RIKEN Z.Y. Lin, K.Y. Huang, W.H. Ip (NCU), Y. Urata(RIKEN), Y. Qiu (BAO), Y.Q. Lou (THCA) on behalf of EAFON report: "We have imaged the GRB 050713A afterglow position (Malesani et al.; Hearity et al.; Guziy et al.; and Monfardini et al.) at 10.3 hours after the burst using Lulin 1-m telescope. The afterglow was not detected in our R band co-add image (300s x 5 frames). Compare with USNOB1.0 stars, we estimate the afterglow would be fainter than 22.4 mag during our observations. This message may be cited." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3597 SUBJECT: GRB 050713A : Swift-BAT Refined Analysis DATE: 05/07/13 18:04:21 GMT FROM: David Palmer at LANL D. Palmer (LANL), S. Barthelmy, L. Barbier (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (NASA GSFC/UMD), J. Nousek (PSU), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama), M. Tripicco (GSFC/SSAI), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the full data set from the recent telemetry downlink, further analysis of Swift-BAT GRB 050713A (Trigger #145675; Falcone et al., GCN Circ 3581) yields a refined position of RA, Dec 320.587, +77.070 {21h 22m 21s, +77d 04' 12"} (J2000) with an uncertainty of 3 arcmin (radius, 90% confidence, statistical+systematic). The burst duration (T90) was determined to be 70 +/- 10 seconds (15-350 keV) starting at T-1.0 seconds. There is an initial ~12 second long basically square hump which shows some structure: three separate peaks of roughly equal intensity in the 15-50 keV energy band, but falling in intensity with time above 100 keV. There are additional, much smaller peaks at T-60, T+50 T+65, and T+105 seconds. The spectrum over the interval from T-70 to T+121 seconds can be fit with a power law with photon index 1.58 +/- 0.07 and yields a fluence of 9.1 +/- 0.6 X 10^-6 erg/cm^2 in the 15-350 keV band. The peak flux in a 1-sec wide window starting at T+1.2 seconds is 6.0 +/- 0.4 ph/cm^2/sec. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3598 SUBJECT: GRB 050713A: Swift/UVOT observation DATE: 05/07/13 18:19:27 GMT FROM: Alexander Blustin at MSSL-UCL A. Blustin (MSSL), A. Falcone (PSU), D. Hinshaw (GSFC-SPSYS), P. Meszaros (PSU) report on behalf of the Swift UVOT team: Using summed images from Swift/UVOT of the field of GRB 050713A, taken from 75 seconds after the BAT trigger, no new source is detected within the XRT error circle (Falcone et al., GCN 3581) in any of the six filters down to the following 3-sigma magnitude upper limits: Filter Exposure (s) T_mid (s) 3-sig limit V 129 252 17.98 B 36 351 18.08 U 39 309 17.81 UVW1 39 325 16.85 UVM2 39 311 17.13 UVW2 29 326 17.08 where T_mid is the mid-point of the summed observation. The image background is significantly higher than expected at this location due to the proximity of a 6.56 V magnitude star (HD 204408). We caution that the instrument is not yet fully calibrated and that the magnitude limits presented here may need to be refined. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3600 SUBJECT: GRB 050713B: Swift-BAT Refined Analysis DATE: 05/07/13 21:02:37 GMT FROM: Ann M. Parsons at NASA/GSFC/Swift A. Parsons (GSFC), S. Barthelmy, L. Barbier (GSFC), J. Cummings (GSFC/NRC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (NASA GSFC/UMD), F. Marshall (GSFC), D. Palmer (LANL), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), A. Smale (NASA HQ), M. Suzuki (Saitama), J. Tueller (GSFC) on behalf of the Swift-BAT team: Using the full data set from the recent telemetry downlink, further analysis of Swift-BAT GRB 050713B (Trigger #145754; Vaughn et al., GCN Circ 3590) yields a refined position of RA, Dec 307.820, +60.938 {20h 31m 17s, +60d 56' 17"} (J2000) with an uncertainty of 3 arcmin (radius, 90% confidence, statistical+systematic). The light curve shows a FRED-like profile of total duration ~75 seconds. The spectrum over the interval from T-2 to T+178 seconds can be fit with a power law with photon index 1.56 +/- 0.13 and yields a fluence of 8.2 +/- 1.0 X 10^-6 erg/cm^2 in the 15-350 keV band. The peak flux in a 1-sec wide window starting at T+4.4 seconds is 2.2 +/- 0.6 ph/cm^2/sec. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3602 SUBJECT: GRB050713b: XRT refined analysis DATE: 05/07/13 21:37:29 GMT FROM: David Burrows at PSU/Swift K. Page, S. Vaughan, M. Goad (Leicester), D. N. Burrows (PSU), M. Ajello (MPE), R. Fink and N. Gehrels (GSFC) report on behalf of the Swift XRT team: We have analysed the first two orbits of data for GRB050713b (GCN 3590, Vaughan et al., 2005). Using xrtcentoid, the refined position is: RA(J2000) = 20h 31m 15.5s Dec(J2000) = +60d 56' 40.4" with an uncertainty of 6 arcsec. This is only 2 arcsec from the original XRT position (GCN 3590, Vaughan et al., 2005). The light-curve shows a steeply fading afterglow during the first orbit, with a decay slope of alpha = 2.88 +/- 0.12 between 143 and 600 seconds after the trigger. After ~5000 seconds (i.e. on the second orbit), the light-curve flattens significantly; more data are required to constrain the slope following the break in the light curve. The WT spectrum can be fitted by an absorbed power-law with a spectral index, Gamma = 1.70 +0.11/-0.09 and excess NH of (1.97 +0.50/-0.43)e21 cm^-2. The unabsorbed 0.3-10 keV flux (averaged over 143 and 330 seconds after the burst) is (9.02 +0.16/0.80)e-10 erg cm^-2 s^-1. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3603 SUBJECT: GRB050713B :Swift/UVOT observations DATE: 05/07/13 22:17:04 GMT FROM: Simon Rosen at MSSL-UCL S. Rosen (MSSL), S. Vaughan (Leicester), R. Fink (GSFC-SPSYS), M. Chester (PSU) report on behalf of the Swift UVOT team: Using summed images from Swift/UVOT of the field of GRB 050713B, taken from 136 seconds after the BAT trigger, no new source is detected within the XRT error circle (Vaughan et al., GCN 3590) in any of the six filters down to the following 3-sigma magnitude upper limits: Filter Exposure (s) T_mid (s) 3-sig limit V 252 598 19.26 B 88 624 19.58 U 88 610 19.31 UVW1 88 596 19.46 UVM2 88 582 19.83 UVW2 88 639 19.87 where T_mid is the mid-point of the summed observation. We caution that the instrument is not yet fully calibrated and that the magnitude limits presented here may need to be refined. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3604 SUBJECT: GRB 050713A: RAPTOR detection of early optical emission DATE: 05/07/13 23:15:38 GMT FROM: James Wren at LANL J. Wren, W.T. Vestrand, P. Wozniak, R. White, S. Evans report on behalf of the RAPTOR team. The RAPTOR-S telescope at Los Alamos National Laboratory began imaging the field of GRB 050713A (Swift trigger 145675) 22.4 seconds after the GRB trigger -- before the end of the interval of prompt gamma-ray emission (Falcone et al. GCN circ 3581). At the location of the fading optical and NIR counterpart identified in later images by Malesani et al. (GCN circ 3582) and Hearty et al. (GCN circ 3583), respectively, we detected a transient optical counterpart. In a stack of eight 10 second unfiltered images starting at 04:29:24.8 UT (with midpoint at 99.3 s after the GRB trigger), we measured the optical transient to have a R-band magnitude of 18.4 (+/- 0.18). Our preliminary transformation to R-band magnitudes was based on field stars from the USNO-B1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3606 SUBJECT: GRB 050713A: XRT refined analysis DATE: 05/07/14 00:16:56 GMT FROM: David Morris at PSU/Swift-XRT D. Morris, D. N. Burrows, A. Falcone, P. Roming (PSU), K. Page, M. Goad (Leicester), M. Trippico (GSFC-SSAI), F. Marshall and N. Gehrels (GSFC) report on behalf of the Swift XRT team: We have analysed the first three orbits of data for GRB050713a (GCN 3581, Falcone et al., 2005). Using xrtcentoid, the refined position is: RA(J2000) = 21h 22m 09.9s Dec(J2000) = +77d 04' 24.2" RA(J2000) = 320.5411 Dec(J2000) = +77.0734 with an uncertainty of 6 arcsec. This is 6 arcsec from the original XRT position (GCN 3581, Falcone et al., 2005). The XRT began taking data at 04:30:14UT, just 72 seconds after the BAT trigger and while the prompt gamma-ray emission was still in progress. The early XRT lightcurve shows flares coincident with the BAT reported peaks (GCN 3597, Palmer et al., 2005) at T+65 (caught on the tail end of the peak) and at T+105. A decay rate has not been determined for the first orbit due to the flaring nature of the emission at that point, with count rates varying between 10-300 cts/s. Data from the 2nd and 3rd orbits span the timeframe 5ks-10ks after the trigger and show a smoothly decaying afterglow at much lower flux, fit well by a powerlaw with alpha = 0.82+/- 0.11. The spectrum from all 3 orbits are well fit by an absorbed power-law with NH significantly greater than the galactic value of 1.1e21 gamma=2.1+/-0.05 NH=4.5e21 ± 0.5e21 The count rate at 5000s after the trigger is ~0.35 cts/s which converts to an unabsorbed flux of 2.24e-11 ergs cm^-2 s^-1. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3617 SUBJECT: GRB 050713b: RTT150 optical observations DATE: 05/07/15 08:19:09 GMT FROM: Irek Khamitov at TUG I. Bikmaev, A. Galeev, N. Sakhibullin (KSU/AST), I. Khamitov, Z. Aslan (TUG), U. Kiziloglu (METU), A. Alpar (SabUni), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), report: We have observed the field of GRB050713b (Vaughan et al. GCN 3590) on July 14, 2005, in Rc-band with ANDOR CCD attached to the 1.5-m Russian-Turkish telescope (RTT150, Antalya, Turkey). The set of 30 sec exposures has been made with total exposure time of 15 min and midpoint at UT = 22h 26min (~ 22 hours after the burst). No new optical source was detected at the position of the X-ray source in the co-added frame with limiting magnitude of Rc = 22.4 mag. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3619 SUBJECT: Konus-Wind observation of GRB 050713A DATE: 05/07/15 16:34:07 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report: The long GRB 050713A (Swift-BAT trigger #145675; Falcone et al., GCN 3581, Palmer et al., GCN 3597) triggered Konus-Wind at T0=16141.745 s UT (04:29:01.745). As observed by Konus-Wind it had a duration of ~16 s, fluence (1.22 ± 0.08)10-5 erg/cm2, peak flux on 64-ms time scale (1.7 ± 0.4)10-6 erg/cm2 s (both in the 20 keV - 4 MeV energy range). Konus-Wind did not detect additional smaller peaks, reported by Swift-BAT. Probably they were too weak to be detected by Konus-Wind. The spectrum integrated over the most instense part of the GRB (from T0 to T0+8.448 s) is well fitted (in 20 keV-4 MeV range) by a power law with exponential cutoff model: dN/dE ~ E^(-alpha) exp(-E/E0) with alpha = 1.12 +/- 0.08, and E0 = 355 ± 70 keV. The peak energy Ep = 312 ± 50 keV. -- Valentin Pal'shin Ioffe Physico-Technical Institute Laboratory for Experimental Astrophysics 26 Polytekhnicheskaya, St Petersburg 194021, Russian Federation email: val@mail.ioffe.ru Tel: (7)-812-2479177 Fax: (7)-812-2471963 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3648 SUBJECT: GRB050713a: Radio Observation DATE: 05/07/19 19:26:53 GMT FROM: Patrick B. Cameron at Caltech P. B. Cameron reports on behalf of the Caltech-NRAO-Carnegie collaboration: "We observed the field of GRB050713a (GCN 3581) with the Very Large Array at 8.5 GHz on July 17.51. No radio source is detected at the position of the optical/NIR transient (GCN 3582, 3583) with a 2-sigma upper limit of 96 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3695 SUBJECT: GRB050713: analysis of the XMM-Newton observation DATE: 05/07/28 19:27:12 GMT FROM: Andrea De Luca at IASF-CNR,Milano Andrea De Luca (IASF Mi) on behalf of a larger collaboraton report: We have analyzed the data from the XMM-Newton observation of GRB050713A, discovered by Swift on 2005, July 13 at 04:29:02.39 UT (Falcone et al., GCN3581). The XMM-Newton observation started on 2005, July 13 at 10:18 UT and lasted for 30.7 ks. We report here on the analysis of data collected with the EPIC/pn detector, which started observing the field at 10:54 UT (~6h 20min after the GRB). As reported by Loiseau et al. (GCN3594), the afterglow of GRB050713A is clearly detected in the pn image, at a position fully consistent with the refined Swift/XRT one (Morris et al., GCN3606). Extracting source events from a circle of 25 arcsec radius (containing ~80% of the total counts), the time-averaged, background-subtracted count rate in the 0.2-8 keV range is 0.547+/-0.005 cts/s. The afterglow is clearly seen to fade along the XMM-Newton observation, spanning the time range 23.5-51.5 ks after the GRB. The background-subtracted light curve (0.5-5 keV) is well fitted (reduced chi2=0.9, 26 d.o.f.) by a power law decay with index delta=1.45+/-0.07 (90% c.l.). The afterglow decay has significantly steepened with respect to the epoch of the earlier Swift observation: Morris et al. (GCN 3606) observed an index delta=0.82+/-0.11 in the time range 5-10 ks after the burst using Swift/XRT data. This implies the presence of a break in the afterglow X-ray light curve between 10 ks and 23.5 ks from the GRB. We extracted the time-averaged spectrum and generated ad-hoc response and effective area files. We quote here errors at 90% level for a single interesting parameter, unless otherwise specified. A fit in the energy range 0.2-8 keV with an absorbed power law model yields a reduced chi2 of 1.25 for 172 d.o.f. The resulting NH=(3.25+/-0.15)x10^21 cm^-2 is higher than the expected Galactic value in the burst direction (NH=1.1x10^21 cm^-2, Dickey & Lockman, 1990); the best fitting power law photon index is Gamma=2.16+/-0.05. Such results are consistent with the XRT ones (Morris et al., GCN 3606), which implies no significant spectral evolution with respect to the earlier phase of the afterglow. A better fit to the pn spectrum (reduced chi2=0.97, 171 dof) may be obtained fixing the NH to the expected Galactic value (NH=1.1x10^21 cm^-2) and adding a neutral, redshifted absorber component to the spectral model. With a simple F-test we evaluate the chance occurrence probability of the improvement to be of 5x10^-11. The best fit value for the intrinsic NH is 4.0x10^21 cm^-2, while the best fit value for the redshift z is 0.55. At 90% c.l. for 2 parameters, we obtain the following ranges: intrinsic NH=(0.4-3.2)x10^22 cm^-2; redshift z=(0.4-2.6). Using such model, the resulting power law photon index is Gamma=2.04+/-0.05. The observed flux is of 2.2x10^-12 erg cm^-2 s^-1 in 0.2-10 keV; the corresponding unabsorbed flux is of 3.8x10^-12 erg cm^-2 s^-1. As a last step, we divided the pn dataset into two time intervals of ~9500 s and ~14600 s (each containing about half of the counts from the afterglow) and we repeated the spectral analysis. We found no significant spectral changes in the two considered intervals. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3701 SUBJECT: GRB050713b: Maidanak optical observations DATE: 05/07/29 21:05:39 GMT FROM: Alexei Pozanenko at IKI, Moscow D. Sharapov, M. Ibrahimov (MAO), V.Rumyantsev (CrAO), A.Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the error box of GRB050713b (Trigger #145754; Vaughn et al., GCN 3590, Parsons et al., GCN 3600) with 1.5m telescope (Maidanak Astronomical Observatory) on July 13, 14, and 15. Limiting magnitude of stacked image of observation obtained on July 13 (start time July 13 UT 18:06, i.e. ~6.0 h after burst) is R=23.2. We detected optical sources S1 which is offset ~1.9 arcsec of the refined XRT error circle (Page et al., GCN3602) and have the following coordinates (uncertainty in each coordinate is about 1 arcsec): S1 RA(J2000)= 20 31 15.96 Dec(J2000) = +60 56 36.4 Photometry of the source based on USNO A2.0 catalog is following: Mean time Exposure S1 (UT) sec. mag. July 13, 18:56 15x300 24.13 +/-0.74 July 14, 19:44 8x300 22.90 +/-0.44 July 15, 19:31 9x300 22.93 +/-0.30 Since the S1 source does not demonstrate fading behavior, it is unlikely that S1 is an OT of GRB050713b. Stacked image of July 13 observations can be found in http://grb.rssi.ru/GRB050713b. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3703 SUBJECT: GRB 050713A: Swift XRT extended light curve DATE: 05/07/30 20:35:49 GMT FROM: David Burrows at PSU/Swift D. Morris, D. N. Burrows, A. Falcone, P. Roming (PSU), K. Page, M. Goad (Leicester), M. Trippico (GSFC-SSAI), F. Marshall and N. Gehrels (GSFC) report on behalf of the Swift XRT team: The Swift XRT has continued to monitor the light curve of GRB050713a with data taken as late as 10 days after the burst trigger. We confirm the XMM observation of a decaying lightcurve with powerlaw slope consistent with alpha=1.45 during the epoch 20ks-50ks after the burst trigger (De Luca et al, GCN3695). We note, however, that the entire XRT dataset, from 4ks to 1000ks after the burst trigger, shows a powerlaw shape very well fit by an alpha=1.15 decay index, with no evidence for a jet break. We suggest that the steeper slope seen between 20ks-50ks may be due to flaring activity. The XRT count rate during the last observation, on July 23rd, was 6e-4 cts/s, equivalent to a flux of 4e-14 ergs/cm^2/s