//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14089 SUBJECT: GRB 121217A: Swift detection of a burst DATE: 12/12/17 07:31:58 GMT FROM: David Palmer at LANL M. H. Siegel (PSU), B. N. Barlow (PSU), D. N. Burrows (PSU), M. M. Chester (PSU), V. D'Elia (ASDC), D. Grupe (PSU), N. P. M. Kuin (UCL-MSSL), C. B. Markwardt (NASA/GSFC), D. M. Palmer (LANL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team: At 07:17:47 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 121217A (trigger=542441). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 153.724, -62.304 which is RA(J2000) = 10h 14m 54s Dec(J2000) = -62d 18' 13" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single peak with some substructure, with a duration of about 60 sec. The peak count rate was ~3200 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 07:18:51.8 UT, 64.0 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 153.70643, -62.35064 which is equivalent to: RA(J2000) = 10h 14m 49.54s Dec(J2000) = -62d 21' 02.3" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 170 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 3.72 x 10^21 cm^-2 (Kalberla et al. 2005). The initial flux in the 2.5 s image was 1.93e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 72 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 8'x8' region for the list of sources generated on-board covers 0.00% of the XRT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the large, but uncertain extinction expected. Burst Advocate for this burst is M. H. Siegel (siegel AT astro.psu.edu). 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: 14090 SUBJECT: GRB 121217A: Enhanced Swift-XRT position DATE: 12/12/17 13:01:45 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 2474 s of XRT Photon Counting mode data and 5 UVOT images for GRB 121217A, 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 = 153.70999, -62.35047 which is equivalent to: RA (J2000): 10h 14m 50.40s Dec (J2000): -62d 21' 01.7" 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: 14091 SUBJECT: GRB 121217A: GROND Detection of the Afterglow DATE: 12/12/17 13:32:56 GMT FROM: Sebastian Schmidl at TLS Tautenburg J. Elliott (MPE Garching), S. Schmidl (TLS Tautenburg), and J.Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 121217A (Swift trigger 542441; Siegel et al., GCN 14089) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile). Observations started on December 17, 2012, at 07:21 UT, 210 s after the GRB trigger. They were performed at an average seeing of 1.6" and at an average airmass of 1.2. We found a fading point source at the border of the enhanced XRT error circle given in Evans et al. (GCN 14090) RA (J2000.0) = 10:14:50.407 DEC (J2000.0) = -62:21:03.53 with an uncertainty of 0.5" in each coordinate. Based on a total exposure time of 456 s in g'r'i'z' and 480 s in JHK, at a midtime of 1882 s after the burst, we estimate preliminary AB magnitudes of g' = 20.3 +/- 0.1, r' = 19.3 +/- 0.1, i' = 18.9 +/- 0.1, z' = 18.6 +/- 0.1, J = 18.1 +/- 0.1, H = 17.7 +/- 0.1, K = 17.4 +/- 0.1. In the r' band the source faded with a decay slope of 0.7 +/- 0.1 between 2000 s and 4200 s after the trigger. The SED can be fit with a power-law with a slope of beta = 0.8 +/- 0.1. Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E(B-V)= 0.38 mag in the direction of the burst (Schlegel et al. 1998). The extinction-corrected SED suggests a photo-z of 3.0 +/- 0.2. We caution, however, that the high Galactic extinction along the line of sight might affect this result. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14092 SUBJECT: GRB 121217A: Swift/UVOT Detection DATE: 12/12/17 18:14:46 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) and M. H. Siegel (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 121217A 73 s after the BAT trigger (Siegel et al., GCN Circ. 14089). A source consistent with the GROND optical position (Elliott et al. GCN Circ. 14091) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 10:14:50.32 = 153.7097 (deg) Dec (J2000) = -62:21:03.3 = -62.35096 (deg) with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 73 222 147 19.58 +/- 0.13 v 616 5906 313 19.01 +/- 0.22 b 541 560 19 18.76 +/- 0.36 u 285 6522 540 20.09 +/- 0.34 w1 666 6317 313 >19.96 m2 641 6112 313 >19.85 w2 591 7138 510 >20.37 The magnitudes in the table are not corrected for the significant Galactic extinction due to the reddening of E(B-V) = 0.37 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14093 SUBJECT: GRB 121217A: Swift-XRT refined Analysis DATE: 12/12/17 21:32:04 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), O.M. Littlejohns (U. Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), G. Stratta (ASDC), M.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester) and M.H. Siegel report on behalf of the Swift-XRT team: We have analysed 7.1 ks of XRT data for GRB 121217A (Siegel et al. GCN Circ. 14089), from 70 s to 30.3 ks after the BAT trigger. The data comprise 655 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 14090). The late-time light curve (from T0+5.5 ks) can be modelled with a power-law decay with a decay index of alpha=0.63 (+/-0.08). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.15 (+0.11, -0.08). The best-fitting absorption column is consistent with the Galactic value of 3.7 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.92 (+0.11, -0.10) and a best-fitting absorption column of 4.02 (+0.51, -0.30) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.6 x 10^-11 (7.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.02 (+0.51, -0.30) x 10^21 cm^-2 Galactic foreground: 3.7 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.92 (+0.11, -0.10) If the light curve continues to decay with a power-law decay index of 0.52, the count rate at T+24 hours will be 0.091 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.2 x 10^-12 (6.7 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00542441. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14094 SUBJECT: GRB 121217A: Fermi GBM observation DATE: 12/12/18 10:26:28 GMT FROM: David Gruber at MPE David Yu and David Gruber (both MPE) report on behalf of the Fermi GBM Team: "At 07:30:01.58 UT on 17 December 2012, the Fermi Gamma-Ray Burst Monitor triggered and located a burst (trigger 377422204 / 121217313), whose location is consistent with the Swift GRB 121217A (Siegel et al. GCN 14089) which triggered BAT ~13 minutes prior to the GBM. Upon closer examination, we found that GRB 121217A is also present in the GBM data. GBM did not trigger on this earlier emission period owing to the triggering being disabled while Fermi was passing through a region of high geomagnetic latitude. The GBM light curve consists of two epochs of emission, separated by an epoch of quiescence of about 700 s. The duration of the first pulse is about 50 s while the second pulse is about 30 s long. The overall event T90 is about 780 s (50-300 keV). The time-averaged spectrum of the first emission epoch, from T0-749.6 s to T0-704.5 s, is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.20 +/- 0.12 and the cutoff energy, parameterized as Epeak, is 264 +/- 75 keV. The time-averaged spectrum of the second emission epoch, from T0-8.2 s to T0+24.6 s, is well fit by the same model, having a power law index of -1.29 +/- 0.14 and an Epeak of 184 +/- 56 keV. The event fluence (10-1000 keV) over the overall event is (1.11 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.68 s in the 10-1000 keV band is 3.47 +/- 0.29 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: 14095 SUBJECT: GRB 121217A theoretical estimate of redshift and of supernova occurrence DATE: 12/12/18 12:28:55 GMT FROM: Remo Rufinni at ICRA R. Ruffini, L. Izzo, G.B. Pisani, C.L. Bianco, on behalf of a larger collaboration, report: GRB 121217A, following our theoretical considerations based on the Induced Gravitational Collapse scenario for GRBs-SNe, allows also for a different solution with a cosmological redshift of z=0.8 (+- 0.1). We base this result on a preliminary analysis of the superposition of the late X-ray afterglow emission, considering GRB 090618 as the prototype of the class. We have considered the first 75 ks of the X-ray afterglow light curve of GRB 121217A in this preliminary analysis. More details on the model will appear soon on the arXiv. We also predict a presence of a SN emerging after about 18 (+- 3) days from the GRB trigger, e.g. in the first days of January 2013. Assuming an interstellar extinction obtained from the Schlegel et al. (1998) extinction map and a supernova emission similar to the 1998bw one, we estimate an observed magnitude of +24.5 (+- 0.5) in the J filter. We further notice that, given the galactic latitude less than 5 deg (-4.89 deg), the calculated extinction value can differ at least of 1 mag. Follow-up photometric and possibly spectroscopical observations are strongly requested. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14096 SUBJECT: GRB 121217A: Swift-BAT refined analysis DATE: 12/12/19 22:23:48 GMT FROM: Scott Barthelmy at NASA/GSFC J. R. Cummings (GSFC/UMBC), T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), A. M. Parsons (GSFC), G. Sato (ISAS), M. H. Siegel (PSU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 121217A (trigger #542441) (Siegel, et al., GCN Circ. 14089). The BAT ground-calculated position is RA, Dec = 153.708, -62.354 deg, which is RA(J2000) = 10h 14m 50.0s Dec(J2000) = -62d 21' 15.5" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 99%. The mask-weighted light curve shows two well-separated periods of emission. The first starts at ~T-110 sec with weak emission, then peaks at ~T+1 sec, and returns to baseline at ~T+80 sec. The second period of emission starts at ~T+500 sec, with weak peaks at ~T+500 and ~T+610 sec and the main peak at ~T+730 sec and returns to baseline out past T+960 sec (where the data ends). There are enough differences in the profiles of these two periods of emission to conclude they are not gravitationally lensed. T90 (15-350 keV) is 778 +- 16 sec (estimated error including systematics). The time-averaged spectrum from T-17.7 to T+783.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.08. The fluence in the 15-150 keV band is 6.2 +- 0.3 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+735.96 sec in the 15-150 keV band is 1.8 +- 0.1 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/542441/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14097 SUBJECT: GRB 121217A: ATCA 44GHz upper limit DATE: 12/12/21 23:17:02 GMT FROM: Paul Hancock at U of Sydney P. Hancock, T. Murphy, B. Gaensler, M. Bell, D. Burlon (University of Sydney/CAASTRO), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI) We observed GRB121217A (GCN 14809) with the Australia Telescope Compact Array at 44GHz for 90 minutes centered on 12:55UT Dec 21 2012 (T0+4.234days) in poor weather. We detect no radio source at the optical location of the GRB (GCN 14091) and place a 3sigma upper limit of 0.6mJy on the flux of an afterglow. These observations were obtained as part of ATCA project C2689. We thank the observatory staff for their support and scheduling the observations. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.