This file contains both GRB 070612A and GRB 070612B //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6509 SUBJECT: GRB 070612: Swift detection of a burst DATE: 07/06/12 02:53:27 GMT FROM: Scott Barthelmy at NASA/GSFC D. Grupe (PSU), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU), W. B. Landsman (NASA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), D. C. Morris (PSU), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 02:38:45 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 070612 (trigger=282066). The BAT on-board calculated location is RA, Dec 121.385, +37.266 which is RA(J2000) = 08h 05m 32s Dec(J2000) = +37d 15' 56" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single hard- spectrum FRED peak with a duration of about 30 sec. The peak count rate was ~1100 counts/sec (15-350 keV), at ~-1 sec after the trigger. Because of a Sun constraint, the spacecraft did not slew promptly to the BAT position, and so there are no XRT or UVOT data products to analyze. XRT and UVOT will not be able to observe this target until the end of August. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6510 SUBJECT: GRB070612 - SDSS Pre-Burst Observations DATE: 07/06/12 03:34:29 GMT FROM: Richard J. Cool at U.of AZ/Steward Obs Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report: The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB070612 prior to the burst. As these data should be useful as a pre-burst comparison and for calibrating photometry, we are supplying the images and photometry measurements for this GRB field to the community. Data from the SDSS, including 5 FITS images, 3 JPGS, and 3 files of photometry and astrometry, are being placed at http://mizar.as.arizona.edu/~grb/public/GRB070612 We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=121.385 (08:05:32.4), dec=37.2660 (37:15:57.6); GCN 6509), as well as 3 gri color-composite JPGs (with different stretches). The units in the FITS images are nanomaggies per pixel. A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS astrometric information. In the file GRB070612_sdss.calstar.dat, we report photometry and astrometry of 396 bright stars (r<20.5) within 15' of the burst location. The magnitudes presented in this file are asinh magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118, 1406). Beware that some of these stars are not well-detected in the u-band; use the errors and object flags to monitor data quality. In the files GRB070612_sdss.objects_flux.dat and GRB070612_sdss.objects_magnitudes.dat, we report photometry of 1013 objects detected within 6' of the GRB position. We have removed saturated objects and objects with model magnitudes fainter than 23.0 in the r-band. The fluxes listed in GRB070612_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB070612_sdss.objects_magnitudes.dat are asinh magnitudes. All quantities reported are standard SDSS photometry, meaning that they are very close to AB zeropoints and magnitudes are quoted in asinh magnitudes. Photometric zeropoints are known to about 2% rms. None of the photometry is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis (1998) predictions for this region are A_U=0.281 mag, A_g=0.207 mag, A_r = 0.150 mag, A_i=0.114 mag, and A_z=0.081 mag. The file GRB070612_sdss.spectro.dat contains a list of the 2 objects with SDSS spectroscopy within 6 arcminutes of the GRB position. In addition to the redshift and 1-sigma error for each object, this file also lists the object spectroscopic classification. SDSS astrometry is generally better than 0.1 arcsecond per coordinate. Users requiring high precision astrometry should take note that the SDSS astrometric system can differ from other systems such as those used in other notices; we have not checked the offsets in this region. More detailed information pertaining to our SDSS GRB releases can be found in our initial data release paper (Cool et al. 2006, PASP 118, 733). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr5. These data have been reduced using a slightly different pipeline than that used for SDSS public data releases. We cannot guarantee that the values here will exactly match those in the data release in which these data are included. In particular, we expect the photometric calibrations to differ by of order 0.01 mag. This note may be cited, but please also cite the SDSS data release paper, Adelman-McCarthy et al. (2006, ApJS, 162, 38), when using the data or referring to the technical documentation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6511 SUBJECT: GRB 070612B: Swift detection of a burst DATE: 07/06/12 06:33:33 GMT FROM: Scott Barthelmy at NASA/GSFC D. Grupe (PSU), S. D. Barthelmy (GSFC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU), W. B. Landsman (NASA/GSFC), C. B. Markwardt (CRESST/GSFC/UMD), D. M. Palmer (LANL), J. L. Racusin (PSU), P. Romano (Univ. Bicocca & INAF-OAB) and M. C. Stroh (PSU) report on behalf of the Swift Team: At 06:21:17 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 070612B (trigger=282073). The BAT on-board calculated location is RA, Dec 261.713, -8.719 which is RA(J2000) = 17h 26m 51s Dec(J2000) = -08d 43' 06" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showes a single peak with a duration of about 20 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. Because of an Earth limb constraint, the spacecraft did not slew promptly to the BAT position, and so there are no immediate XRT or UVOT data products to analyze. XRT and UVOT will begin observing this target at 07:13 UT. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6514 SUBJECT: GRB 070612B: Swift XRT position from downlink data DATE: 07/06/12 07:49:35 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe (PSU), P. Evans (U Leicester), report on behalf of the Swift Team: Swift XRT started observing the afterglow of GRB 070612B (GCN circ 6511) at 07:15:15.59, 3239s after the BAT trigger. We found a bright, uncatalogued, possibly fading source in the XRT data. Using 272 of prompt downlinked data, we find a position RA, Dec 261.7267, -8.7524 which is RA(J2000) = 17 26 54.4 Dec(J2000) = -08 45 08.7 with an uncertainty of 4.7 arcsec (radius, 90% containment). Further analysis of the data will be performed with the ground-processed data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6515 SUBJECT: GRB 070612A: SARA detection of possible OT DATE: 07/06/12 08:20:57 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike, Dieter H. Hartmann (Clemson University), Gary Henson (ETSU), Robert Mesler, Christina Bunker, and Jason Carson (ETSU/SARA REU program) report: We imaged the field of GRB 070612 (GCN 6509, Grupe et al.) beginning 1 hour and 17 minutes after the trigger (282006) with the SARA 0.9m at Kitt Peak under decent weather conditions and high airmass. We obtained 20 minutes of exposures in the R band before the target set. We detect a source at RA 08:05:28.533, Dec +37:16:09.57 (+/- 1") at an R-band magnitude of 17.16 +/- 0.17 calibrated relative to 5 USNO B1.0 stars. It appears that this coincides with a source in the SDSS images near this location (GCN 6510, Cool et. al), but appears significantly brighter than two nearby sources of similar magnitude. Thus, we identify this as a possible afterglow signature, however we cannot establish whether or not it is fading. We encourage further observations. The SARA Homepage can be found at: http://saraobservatory.org This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6516 SUBJECT: GRB 070612B: KAIT limits DATE: 07/06/12 08:32:16 GMT FROM: Weidong Li at UC Berkeley KAIT/LOSS W. Li, R. J. Foley, D. A. Perley, J. S. Bloom, and A. V. Filippenko, University of California, Berkeley, on behalf of the KAIT GRB team, report: The robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory observed GRB 070612B detected with Swift (Trigger 282073; Grupe et al. GCN 6511). The automatic sequence started at 06:22:01, 44 s after the burst. The BAT location and the XRT position (Grupe & Evans GCN 6514) have been monitored in V, I, and clear filters, with varying exposure times. The observations are still on-going. Our image processing pipeline did not find any new objects within the XRT error circle, with the following photometry limits (calibrated with USNO B1.0). These magnitudes have not been corrected for Galactic extinction, which as estimated by the NED extinction calculator is approximately E(B-V) = 0.838 mag in this direction. ====================================================================== Start UT t(GRB) Filter Exp(s) 3sigma-limit 06:22:01 44s clear 5.0 18.1 06:22:09 52s clear 5.0 18.2 06:22:17 60s clear 5.0 18.2 06:22:25 68s clear 5.0 18.1 06:22:34 77s clear 5.0 18.1 06:22:42 85s clear 5.0 18.1 06:23:10 113s V 15.0 17.1 06:23:36 139s I 15.0 18.0 06:24:00 163s clear 15.0 18.8 06:24:31 194s V 45.0 17.6 06:25:27 250s I 45.0 18.5 06:26:21 304 clear 45.0 19.3 ======================================================================== More images, mostly 60 s exposures in the I and clear filters, have been obtained. No obvious OA was found in the XRT error circle to a limiting magnitude of 19.0 - 19.9 mag, at t= 304s to 6642s after the burst. More analyses are in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6517 SUBJECT: GRB070612B: P60 Observations DATE: 07/06/12 08:56:35 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko, A. Rau (Caltech) and D. B. Fox (Penn State) report on behalf of a larger collaboration: We have imaged the field of GRB070612B (Grupe et al., GCN 6511) with the automated Palomar 60-inch telescope. Images were taken in the Kron R and Sloan i' and z' filters beginning approximately 12 minutes after the burst. We find no sources inside the XRT error circle (Grupe and Evans, GCN 6514). Photometric calibration for the limits below was performed using USNO B-1 mangitudes converted to the SDSS photometric sytem using empirical relations from Jordi, Grebel & Ammon (A&A 460, 339, 2006): t_b (min.) Filter Mag. Limit ----------------------------------------------------------------------- 21.2 i' > 21.0 22.7 z' > 20.5 We marginally detect a source just outside of the XRT error circle in our i' coaddition. The source, with i' magnitude ~ 22.0, is located at coordinates (J2000.0): RA: 17:26:54.936 Dec: -08:45:08.35 This source is not present in either our R- our z'-band imaging of this field. Because of the faintness, we cannot assess the variability of this source at the present time. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6518 SUBJECT: GRB 070612B: FRAM limit DATE: 07/06/12 13:16:52 GMT FROM: Martin Jelinek at Inst.Astrophys.Andalucia,Granada Martin Jelínek, Petr Kubánek (IAA CSIC Granada, Spain), and Michael Prouza (Columbia U. New York, USA and FZU Praha, Czech Rep.) on behalf of the FRAM team, coordinated by FZU Praha, Czech Rep. report "The wide field camera of the telescope FRAM, located at Pierre Auger observatory in Malargue, Argentina, followed the Swift GRB 070612B (Grupe et al. GCNs 6511 and 6514). 20s R-band (lambda_eff = 640nm, limmag = 14.8) images were obtained starting 62s after the GRB (45s after receiving the notification). We do not detect any new source in single nor combined images within the BAT or XRT errorboxes." this message may be cited //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6519 SUBJECT: GRB 070612B: Swift/UVOT upper limits DATE: 07/06/12 15:15:50 GMT FROM: Wayne Landsman at GSFC/SSAI W. Landsman (NASA/GSFC) and D. Grupe (PSU) report on behalf of the Swift/UVOT team. The Swift/UVOT observed the field of GRB 070612B starting 3256 s after the BAT trigger (Grupe et al., GCN Circ. 6511). The UVOT observations were delayed due to a Earth-limb constraint. We do not find any source in any of the UVOT observations inside the refined XRT error circle (Grupe et al., GCN Circ. 6514). The 3-sigma upper limits for detecting a source in the first finding chart (FC) exposure and co-added frames are: Filter T_start(s) T_stop(s) Exp(s) Mag (3-sigma UL) Wh (FC) 3256 3356 98 >20.3 Wh 3256 9882 1201 >21.7 V 3238 11624 1113 >20.0 B 4180 5813 393 >20.4 U 3975 5608 393 >20.1 UVW1 3772 5404 393 >20.1 UVM2 3567 5199 393 >20.0 UVW2 4590 10888 1082 >20.9 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6521 SUBJECT: GRB 070612B: Swift-XRT refined analysis DATE: 07/06/12 20:01:19 GMT FROM: Dirk Grupe at PSU/Swift-XRT D. Grupe (PSU) reports on behalf of the Swift/XRT team We have analyzed two orbits of GRB 070612B (Grupe et al., GCN 6509) with total observing times of 4.7 ks in Photon Counting mode in the Swift XRT. Due to Earth-constrain Swift did not slew immediately and XRT observations were delayed by almost one hour (Grupe \& Evans, GCN 6514). The Photon Counting mode image provides a refined XRT position at Ra, Dec= 261.7271, -8.7517, which is RA(J2000) = 17h 26m 54.49s Dec(J2000) = -08d 45' 06.3" with an error of 4.0" (90% confidence). This position is 2.7 " away from the preliminary XRT position reported in GCN 6514. The X-ray light curve shows a decaying source. While the afterglow is clearly detected in the first orbit, only a 3sigma upper limit of 0.012 counts/s can be given for the second orbit. Based on this result, we estimated a decay slope of 2.8+/-0.6. The X-ray data can be fitted by a single power law with a photon index Gamma=1.7+-0.8 and the absorption column density fixed to the Galactic value of NH=1.68e21 cm-2 (Dickey & Lockman, 1990) with chi2/dof=4/3. This circular is an official product of the Swift XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6522 SUBJECT: GRB 070612A, Swift-BAT refined analysis DATE: 07/06/12 20:36:55 GMT FROM: Scott Barthelmy at NASA/GSFC S. D. Barthelmy (GSFC), L. Barbier (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 070612A (trigger #282066) (Grupe, et al., GCN Circ. 6509). The BAT ground-calculated position is RA, Dec = 121.355, 37.258 deg which is RA(J2000) = 8h 5m 25.2s Dec(J2000) = 37d 15' 30" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%. The mask-weighted light curve shows two main overlapping peaks with the first starting at ~T-20 sec and the second ending at ~T+400 sec. The two peaks are at T+5 and T+200 sec. T90 (15-350 keV) is 370 +- 10 sec (estimated error including systematics). The time-averaged spectrum from T-4.7 to T+418 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.69 +- 0.10. The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+10.39 sec in the 15-150 keV band is 1.5 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6523 SUBJECT: GRB 070612B, Swift-BAT refined analysis DATE: 07/06/12 20:39:42 GMT FROM: Scott Barthelmy at NASA/GSFC J. Cummings (GSFC/UMBC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 070612B (trigger #282073) (Grupe, et al., GCN Circ. 6511). The BAT ground-calculated position is RA, Dec = 261.716, -8.747 deg which is RA(J2000) = 17h 26m 51.8s Dec(J2000) = -8d 44' 48" with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 17%. The mask-weighted light curve shows a single roughly symetrical peak starting at T-5 sec, peaking at T+0 sec, and ending at T+12 sec. T90 (15-350 keV) is 13.5 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-6.4 to T+10.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.11. The fluence in the 15-150 keV band is 1.7 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.16 sec in the 15-150 keV band is 2.6 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6524 SUBJECT: GRB 070612B: SARA upper limit DATE: 07/06/12 21:22:00 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike, Dieter H. Hartmann (Clemson University), Gary Henson (ETSU), Robert Mesler, Christina Bunker, and Jason Carson (ETSU/SARA REU program) report: Using the 0.9m SARA telescope at Kitt Peak, we imaged the field of GRB 070612B (GCN 6511, Grupe et al.). Observations began 24 minutes after the trigger (282073) and consisted of 65 minutes of R-band images. We do not detect any new sources in the refined XRT error box (GCN 6521, Grupe et al.) or at the position indicated by P60 (GCN 6517, Cenko et al.) down to a limiting magnitude of 20.6 +/- 0.6 in the R-band as calibrated relative to 10 USNO B1.0 stars. The SARA Homepage can be found at: http://saraobservatory.org This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6525 SUBJECT: GRB 070612A: P60 Confirmation of Afterglow and An Underlying, Nearby DATE: 07/06/12 22:15:19 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko, E. O. Ofek (Caltech) and D. B. Fox (Penn State) report on behalf of a larger collaboration: We have imaged the field of GRB 070612A (Grupe et al., GCN 6509) with the automated Palomar 60-inch telescope. Images were taken in the Sloan i' filter beginning at 4:27:29 12 June UT (~ 1.8 hr after the burst) at large airmass (> 2.5). Inside the BAT error circle we identify a bright, stationary, variable source located at coordinates (J2000.0): RA: 08:05:29.61 Dec: +37:16:15.2 The object increases in brightness over the duration of our exposure, ranging from i' = 16.97 in our first image to i' = 16.27 approximately 2.2 hours after the burst. Given the brightness, we consider it likely this is the same candidate proposed by Updike et al. (GCN 6515), despite the fact that their position differs from ours by ~ 14". Furthermore, as first noted by this group, there is a faint galaxy underlying the OT visible in the SDSS images of this field (Cool et al., GCN 6510) located at RA: 08:05:29.64, Dec: +37:16:14.6 (J2000.0). The photometric redshift, taken from the SDSS database, for this putative host is z = 0.096 +/- 0.023. Altogether, GRB 070612A has 1) a very long duration (t90 ~ 370 s; Barthelmy et al., GCN 6522), 2) a bright, rising optical afterglow at t ~ 2 hr, and 3) an underlying, nearby (z ~ 0.1) putative host galaxy. In all these ways it is similar to XRF 060218. Despite its proximity to the sun (~ 38 degrees away and setting), we encourage follow-up observations at all wavelengths while still possible to further investigate this interesting source and search for signs of an associated supernova. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6526 SUBJECT: GRB 070612A: MDM Observations DATE: 07/06/13 04:38:28 GMT FROM: Nestor Mirabal at Columbia U N. Mirabal, I. D. McGreer, J. P. Halpern (Columbia U.), M. Dietrich, B. M. Peterson (Ohio State U.) report on behalf of the MDM GRB follow-up team: "We observed the candidate optical afterglow of Swift GRB 070612A (Updike et al. GCN 6515, Cenko et al. GCN 6525) using the MDM 2.4m telescope. Preliminary calibration with respect to USNO magnitudes of nearby stars yields r' ~ 19.0 +/- 0.3 on June 13 03:59 UT and i' ~ 18.4 +/- 0.2 on June 13 03:49 UT respectively. These measurements indicate that the afterglow has faded with respect to previous reports." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6529 SUBJECT: GRB 070612A: spectral lag DATE: 07/06/13 19:28:21 GMT FROM: Jay Norris at Stanford U J.P. Norris (U.Denver), S.D. Barthelmy (GSFC), N. Gehrels (GSFC): Spectral lag analysis of the two main emission episodes in GRB 070612A, described in GCN Circ. 6522 (Barthelmy et al.) indicate that this burst has relatively long lags, comparable to and longer than that of GRB 980425 (~ 2-3 s), the first burst associated with a supernova. For the first, brighter FRED-like pulse structure, the lag measurement between BAT energy bands 15-25 keV and 50-100 keV (25-50 and 100-350 keV) is 2.5 s +2.1-1.8 s (2.5 +0.7-0.5 s). For the second, dimmer pulse structure, the 15-25 keV to 50-100 keV lag is 5.8 s +2.6-1.9 s. The flux in the 100-350 keV band for this second episode was too low to make a useful measurement. Spectral lags of several seconds indicate a relatively low luminosity burst, consistent with the nearby host (z ~ 0.1) described in GCN Circ. 6525 (Cenko et al.). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6530 SUBJECT: GRB 070612A: continued SARA observations DATE: 07/06/13 21:02:58 GMT FROM: Adria C. Updike at Clemson U Adria C. Updike, Jason Puls, Dieter H. Hartmann (Clemson University), Matt Wood (FIT), Josh Cardenzana (U Missouri - Rolla), and Shelsea Pederson (MIT) report: We re-imaged the field of GRB 070612A (GCN 6509, Grupe et al.) with the SARA 0.9m telescope at Kitt Peak under decent weather conditions. We obtained 15 minutes of R-band images beginning 24 hours after the trigger (282006). The afterglow (Updike et al. GCN 6515, Cenko et al. GCN 6525) is detected at a R-band magnitude of 18.3 +/- 0.4 as calibrated relative to 9 USNO B1.0 stars, thus confirming the fading behavior. The SARA Homepage can be found at: http://saraobservatory.org This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6531 SUBJECT: GRB070612A: MITSuME Okayama Observation DATE: 07/06/13 23:25:29 GMT FROM: Michitoshi Yoshida at Okayama Astrophysical Obs M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We performed optical imaging observations (Rc and Ic) of the field of GRB 070612A (Grupe et al., GCN 6509) with 50cm MITSuME telescope at Okayama Astrophysical Observatory from UT 11:19 to UT 11:27 on June 12 2007. We coadded 4 CCD frames for each band. Exposure time of each frame is 1 minute. We made flux calibration using USNO B1.0 catalg. We found a faint source at the position of the afterglow candidate reported by Cenko et al. (GCN 6525, RA:08:05:29.6, DEC:+37:16:15) in Ic band. The Ic magnitude was 17.1 +/- 0.3. There was no source brigher than 16.7 magnitude in Rc band. Flux calibration was made with three USNO-B stars around the object. --------------------------------------------------------------- band mid-UT exp.time magnitude Rc June 12 11:23 4 x 1 min. > 16.7 mag (upper limit) Ic June 12 11:34 4 x 1 min. 17.1 mag +/- 0.3 mag --------------------------------------------------------------- //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6533 SUBJECT: GRB 070612A: Suzaku/WAM observation of the prompt emission DATE: 07/06/14 03:01:27 GMT FROM: Takeshi Uehara at Hiroshima U T. Uehara, M. Ohno, T. Takahashi, C. Kira, Y. Fukazawa (Hiroshima U.), T. Enoto, R. Miyawaki, K. Nakawaza, K. Makishima (Univ. of Tokyo), K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.), Y. Urata, K. Onda, M. Suzuki, K. Morigami, N. Kodaka, M. Tashiro, A. Endo (Saitama U.), T. Tamagawa, Y. Terada (RIKEN), S. Hong (Nihon U.), M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), E. Sonoda, M.Yamauchi, S. Maeno, H. Tanaka, R. Hara(Univ. of Miyazaki), and Suzaku WAM team report: The long burst, GRB 070612A (Swift/BAT trigger #282066; D. Grupe et al., GCN Circ. 6509 ), was triggered at 02:38:41 UT (=T0) by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV. The observed light curve shows a single peaked structure with a duration (T90) of nearly 35 seconds. The fluence in 100-1000 keV was (8.2 +/- 2.4) * 10^-6 erg/cm^2. The 1-s peak flux was 1.2 (+0.4, -0.3) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-4 to T0+36 sec is well fitted by a single power law model with a photon index of 2.5 +/ -0.3 (chi^2/d.o.f. = 31/21). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The WAM light curve of this event is available at the following web cite. http://www.astro.isas.ac.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6534 SUBJECT: GRB 070612A: Rapid Decay DATE: 07/06/14 04:45:10 GMT FROM: Nestor Mirabal at Columbia U N. Mirabal, I. D. McGreer and J. P. Halpern (Columbia U.) report on behalf of the MDM GRB follow-up team: "We have re-observed the optical afterglow of Swift GRB 070612A (Updike et al. GCN 6515, Cenko et al. GCN 6525) in the R and i' filters using the same instrumental setup as in Mirabal et al. (GCN 6526). Preliminary calibration referenced to the SDSS photometry of field stars (Cool et al. GCN 6510) shows that the afterglow has faded by 1.88 mag since the previous night. This corresponds to a decay rate steeper than ~ -2.5, which might represent the end of an optical flash from reverse shock emission (Meszaros & Rees 1997, ApJ, 306, 301; Sari & Piran 1999, ApJ, 496, L1). Alternatively, the steepening could be the signature of a "jet break". Further observations are encouraged to distinguish between various possibilities." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6535 SUBJECT: GRB 070612A: Super-LOTIS observations DATE: 07/06/14 06:27:26 GMT FROM: Adria C. Updike at Clemson U A. C. Updike (Clemson University), P. A. Milne (Steward Observatory), G. G. Williams (MMT), and D. H. Hartmann (Clemson University) report on behalf of the Super-LOTIS collaboration: We observed the field of GRB 070612A with the 0.6m Super-LOTIS telescope on June 13, beginning at 03:42:00 UT, or 25 hours and 4 minutes after the burst trigger (282066). In 6 minutes of stacked exposures, we marginally detect the afterglow (Updike et al. GCN 6515, Cenko et al. GCN 6525) at an R-band magnitude of 17.73 +/- 0.76 as calibrated relative to 6 USNO B1.0 stars. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6541 SUBJECT: GRB 070612B: optical observations DATE: 07/06/16 09:01:57 GMT FROM: Giuseppe Greco at U Bologna G. Greco (Bologna University), F. Terra (Second University of Roma "Tor Vergata"), C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University), G. Pizzichini (INAF/IASF Bologna), D. Nanni (INAF/OAR and Second University of Rome "Tor Vergata"), R. Gualandi (Bologna Observatory) report: We imaged the field of GRB 070612B (Grupe et al., GCN 6511) with the 152 cm Loiano telescope in the Rc and Ic filters in clear sky conditions. We do not detect any new sources in the combined images within the XRT error box (Grupe and Evans, GCN6521) with the following upper limits: tmid (UT) filter Exp. Limit June 13.917 Rc 3x1800 22.2 (3 sigma) June 13.975 Ic 3x1200 22.0 (3 sigma) We detect the faint source indicated by Cenko et al. (GCN 6521) at an Ic-band magnitude of 21.9+/-0.16 Magnitude and upper limits were estimated by comparison with the USNO-B1 stars and are not corrected for galactic dust extinction. The co-added Ic image, in which the comparison stars are marked, has been posted in our public directory from where it can be retrieved by sftp using hostname: ermione.bo.astro.it username: publicGRB password: GRB_bo. directory: GRB070612B [GCN OPS NOTE(17jun07): Per author's request, the reference to "GCN 6517" was corrected to "GCN 6521", and "GCN6514" was corrected to "GCN 6521".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6549 SUBJECT: GRB 070612A: Possible WSRT Radio Detection DATE: 07/06/17 10:46:54 GMT FROM: Alexander van der Horst at U of Amsterdam A.J. van der Horst, R.A.M.J. Wijers, K. Wiersema (University of Amsterdam), and E. Rol (University of Leicester) report on behalf of a larger collaboration: "We observed the position of the GRB 070612A afterglow (GCN 6509) at 4.9 GHz with the Westerbork Synthesis Radio Telescope at June 15 8.10 UT to 20.09 UT, i.e. 3.23 - 3.73 days after the burst. We tentatively detect a radio source at 3 sigma significance, located at the position of the optical counterpart (GCN 6515, GCN 6525), with a flux of 78 +/- 25 microJy. Further observations at radio wavelengths of this afterglow are planned and encouraged, especially given the suggested association with a nearby low-redshift host galaxy (GCN 6525). We would like to thank the WSRT staff for scheduling and obtaining these observations." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6553 SUBJECT: GRB 070612B: Optical Observation by MITSuME Akeno DATE: 07/06/18 06:36:27 GMT FROM: Nobuyuki Kawai at Tokyo Tech Y.kudo, T. Ishimura, Y. Yatsu, T. Shimokawabe, N. Vasquez, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration: We observed the error box of GRB070612B (Grupe et al., GCN 6511) with the 3-color 50cm MITSuME Telescope at Akeno, Japan starting at 11:46:53 June 12 UT, 5.1 hours after the trigger. In the co-added images of Ic, Rc, and g' bands, we did not detect any new source in the XRT error circle. The 3-sigma limiting magnitudes based on USNO-B1.0 (I-band) and NOMAD (R-band,g'-band) stars are following. Filter start time end time Exp(s) Mag (3-sigma upper limit) ----------------------------------------------------------------- g' 11:46:53 12:16:35 25 x 60s 17.4 Rc 11:46:53 12:16:35 25 x 60s 18.6 Ic 11:46:53 12:16:35 25 x 60s 18.6 ----------------------------------------------------------------- //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6555 SUBJECT: GRB 070612A: NOT observations DATE: 07/06/18 21:24:53 GMT FROM: Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center D. Malesani, J. Hjorth, J.P.U. Fynbo (DARK), J. Sollerman (DARK & Stockholm obs.), G. Olofsson (Stockholm Obs.), D. Paraficz (NOT & DARK), M. Durant (IAC), report: We observed the afterglow (Updike et al., GCN 6515; Cenko et al., GCN 6525) of GRB 070612A (Grupe et al., GCN 6509) with the NOT telescope at several epochs. The afterglow is detected in all our images. The galaxy seen in the SDSS images (first noted by Updike et al., GCN 6515) may be resolved into two components, one roughly coincident with the afterglow, and the other 1.8" South. From our measurements, the light curve has been slowly declining between Jun 14.9 and Jun 17.9 UT. The data after 1 day (including the MDM points by Mirabal et al., GCNs 6526, 6529) are consistent with a steep power-law decay (alpha ~ 3) superimposed on a constant contribution. From our latest image (Jun 17.90 UT) we measure R=21.45+-0.2 (against USNO-B1.0), where the error is mostly due to calibration. This value includes some contribution from the underlying host galaxy. If the redshift of the GRB is z=0.096, our measurement implies that any associated SN was fainter than SN1998bw by at least 1.5 mag (and likely more, after considering the host contribution). Alternatively, an unextinguished SN as bright as SN1998bw should be at redshift >0.2. We note that the SDSS catalog provides two redshift determinations for this object, the largest one being z=0.42+-0.14: http://cas.sdss.org/astrodr5/en/tools/explore/obj.asp?id=587728931336684102 Our data are consistent with a SN akin to SN1998bw at z=0.4. In this case, a rebrightening by ~0.5 mag is expected during the next week. Observations will continue for as long as visibility contraints allow. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6556 SUBJECT: GRB070612A: Gemini Spectroscopic Redshift DATE: 07/06/19 04:37:40 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (Caltech), D. B. Fox, A. Cucchiara (Penn State), B. P. Schmidt (Australia National University), E. Berger (Carnegie), P. A. Price (IfA), and K. C. Roth (Gemini) report on behalf of a larger collaboration: Starting on 2007 June 17 at 06:10 UT we used GMOS on the Gemini North telescope to obtain a 600 s spectrum of the afterglow + host galaxy of GRB 070612A (Grupe et al., GCN 6509). The spectrum was taken in twilight at very high airmass (~ 3.2) and covers the wavelength range ~ 4000-8120 A. We find a strong, broad (~ 10 A) emission line at ~ 6229 A that, based on the lack any blueward emission features, we identify as [O II] 3727 at z=0.617. We also notice another possible emission feature at the very red edge of our spectrum corresponding to H-beta at the same redshift. No other features are detected either in emission nor in absorption. We note that this redshift is significantly larger than the original SDSS photometric redshift (z ~ 0.1) noted by Cenko, Ofek, and Fox (GCN 6525), and is more consistent with the larger redshift (z ~ 0.4) noted by Malesani et al. (GCN 6555). The larger distance would naturally explain the faintness of any associated SN emission, as noted by these authors. We wish to thank and acknowledge the effort of the staff at Gemini North in undertaking these difficult observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6558 SUBJECT: GRB 070612A: TNG optical observations DATE: 07/06/20 10:55:14 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, S. Covino (INAF-OAB), M. Della Valle (INAF-OA Arcetri), E. Pian (INAF - OATs), G. Tagliaferri on behalf of the CIBO collaboration, P. Mazzali (INAF - OATs & MPA), A. Magazzu` and Noemi Pinilla-Alonso (INAF - TNG) report: We observed the afterglow (Updike et al., GCN 6515; Cenko et al., GCN 6525) of GRB 070612A (Grupe et al., GCN 6509) with the Italian 3.6m TNG telescope equipped with the DOLORES camera on 2007 Jun 18.89 and 19.90 UT. Because of visibility constraints, images have been taken at high airmass (~ 3). The average seeing was of about 1.7". An extended object is clearly visible at the position of the optical afterglow (Cenko et al., GCN 6525) and its brightness remains constant at both epochs at a level of R ~ 21.4 (calibrated against the USNO B1.0 catalog). This is consistent to what reported by Malesani et al. (GCN 6555) and suggests that the afterglow's brightness is now below the host galaxy level. We acknowledge the support of the TNG staff. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6566 SUBJECT: Observations of GRB070612A at Calar Alto DATE: 07/06/22 08:24:34 GMT FROM: Elena Pian at ITESRE-CNR,Bologna S. Taubenberger (MPA), P. Mazzali (MPA & INAF - OATs), W. Hillebrandt (MPA), J. Alves (CAHA), U. Thiele (CAHA), S. Pedraz (CAHA), A. Guijarro (CAHA), M. Alises (CAHA) and E. Pian (INAF - OATs) report: We observed the afterglow (Updike et al., GCN 6515; Cenko et al., GCN 6525) of GRB 070612A (Grupe et al., GCN 6509) with the Calar Alto 2.2m Telescope equipped with CAFOS on 2007 Jun 13.86, 14.86 and 15.87 UT. In all three nights images were taken in the BVRI bands, at high airmass (~ 3), and under variable seeing and transparency conditions (2.0" - 5.6" fwhm, clear - thin clouds). The afterglow was detected on Jun 13.86 at V = 20.40+-0.23 and R = 19.79+-0.10 (calibrated against the Landolt field PG1633 under photometric conditions; only measurement errors reported). In R up to 25% of contamination from the underlying galaxy can be expected (D'Avanzo et al., GCN 6558). From the rest of the images only limits could be derived, in particular V > 20.0 / 19.8 and R > 18.9 / 19.6 on Jun 14.86 / 15.87, respectively. Our Jun 13.86 R-band magnitude is consistent with the afterglow's steep power-law decay suggested by observations with other telescopes (cf. Malesani et al., GCN 6555, and references therein). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6576 SUBJECT: GRB 070612A: Second Epoch WSRT Radio Observations DATE: 07/06/24 10:19:49 GMT FROM: Alexander van der Horst at U of Amsterdam A.J. van der Horst, R.A.M.J. Wijers, K. Wiersema (University of Amsterdam), and E. Rol (University of Leicester) report on behalf of a larger collaboration: "We reobserved the position of the GRB 070612A afterglow (GCN 6509) at 4.9 GHz with the Westerbork Synthesis Radio Telescope at June 20 7.91 UT to 19.76 UT, i.e. 8.22 - 8.71 days after the burst. At the position of the optical counterpart (GCN 6515, GCN 6525) and the tentative radio counterpart (GCN 6549), we measure a formal flux of 72 +/- 27 microJy, i.e. a possible radio source at 2.7 sigma significance. In a combined image of the two epochs of WSRT observations, at June 15 and June 20, the average formal flux is 53 +/- 19 microJy, a 2.8 sigma detection. Therefore, we cannot state with certainty whether the radio afterglow (or the possible host galaxy) of GRB 070612A is detected. We would like to thank the WSRT staff for scheduling and obtaining these observations." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6583 SUBJECT: GRB 070612A: Allen Telescope Array Observations DATE: 07/06/27 23:06:44 GMT FROM: Josh Bloom at UC Berkeley R. Forster, M. Wright, J. Hare, J. S. Bloom, G. C. Bower (UC Berkeley) report on behalf of a large collaboration: "Using the Allen Telescope Array (ATA, http://ral.berkeley.edu/ata/), we observed GRB 070612A (Grupe et al., GCN 6509) at 1.4 GHz on 2007 June 16 UT and at 5 GHz on 2007 June 17 UT. The observations made use of 8 antennas outfitted with dual-polarization receivers. At the location of the optical afterglow (Updike et al., GCN 6515), we obtained 3-sigma limits of 50 mJy at 1.4 GHz and 10 mJy at 5 GHz for the flux density of GRB 070612A at these epochs. The data were calibrated versus the QSS 0927+392. At L-band the 8 brightest NVSS were measured to be located within 10% of the synthesized beamwidth and 100 mJy of the NVSS flux densities. The limits reported herein are consistent with the tentative WSRT detection at 4.9 GHz (Horst et al. GCNs 6549, 6576). A 42-antenna ATA is currently being commissioned." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6600 SUBJECT: VLA detection of GRB 070612A in C Band DATE: 07/07/05 21:49:36 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (NRAO/UVA) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We used the Very Large Array to observe the field of view toward GRB 070612A (GCN 6509) at a frequency of 4.88 GHz on 2007 June 30th at 20.66 UT. We detect the GRB afterglow at P60 optical afterglow position (GCN 6517). The flux density of the GRB is 189+/-56 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6714 SUBJECT: GRB070612A: Radio upper limit from GMRT DATE: 07/08/07 05:39:00 GMT FROM: Dipankar Bhattacharya at IUCAA Sabyasachi Pal, C.H. Ishwara-Chandra, Dipankar Bhattacharya and Atish P. Kamble report on behalf of a larger collaboration: We observed the field of GRB 070612A (Grupe et al, GCN 6509) at 1280 MHz, using the Giant Meterwave Radio Telescope, from MJD 54305.08 to 54305.26 (UT 2007 Jul24 01:55:21 to 06:12:36). This interval corresponds to 41.97-42.15 days after the burst. The afterglow was not detected. The formal flux density at the position of the optical afterglow (Cenko et al, GCN 6525) was 109 +/- 64 micro Jy (1-sigma). We thank the GMRT staff who made this observation possible. GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. This message may be cited. -- This message has been scanned for viruses and dangerous content by OpenProtect(http://www.openprotect.com), and is believed to be clean.