//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10401 SUBJECT: GRB 100212A: Swift detection of a burst DATE: 10/02/12 14:25:34 GMT FROM: Scott Barthelmy at NASA/GSFC D. Grupe (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), S. Campana (INAF-OAB), V. D'Elia (ASDC), P. A. Evans (U Leicester), J. M. Gelbord (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), J. A. Kennea (PSU), O. M. Littlejohns (U Leicester), V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB), R. Margutti (Univ Bicocca&OAB), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), M. Perri (ASDC), P. Romano (INAF-IASFPA), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), R. L. C. Starling (U Leicester), G. Tagliaferri (INAF-OAB), T. N. Ukwatta (GSFC/GWU) and L. Vetere (PSU) report on behalf of the Swift Team: At 14:07:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 100212A (trigger=412081). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 356.462, +49.497 which is RA(J2000) = 23h 45m 51s Dec(J2000) = +49d 29' 50" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 2 sec. The peak count rate was ~5500 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 14:08:19.8 UT, 57.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 356.41805, 49.49497 which is equivalent to: RA(J2000) = 23h 45m 40.33s Dec(J2000) = +49d 29' 41.9" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 103 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 (1.3e+21 cm^-2, Kalberla et al. 2005), with an excess column of 2.5 (+1.73/-1.52) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 1.39e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 250 seconds with the U filter starting 280 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 typical 3-sigma upper limit has been about 19.2 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.18. Burst Advocate for this burst is D. Grupe (grupe 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: 10402 SUBJECT: GRB 100212A: candidate optical afterglow DATE: 10/02/12 21:32:58 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani, G. Leloudas, J. P. U. Fynbo (DARK/NBI), D. Xu (WIS and DARK/NBI), P. Jakobsson (Univ. Iceland), A. Somero, S. Katajainen (Tuorla Obs.), T. Pursimo (NOT), report on behalf of a larger collaboration: We observed the field of GRB 100212A (Grupe et al., GCN 10401) with the NOT equipped with ALFOSC. Observations started on Feb 12.841 UT (6.05 hr after the GRB), in the R band. Close to the refined XRT error circle (as reported in the SPER web page http://www.swift.ac.uk/sper/index.php at 21:30 UT), we detect a source which is not visible in the DSS. Its coordinates are (J2000): RA = 23:45:40.23 Dec = +49:29:40.7 The object is 2.5" away from the centre of the XRT position, currently reported to have a 2.2" error radius. The R-band magnitude of the source is R = 20.3 assuming R = 17.3 for the USNO star at RA = 23:45:42.93, Dec = +49:30:29.3. The source looks pointlike under a seeing of 1" and is clearly brighter than other closeby objects visible in the DSS. We suggest this object to be the afterglow of GRB 100212A. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10403 SUBJECT: GRB 100212A: Enhanced Swift-XRT position DATE: 10/02/13 03:11:08 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 699 s of XRT Photon Counting mode data and 3 UVOT images for GRB 100212A, 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 = 356.41830, +49.49432 which is equivalent to: RA (J2000): 23h 45m 40.39s Dec (J2000): +49d 29' 39.6" with an uncertainty of 2.0 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: 10404 SUBJECT: GRB 100212A: Swift-BAT refined analysis DATE: 10/02/13 03:44:18 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (GWU), 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/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) (i.e. the Swift-BAT team): Using the data set from T-61 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 100212A (trigger #412081) (Grupe, et al., GCN Circ. 10401). The BAT ground-calculated position is RA, Dec = 356.445, 49.492 deg, which is RA(J2000) = 23h 45m 46.9s Dec(J2000) = +49d 29' 30.5" with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 86%. The mask-weighted light curve shows multiple peaks. The main peak starts with weak emission at ~T-45 sec with the peak at ~T+0.2 sec and ends at ~T+30 sec. A second peak starts at ~T+75 and ends at ~T+135 sec. T90 (15-350 keV) is 136 +- 14 sec (estimated error including systematics). The time-averaged spectrum from T-4.8 to T+134.0 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.20 +- 0.22. The fluence in the 15-150 keV band is 9.1 +- 1.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.34 sec in the 15-150 keV band is 2.2 +- 0.2 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/412081/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10405 SUBJECT: GRB 100212A: Swift XRT refined analysis DATE: 10/02/13 04:52:41 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe (PSU) reports on behalf of the Swift-XRT team: We have analyzed 1.9 ks of XRT data for GRB 100212A (Grupe et al. GCN Circ. 10401), from 64 s to 7 ks after the BAT trigger. The data comprise 409 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 10403). The light curve is complicated displaying several strong flares up to 700s after the burst. The underlying afterglow light curve suggests a step decay slope of alpha=2.89+/-0.09. However, the data of the second orbit indicate the beginning of the plateau phase with a significantly flatter decay slope. Predictions of the further development of the X-ray light curve are not reliable at this point. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.03 (+/-0.03). The best-fitting absorption column is 1.97 (+/-0.08) x 10^21 cm^-2, in excess of the Galactic value of 1.3 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (5.6 x 10^-11) ergs cm^-2 count^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00412081. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10406 SUBJECT: GRB 100212A: Fermi GBM detection DATE: 10/02/13 05:36:10 GMT FROM: Sylvain Guiriec at UAH Sylvain Guiriec (UAH) and Dave Tierney (UCD/MPE) report on behalf of the Fermi GBM Team: "At 14:07:29 UT on 12 February 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100212A (trigger 287676444 / 100212588). This GRB has also been detected independently with Swift/BAT and the GBM location is consistent with the Swift/XRT location within the error bars (Grupe et al. GCN Circ. 10401). The angle from the Fermi LAT boresight is 15 degrees. The GRB duration (T90) is about 2.30+/-0.14 s (8-1000 keV). The time-averaged spectrum from T0-0.51 s to T0+0.26 s is adequately fit by a power law with an index of -1.62+/-0.06 (Castor C-stat 394 for 363 d.o.f.). It is also adequately fit by a power law function with an exponential high energy cutoff. The power law index is -1.15 +/- 0.20 and the cutoff energy, parameterized as Epeak, is 159.30 +/- 45.10 keV (Castor C-stat 389 for 362 d.o.f.). The event fluence (8-1000 keV) in the T90 time interval is (3.81+/-0.06)E-7 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.7 s in the 8-1000 keV band is 3.16 +/- 0.22 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: 10407 SUBJECT: GRB 100212A: LOAO R-band Detection/V-band Observation DATE: 10/02/13 11:04:10 GMT FROM: Myungshin Im at Seoul Nat U M. Im (CEOU/Seoul National Univ) and Y. Urata (NCU) on behalf of EAFON team. We observed GRB100212A (Grupe et al. GCN 10401) in R and V using the 1.0m telescope at Mt. Lemmon (Arizona, US) operated by the Korea Astronomy Space Science Institute. The observation started at Feb. 13, 02:05:14 UT, about 12 hours after the BAT trigger. The stacked R-band image shows a marginal detection of the afterglow with R ~ 22.5 +- 0.2 mag, at the location reported by Malesani et al. (GCN 10402). The mid-point for the R-band imaging is 02:17:36 UT. The object does not appear in a stacked V-band image, which was taken right after the R-band observation. Our obseravation shows that the afterglow candidate faded significantly since the report by Malesani et al. (GCN 10402), confirming that this is indeed a GRB afterglow. The photometry was calibrated against the USNO star (GCN 10402). We thank the LOAO operator, J. Yoon for her assistance of this observation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10408 SUBJECT: Swift/UVOT observations of GRB120212A DATE: 10/02/13 15:32:09 GMT FROM: Massimiliano de Pasquale at MSSL-UCL M. De Pasquale (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 100212A 68 s after the BAT trigger (Grupe et al., GCN Circ. 10401) with the finding chart in the white filter. No optical afterglow is detected within the enhanced XRT error circle position (Osborne et al., GCN Circ 10403) in the initial UVOT exposure and in all other summed exposures at 3 sigma level. The optical source detected by NOT (Malesani et al, GCN circ 10402) is not detected either at 3 sigma level. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 68 218 147 >20.6 u_FC 281 530 246 >19.8 white 68 1181 353 >21.2 v 610 1231 78 >18.7 b 536 1156 58 >19.5 u 281 1304 304 >19.8 w1 660 1280 78 >19.2 m2 635 1255 78 >19.3 w2 586 1206 78 >19.6 The values quoted above are not corrected for the strong Galactic extinction due to the reddening of E(B-V) = 0.18 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 10409 SUBJECT: Swift/UVOT observations of GRB100212A - correction of the name of the burst DATE: 10/02/13 15:37:53 GMT FROM: Massimiliano de Pasquale at MSSL-UCL The previous GCN 10408 dealt with GRB100212A, not GRB120212A as erroneously written. I apologize for the mistake.