//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14064 SUBJECT: GRB 121212A: Swift detection of a burst DATE: 12/12/12 07:05:59 GMT FROM: David Palmer at LANL D. Grupe (PSU), W. H. Baumgartner (GSFC/UMBC), C. Guidorzi (U Ferrara), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift Team: At 06:56:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 121212A (trigger=541371). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 177.841, +78.034 which is RA(J2000) = 11h 51m 22s Dec(J2000) = +78d 02' 04" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a FRED-like structure with a duration of about 20 sec. The peak count rate was ~2300 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 06:57:21.7 UT, 68.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 177.78252, 78.03720 which is equivalent to: RA(J2000) = 11h 51m 07.80s Dec(J2000) = +78d 02' 13.9" with an uncertainty of 4.1 arcseconds (radius, 90% containment). This location is 45 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 (3.67 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 4.2 (+2.54/-2.19) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 71 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 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.07. Burst Advocate for this burst is D. Grupe (dxg35 AT 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: 14065 SUBJECT: GRB 121212A: A long GRB detected by INTEGRAL DATE: 12/12/12 09:54:06 GMT FROM: Sandro Mereghetti at IASF/CNR S.Mereghetti (IASF-Milano), C.Ferrigno, E.Bozzo, I.Vovk (ISDC, Versoix), D.Gotz (CEA, Saclay), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: a gamma ray burst lasting about 10 s has been detected by IBAS in the IBIS/ISGRI data at 06:56:12 UT of December 12. Its refined coordinates (J2000) are: R.A.= 177.8217 deg DEC.= 78.0257 deg with an uncertainty of 2 arcmin (90% c.l.). The burst has a peak flux of 0,4 counts/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 8e-8 erg/cm2. This burst has also been detected by Swift (Grupe et al. GCN Circ.14064). Due to the significance of the detection below the high confidence threshold, only an Alert Packet of WEAK type was distributed by IBAS in real time (Packet n. 6720). A plot of the light curve has been posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14066 SUBJECT: GRB 121212A: Enhanced Swift-XRT position DATE: 12/12/12 12:02:15 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 1934 s of XRT Photon Counting mode data and 2 UVOT images for GRB 121212A, 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 = 177.79152, +78.03739 which is equivalent to: RA (J2000): 11h 51m 9.96s Dec (J2000): +78d 02' 14.6" 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: 14068 SUBJECT: GRB 121212A: Swift-BAT refined analysis DATE: 12/12/12 13:47:49 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 121212A (trigger #541371) (Grupe, et al., GCN Circ. 14064). The BAT ground-calculated position is RA, Dec = 177.787, 78.052 deg, which is RA(J2000) = 11h 51m 08.8s Dec(J2000) = +78d 03' 05.4" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a couple peaks starting at ~T-3 sec, peaking at ~T+0 sec, and ending at ~T+16 sec. T90 (15-350 keV) is 6.8 +- 1.3 sec (estimated error including systematics). The time-averaged spectrum from T+0.02 to T+7.84 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.65 +- 0.40. The fluence in the 15-150 keV band is 1.2 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.02 sec in the 15-150 keV band is 0.7 +- 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/541371/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14069 SUBJECT: GRB121212A: Swift/UVOT Detection DATE: 12/12/12 17:14:59 GMT FROM: Paul Kuin at MSSL N.P.M. Kuin (MSSL-UCL) and D. Grupe (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 121212A 72 s after the BAT trigger (Grupe et al., GCN Circ. 14064). A source consistent with the enhanced XRT position (Beardmore et al. GCN Circ. 14066) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 11:51:10.30 = 177.79292 (deg.) Dec (J2000) = +78:02:14.3 = 78.03730 (deg.) with an estimated uncertainty of 0.62 arc sec. (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 72 7133 824 21.23 +/- 0.17 v 615 6108 352 >20.3 b 540 13527 1160 >20.9 u 285 1138 285 20.25 +/- 0.25 w1 664 11960 1238 >20.8 m2 639 6313 216 >20.5 w2 763 5904 255 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.07 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14070 SUBJECT: GRB 121212A: Keck observations DATE: 12/12/12 17:24:46 GMT FROM: Daniel Perley at Caltech D. A. Perley and A. Horesh (Caltech) report: We slewed to the position of GRB121212A (rupe et al., GCN 14064) with the Keck I telescope (+LRIS) and acquired a series of exposures with the slit guider beginning at 15:40 UT, 8.7 hours after the event. We identified a source near the DSS limit consistent with the XRT position, at coordinates (J2000) of: RA = 11:51:10.43 Dec = +78:02:15.3 (+/- 1.5 arcsec) This is consistent with the XRT and UVOT positions (Beardmore et al., GCN 14066; Kuin et al., GCN 14069). The magnitude is approximately R~21 on the guider camera at this time. A series of 600s spectroscopic exposures were then taken during brightening morning twilight. A provisional reduction of the (low S/N) spectrum shows a significant flux across the spectral range, extending to at least 3500 Angstroms with no break or strong absorption lines, suggesting z ~< 2 and consistent with the detection in the UVOT u filter. Analysis is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14071 SUBJECT: GRB 121212A: optical observations in ISON-NM observatory DATE: 12/12/12 18:12:28 GMT FROM: Alexei Pozanenko at IKI, Moscow L. Elenin (KIAM), A. Pozanenko (IKI), A. Volnova (SAI MSU, IKI), V. Savanevych (KNURE), A. Bryukhovetskiy (NSFCTC), I. Molotov (KIAM), report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 121212A (Grupe et al., GCN 14064) with 0.45-m telescope of ISON-NM observatory starting on Dec. 12 (UT) 06:58:31, i.e 138 s after burst trigger. We took several unfiltered images of 30 s exposures. An automatic real-time pipeline did not detect any new object. However after stacking all images we marginally detected the source not visible in any filter of DSS2 in coordinates 11 51 10.40 +78 02 15.3 with uncertainty of 0.3 arcsec in both coordinates. The source is consistent with enhanced XRT afterglow position (Beardmore et al. GCN 14066) and optical transient (Kuin et al. GCN 14069; Perley and Horesh GCN 14070) . A preliminary photometry of co-added frames is based on the USNO-B1.0 (R2) nearby stars is following: UT start, Exposure, OT, UL (3 sigma) 06:58:31 30 n/d 18.3 06:58:31 3x30 n/d 18.7 06:58:31 10x30 n/d 19.4 06:58:31 40x30 20.7 +/- 0.4 20.5 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14072 SUBJECT: GRB 121212A: P60 Observations DATE: 12/12/12 18:26:40 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration: We have imaged the field of the Swift (Grupe et al., GCN 14064) and Integral (Mereghetti et al., GCN 14065) GRB121212A with the robotic Palomar 60 inch telescope. Observations began at 08:06 UT on 12 December 2012 (~ 1.2 hours after the Swift trigger) and were obtained in the r', i', and z' filters. At the location of the UVOT (Kuin et al., GCN 14069) and Keck/LRIS (Perley and Horesh, GCN 14070) afterglow, we identify a faint source in our r' and i' images. Using several nearby USNO-B1 point sources for reference, we measure a magnitude of R = 20.45 +/- 0.19 at this time. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14073 SUBJECT: GRB 121212A: Swift-XRT refined Analysis DATE: 12/12/12 19:06:05 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), O.M. Littlejohns (U. Leicester), V. Mangano (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU) and D. Grupe report on behalf of the Swift-XRT team: We have analysed 9.1 ks of XRT data for GRB 121212A (Grupe et al. GCN Circ. 14064), from 81 s to 19.3 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 14066). The late-time light curve (from T0+5.3 ks) can be modelled with a power-law decay with a decay index of alpha=0.80 (+/-0.24). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.48 (+0.17, -0.16). The best-fitting absorption column is 2.2 (+/-0.4) x 10^21 cm^-2, in excess of the Galactic value of 3.7 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.1 x 10^-11 (6.2 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.2 (+/-0.4) x 10^21 cm^-2 Galactic foreground: 3.7 x 10^20 cm^-2 Excess significance: 7.7 sigma Photon index: 2.48 (+0.17, -0.16) If the light curve continues to decay with a power-law decay index of 0.80, the count rate at T+24 hours will be 0.011 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.3 x 10^-13 (6.6 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/00541371. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14074 SUBJECT: GRB 121212A: PAIRITEL NIR Observations DATE: 12/12/12 22:17:33 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan (UC Berkeley) reports: We observed the field of GRB 121212A (Grupe et al., GCN 14064) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2012-Dec-12 09h50m10s UT, ~2.9 hours after the Swift trigger. In mosaics (effective exposure time of 1.96 h) taken simultaneously in the J, H, and Ks filters, we do not detect any source at the afterglow location (Kuin et al., GCN 14069; Perley and Horesh, GCN 14070; Elenin et al., GCN 14071; Cenko, GCN 14072). post burst t_mid (hr) exp.(hr) filt U. Limit (3 sig). 4.79 1.96 J > 19.0 4.79 1.96 H > 17.9 4.79 1.96 Ks > 17.1 All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14076 SUBJECT: GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval DATE: 12/12/13 01:06:51 GMT FROM: James Wren at LANL J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis, of Los Alamos National Laboratory report: The RAPTOR network of robotic optical telescopes made observations of Swift trigger 541371 (Grupe, et al., GCN 14064). The burst location was within the field of our wide-field monitor located near Los Alamos, NM USA, which began a 10 s exposure of the location at 06:56:03.18 UT, 10.2 s before the Swift trigger time and covering the initial few seconds of gamma-ray emission as detected by the BAT (Barthelmy, et al., GCN 14068). The next 10 s exposure begins at 06:56:23.58 UT, 10.2 s after the Swift trigger time and overlapping the end stages of the gamma-ray emission. We do not detect the optical counterpart detected by the UVOT (Kuin, et al., GCN 14069) and others. Our 3-sigma limiting magnitudes are R~10.1 based on comparison of our unfiltered images to the Tycho-2 V-band catalog. Our narrow-field instruments began a series of 10 s exposures at 06:58:08.59 UT, 115 s after the Swift trigger. These images also do not show the optical counterpart to a limiting magnitude of R~16.4 based on comparison to the USNO-B1 R-band. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14079 SUBJECT: GRB 121212A: Maidanak optical observations DATE: 12/12/13 20:46:21 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), A. Sergeev (Institute of Radio Astronomy of NASU), A. Volnova (SAI MSU), O. Burhonov (UBAI), I. Molotov (KIAM) report on behalf GRB follow-up collaboration: We observed the field of Swift GRB 121212A (Grupe et al., GCN 14064) with AZT-22 telescope of Maidanak observatory starting on Dec. 12 (UT) 20:51:02 under mean seeing (FWHM) of about 1 arcsec. Totally we obtained 6 images of 600 s exposure in R filter. At the position of the OT of GRB 121212A (Kuin et al., GCN 14069; Perley and Horesh, GCN 14070; Elenin et al., GCN 14071) we marginally detected an extended object. If it will be confirmed the object might be a host galaxy of GRB 121212A. A preliminary photometry of the object: T0+ Filter, Exposure, OT (mid, d) (s) 0.60088 R 6x600 23.0 ± 0.35 is based on USNO-B1.0 nearby stars: USNO-B1.0 1680-0064718 11:51:09.04 +78:00:39.9 R2 = 16.34 USNO-B1.0 1680-0064713 11:51:05.10 +78:02:00.1 R2 = 19.35 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14082 SUBJECT: GRB121212A: NOT optical imaging DATE: 12/12/14 06:48:13 GMT FROM: Steve Schulze at U of Iceland S. Schulze (PUC, MCSS), D. Malesani (DARK/NBI), T. Pursimo, J. Jessen-Hansen (NOT) and P. Jakobsson (U Iceland) report on behalf a larger collaboration: We observed the field of GRB 121212A, detected by Swift (Grupe et al., GCN 14064) and INTEGRAL (Mereghetti et al., GCN 14065), with ALFOSC mounted at the NOT. Observations started at 03:07:39 UT on 14 December, i.e. 1.8412 days after the trigger. We obtained a series of four R-band images with an individual exposure time of 300 s. We detect an object inside the UVOT-refined XRT (http://www.swift.ac.uk/xrt_positions/00541371/) at RA (J2000): 11:51:10.22 Dec (J2000): +78:02:14.51 We measured an R-band brightness of 23.5 +/- 0.1 mag with respect to four USNO B1.0 stars (R2 magnitude). We did not apply any correction for foreground extinction. Our measurement is consistent with Pozanenko et al. (GCN 14079) and confirms that the object first reported by Kuin et al. (GCN 14069) is the optical afterglow of GRB 121212A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14083 SUBJECT: GRB 121212A: PdBI mm observations DATE: 12/12/14 08:43:04 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia A. J. Castro-Tirado (IAA-CSIC Granada), M. Bremer and J.-M. Winters (IRAM Grenoble), on behalf of a larger collaboration, report: "We conducted mm observations towards GRB 121212A (Grupe et al. GCNC 14064, Mereghetti et al. GCNC 14065) starting at 10.5 hr post burst with the PdBI at 90 GHz. At the position of the X-ray/optical afterglows (Beardmore et al. GCNC 14066, Kuin et al. GCNC 14069), no emission is detected down to 0.3 mJy (3 sigma limit)." This message can be quoted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 14085 SUBJECT: GRB 121212A: LOAO IzY Observation DATE: 12/12/14 15:44:35 GMT FROM: Minsung Jang at Seoul National U M. Jang, M. Im (SNU), and Y. Urata (NCU), on behalf of EAFON We observed GRB 121212A in IzY-bands starting at UT 08:51:52, 2012-12-12, ~ 2 hrs after the BAT trigger (Grupe et al, GCN 14064), using the 1.0m telescope at Mt.Lemmon in Arizona, U.S. We do not detect the GRB afterglow in all bands at the position of the Swift/UVOT detection (Kuin et al. 14069). We estimate the 3-sigma limiting magnitude (AB system) of the afterglow for each band, I > 20.0 (T0+7900s) z > 18.3 (T0+9370s) Y > 17.7 (T0+8260s), by calibrating it against USNO-B1 stars with I2 magnitudes and 2MASS point sources without the galactic extinction correction. We thank the LOAO operator, I. Baek, for performing the observation.