//////////////////////////////////////////////////////////////////////// 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: 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: 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: 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.