//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20296 SUBJECT: GRB 161219B: Swift detection of a burst with an optical afterglow DATE: 16/12/19 19:07:03 GMT FROM: David Palmer at LANL A. D'Ai (INAF-IASFPA), J. A. Kennea (PSU), H. A. Krimm (CRESST/NSF/USRA), N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 18:48:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 161219B (trigger=727541). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 91.717, -26.790 which is RA(J2000) = 06h 06m 52s Dec(J2000) = -26d 47' 23" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single triangle- shaped structure with a duration of about 10 sec. The peak count rate was ~3900 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 18:50:27.5 UT, 108.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 91.7140, -26.7915 which is equivalent to: RA(J2000) = 06h 06m 51.35s Dec(J2000) = -26d 47' 29.4" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 11 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 in excess of the Galactic value (3.06 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 4 (+2.38/-1.96) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 111 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 06:06:51.41 = 91.71421 DEC(J2000) = -26:47:29.2 = -26.79144 with a 90%-confidence error radius of about 0.5 arc sec. This position is 0.9 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.10 with a 1-sigma error of about 0.03. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03. Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.inaf.it). 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.) [GCN OPS NOTE(20dec16): Per author's request, the "-29:47:29.2" in the 4th paragraph was changed to "-26:47:29.2".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20297 SUBJECT: GRB 161219B: Enhanced Swift-XRT position DATE: 16/12/20 01:22:43 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 2622 s of XRT Photon Counting mode data and 5 UVOT images for GRB 161219B, 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 = 91.71401, -26.79163 which is equivalent to: RA (J2000): 06h 06m 51.36s Dec (J2000): -26d 47' 29.9" 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: 20298 SUBJECT: GRB 161219B: Swift-XRT refined Analysis DATE: 16/12/20 04:36:01 GMT FROM: Phil Evans at U of Leicester B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and A. D'Ai report on behalf of the Swift-XRT team: We have analysed 7.7 ks of XRT data for GRB 161219B (D'Ai et al. GCN Circ. 20296), from 92 s to 22.7 ks after the BAT trigger. The data comprise 238 s in Windowed Timing (WT) mode (the first 9 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 Beardmore et al. (GCN Circ. 20297). The late-time light curve (from T0+4.7 ks) can be modelled with a power-law decay with a decay index of alpha=0.75 (+/-0.07). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.05 (+/-0.08). The best-fitting absorption column is 1.21 (+0.21, -0.20) x 10^21 cm^-2, in excess of the Galactic value of 3.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.82 (+/-0.07) and a best-fitting absorption column of 1.64 (+0.23, -0.22) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.64 (+0.23, -0.22) x 10^21 cm^-2 Galactic foreground: 3.1 x 10^20 cm^-2 Excess significance: 9.8 sigma Photon index: 1.82 (+/-0.07) If the light curve continues to decay with a power-law decay index of 0.75, the count rate at T+24 hours will be 0.22 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.3 x 10^-12 (1.0 x 10^-11) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00727541. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20299 SUBJECT: GRB 161219B: GROND afterglow observations DATE: 16/12/20 07:57:56 GMT FROM: Thomas Kruehler at MPE Garching T. Kruehler, P. Wiseman and J. Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 161219B (Swift trigger 727541; D'Ai, GCN #20296) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla Observatory (Chile). Observations started at 01:33 UT on 2016-12-20, 6.7 hr after the GRB trigger. They were performed at an average seeing of 1".1, and at an average airmass of 1.3. Based on combined images with 14.5 min of total exposures in g'r'i'z' and 12.0 min in JHK at a mid-time of 01:42 UT on 2016-12-20, we derive the following preliminary magnitudes (all in AB system) for the optical/NIR afterglow (D'Ai et al., GCN 20296). g' = 18.04 +- 0.05 mag r' = 18.08 +- 0.05 mag i' = 17.98 +- 0.05 mag z' = 17.88 +- 0.05 mag J = 17.68 +- 0.05 mag H = 17.57 +- 0.07 mag K = 17.54 +- 0.08 mag Given magnitudes are calibrated against Pan-STARRS/2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.028 mag in the direction of the burst (Schlafly & Finkbeiner 2011). We note the presence of a bright (r=21 mag) and visibly extended galaxy in the Pan-STARRS data at the position of GRB 161219B. This is likely the host galaxy of the GRB and would, if confirmed, indicate a relatively low redshift. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20300 SUBJECT: GRB 161219B: LCO Sutherland observations DATE: 16/12/20 08:31:43 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), S. Kobayashi, I.A. Steele (LJMU), A. Gomboc (U. Nova Gorica), C.G. Mundell (U. Bath) on behalf of a large collaboration report: We observed Swift GRB 161219B (D'Ai et al. GCN 20296) on December 19, from 20:43 to 20:56 UT (1.9-2.1 hours since the GRB) with 1-m LCO telescope units in Sutherland with SDSS r and i filters. Within the enhanced enhanced XRT error circle (Beardmore et al. GCN 20297) we clearly detect the optical counterpart reported by UVOT (D'Ai et al.) with the following values: Mid Time Exposure Filter Magnitude (hours) (s) ------------------------------------------------------- 1.93 120 SDSS-R 17.38 +- 0.02 1.93 120 SDSS-I 16.72 +- 0.02 ------------------------------------------------------- as calibrated against nearby USNOB-1 source RA(J2000)=06:06:52.743, DEC(J2000)=-26:46:29.49 using nominal R2=15.12 mag, I=14.37 mag. We however point out that the source is positionally coincident with a USNOB-1 source: 06:06:51.366, -26:47:29.80, which has nominal R2=20.14 mag. This likely corresponds to the extended galaxy mentioned by Kruehler et al (GCN 20299) in Pan-STARRS data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20305 SUBJECT: GRB 161219B: Watcher optical observations DATE: 16/12/20 14:15:30 GMT FROM: Antonio Martin-Carrillo at UCD,Space Science Group A. Martin-Carrillo (UCD), D. Murphy (UCD), L. Hanlon (UCD), H. J. van Heerden (UFS), B. van Soelen (UFS) and P. J. Meintjes (UFS) We observed the field of GRB 161219B (D'Ai et al, GCN 20296) using the 40cm UCD Watcher telescope at Boyden Observatory in South Africa. Due to bad weather, observations were delayed until December 20th at 00:30 UT (T0+5.67h) and were taken under poor seeing. Based on combined images in SDSS r’ filter, at a mid-time of 00:45 UT we derive a preliminary magnitude of r'=18.06 (AB system). This value is in agreement with the magnitude reported by Kruehler et al (GCN 20299) at 01:42 UT, one hour after our reported mid-time. In fact, our data shows no indication of fading between 00:30 UT to 02:00 UT when our observations stopped, indicating an optical plateau. Magnitudes were calibrated using several nearby APASS stars. No correction for Galactic extinction in the direction of the GRB has been applied. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20306 SUBJECT: GRB 161219B: Swift/UVOT Detection DATE: 16/12/20 17:08:41 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and A. D'Ai (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 161219B 112 s after the BAT trigger (D'Ai et al., GCN Circ. 20296). A source consistent with the XRT position (Beardmore et al. GCN Circ. 20297) is detected in the initial UVOT exposures. The source is detected in the first white exposure at the position: RA(J2000) = 06:06:51.43 = 91.71428 DEC(J2000) = -26:47:29.5 = -26.79152 with an uncertainty of 0.42" (90% confidence) Preliminary detections using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are in the table below. Fading is seen in all filters. The detection in the w2 filter is consistent with a relatively low redshift as suggested by Kruehler et al. (GCN Circ. 20299). Filter T_start(s) T_stop(s) Exp(s) Mag white 112 261 147 16.1 +/- 0.1 v 653 673 19 16.7 +/- 0.2 b 579 599 20 16.9 +/- 0.1 u 324 573 246 16.0 +/- 0.1 u 44962 45868 875 18.0 +/- 0.1 w1 702 722 20 15.6 +/- 0.1 m2 677 697 19 15.7 +/- 0.2 w2 629 649 20 15.9 +/- 0.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20308 SUBJECT: GRB 161219B: Swift-BAT refined analysis DATE: 16/12/20 18:22:59 GMT FROM: Hans Krimm at NSF/NASA-GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. D'Ai (INAF-IASFPA), N. Gehrels (GSFC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 161219B (trigger #727541) (D'Ai, et al., GCN Circ. 20296). The BAT ground-calculated position is RA, Dec = 91.717, -26.801 deg which is RA(J2000) = 06h 06m 52.0s Dec(J2000) = -26d 48' 02.1” with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 50%. The mask-weighted light curve shows a soft, weak peak at around T-10 sec,then the main peak starts at T-2 sec, peaks at T+2 sec and decays to background by T+8 sec. T90 (15-350 keV) is 6.94 +- 0.79 sec (estimated error including systematics). The time-averaged spectrum from T-0.54 to T+8.38 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.29 +- 0.35, and Epeak of 61.9 +- 16.8 keV (chi squared 44.89 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+1.56 sec in the 15-150 keV band is 5.3 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.84 +- 0.08 (chi squared 53.05 for 57 d.o.f.). 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/727541/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20309 SUBJECT: GRB 161219B: ISON/Terskol optical observations DATE: 16/12/20 21:25:52 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), A. Mokhnatkin (KIAM), A. Pozanenko (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 161219B (Swift trigger 727541; D'Ai, GCN 20296) with K-800 (0.8m) telescope of ISON/Terskol observatory starting on December, 19 (UT) 18:57:51, i.e. about 9 minutes after GRB onset. We obtained several unfiltered images of 30 s exposure. The optical afterglow (D'Ai et al., GCN 20296; Kruehler et al., GCN 20299; Guidorzi et al., GCN 20300; Martin-Carrillo et al., GCN 20305) is clearly visible in separate images. Preliminary light curve of the afterglow can be found in http://grb.rssi.ru/GRB161219B/GRB161219B_161219_K800.png Photometry is based on nearby USNO-B1.0 stars USNO-B.1_id R2 0631-0120570 13.78 0632-0119151 14.86 0632-0119187 14.03 0632-0119198 15.05 0632-0119218 14.66 0631-0120752 14.81 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20313 SUBJECT: GRB 161219B: VLA Detection DATE: 16/12/21 02:13:57 GMT FROM: Kate Alexander at Harvard K. D. Alexander (Harvard), T. Laskar (NRAO / UC Berkeley), and E. Berger (Harvard) report on behalf of a larger collaboration: We observed the Swift GRB 161219B (D’Ai et al. GCN 20296) at multiple frequencies with the Karl G. Jansky Very Large Array (VLA) beginning 2016 December 20.26 UT (11.4 hours after the burst). At a mean frequency of 14.75 GHz, we detect a radio source with a preliminary flux density of ~0.9 mJy at RA (J2000) = 06:06:51.428 +/- 0.001 Dec (J2000) = -26:47:29.52 +/- 0.01 consistent with the position of the optical afterglow and the refined Swift/XRT position (Beardmore et al. GCN 20297). Follow-up observations are planned. We thank the VLA staff for rapidly executing these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20314 SUBJECT: GRB 161219B: MITSuME Akeno Optical Observation DATE: 16/12/21 05:31:31 GMT FROM: Taketoshi Yoshii at Tokyo Tech T.Fujiwara, Y.Saito, Y. Tachibana, T. Yoshii, Y.Ono, S.Harita, Y.Muraki, K.Morita, T.Ozawa, K.Saisho,Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We searched for the optical counterpart of GRB 161219B (A. D'Ai et al., GCN Circular #20296) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started on 2016-12-20 11:49:20 UT (~17.0 hour after the burst) and we detected the optical counterpart in g', Rc and Ic band. The measured magnitudes were listed as follows. We obtained following results for the magnitudes. T0+[hour] MID-UT T-EXP[sec] g' Rc Ic ------------------------------------------------------------------------------------------------------- ~17.8 12:34:26 4920 18.83 +/- 0.11 18.23 +/- 0.09 18.14 +/- 0.11 ------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used GSC2.3 catalog for flux calibration. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20321 SUBJECT: GRB 161219B: VLT/X-shooter redshift DATE: 16/12/21 14:25:47 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst N. R. Tanvir (U. Leicester), T. Kruehler (MPE), K. Wiersema (U. Leicester), D. Xu (NAOC/CAS), D. Malesani (DARK/NBI), B. Milvang-Jensen (DARK/NBI), and J. P. U. Fynbo (DARK/NBI) report on behalf of a larger collaboration: We observed the optical counterpart of GRB 161219B (Swift trigger 727541; D'Ai et al., GCN #20296) with the ESO Very Large Telescope UT 2 (Kueyen) equipped with the X-shooter spectrograph, covering the wavelength range 3200-22000 AA. Observations started at 06:34 UT on 2016-12-21, roughly 36 hr after the burst and consisted of 4 exposures of 600 s each. We measure r ~ 19.5 mag from the acquisition image. Our spectrum exhibits absorption features from Mg II, Mg I, Ca H, Ca K, all at a common redshift of z = 0.1475. We also detect nebular lines from the Balmer series, [O II] and [O III] at a consistent redshift, which we conclude is the redshift of the GRB. The emission features are likely coming from the object visible in the PanSTARRS data, first noticed by Kruehler et al. (GCN 20299). We acknowledge excellent support from the ESO observing staff in Paranal, in particular Julien Milli, Thomas Rivinius, and Dimitri Gadotti. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20322 SUBJECT: GRB 161219B: SALT observations DATE: 16/12/21 17:29:49 GMT FROM: Soebur Razzaque at U of Johannesburg D.A.H. Buckley (SAAO/SALT), A. Hamanowicz (Warsaw U.), A. Martin-Carrillo (UCD), S. Razzaque (U. Johannesburg), T. Garrigoux (North-West U.), L. Hanlon (UCD), M. M. Kotze (SAAO/SALT) and R. Kuhn (SAAO/SALT) report on behalf of a larger collaboration. We observed the Swift GRB 161219B (D’Ai et al. GCN 20296) on December 20 using the Southern African Large Telescope (SALT) in Sutherland, South Africa, 24.73 h after the Swift GRB trigger. A 20 s r'-band image was obtained using SALTICAM at 19:32:30 UTC, just prior to the commencement of the spectroscopy, and the optical counterpart reported by D'Ai et al. (GCN 20296), Kruehler et al. (GCN 20299), Guidorzi et al. (GCN 20300), Martin-Carrillo et al. (GCN 20305), Mazaeva et a. (GCN 20309), Tanvir et al. (GCN 20321) was clearly visible in the SALT image. From photometry of the source and six APASS reference stars in the field, we determined the brightness to be r' = 18.94 +/- 0.06. Spectroscopy with the Robert Stobie Spectrograph (RSS) started at 19:37:39 UTC and ran until 20:27:51 UTC during which two 1500 s spectra were obtained, nominally covering the spectral region from 340 to 1000 nm at a mean resolution of R = 350. The optical spectrum was characterised by a blue continuum and was heavily contaminated by sky emission lines above 850 nm. No obvious spectral faetures were seen in the combined spectrum. ________________________________ This email and all contents are subject to the following disclaimer: http://disclaimer.uj.ac.za //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20323 SUBJECT: Konus-Wind observation of GRB 161219B DATE: 16/12/21 17:31:16 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 161219A (Swift-BAT trigger #727541: D'Ai et al., GCN 20296; Palmer et al., GCN 20308; T0(BAT)=18:48:19.308 UT) was detected by Konus-Wind (KW) in the waiting mode. The light curve shows a single pulse with a duration of ~10 s. Modeling the KW 3-channel time-integrated spectrum (from T0(BAT)-0.134 s to T0(BAT)+8.698 s) by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -1.59 ± 0.71 and Ep = 91 ± 21 keV. The corresponding 20-1000 keV energy fluence for this time interval is (3.1 ± 0.8)x10^-6 erg/cm2. Assuming the redshift z=0.1475 (Tanvir et al., GCN 20321) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the burst isotropic energy release E_iso to ~1.6x10^50 erg and the rest-frame peak energy of the time-integrated spectrum, Ep,i, to ~104 keV. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB161219B/ All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20327 SUBJECT: Correction to GCN 20323 "Konus-Wind observation of GRB 161219B" DATE: 16/12/21 21:34:19 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks reports on behalf of the Konus-WIND team: The first line of GCN 20323 should read: "The long GRB 161219B (Swift-BAT trigger #727541: D'Ai et al.,", not " ... GRB 161219A ..." We thank Sandro Mereghetti for pointing this out and we apologize for any confusion this may have caused. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20328 SUBJECT: GRB 161219B: Rapid ALMA Observations & Detection DATE: 16/12/22 00:08:08 GMT FROM: Tanmoy Laskar at UC Berkeley T. Laskar (NRAO / UC Berkeley), K. D. Alexander (Harvard), and E. Berger (Harvard) report on behalf of a larger collaboration: We observed the Swift GRB 161219B (D’Ai et al. GCN 20296) at 3 mm with the Atacama Large Millimeter/submillimeter Array (ALMA) beginning 2016 December 21.08 UT (1.30 days after the burst). At a mean frequency of 97 GHz, we detect a radio source with a preliminary flux density of ~ 1 mJy at RA (J2000) = 06:06:51.429 +/- 0.001 Dec (J2000) = -26:47:29.62 +/- 0.01 consistent with the position of the optical afterglow, the refined Swift/XRT position (Beardmore et al. GCN 20297), and the radio afterglow (Alexander et al. GCN 20313). Follow-up observations are planned. We thank the JAO staff for rapidly executing these observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20330 SUBJECT: GRB161219.78 MASTER-Net OT detection DATE: 16/12/22 03:38:33 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory V.Yurkov, A. Gabovich, Yu.Sergienko Blagoveschensk Educational State University, Blagoveschensk K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University R. Podesta, Claudio Mallamaci, Carlos Lopez and Federico Podesta Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was pointed to the GRB161219.78 26 sec after notice time and 42 sec after trigger time at 2016-12-19 18:49:21 UT. On our first (10s exposure) set we found 1 optical transient within SWIFT error-box (ra=91.7125 dec=-26.7897 r=0.05) brighter then 16.64. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 47 2016-12-19 18:49:21 10 (06h 06m 51.43s , -26d 47m 29.8s) 15.90 The 5-sigma upper limit has been about 16.64mag The message may be cited. [GCN OPS NOTE(22dec16): Per Operator, it is noted that GRB161219.78 is the same as GRB 161219B.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20331 SUBJECT: GRB 161219B: POLAR Observation DATE: 16/12/22 10:38:13 GMT FROM: Haulin Xiao at PSI/POLAR Hualin Xiao (PSI), Wojtek Hajdas (PSI) and Radek Marcinkowski (PSI) report on behalf of the POLAR collaboration: At 2016-12-19T18:48:39.0 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 161219B, which was also observed by Swift BAT (trigger #727541). The POLAR light curve consists of one peak with duration (T90) of 4.0 +- 0.5 s measured from T0. The 0.5 s peak flux at T0+1.75 s is equal to 248 +-44 cnts/sec. Above measurements are in the energy range of about 80 - 500 keV. LC_URL: http://polar.psi.ch/triggers/GRB161219B.png and http://polar.psi.ch/pub/lc.php?event=GRB+161219B Using the best location from the Swift BAT, which is (J2000): RA: 91.717 [deg] Dec: -26.790 [deg] the incident angle in the POLAR coordinate at T0 is: Theta: 96.6 [deg] Phi: 201.2 [deg] The analysis results presented above are preliminary. Calibration of the instrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) on Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV. More information about POLAR can be found at http://polar.psi.ch/pub , http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ . This message is quotable in publications. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20332 SUBJECT: GRB 161219B: UKIRT near-IR afterglow detection DATE: 16/12/22 23:40:43 GMT FROM: Wen-fai Fong at U of Arizona W. Fong and P. Milne (University of Arizona) report: "We observed the field of the long-duration GRB 161219B (D'Ai et al., GCN 20296) with the Wide Field Camera (WFCAM) mounted on the 3.8-m United Kingdom Infrared Telescope (UKIRT) on Mauna Kea beginning on 2016 Dec 22.368 UT (2.58 days post-burst). We obtained observations in the J-, H- and K-bands in 0.72" seeing. Using the quick-look pipeline ORAC-DR, we detect the near-IR afterglow in coincidence with the X-ray (Beardmore et al., GCN 20297), optical (Kruehler et al., GCN 20299; Guidorzi et al., GCN 20300; Martin-Carrillo et al., GCN 20305; Marshall et al., GCN 20306; Mazaeva et al., GCN 20309; Buckley et al., GCN 20322), and radio (Alexander et al., GCN 20313; Laskar et al., GCN 20328) afterglows. Calibrated to 2MASS, we estimate a preliminary brightness of J(AB)=18.8 +/- 0.1 mag for the near-IR afterglow of GRB 161219B. Further observations are planned. We thank Watson Varricatt and Sam Benigni for their assistance in planning and executing these observations." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20342 SUBJECT: GRB 161219B: Spectroscopic detection of the associated SN with OSIRIS/GTC DATE: 16/12/27 11:13:04 GMT FROM: Antonio de Ugarte Postigo at IAA-CSIC A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), Z. Cano, L. Izzo, C. Thoene, R. Sanchez-Ramirez, K. Bensch (IAA-CSIC), D. A. Kann (IAA-CSIC, TLS), N. Tanvir (U. Leicester), S. Schulze, G. Leloudas (Weizmann Institute), S. Geier (IAC, GRANTECAN), A. Tejero (GRANTECAN) report on behalf of a larger collaboration: We observed the optical counterpart of GRB 161219B (D’Ai et al. GCN 20296) with OSIRIS at the 10.4m GTC telescope on La Palma (Spain). The observations consisted of 3 x 900 s spectra using grism R1000B, which covers the spectral region between 3700 and 7800 AA, plus g, r, i and z-band imaging. The point-like GRB counterpart is prominent on top of the elongated host galaxy. The combined spectrum has mean UT epoch on 27.02 December (7.24 days after the burst) and shows a strong continuum with clear broad features typical of a type Ic-BL supernova, implying that the supernova contribution is already significant. We also detect several emission features of the host galaxy (due to [OIII], [OII], [NII] and H) as well as CaII in absorption at the redshift of z = 0.1475 proposed for the GRB (Tanvir et al. GCN 20321). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20344 SUBJECT: GMRT radio detection of GRB 161219B DATE: 16/12/27 16:44:35 GMT FROM: Nayana A J at NCRA-TIFR A. J. Nayana (NCRA-TIFR) and Poonam Chandra (NCRA-TIFR) reports: We carried out Giant Metrewave Radio Telescope (GMRT) observations of GRB 161219B (D'Ai et al. GCN Circ. 20296) in the 1390 MHz band on 2016 Dec 26.68 UT. We detect the radio afterglow of the GRB in the Swift error circle (Beardmore et al. GCN Circ. 20297). The 1390 MHz band flux density of the afterglow is 397+/-55 uJy. Map rms is 40 uJy/beam. Further observations are planned. We thank GMRT staff for making these observations possible. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20346 SUBJECT: GRB161219B - Anticipated hyperluminal evidence DATE: 16/12/29 07:49:28 GMT FROM: Arnon Dar at Technion-Israel Inst. of Tech S. Dado, A. Dar and A. De Rujula report: High resolution VLA/VLBI follow-up observations of the radio afterglow of GRB161219B [1,2] may provide direct measurements of the hyperluminal motion and of the initial Lorentz factor of the afterglow's source, relative to its parent supernova [3]. The small isotropic energy Eiso~1.6xE52 erg and the peak energy E'p~104 keV of the relatively nearby GRB161219B measured by Konus- Wind [4] indicate, in the cannonball model of GRBs, that this is an ordinary GRB viewed far off-axis [5]. In this model ordinary GRBs viewed on or near the axis of their relativistic ejecta satisfy E'p~150 (Eiso/E52)^{1/2} keV. The Konus-Wind measurements imply [5] a viewing angle @~3/Gamma and a linear polarization P = 2 @^2 Gamma^2/(1+@^4 Gamma^4)~20% where Gamma is the bulk-motion Lorentz factor of the jet which produced GRB161219B in a broad-line Ic supernova explosion akin to that of SN1998bw [3]. The bright radio afterglow of the relatively nearby GRB161219B [1,2] at redshift z=0.1475 [6] provides an excellent opportunity to measure the apparent superluminal speed V of its jet in the plane of the sky. As long as @^2 x Gamma^2 >> 1, V=2c/(1+z)@ and a measurement of V yields Gamma~3(1+z)V/2. If the jet decelerates in a constant density environment and reaches @^2 x Gamma^2 << 1 before its superluminal speed could be measured, then its late-time apparent superluminal speed in the plane of the sky, which is expected to decrease like t^{-1/2), if measured, may be extrapolated to obtain an estimate of Gamma at early time [5]. [1] K. D. Alexander, et al. GCN 20313 [2] A. J. Nayana & and P. Chandra, GCN 20344 [3] A. de Ugarte Postigo, et al. GCN 20342 [4] D. Frederiks, T. Laskar, E. Berger, GCN 20323 [5] S. Dado, A. Dar, A. De Rujula, arXiv:1610.01985 [6] N. R. Tanvir, et al. GCN 20321 [GCN OPS NOTE(29dec16): The suffix "B" was added to the GRB name in the SUBJECT-line.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20380 SUBJECT: PESSTO follow-up of GRB 161219B/SN2016jca DATE: 17/01/06 11:08:31 GMT FROM: Ting-Wan Chen at MPE T.-W. Chen (MPE), J. Greiner (MPE), S. Klose (TLS), K. W. Smith (QUB), A. Cikota (ESO), M. Magee (QUB), C. Inserra (QUB), J. Lyman (Univ. of Warwick), E. Kankare (QUB), K. Maguire (QUB), S. J. Smartt (QUB), M. Sullivan (Southampton), S. Valenti (UC Davis), O. Yaron (Weizmann), D. Young (QUB), and I. Manulis (Weizmann) report: We acquired spectroscopic followup of SN2016jca (de Ugarte Postigo et al., GCN 20342; Pian et al. on Transient Name Server >), the SN associated with GRB 161219B (D'Ai et al. GCN 20296), using the ESO New Technology Telescope at La Silla at 04:48 UT on 2017-01-04 (15.4 days after the GRB trigger) with EFOSC2 and Grism 13 (3985-9315A, 18A resolution) in the framework of the PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A&A, 579, 40 >). The spectrum shows several broad emission features and a significant decrease in flux toward both the blue and red ends, as a broad-line Type Ic supernova around the maximum light. A good match is achieved with SN1998bw at +1.3d using GELATO (Harutyunyan et al., 2008, A&A, 488, 383) and also with SN2002ap at -2d using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20442 SUBJECT: GRB 161219B: afterglow and SN2016jca optical observations DATE: 17/01/12 17:57:30 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), E. Mazaeva (IKI), R. Inasaridze (AbAO), A. Moskvitin (SAO RAS), E. Klunko (ISTP), V. Rumyantsev (CrAO), I. Korobtsev (ISTP), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Inasaridze (AbAO), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 161219B (Swift trigger 727541; D'Ai,GCN 20296) with AZT-33IK (Mondy), ZTSh (CrAO), AS-32 (AbAO) and Zeiss-1000 (SAO RAS) telescopes. We obtained unfiltered images (AbAO) and images in R-filter (other observatories). The optical source associated with the afterglow (D'Ai et al., GCN 20296; Kruehler et al., GCN 20299; Guidorzi et al., GCN 20300; Martin-Carrillo et al., GCN 20305) and SN2016jca (de Ugarte Postigo et al., GCN 20342; Chen et al., GCN 20380) is clearly visible in all our observations. Preliminary light curve of the afterglow and SN2016jca can be found at http://grb.rssi.ru/GRB161219B/GRB161219B_LC.png Photometry is based on nearby USNO-B1.0 stars (R2) common for all images. Late time photometry is contaminated by Pan-STARRS galaxy previously reported by Kruehler et al. (GCN 20299), and also presented in USNO-B1.0. Apparent maximum brightness of the SN2016jca was observed at about 11 days after burst onset (R = 19.2 at 2016-12-30 (UT) 20:04:59) and actual SN peak could be slighter later, between 11 and 14 days after burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 22608 SUBJECT: Chandra observations of GRB161219B 400 days after the explosion DATE: 18/04/06 02:38:08 GMT FROM: Aprajita Hajela at Northwestern U A. Hajela, R. Margutti (Northwestern University), C. Guidorzi (U Ferrara), A. Kamble (Harvard), A. MacFadyen (NYU), D. Milisavljevic (Purdue), J. Parrent (Harvard), A. Zauderer (NSF) report: "We started deep X-ray follow-up observations of GRB161219B with the Chandra X-ray Observatory on 2017, August 8 UT (dt ~ 232 days after explosion, exposure time of 15 ks), PI Margutti, program 18500396. An X-ray source is detected at the location of GRB161219B with count-rate of ~ 0.0024 cts/s (0.5 - 8 keV) and significance of 16 - sigma. The spectrum is well modeled with an absorbed simple power law with best-fitting photon index, Gamma = 1.95 +/- 0.38 and Galactic absorption, N_h = 2.8e+20 cm-2. We do not find any evidence of intrinsic absorption. For these parameters, the unabsorbed flux is (3.41 +/- 0.76) x 10^-14 ergs cm-2 s-1 (0.3 - 10 keV). A second Chandra observation was acquired between 2018, January 16th and January 18th (dt ~ 393-395 days since explosion, exposure time of 32 ks). GRB161219B is detected with the count-rate of ~ 0.0013 cts/s (0.5 - 8 keV) and a significance of 9 -sigma. The best-fitting photon-index is Gamma = 2.05 +/- 0.34 . The corresponding unabsorbed flux is (1.72 +/- 0.28) x 10^-14 ergs cm-2 s-1 (0.3 - 10 keV). We find that GRB161219B continues to decay following a power-law with index, alpha = 1.22 +/- 0.04 , which is consistent with the decay inferred from XRT data at t < 115 days. We thank the entire Chandra team for making these observations possible." [GCN OPS NOTE(06apr18): Per author's request, the last two paragraphs were added.]