GRB130912A

This page lists all entries on GRB130912A in GRBweb

Summary Fermi GBM IPN Swift GCN 15212 GCN 15213 GCN 15214 GCN 15215 GCN 15216 GCN 15217 GCN 15218 GCN 15219 GCN 15221 GCN 15222 GCN 15224 GCN 15225 GCN 15226 GCN 15227 GCN 15229 GCN 15239

Summary table
Variable Value Source
GRB_name_Fermi GRB130912358
T0 8:34:57 UTC GCN_circulars,Swift Det
ra 47.5925° Swift
decl 13.9970° Swift
pos_error 1.94e-04° Swift
T90 0.512 s Fermi_GBM
T90_error 0.143 s Fermi_GBM
T90_start 8:34:57.932 UTC Fermi_GBM
fluence 7.01e-07 erg/cm² Fermi_GBM
fluence_error 1.77e-08 erg/cm² Fermi_GBM
T100 1.444 s
GBM_located False
mjd 56547.35760416667 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB130912358
trigger_name bn130912358
ra 47.5904°
decl 13.9956°
pos_error 6.28e+00°
datum 2013-09-12
t_trigger 8:34:57.996 UTC
T90 0.512 s
T90_error 0.143 s
T90_start 8:34:57.932 UTC
fluence 7.01e-07 erg/cm²
fluence_error 1.77e-08 erg/cm²
flux_1024 4.37e+00 erg/cm²/s
flux_1024_error 2.84e-01 erg/cm²/s
flux_1024_time -1.92e-01 erg/cm²/s
flux_64 1.56e+01 erg/cm²/s
flux_64_error 1.47e+00 erg/cm²/s
IPN table
GRB_name GRB130912A
ra 47.6167°
decl 13.9667°
pos_error 5.00e-02°
Swift table
GRB_name GRB130912A
t_trigger 8:34:57 UTC
ra 47.5925°
decl 13.9970°
pos_error 1.94e-04°
T90 0.28 s
fluence 1.70e-07 erg/cm²
GCN 15212 table
GRB_name GRB130912A
GCN_number 15212
Detection_method Swift Det
t_trigger 8:34:57 UTC
ra 47.6150°
decl 13.9740°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15212 SUBJECT: GRB 130912A: Swift detection of a short burst DATE: 13/09/12 08:57:42 GMT FROM: David Palmer at LANL V. D'Elia (ASDC), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), D. Malesani (DARK/NBI), C. B. Markwardt (NASA/GSFC), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team: At 08:34:57 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130912A (trigger=570465). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 47.615, +13.974 which is RA(J2000) = 03h 10m 28s Dec(J2000) = +13d 58' 28" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a short spike with substructure with a duration of about 0.5 sec. The peak count rate was ~11000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 08:36:31.7 UT, 93.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 47.59060, 13.99546 which is equivalent to: RA(J2000) = 03h 10m 21.74s Dec(J2000) = +13d 59' 43.7" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 115 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 (1.24 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 2.1 (+1.66/-1.48) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 98 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 none of the XRT error circle. 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 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.28. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.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 15213 table
GRB_name GRB130912A
GCN_number 15213
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15213 SUBJECT: GRB 130912A: KAIT optical upper limit DATE: 13/09/12 09:58:32 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to the short-duration GRB 130912A (D'Elia et al., GCN 15212) starting at 08:48:04 UT, ~13 minutes after the burst. Observations were performed with an automatic sequence in V, I, and clear filters (20 s exposure for each image). Due to a technical issue, the first useful image begain ~35 minutes after the burst. We do not detect any new source in the XRT error circle. The estimated limiting magnitude in our first clear-band (close to R) image is about 19.6 (calibrated to USNO B1.0) at a midtime of ~36 minutes after the burst.
GCN 15214 table
GRB_name GRB130912A
GCN_number 15214
Detection_method GROND
Circular_text TITLE: GCN CIRCULAR NUMBER: 15214 SUBJECT: GRB 130912A: GROND observations DATE: 13/09/12 11:49:50 GMT FROM: Vladimir Sudilovsky at MPE M. Tanga (MPE Garching), S. Klose (TLS Tautenburg), V. Sudilovsky (MPE Garching), R. Filgas (IEAP Prague), J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of GRB 130912A (Swift trigger 570465; D'Elia et al. 2013, GCN #15212) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile). Observations started at 08:50 UT on 12 Sep 2013, 16 min after the GRB trigger. At the northern edge of the r=2.2 arcsec XRT error circle (D'Elia et al., GCN #15173) we detect a faint source at coordinates RA (J2000) = 03:10:22.23 Dec. (J2000) = 13:59:48.7 with an error of 0".3 arcseconds. However, the object seems to be constant over the first hour of our observations, with a preliminary magnitude of r' = 22.0+-0.2 mag, calibrated against the GROND zeropoint. Given the constant flux, this might be the host galaxy of GRB 130912A.
GCN 15215 table
GRB_name GRB130912A
GCN_number 15215
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15215 SUBJECT: GRB 130912A: REM optical/NIR upper limits DATE: 13/09/12 12:39:24 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, D. Fugazza, A. Melandri (INAF-OAB), V. D'Elia (ASI/ASDC) report on behalf of the REM team: We observed the field of the short GRB 130912A (D'Elia et al., GCN 15212) simultaneously in the optical and near infrared with the the 60-cm robotic telescope REM at La Silla Observatory (Chile). The observations started at 08:47:33 UT, 12.6 min after the GRB. No source is detected within the XRT error circle nor at the position of the possible host galaxy reported by Tanga et al. (GCN 15214). The limiting magnitudes are r'=19.6 and H=16.1 (Vega; calibrated against the USNOB1 and the 2MASS catalogue, respectively) at a mid t-t0=17.5 minutes.
GCN 15216 table
GRB_name GRB130912A
GCN_number 15216
Detection_method Swift-BAT Det
ra 47.6060°
decl 13.9990°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15216 SUBJECT: GRB 130912A, Swift-BAT refined analysis DATE: 13/09/12 13:43:47 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), E. E. Fenimore (LANL), N. Gehrels (GSFC), A. Y. Lien (NASA/GSFC/ORAU), 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-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130912A (trigger #570465) (D'Elia, et al., GCN Circ. 15212). The BAT ground-calculated position is RA, Dec = 47.606, 13.999 deg which is RA(J2000) = 03h 10m 25.6s Dec(J2000) = +13d 59' 55.7" with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment). The partial coding was 31%. The mask-weighted light curve shows two overlapping peaks. T90 (15-350 keV) is 0.28 +- 0.03 sec (estimated error including systematics). The time-averaged spectrum from T+0.00 to T+0.32 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.20 +- 0.20. The fluence in the 15-150 keV band is 1.7 +- 0.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T-0.34 sec in the 15-150 keV band is 2.2 +- 0.3 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/570465/BA/
GCN 15217 table
GRB_name GRB130912A
GCN_number 15217
Detection_method Swift-XRT Det
ra 47.5926°
decl 13.9970°
Circular_text TITLE: GCN CIRCULAR NUMBER: 15217 SUBJECT: GRB 130912A: Enhanced Swift-XRT position DATE: 13/09/12 15:48:56 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 1499 s of XRT Photon Counting mode data and 2 UVOT images for GRB 130912A, 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 = 47.59265, +13.99703 which is equivalent to: RA (J2000): 03h 10m 22.24s Dec (J2000): +13d 59' 49.3" with an uncertainty of 1.6 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.
GCN 15218 table
GRB_name GRB130912A
GCN_number 15218
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15218 SUBJECT: GRB 130912A: Skynet DSO-14/Yerkes-41/PROMPT-CTIO observations DATE: 13/09/12 17:07:49 GMT FROM: Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet A. Trotter, D. Reichart, J. Haislip, A. LaCluyze, A. B. Smith, D. Caton, L. Hawkins, V. Hoette, K. Cudworth, D. Harper, R. Kron, T. Linder, R. Russell, E. Struble, T. Berger, H. T. Cromartie, R. Egger, A. Foster, N. Frank, K. Ivarsen, M. Maples, J. Moore, M. Nysewander, and J. A. Crain report: Skynet observed the Swift/XRT localization of GRB 130912A (D'Elia et al., GCN 15212, Swift trigger 570465) with the 14" telescope at the Appalachian State University Dark Sky Observatory (DSO-14) in NC, USA (R and I bands), the 41" telescope of Yerkes Observatory in WI, USA (r' and i' bands), and with four 16" telescopes of the PROMPT array at CTIO, Chile (B, V, R, and I bands). Starting at 2013-09-12, 08:47 UT and continuing until 10:26 UT (t=12m-111m post-trigger), Skynet took a total of 72 160s exposures. In stacked images, we do not detect an optical source in any band in or near the XRT error circle. Our 3-sigma limiting magnitudes are tabulated below: ================================== tmid scope expos fil limit ================================== 21m DSO-14 2x160s I >18.7 24m DSO-14 2x160s R >19.6 61m Prompt5 10x160s I >20.6 61m Prompt4 10x160s R >21.0 61m Prompt1 10x160s V >21.3 61m Prompt3 10x160s B >21.1 63m Y-41 11x160s i' >21.6 60m Y-41 9x160s r' >21.9 66m Y-41 8x160s g' >21.8 ================================== BVRI magnitudes are in the Vega System, and g'r'i' magnitudes are in the AB system, calibrated to 4 APASS stars in the field. Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.28 (Schlegel et al. 1998). No further Skynet observations are scheduled.
GCN 15219 table
GRB_name GRB130912A
GCN_number 15219
Detection_method Fermi GBM Det
t_trigger 8:34:58 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 15219 SUBJECT: GRB 130912A: Fermi GBM detection DATE: 13/09/12 17:43:08 GMT FROM: Binbin Zhang at PSU Bin-Bin Zhang (UAH), Suzanne Foley (UCD) and Narayana Bhat (UAH) report on behalf of the Fermi GBM Team: "At 08:34:58.00 UT on 12 September 2013, the Fermi Gamma-Ray Burst Monitor triggered and located a short GRB 130912A (trigger 400667700 / 130912358), which was also detected by the Swift (D'Elia et al., GCN 15212). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 102 deg from Swift/XRT position (Beardmore et al. GCN 15217). The GBM light curve consists of a single pulse with of multiple peaks with a duration (T90) of about 0.5 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.448 s is well fit by a Band function with alpha = -1.0 +/- 0.1, beta = -1.9 +/- 0.2 and Epeak= 1225 +/- 599 keV. The event fluence (10-1000 keV) in this time interval is (2.29 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.13 s in the 10-1000 keV band is 4.5 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 15221 table
GRB_name GRB130912A
GCN_number 15221
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15221 SUBJECT: GRB 130912A: Swift-XRT refined Analysis DATE: 13/09/12 20:57:04 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), V. Mangano (PSU), M.C. Stroh (PSU) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 6.6 ks of XRT data for GRB 130912A (D'Elia et al. GCN Circ. 15212), from 104 s to 13.1 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 15217). The light curve can be modelled with a power-law decay with a decay index of alpha=1.24 (+/-0.05). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.49 (+0.20, -0.12). The best-fitting absorption column is 1.29 (+0.67, -0.05) x 10^21 cm^-2, consistent with the Galactic value of 1.2 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 5.0 x 10^-11 (5.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.29 (+0.67, -0.05) x 10^21 cm^-2 Galactic foreground: 1.2 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.49 (+0.20, -0.12) If the light curve continues to decay with a power-law decay index of 1.24, the count rate at T+24 hours will be 1.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.0 x 10^-14 (9.2 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00570465. This circular is an official product of the Swift-XRT team.
GCN 15222 table
GRB_name GRB130912A
GCN_number 15222
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15222 SUBJECT: GRB 130912A: P60 Observations DATE: 13/09/12 21:02:47 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (NASA/GSFC), V. Sudilovsky, M. Tanga, and J. Greiner (MPE Garching), report on behalf of a larger collaboration: We have imaged the field of the Swift short GRB130912A (D'Elia et al., GCN 15212) with the robotic Palomar 60 inch telescope in the r', i', and z' filters. Observations began at 8:48 UT on 2013 September 12 (13 min after the Swift trigger). Within the enhanced XRT error circle (Beardmore et al., GCN 15217) we detect the faint source reported by Tanga et al. (GCN 15214) in all three filters. Using calibration stars from GROND, we measure an AB magnitude of r' = 21.77 +/- 0.20 mag at a mean time of 8:58 UT and r' = 22.09 +/- 0.25 at 09:28 UT (23 and 53 min after the Swift trigger, respectively). The lack of significant variability implies either a shallow afterglow decay index, or this source may be the host galaxy of GRB130912A, as suggested by Tanga et al. (GCN 15214).
GCN 15224 table
GRB_name GRB130912A
GCN_number 15224
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15224 SUBJECT: GRB 130912A: WHT confirmation of optical counterpart DATE: 13/09/13 12:59:55 GMT FROM: Andrew Levan at U.of Leicester N.R. Tanvir, K. Wiersema (U. Leicester), A.J. Levan (U. Warwick) report for a larger collaboration: "We observed the location of GRB 130912A (D'Elia et al. GCN 15212) with the William Herschel Telescope, beginning at approximately 05 UT on 13 September 2013, roughly 20 hours after the burst trigger. At this epoch we obtained observations in the g,i and J-bands utilising ACAM and LIRIS. At the location of the counterpart identified by Tanga et al. (GCN 15214) and Cenko et al. (GCN 15222) we detect no source in our g-band observations (limiting magnitude g~25), and a source which is only weakly detected in the i-band and J-band (i~24). This implies that the light observed at earlier epochs when the source was measured at r=22 was due to a significant contribution from the optical transient, and that any underlying host galaxy is faint."
GCN 15225 table
GRB_name GRB130912A
GCN_number 15225
Detection_method Konus-Wind Det
t_trigger 8:35:02.290 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 15225 SUBJECT: Konus-Wind observation of GRB 130912A DATE: 13/09/13 13:20:09 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline, on behalf of the Konus-Wind team, report: The short-duration GRB 130812A (Swift-BAT trigger 570465: D'Elia et al. GCN 15212, Krimm et al. GCN 15216; Fermi-GBM detection: Zhang et al. GCN 15219) triggered Konus-Wind at T0=30902.290 s UT (08:35:02.290). The burst light curve shows two peaks in the time interval from ~T0-0.1 s to ~T0+0.3 s. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130912_T30902/ As observed by Konus-Wind, the burst had a fluence of (1.6 0.2)x10-6 erg/cm2, and a 16-ms peak flux, measured from T0-0.032, of (2.2 0.6)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The 3-channel time-integrated spectrum (measured from T0-0.128 to T0+0.256 s) can be modeled, in the 25 keV - 1.5 MeV range, by the cutoff power law with the following model parameters: the photon index alpha = -0.96 0.08, and the peak energy Ep = 580 65 keV. The 3-channel spectrum at the maximum count rate (measured from T0-0.128 to T0+0.256 s) can be modeled, in the 25 keV - 1.5 MeV range, by the cutoff power law with the following model parameters: the photon index alpha = -1.07 0.12, and the peak energy Ep = 1020 320 keV. All the quoted results are preliminary.
GCN 15226 table
GRB_name GRB130912A
GCN_number 15226
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15226 SUBJECT: GRB 130912A: RATIR Optical and NIR Upper Limits DATE: 13/09/13 15:25:38 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos A. de Diego (UNAM), Leonid Georgiev (UNAM), Jess Gonzlez (UNAM), Carlos Romn-Ziga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report: We observed the field of GRB 130912A (D'Elia et al., GCN 15212) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronmico Nacional on Sierra San Pedro Mrtir from 2013/09 13.30 to 2013/09 13.49 UTC (22.58 to 27.11 hours after the BAT trigger), obtaining a total of 5.33 hours exposure in the r and i bands and 2.24 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle, in comparison with USNO-B1 and 2MASS, we obtain the following upper limits (3-sigma): r > 23.89 i > 23.79 Z > 22.86 Y > 22.38 J > 22.30 H > 21.78 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Our observations confirm that the source faded and is therefore the short GRB afterglow. We thank the staff of the Observatorio Astronmico Nacional in San Pedro Mrtir.
GCN 15227 table
GRB_name GRB130912A
GCN_number 15227
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15227 SUBJECT: GRB 130912A: 5.8 GHz VLA upper limit DATE: 13/09/13 21:59:59 GMT FROM: Wen-fai Fong at CFA W. Fong, B. A. Zauderer and E. Berger (Harvard) report: "We observed the field of the short-duration GRB 130912A (D'Elia et al., GCN 15212; Zhang et al., GCN 15219; Golenetskii et al., GCN 15225) with the Karl G. Jansky Very Large Array (VLA) beginning on 2013 Sep 13.26 UT (21.85 hr post-burst) at a mean frequency of 5.8 GHz. In 1 hour of observations, we do not detect any radio source in coincidence with the optical afterglow (Tanga et al., GCN 15214; Cenko et al., GCN 15222; Tanvir et al., GCN 15224; Butler et al., GCN 15226) or within the enhanced XRT position (Beardmore et al., GCN 15217). We therefore place a 3-sigma limit of 29 microJy on the radio afterglow of GRB 130912A at 21.85 hr after the burst. We thank the VLA staff for quickly executing these observations."
GCN 15229 table
GRB_name GRB130912A
GCN_number 15229
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 15229 SUBJECT: GRB 130912A: Swift/UVOT Upper Limits DATE: 13/09/15 20:52:11 GMT FROM: Margaret Chester at PSU M. M. Chester (PSU) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130912A 99 s after the BAT trigger (D'Elia et al., GCN Circ. 15212). No optical afterglow consistent with the enhanced XRT position (Beardmore et al. GCN Circ. 15217) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposures and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 99 249 147 >20.7 u_FC 311 561 246 >20.2 white 99 6848 785 >21.4 v 640 23984 1395 >20.3 b 566 30470 1907 >21.6 u 311 36236 3907 >21.6 w1 690 35508 3836 >22.1 m2 1070 34601 2827 >21.8 w2 616 23070 1376 >21.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.28 in the direction of the burst (Schlegel et al. 1998).
GCN 15239 table
GRB_name GRB130912A
GCN_number 15239
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 15239 SUBJECT: GRB 130912A: AAO optical upper limit DATE: 13/09/21 16:53:43 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), R. Inasaridze (AAO), O. Kvaratskhelia (AAO), V. Ayvazian(AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of Swift GRB 130912A (D'Elia et al., GCN 15212) with AS-32 (0.7m) telescope of Abastumani Observatory starting Sep., 13 (UT) 00:18:46. We obtained several unfiltered frames with exposures of 120 s. On stacked images within the enhanced XRT circle (Beardmore et al., GCN 15217) we did not detect an optical counterpart reported by Tanga et al. (GCN 15214). The details of the photometry are the following: t_start, UT filter exptime,s t-t0, mid, days OT uplim 21:39:21 None 31*120 0.68394 n/d 22.3 The photometry is based 3 USNO-B1.0 stars: USNO-B1.0 id RA Dec R2 1040-0030312 03:10:30.46 +14:01:11.1 19.44 1040-0030310 03:10:29.14 +14:01:21.6 17.38 1040-0030302 03:10:25.12 +14:00:31.6 15.90