//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12720 SUBJECT: GRB 111225A: Swift detection of a burst with an optical counterpart DATE: 11/12/25 04:12:26 GMT FROM: David Palmer at LANL M. H. Siegel (PSU), W. H. Baumgartner (GSFC/UMBC), M. M. Chester (PSU), N. Gehrels (NASA/GSFC), D. Grupe (PSU), F. E. Marshall (NASA/GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (NASA/UMBC), C. A. Swenson (PSU), T. N. Ukwatta (MSU) and B.-B. Zhang (PSU) report on behalf of the Swift Team: At 03:50:37 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 111225A (trigger=510341). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 13.102, +51.589 which is RA(J2000) = 00h 52m 24s Dec(J2000) = +51d 35' 19" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The immediately available lightcurve was truncated for contact with the ground station. The BAT lightcurve showed a rise at around T-10 seconds with flux continuing at least until T+8 seconds, the limit of of the immediately available data. The peak count rate was ~1300 counts/sec (15-350 keV), at ~-2 sec after the trigger. The XRT began observing the field at 03:52:05.9 UT, 88.1 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 13.1548, 51.5741 which is equivalent to: RA(J2000) = +00h 52m 37.15s Dec(J2000) = +51d 34' 26.8" with an uncertainty of 5.0 arcseconds (radius, 90% containment). This location is 129 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. The initial flux in the 2.5 s image was 2.96e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 250 seconds with the U filter starting 95 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 00:52:37.21 = 13.15503 DEC(J2000) = +51:34:19.5 = 51.57207 with a 90%-confidence error radius of about 0.75 arc sec. This position is 7.3 arc sec. from the center of the XRT error circle. The estimated magnitude is 19.42 with a 1-sigma error of about 0.20. No correction has been made for the expected extinction corresponding to E(B-V) of 0.26. 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: 12721 SUBJECT: GRB 111225A: TAROT Calern observatory optical observations DATE: 11/12/25 04:31:51 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-CNRS-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (OHP-CNRS), Atteia J.L. (IRAP-CNRS-OMP) report: We imaged the field of GRB 111225A detected by SWIFT (trigger 510341) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 59.7s after the GRB trigger (15.5s after the notice). The elevation of the field decreased from 10 degrees above horizon and weather conditions were good. The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). We do not detect any OT in the XRT error box (Siegel et al. CGNC 12720) with a limiting magnitude of: t0+59.7s to t0+119.7s : R > 15.9 The second image is 30.0s exposure in tracking mode: t0+134.4s to t0+164.4s : R > 16.2 We co-added a series of exposures: t0+134.4s to t0+326.7s : R > 18.0 No OT was detected in the next images until t0+1700s at the level R > 17.6. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12722 SUBJECT: GRB 111225A: TAROT Calern observatory optical detection DATE: 11/12/25 04:59:02 GMT FROM: Alain Klotz at CESR-CNRS Klotz A. (IRAP-OMP), Gendre B. (ASDC/INAF-OAR), Boer M. (OCA-CNRS), Atteia J.L. (IRAP-OMP) report: We imaged the field of GRB 111225A detected by SWIFT (trigger 510341) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. Following the previous report (Klotz et al. GCNC 12721) we co added only long exposure images obtained later than 1100 seconds after the trigger and we detect marginally the UVOT OT mentioned by Siegel et al. (CGNC 12720): t0+1100s to t0+1800s : R = 19.1 (+/- 0.6) The OT detected by TAROT has a comparable magnitude as NOMAD1 1415-0026136 locaded 20 arcsec from the UVOT OT position. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12723 SUBJECT: GRB 111225A: Super-LOTIS early detection DATE: 11/12/25 05:51:01 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike (Dickinson College), Dieter H. Hartmann (Clemson University), Peter A. Milne (Steward Observatory) and G. Grant Williams (MMT Observatory) report: We observed the field of GRB 111225A (Siegel et al., GCN 12720) with the 0.6m Super-LOTIS telescope located at Kitt Peak National Observatory under good conditions and airmass of 1.1. Observations began 49 seconds after the trigger. The OT (Siegel et al. GCN 12720, Klotz et al. GCN 12722) is marginally detected in 300 seconds of stacked images (with a midtime of 480 seconds after the trigger) with an R-band magnitude of 19.9 +/- 0.2 (on comparison to the USNO B1.0 catalog). Observations are continuing. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12724 SUBJECT: GRB 111225A: Enhanced Swift-XRT position DATE: 11/12/25 08:38:19 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 1857 s of XRT Photon Counting mode data and 2 UVOT images for GRB 111225A, 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 = 13.15557, +51.57157 which is equivalent to: RA (J2000): 00h 52m 37.34s Dec (J2000): +51d 34' 17.6" with an uncertainty of 2.2 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: 12725 SUBJECT: GRBv111225A: Xinglong TNT optical afterglow DATE: 11/12/25 13:27:24 GMT FROM: L.P. Xin at NAOC L.P. Xin, J.Y. Wei, Y. L. Qiu, J. Wang, J.S. Deng, C. Wu, X. H. Han on behalf of EAFON report: We began to observe GRB 111225A ( Siegel et al., GCN 12720) with Xinglong TNT telescope from 10:50:40 (UT), about 7 hour after the burst. Preliminary analysis shows that the brightness of the optical afterglow counterpart ( Siegel et al., GCN 12720, Klotz et al. GCN 12722, Adria et al. GCN 12723) has decayed to about R~20.4 mag relatively to USNO B1.O R2 mag, at the mean time of 7.7 hour after the burst. More observations are encouraged. This message may be cited. Thanks for the observation assistant of TNT telescope at Xinglong observatory. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12726 SUBJECT: GRB 111225A, Swift-BAT refined analysis DATE: 11/12/25 15:51:38 GMT FROM: Takanori Sakamoto at NASA/GSFC W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. H. Siegel (PSU) 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+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 111225A (trigger #510341) (Siegel, et al., GCN Circ. 12720). The BAT ground-calculated position is RA, Dec = 13.158, 51.573 deg which is RA(J2000) = 00h 52m 37.9s Dec(J2000) = +51d 34' 21.8" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 93%. The mask-weighted light curve shows a FRED like structure with the emission starting at ~T-15 sec, peaking at ~T-5 sec and ending at ~T+150 sec. T90 (15-350 keV) is 106.8 +- 26.7 sec (estimated error including systematics). The time-averaged spectrum from T-14.28 to T+111.24 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.70 +- 0.15. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-4.40 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/510341/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12727 SUBJECT: GRB 111225A: Swift-XRT refined Analysis DATE: 11/12/25 16:01:44 GMT FROM: Binbin Zhang at PSU B.-B. Zhang and M. H. Siegel (PSU) reports on behalf of the Swift-XRT team: We have analysed 10 ks of XRT data for GRB 111225A (Siegel et al. GCN Circ. 12720), from 94 s to 23.3 ks after the BAT trigger. The data comprise 556 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 12724). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.6 (+0.4, -0.3). At T+114 s the decay steepens to an alpha of 1.83 (+0.10, -0.09). The light curve breaks again at T+353 s to a decay with alpha=3.1 (+/-0.5), before a final break at T+590 s s after which the decay index is 1.80 (+0.11, -0.12). An early time flare (from T+214.6 to T+321.8 s) and a possible late time flare (from ~T+20000s) are excluded from the fit. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.43 (+/-0.07). The best-fitting absorption column is 2.09 (+0.16, -0.15) x 10^21 cm^-2, in excess of the Galactic value of 1.7 x 10^21 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.71 (+0.17, -0.15) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.5 x 10^-11 (5.7 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 0 (+7.7, -0) x 10^20 cm^-2 Galactic foreground: 1.7 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.71 (+0.17, -0.15) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00510341. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12728 SUBJECT: GRB 111225A: 1.23m CAHA optical observations DATE: 11/12/25 22:59:12 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC), P. Martorell (Obs. Guirguillano), P. Kubanek (IAA-CSIC & U. Valencia), S. Mottola (DLR, Berlin), report on behalf of a larger collaboration: "We have observed the field of GRB 111225A (Siegel et al. GCNC 12720) with the 1.23m CAHA telescope. The observations were carried out in Dec 25.74725 - 25.83561 UT (14.1--16.2 hours post burst) in the R-band with a total exposure time of 11x300+15x180s. We detect the optical afterglow of the burst with an R-band magnitude of R=21.60+/-0.16, with respect to the USNO B1.0 catalogue." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12729 SUBJECT: GRB 111225A: GRT Optical Observation DATE: 11/12/26 00:16:14 GMT FROM: Takanori Sakamoto at NASA/GSFC T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC), T. Okajima (GSFC), Y. Urata (NCU) We observed the field of GRB 111225A detected by Swift (trigger #510341; Siegel et al., GCN Circ. 12720) with the 14-inch Goddard Robotic Telescope (GRT) located at the Goddard Geophysical and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/). A total 20 images of 60 sec (10 images), 180 sec (5 images) and 300 sec (5 images) exposures were taken in the R filter starting from December 25 03:52:12 (UT) about 94 seconds after the trigger (50 seconds after the BAT position notice) and stopped on December 25 04:43:53 (UT). We do not detect the optical afterglow both in the individual images and the stacked image inside the enhanced XRT position (Evans et al., GCN #12724). The estimated upper limit of the combined image (total exposure of 3000 sec) is ~18.5 mag using the USNO-B1 catalog. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12730 SUBJECT: GRB111225A: MITSuME Okayama optical upper limits DATE: 11/12/26 02:09:16 GMT FROM: Daisuke Kuroda at OAO/NAOJ D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 111225A (Siegel et al., GCNC 12720) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. The observation started on 2011-12-25 09:00:08 UT (~5.2 hours after the burst). We did not find any new point source within the enhanced XRT error circle (Evans et al., GCNC 12724) and could not detect the previously reported afterglow (Klotz et al., GCNC 12722; Updike et al., GCNC 12723) in g' and Ic bands. Three sigma upper limits of the OT are listed below. We used GSC2.3 catalog for flux calibration. T0+[day] MID-UT T-EXP[sec] g' Ic ------------------------------------------------------ 0.25569 09:58:49 5700.0 >20.2 >19.6 ------------------------------------------------------ T0+ : Elapsed time after the burst [day] T-EXP: Total Exposure time [sec] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12731 SUBJECT: GRB 111225A: PAIRITEL NIR Upper Limits DATE: 11/12/26 06:06:41 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan (UC Berkeley) reports: We observed the field of GRB 111225A (Siegel et al., GCN 12720) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2011-12-26 01h13m05 UT, ~21.35 hr after the Swift Trigger. In mosaics taken simultaneously in the J, H, and Ks filters, we do not detect the optical afterglow (Siegel et al., GCN 12720; Klotz et al., GCN 12722; Updike et al., GCN 12723; Xin et al., GCN 12725; Gorosabel et al., GCN 12728). The preliminary photometry yields: post burst t_mid(h) exp.(s) filt U. Limit (3 sig) 22.45 4774 J > 18.4 22.45 4774 H > 17.6 22.45 4774 Ks > 16.9 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: 12733 SUBJECT: GRB 111225A: Keck/LRIS Afterglow Photometry DATE: 11/12/27 06:20:27 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko, J. S. Bloom, J. M. Silverman, A. N. Morgan (UC Berkeley), D. A. Perley (Caltech), A. Cucchiara, J. X. Prochaska (UCSC / UCO Lick), A. V. Filippenko (UC Berkeley), and P. E. Nugent (LBNL / UC Berkeley) report on behalf of a larger collaboration: We have imaged the field of GRB111225A (Siegel et al., GCN 12720) with the Low-Resolution Imaging Spectrometer (LRIS) mounted on the 10 m Keck I telescope beginning at 4:56 UT on 2012 Dec 26 (~ 25.1 hours after the Swift BAT trigger). We detect the optical afterglow in both the g' and R-band filters, with an approximate magnitude at this time of R ~ 23.2 (estimated uncertainty of 0.3 mag, due largely to preliminary calibration with respect to the USNO-B1 catalog). Compared with previously reported detections (Xin et al, GCN 12725, Gorosabel et al., GCN 12728), this suggests a steep fading of the afterglow emission at this late time (power-index alpha ~ 2.5). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12735 SUBJECT: GRB 111225A: Swift/UVOT Observations DATE: 11/12/27 16:51:36 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 111225A 95 s after the BAT trigger (Siegel et al., GCN Circ. 12720). A source consistent with the XRT position is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 00:52:37.22 = 13.15510 (deg.) Dec (J2000) = +51:34:19.5 = 51.57208 (deg.) with an estimated uncertainty of 0.67 arc sec. (radius, 90% confidence). The afterglow has not been detected since the first orbit. 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 u (fc) 95 345 246 19.46 +/- 0.17 v 610 18443 2140 >21.1 u 4385 16744 1475 >20.66 uvw1 659 12668 1212 >20.4 uvm2 634 11879 1337 >20.5 uvw2 354 17652 1780 21.36 +/- 0.31 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.26 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12740 SUBJECT: GRB 111225A, optical observations DATE: 11/12/28 18:26:56 GMT FROM: Eda Sonbas at NASA/GSFC TITLE: T100 observations of GRB 111225A Sonbas, E.(Adiyaman Univ.), Guver, T. (Sabanci Univ.), Gogus, E. (Sabanci Univ.), Uysal, O. (Akdeniz Univ.), Sahin T. (Akdeniz Univ.), Eker, Z. (TUG), T. Ozisik (TUG) on behalf of a larger collaboration. We observed the field of GRB 111225A (Siegel et al., GCN #12720) with the 1.0 meter T100 telescope (TUBITAK National Observatory, Antalya - Turkey), starting on December 25, 21:14 UT (~ 17 hours after the trigger). We obtained 3 x 60 s + 2 x 300 s exposures with R and B filters under moderate weather conditions (seeing 1.8"). We do not detect an optical afterglow at the enhanced XRT error circle reported by Evans et al., GCN #12724 in the combined R and B band images. We determine the following 3-sigma upper limits (calibrated to R2 and B2 mag. of USNO-B1) in the two bands: t - t0 Exposure (s) Filter mag. ~17.4 h 780 R > 22.5 ~17.5 h 780 B > 21.9 We are grateful to the TUBITAK National Observatory staff for promptly scheduling the observations and their technical support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12772 SUBJECT: GRB 111225A: Lightbuckets Optical Observations DATE: 11/12/29 20:12:26 GMT FROM: Tilan Ukwatta at MSU T. N. Ukwatta (MSU), E. Sonbas (GSFC/Adiyaman Univ.), T. Sakamoto (GSFC/UMBC), N. Gehrels (GSFC), J. Linnemann (MSU), K. Tollefson (MSU), and U. Abeysekara (MSU) We observed the field of Swift GRB 111225A (Siegel et al., GCN 12720) with the Lightbuckets 0.43m rental telescope LB-0002 in South Alpen, France. Ten 60 s observations were carried out in the R filter starting 2011-12-25 at 17:01:47 UT (~ 47 ks after the GRB trigger). We do not detect the optical afterglow both in the individual images and in the stacked image inside the XRT location. Our upper-limit based on the stacked observation (using the USNO-B1 catalog) is given below. Time after trigger Exposure (s) Filter Magnitude 13.2 hours 10 x 60 R > 19.7 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12793 SUBJECT: GRB 111225A: optical observations in CrAO DATE: 11/12/31 15:26:40 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 111125A (Siegel et al. GCN 12720) with Shajn telescope of CrAO observatory on Dec. 28 between (UT) 21:28: and 22:38 under a mean seeing of 1.7 arsces. We took several frames with exposure of 60 s in R-band. We clearly detect afterglow of GRB 111225A (Klotz et al. GCN 12722) on a stacked image. A photometry is based on the USNO B1.0 star 1415-0025726 (00 52 35.11 +51 33 58.9, J2000) assuming R=16.50. T_start UT T0+ Filter, Exposure, OT, uplim (3 sigma) (mid, d) (s) 21:28:14 3.7590 R 62x60 22.51 +/- 0.10 24.0 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12803 SUBJECT: GRB111225A: RAPTOR Early Detection of the Optical Counterpart DATE: 12/01/04 01:15:03 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 responded to Swift trigger 510341 (GRB 111225A, Siegel et al., GCN 12720). Unfiltered observations of the source location began at 03:51:27.2 UTC, 49.4 seconds after the BAT trigger time. The initial short exposures during the first two mintues of our response sequence do not clearly show the counterpart. However, stacking those images, 8 5-second exposures taken between 03:51:37.6 UTC and 03:52.46.0 UTC, gives a 5-sigma detection at counterpart location (Klotz et al., GCN 12722, and Updike et al., GCN 12723). Based on comparison to the USNO-B1 R-band, the measured brightness is R~18.7 +\- 0.3 at a t-mid of 03:52:12 UTC, 94 seconds after the Swift BAT trigger. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12808 SUBJECT: GRB 111225A, the review of the sky area in plate archives DATE: 12/01/05 13:04:16 GMT FROM: Valentyna Golovnya at Main Astro Obs,Kyiv V.V.Golovnya, L.M.Kizyun, L.K.Pakuliak (Main Astro Obs, Kyiv) report: We have undertaken the review of the sky area in vicinity of GRB 111225A (M. H. Siegel, GCN Circ.12735) on astronegatives, collected in Ukrainian NAS Main astronomical observatory plate archive (1976-1996). All the plates with the possible object appearance are digitized using Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL flatbed scanners and have been placed into Golosiiv Plate Archive database DBGPA with open access to them. The list of plates is given in the table: YYYYMMDD/TimeUT --Plates-- Exp. LimMag Star USNOA2 19831109/192323 GUA040C000250A 13.5 15.70 1350-00882390 19831109/194519 GUA040C000251A 13.0 15.20 1350-00878189 19840828/001418 GUA040C000469A 16.0 15.70 1350-00882390 19841019/211508 GUA040C000511A 15.9 15.70 1350-00882390 19841020/205803 GUA040C000525A 16.0 14.85 1350-00882046 Plates: –the plates archive identifier of DWA (D/F=400/2000, GUA040C M=103"/mm) of the Ukrainian NAS Main Astro obs. (Marsden's number - 83) the plate number [1]. Exp. - Duration of the maximum exposure (minutes). LimMag - Limited V mag, derived in the 20 minutes area around the location given in GCN Circ.12735: RA (J2000) = 00:52:37.22, Dec (J2000) = +51:34:19.5 Star USNOA2 - Comparison star. The preview images of 5 areas together with the 20x20 min.of arc area from SkyMap can be found in http://gua.db.ukr-vo.org/img/grb/111225A/index.html The images with full resolution are available via e-mail on demand. References: 1.L.Pakuliak DATABASE of GOLOSIIV PLATE ARCHIVE (DBGPA V2.0), http://gua.db.ukr-vo.org //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 12893 SUBJECT: GRB 111225A: optical observations DATE: 12/01/21 22:04:47 GMT FROM: Alexei Pozanenko at IKI, Moscow A.Volnova (SAI MSU), E. Klunko (ISTP), M. Andreev, A. Sergeev (Terskol Branch of INASAN), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the field of GRB 111225A (Siegel et al., GCN 12720) with AZT-33IK telescope of Sayan observatory (Mondy) on Dec. 25 between (UT) 17:37:41 - 18:25:58 in R filter under mean seeing (FWHM) of about 2.0". We also observed the field with Zeiss-2000 telescope of Mt. Terskol observatory on Dec. 26 between (UT) 17:37:23-18:46:37 in BRI filters under poor seeing (FWHM) of about 4.4". On stacked images of both epochs we did not find an optical counterpart (Siegel et al., GCN 12720; Klotz et al., GCN 12722; Adria et al., GCN 12723; Wren et al., GCN 12803). The photometry is based on the USNO-B1.0 star 1415-0025726 (J2000) 00:52:35.11 +51:33:58.9, assuming B = 17.56, R =16.50, I = 16.20: T0+, Filter, Exposure, OT, UL(3 sigma), Telescope (mid, d) (s) 0.63278 R 24 x 120 n/d 22.5 AZT-33IK 1.58789 B 10 x 90 n/d 22.0 Zeiss-2000 1.60285 R 10 x 90 n/d 21.5 Zeiss-2000 1.61677 I 10 x 90 n/d 20.5 Zeiss-2000 Upper limits above are consistent with upper limits of R~22.5 reported by Sonbas et al. (GCN 12740) and observations of the afterglow at R ~ 23.2 on ~ 1day after burst trigger (Cenko et al., GCN 12733). Taking into account the positive detection of the afterglow on 3.7590 days at R~22.5 (Rumyantsev et al., GCN 12793) one can suggest a strong rebrightening of the afterglow which is a rare case of late afterglow (3.7590 days) of an apparently nearby burst (cf. UVOT optical detection in uvw2 filter (Siegel, GCN 12735). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16079 SUBJECT: GRB 111225A: Archeological redshift of the Christmas Burst 2011 from GTC DATE: 14/04/04 11:37:47 GMT FROM: Christina Thoene at IAA-CSIC C.C. Thoene (IAA-CSIC) and A. de Ugarte Postigo (IAA-CSIC, DARK/NBI) report on behalf of a larger collaboration: We observed the Christmas burst of 2011, GRB 111225A (Siegel et al. GCN 12720), with the 10.4m GTC telescope+OSIRIS on December 25, 2011 at a mean time 23:27 UT, 19.61 hrs after the burst. The observations consisted of 2x1800 s exposure with grism R1000B, covering the wavelength range from 3700 to 7870A with a resolution of around R=1000. Initial analysis of the spectrum revealed continuum emission over the complete range but no significant features neither in absorption nor emission. However, a more careful analysis recently performed on the data with an improved pipeline revealed faint emission features of [OII], H-beta and [OIII], and marginal absorption of CaII at a common redshift of z=0.297, which we therefore identify as the redshift of the GRB. We apologise for the late notification. Better late than never.