//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15516 SUBJECT: GRB 131127A: Swift detection of a burst DATE: 13/11/27 10:33:41 GMT FROM: Scott Barthelmy at NASA/GSFC C. B. Markwardt (NASA/GSFC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), V. D'Elia (ASDC), D. Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and P. Romano (INAF-IASFPA) report on behalf of the Swift Team: At 10:11:35 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 131127A (trigger=579571). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 332.751, +36.590 which is RA(J2000) = 22h 11m 00s Dec(J2000) = +36d 35' 24" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows several overlapping peaks with a duration of about 50 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at 0 sec after the trigger. The XRT began observing the field at 10:13:09.3 UT, 93.8 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 332.7293, 36.6098 which is equivalent to: RA(J2000) = 22h 10m 55.03s Dec(J2000) = +36d 36' 35.2" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 94 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.15 x 10^21 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 1.33e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 102 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. Data from the list of sources generated on-board are not available at this time. No correction has been made for the expected extinction corresponding to E(B-V) of 0.14. Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15517 SUBJECT: GRB 131127A: MASTER-NET optical observations DATE: 13/11/27 10:38:24 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, A.Sankovich Sternberg Astronomical Institute, Moscow State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to the GRB131127A 503 sec after GRB time and 40 sec after notice time at 2013-11-27 10:19:58 UT in two polarizations. On our first (100s exposure) set we haven`t found optical transient within SWIFT error-box (ra=22 11 00 dec=+36 35 24 r=0.050000). The 5-sigma upper limit has been about 17.5 mag The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15518 SUBJECT: GRB 131127A: Nanshan optical upper limit DATE: 13/11/27 12:33:21 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), J.-Z. Liu, G.-J. Feng, H.-B. Niu, C.-H. Bai, A. Esamdin, L. Ma (XAO) report: We observed the field of GRB 131127A (Markwardt et al., GCN 15516) using 1m telescope located on Mt. Nanshan, Xinjiang, China. Observations started at 11:45:12 UT on 2013-11-27 (i.e., 1.56 hr after the BAT trigger) and a series of R-band frames were obtained. Within the SPER XRT error circle (http://www.swift.ac.uk/sper/) of this burst, no crediable optical source is detected down to a limiting magnitude of R=20.5 mag, calibrated with nearby USNO B1 field. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15519 SUBJECT: GRB 131127A: Mondy optical upper limit DATE: 13/11/27 13:18:01 GMT FROM: Alina Volnova at SAI MSU E. Klunko (ISTP), A.Volnova (IKI), M. Eselevich (ISTP), A. Pozanenko(IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 131127A (Markwardt et al., GCN 15516) with AZT-33IK telescope of Sayan observatory (Mondy) starting Nov., 27 (UT) 10:40:06. We obtained several images in R-filter with exposure of 30 and 60 seconds. Within the XRT circle (Markwardt et al., GCN 15516) we did not detect any optical object. The details of the photometry are the following: UT start, t-T0 Filter Exp. OT UL (mid, days) (s) (3 sigma) 10:40:06 0.02839 R 7*30+21*60 n/d 21.3 The photometry is based on 3 USNO-B1.0 stars: USNO-B id RA Dec R2 1265-0518495 22:11:06.80 +36:35:45.6 16.06 1265-0518432 22:10:59.37 +36:35:56.7 16.45 1266-0522367 22:10:48.55 +36:36:43.7 15.45 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15520 SUBJECT: GRB 131127A: Enhanced Swift-XRT position DATE: 13/11/27 20:23:42 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 3638 s of XRT Photon Counting mode data and 7 UVOT images for GRB 131127A, 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 = 332.73008, +36.60929 which is equivalent to: RA (J2000): 22h 10m 55.22s Dec (J2000): +36d 36' 33.5" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15521 SUBJECT: GRB 131127A, Swift-BAT refined analysis DATE: 13/11/27 20:49:44 GMT FROM: Craig Markwardt at NASA/GSFC C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+960 sec from the recent telemetry downlink, we report further analysis of BAT GRB 131127A (trigger #579571) (Markwardt, et al., GCN Circ. 15516). The BAT ground-calculated position is RA, Dec = 332.714, 36.596 deg which is RA(J2000) = 22h 10m 51.3s Dec(J2000) = +36d 35' 46.9" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted light curve has multiple peaks. The first set of about 3 peaks occurs before the initial trigger between T-60 and T-38 sec. The main set of about 7-8 peaks occurs between T-5 and T+40 sec. The peak emission occurs at about T+0 sec. T90 (15-350 keV) is 92.1 +- 10.2 sec (estimated error including systematics). The time-averaged spectrum from T-59.4 to T+37.5 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.34 +- 0.16. The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.54 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/579571/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15522 SUBJECT: GRB 131127A. 1.5m OSN optical limit DATE: 13/11/27 22:24:50 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia A. Sota, J. Gorosabel and A. J. Castro-Tirado (IAA-CSIC Granada) on behalf of a larger collaboration, report: "Following the detection of GRB 131127A by Swift (Markwardt et al. GCNC 15516), we have conducted I-band observations with the 1.5m OSN telescope at Observatorio de Sierra Nevada (Granada, Spain), starting on 27 Nov 18:26 UT,(i.e. 8.2-hr post burst). A stack of 17 x 300s images shows nothing at the enhanced Swift/XRT position (Evans et al. GCNC 15520) down to I = 21". //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15523 SUBJECT: GRB 131127A: Swift-XRT refined Analysis DATE: 13/11/27 22:33:03 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU) and C.B. Markwardt report on behalf of the Swift-XRT team: We have analysed 6.5 ks of XRT data for GRB 131127A (Markwardt et al. GCN Circ. 15516), from 84 s to 24.3 ks after the BAT trigger. The data comprise 62 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 15520). The late-time light curve (from T0+4.5 ks) can be modelled with a power-law decay with a decay index of alpha=1.55 (+0.26, -0.22). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.8 (+0.4, -0.3). The best-fitting absorption column is 3.9 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of 1.2 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.22 (+/-0.15) and a best-fitting absorption column of 2.5 (+0.5, -0.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (6.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.5 (+0.5, -0.4) x 10^21 cm^-2 Galactic foreground: 1.2 x 10^21 cm^-2 Excess significance: 5.1 sigma Photon index: 2.22 (+/-0.15) If the light curve continues to decay with a power-law decay index of 1.55, the count rate at T+24 hours will be 2.3 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.0 x 10^-14 (1.4 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00579571. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15525 SUBJECT: GRB 131127A: RATIR Optical and NIR Observations, High-z Candidate DATE: 13/11/28 08:41:53 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 131127A (Markwardt, et al., GCN 15516) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/11 28.11 to 2013/11 28.26 UTC (16.42 to 19.94 hours after the BAT trigger), obtaining a total of 2.49 hours exposure in the r and i bands and 1.04 hours exposure in the Z, Y, J, and H bands. We do not detect any sources within the Enhanced Swift-XRT error circle (Evans et al., GCN 15520), in comparison with 2MASS, we obtain the following upper limits (3-sigma): r > 24.19 i > 23.53 Z > 22.78 Y > 22.16 J > 22.04 H > 21.48 However, we do detect a red source just outside (3.3" away from the center) of the XRT position, at a position RA, DEC = 332.731227 , 36.609171 (J2000, +/- 0.5"). We measure: r = 24.21 +/- 0.35 i = 22.48 +/- 0.11 Z = 21.85 +/- 0.16 Y = 21.22 +/- 0.15 J = 21.03 +/- 0.14 H = 20.88 +/- 0.20 The faint flux in r band relative to the redder bands could be due to IGM attenuation at high redshift, z ~ 5. We cannot confirm fading of this source. Further observations of this source are encouraged. The magnitudes above are in the AB system and are not corrected for Galactic extinction, E[B-V]~0.1, in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15526 SUBJECT: GRB 131127A: AROMA-N Optical Observation DATE: 13/11/28 11:36:56 GMT FROM: Takanori Sakamoto at AGU D. Kawamura, T. Sakamoto, I. Takahashi, S. Sugai, A. Yoshida (AGU) We observed the field of GRB 131127A detected by Swift (trigger #579571; Markwardt et al., GCN Circ. 15516) with the 12-inch AGU Robotic Optical Monitor for Astrophysical object - Narrow (AROMA-N) located at the Sagamihara campus of Aoyama Gakuin University. 60 images of 60 sec exposures were taken in the R filter starting from November 27 10:42:18 (UT) about 30 minutes after the trigger and stopped on November 27 11:48:15 (UT). We do not detect the optical afterglow both in the individual images and the stacked image, which combined 57 good quality images, inside the enhanced XRT position (Evans, et al., GCN #15520). The estimated five sigma upper limit of the combined image (total exposure of 3420 sec) is ~16.6 mag using the USNO-B1 catalog. [GCN OPS NOTE(29nov13): Per author's request, the "November 11" date was changed to "November 27" in two places.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15527 SUBJECT: GRB 131127A: Swift/UVOT Upper Limits DATE: 13/11/28 11:56:24 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and C. B. Markwardt (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 131127A 102 s after the BAT trigger (Markwardt et al., GCN Circ. 15516). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 15520) nor the RATIR position (Butler et al. GCN Circ. 15525) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 102 252 147 >21.4 u_FC 315 565 246 >20.6 white 102 6711 746 >22.3 v 645 7024 373 >20.3 b 571 6506 452 >21.2 u 315 6300 678 >21.1 w1 694 6095 432 >20.6 m2 669 5890 269 >20.1 w2 621 6916 471 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.14 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15528 SUBJECT: GRB 131127B: Fermi GBM detection DATE: 13/11/28 12:53:49 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 14:12:18.36 UT on 27 November 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131127B (trigger 407254341 / 131127592). The on-ground calculated location, using the GBM trigger data, is RA = 306.1, DEC = -0.8 (J2000 degrees, equivalent to 20h 24m, -00d 48'), with an uncertainty of 1.0 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 88 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. Three candidates for an optical afterglow were found by iPTF (Singer et al, GCN 15524) using the GBM on-ground location. The GBM light curve is multi-peaked with a duration (T90) of about 18 s (50-300 keV). The time-averaged spectrum from T0-0.003 s to T0+20.480 s is best fit by a Band function with Epeak = 181.7 (+7.9/-7.2) keV, alpha = -1.05 +/- 0.02 , and beta = -2.24 (+0.05/-0.06) The event fluence (10-1000 keV) in this time interval is (3.85 +/- 0.03)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+5.824 s in the 10-1000 keV band is 37.6 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15529 SUBJECT: IPN Triangulation of GRB 131127B DATE: 13/11/28 13:02:01 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi GBM team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and K. Hurley on behalf of the IPN team, report: The long-duration, intense GRB 131127B (von Kienlin, GCN 15528) has been observed by Fermi (GBM: trigger 407254341), INTEGRAL (SPI-ACS), and Konus-Wind, so far, at about 51138 s UT (14:12:18). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 304.839 (20h 19m 21s) -2.830 ( -2d 49' 46") Corners: 304.599 (20h 18m 24s) -0.050 ( +0d 03' 01") 305.856 (20h 23m 26s) -5.612 ( -5d 36' 45") 305.066 (20h 20m 16s) -5.608 ( -5d 36' 28") 303.808 (20h 15m 14s) -0.033 ( +0d 02' 00") --------------------------------------------- The error box area is 4.38 sq. deg, and its maximum dimension is 5.9 deg (the minimum one is 0.77 deg). The Sun distance was 62 deg. This box can be improved. All optical afterglow candidates reported by iPTF (Singer, GCN 15524) are far outside of the box. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB131127_T51139/IPN/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15530 SUBJECT: Konus-Wind observation of GRB 131127B DATE: 13/11/28 13:06:06 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The bright, long-duration GRB 131127B (Fermi GBM detection: von Kienlin, GCN 15528; IPN triangulation: Golenetskii at al., GCN 15529) triggered Konus-Wind at T0=51139.678 s UT (14:12:19.678). The burst light curve shows multiple overlapped pulses from ~T0-0.5 s to ~T0+20 s. The emission is seen up to ~12 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB131127_T51139/ As observed by Konus-Wind, the burst had a fluence of (4.1 ± 0.3)x10-5 erg/cm2, and a 64-ms peak flux, measured from T0+4.160 s, of (1.15 ± 0.08)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+21.760 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.20 ± 0.11, the high energy photon index beta = -2.51 ± 0.19, the peak energy Ep = 165 ± 17 keV, chi2 = 140/97 dof. The spectrum near the maximum count rate (measured from T0 to T0+5.376 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.92 ± 0.14, the high energy photon index beta = -2.43 ± 0.19, the peak energy Ep = 218 ± 27 keV, chi2 = 128/97 dof. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15531 SUBJECT: GRB 131127B: Nanshan optical observations DATE: 13/11/28 13:25:05 GMT FROM: Dong Xu at DARK/NBI D. Xu (DARK/NBI), H.-B. Niu, J.-Z. Liu, G.-J. Feng, C.-H. Bai, A. Esamdin, L. Ma (XAO) report: We observed the fields of the three afterglow candidates of GRB 131127B (von Kienlin, GCN 15528; Singer & Kasliwal, GCN 15524; Golenetskii et al., GCN 15530), using the 1m telescope located on Mt. Nanshan, Xinjiang, China. Observations started at 11:37:34 UT on 2013-11-28, (i.e., 21.42 hr after the Fermi trigger) and a series of R-band frames were obtained. The three optical afterglow candidates are clearly detected in their stacked images. For the one dubbed iPTF13ecv, we measure its magnitude m(R)=18.66+/-0.14, calibrated with two nearby SDSS stars and using the Lupton (2005) transformation. This magnitude is basically consistent with the value reported in Singer & Kasliwal (GCN 15524), indicating that its significant fading is ruled out. For the other two dubbed iPTF13ect and iPTF13ecu, given that they are very close to the cores of the galaxies and not well resolved in our images, we are not able to put good constraints on their magnitudes at the moment. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15532 SUBJECT: GRB 131127A: Bassano Bresciano Observatory optical upper limit DATE: 13/11/28 15:00:35 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla and R.Girelli report: We imaged the field of GRB 131127A detected by SWIFT(trigger 00579571) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy (www.osservatoriobassano.org). The observations started 9h 2m. after the GRB trigger,with our schmidt telescope D=320/400 mm F/D=3.1. Weather conditions were good. We co-added a series of 5 exposures of 120 sec each. We did not found any optical counterpart in the error box of the XRTcandidate (Markwardt et al., GCN 15516). Start End R.lim 542min 554min 18.5 Magnitudes were estimated with the USNO-B1 cat. and are not corrected for galactic dust extinction. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15534 SUBJECT: GRB 131127B: MASTER-Net optical observations DATE: 13/11/28 15:22:44 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, Sternberg Astronomical Institute, Moscow State University V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Yekaterinburg, Kourovka Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka was pointed to the GRB131127.59 73 sec after GRB time at 2013-11-27 14:13:31.093 UT. Fortunately, the central part (42%) of the IPN error box (Golenetskii et al., GCN 15529) was covered by first MASTER image (10s exposure). Unfortunatelly, observations was done at the very high zenit distance (~85 degrees). We haven`t found optical transient. The 5-sigma upper limit has been about 14.1 mag We have 4 images (the one of the tube was under horizont): Id (image) Coord Pro.type time Exp.time Limit 587443 20h 19m 27.4s -02d 51m 25s Alert 14:13:31 10 14.1 587444 20h 19m 27.3s -02d 51m 31s Alert 14:14:29 30 15.0 587446 20h 19m 27.0s -02d 51m 41s Alert 14:15:52 40 14.8 587448 20h 19m 27.1s -02d 51m 42s Alert 14:17:38 60 15.0 The fist image (FOW = 2x2 degrees) with IPN error box is available at http://master.sai.msu.ru/static/GRB/grb131127_IPN.jpeg . The reduction is continued. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15543 SUBJECT: GRB 131127B: Bassano Bresciano Observatory optical observations DATE: 13/11/29 09:49:11 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla and R.Girelli report: We imaged the fields of GRB 131127B (von Kienlin, GCN 15528; Singer & Kasliwal, GCN 15524; Golenetskii et al., GCN 15530) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy (www.osservatoriobassano.org). The observations started 27h 55m. after the Fermi-GBM trigger (Fermi407254341) , with our schmidt telescope D=320/400 mm F/D=3.1. Weather conditions were good. We co-added 3 series of 5 unfiltered exposures of 120 sec each. We detected the candidate couterpart of iPTFecv (Singer et al, GCN 15524) at the following position (+/- 1 arcsec): RA (J2000.0) = 20h 31m 47.79s DEC(J2000.0) = +00d 59m 22.8s The results of our photometry are: Date UT Exp R-mag Middle (s) (rough) 2013 11 28.75862 600 18.84 +/- 0.2 2013 11 28.76579 600 18.85 +/- 0.2 2013 11 28.77297 600 19.08 +/- 0.3 Magnitudes were estimated with the USNO-B1 cat. and are not corrected for galactic dust extinction. The images are available at: http://www.osservatoriobassano.org/GRB.asp The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15548 SUBJECT: GRB 131127A: CQUEAN riz Observation DATE: 13/11/29 14:43:29 GMT FROM: Myungshin Im at Seoul Nat U Myungshin Im, Changsu Choi (CEOU/SNU), Hyein Lee, Huynh Ahn N. Le, and Soojong Pak (Kyunghee Univ.) We observed the field of GRB 131127A (Markwardt et al. GCN 15516), using CQEUAN (Park et al. 2012) on the 2.1-m Otto-Struve telescope at the McDonald Observatory in Texas, US. The observation started at 2013-11-29 01:31:43 UT, or about 1.63 days after the BAT alert. A series of images were taken in r, i, and z-band for about 45 min. We identify the red source reported in Butler et al. (GCN 15525), but no significant fading of the source was found with z = 21.90 +- 0.15 AB mag, consistent with Z = 21.85 +- 0.16 mag from Butler et al. (GCN 15525). This suggests that the red source may not be the GRB afterglow, or the light curve is changing very slowly. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15555 SUBJECT: GRB 131127A: RATIR Rejection of High-z Candidate DATE: 13/11/29 20:57:31 GMT FROM: Nat Butler at UC berkeley Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), José A. de Diego (UNAM), Leonid Georgiev (UNAM), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We again observed the field of GRB 131127A (Markwardt, et al., GCN 15516) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2013/11 29.09 to 2013/11 29.17 UTC (40.06 to 41.98 hours after the BAT trigger), obtaining a total of 1.42 hours exposure in the r and i bands and 0.60 hours exposure in the Z, Y, J, and H bands. For the red source 3.3" away from the center of the XRT positions (Butler et al., GCN 15525), in comparison with 2MASS, we obtain: r > 23.78 i = 22.68 +/- 0.16 (0.20 +/- 0.19) Z = 22.02 +/- 0.26 (0.17 +/- 0.31) Y = 21.31 +/- 0.24 (0.09 +/- 0.28) J = 21.26 +/- 0.29 (0.23 +/- 0.32) H = 20.55 +/- 0.24 (-0.33 +/- 0.31) The change in magnitude relative to the observations on the previous night are given in the parentheses. There is slight (~<1-sigma) evidence for a fade in most bands, but the shallowness ~t^(-0.2) of the fade is not expected for a GRB afterglow. We conclude, as did Im et al. (GCN 15548), that this source is not the afterglow of GRB 131127A. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15558 SUBJECT: GRB 131127B: Bassano Bresciano Observatory optical observations of iPTF13ecv DATE: 13/12/01 21:25:56 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla and R.Girelli report: We imaged again the field of iPTF13ecv optical afterglow candidate of GRB 131127B (Leo Singer: GCN 15524) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy (member of ISSP:Italian Supernovae Search Project). We have observed that the brightness of this object is not decreased during 5 days after the discovery. Follow the results of our photometry +/- 0.2 mag: Date UT Exp R-mag Middle (s) (rough) 2013 11 28.76209 600 18.77 2013 11 28.76914 600 18.69 2013 11 28.76926 600 18.58 2013 11 28.77644 600 18.89 2013 11 29.75051 600 18.47 2013 12 01.72377 600 18.85 2013 12 01.73159 600 18.85 2013 12 01.74629 600 18.93 Magnitudes were estimated with the USNO-B1 cat. and are not corrected for galactic dust extinction. The images are available at: http://www.osservatoriobassano.org/GRB.asp The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15570 SUBJECT: GRB 131127A: optically dark burst DATE: 13/12/03 16:26:09 GMT FROM: Alina Volnova at SAI MSU A.Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), A. Pozanenko(IKI) report on behalf of larger GRB follow-up collaboration: We report about revised photometry of the GRB 131127A (Markwardt et al., GCN 15516) published earlier (Klunko et al., GCN 15519). Using combined image of full data set of the observations on Nov. 27 we do not detect any optical counterpart in the enhanced XRT error circle (Evans et al., GCN 15520). The details of the photometry are the following: UT start t-T0 Filter Exp. OT UL (mid, days) (s) (3 sigma) 10:40:06 0.04680 R 4650 n/d 22.5 The photometry is based on the same 3 USNO-B1.0 stars listed in the GCN 15519. The deep upper limit obtained at ~67 min (mid time) after burst trigger together with Swift/XRT observations (www.swift.ac.uk/xrt_curves/00579571/flux.qdp) suggests the upper limit of optical-to-X-ray spectral slope beta_OX = -0.02 and classify the GRB 131127A as a dark burst according to Jakobsson (Jakobsson et al., 2004, ApJ, 614, L21). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15574 SUBJECT: GRB 131127B: rejection of optical counterpart candidates DATE: 13/12/04 04:42:30 GMT FROM: Leo Singer at CIT/PTF L. P. Singer (Caltech), M. M. Kasliwal (Carnegie Observatories), S. B. Cenko (NASA/GSFC), Yi Cao (Caltech), Daniel Perley (Caltech), and Annalisa De Cia (Weizmann) report on behalf of the intermediate Palomar Transient Factory (iPTF) collaboration: We report our continued observations of the optical transient iPTF13ecv (Singer & Kasliwal, GCN 15524; Xu et al., GCN 15531; Quadri et al., GCN 15543; Quadri et al., GCN 15558), which was spatially coincident with the Fermi GBM localization of GRB 131127B (von Kienlin, GCN 15528) but was well outside the IPN error box (Golenetskii et al., GCN 15529). No X-ray source coincident with iPTF13ecv was detected in a 5 ks Swift XRT observation starting at 2013-11-28 10:10 (0.83 days after the Fermi-GBM trigger). We calculate a 3 sigma upper limit on the count rate of < 2.2e-3 cps at this time. We obtained further optical photometry with the robotic Palomar 60-inch telescope (P60), yielding r=19.0 +/- 0.1 mag at 2013-11-30 03:36. On 2013-11-29, we obtained a spectrum with the DEIMOS instrument on the Keck II telescope. The spectrum was blue and featureless from about 5000 to 8500 angstroms. On 2013-12-02, we obtained a second spectrum with the LRIS instrument on Keck I. This spectrum had a blue continuum with prominent Balmer absorption lines at a redshift of z=0. Considering the position well outside the IPN localization, the continued optical detection of iPTF13ecv, its blue optical SED, and the Balmer absorption lines, we conclude that iPTF13ecv is unrelated to the GRB trigger and is likely a cataclysmic variable in outburst. We also note that the other two iPTF candidates reported in GCN 15524, iPTF13ect and iPTF13ecu, are probably due to AGN activity. In the 6dFGS survey (Jones et al., MNRAS, 355, 747), iPTF13ect displays a Seyfert I-type spectrum (broad H-alpha and strong [N II] emission lines) and iPTF13ecu a Seyfert II spectrum (no broad H-alpha emission, but strong [N II] emission lines). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15575 SUBJECT: GRB 131127B: archival confirmation of iPTF13ecv as a CV DATE: 13/12/04 15:06:54 GMT FROM: Denis Denisenko at SAI MSU D. Denisenko (Sternberg Astronomical Institute at Moscow State University) reports: The position of the optical transient iPTF13ecv (Singer et al., GCN 15524) in the Fermi field of GRB 131127B (von Kienlin, GCN 15528) was observed in the past with the NEAT project (Teegarden et al., ApJ Vol. 589, pp. L51-L53, 2003). A total of 87 images were obtained on 33 different nights from 1998 July 19 to 2005 Sep. 08. Images can be downloaded from the SkyMorph website at http://skyview.gsfc.nasa.gov/skymorph/obs.html The object at the position of iPTF13ecv was detected in outburst on four last nights, namely on 2005 Aug. 21, Sep. 01, 07 and 08. It was below the detection limit (typically 19.5-20.0m) on the other nights. The following photometry was obtained from the unfiltered NEAT images using SDSS J203153.05+005858.4 as a reference star with r=16.40: 20050821.372 17.0 20050901.371 18.1 20050908.271 19.3 The coordinates of the object measured from the combination of three 2005-08-21 images are (J2000.0): 20 31 47.76 +00 59 23.8, consistent to 0.4" with the position reported by Singer et al. and to 1" with those by Quadri et al. (GCN 15543). Comparison of NEAT images of the variable object in outburst (2005 Aug. 21, Sep. 01 and 08) and at quiescence is uploaded to http://master.sai.msu.ru/static/OT/iPTF13ecv-NEAT-2005.jpg (5'x5' FOV centered at the variable). Reference star is marked on the bottom left (2005-09-01) panel as 16.4r. No object is detected at this position on the combination of 26 good quality NEAT images to the limit ~22.5m. No previous outbursts were found on 15 DSS plates. Combination of DSS plates and SDSS color image suggests that the object is fainter than 23m at quiescence. 2005 outburst amplitude about 6 mag and duration of at least about 20 days are typical for superoutbursts of SU UMa-type dwarf novae. Thus, the cataclysmic variable nature of iPTF13ecv already determined spectroscopically by Keck telescopes (Singer et al., GCN 15574) is independently confirmed by the archival light curve, once again showing the powerful capabilities of data mining methods. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 15577 SUBJECT: GRB 131127B: Bassano Bresciano Observatory,archival confirmation of iPTF13ecv DATE: 13/12/04 16:29:52 GMT FROM: Ulisse Quadri at Bassano Bresciano Obs U.Quadri, L.Strabla and R.Girelli of the (IAU station 565) Bassano Bresciano Observatory, Italy (member of ISSP:Italian Supernovae Search Project) report: Follow the GCN 15575 (D. Denisenko - Sternberg Astronomical Institute at Moscow State University), we communicate that the optical transient iPTF13ecv (Singer et al., GCN 15524) is also present in the POSS1-BLUE plate on 1953-08-16. with magnitude = 20.1 +/- 0.2 Magnitude were estimated with the USNO-B1 cat. The image are available at: http://archive.stsci.edu/cgi-bin/dss_search?v=poss1_blue&r=20+31+48&d=00+59+23&e=J2000&h=15.0&w=15.0&f=gif The message may be cited.