//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6882 SUBJECT: GRB 071011: Swift detection of a burst DATE: 07/10/11 12:51:21 GMT FROM: Scott Barthelmy at NASA/GSFC F. E. Marshall (NASA/GSFC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), O. Godet (U Leicester), S. T. Holland (CRESST/USRA/GSFC), V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (Univ. Bicocca & INAF-OAB), B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU), E. Troja (INAF-IASFPA) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 12:40:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071011 (trigger=293924). Swift did not execute an immediate slew because of an Earth-observing constraint, but it will at ~T+2700 sec. The BAT on-board calculated location is RA, Dec 8.400, +61.072 which is RA(J2000) = 00h 33m 36s Dec(J2000) = +61d 04' 21" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two peaks each of ~10 sec duration. The second peak is at ~T+48 sec. The peak count rate was ~1800 counts/sec (15-350 keV), at ~1 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 data products to analyze. The UVOT is currently in safe and will not observe this burst. Burst Advocate for this burst is F. E. Marshall (marshall AT milkyway.gsfc.nasa.gov). 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: 6883 SUBJECT: GRB 071011: Optical afterglow candidate DATE: 07/10/11 13:58:13 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, J. S. Bloom, M. Modjaz, and D. Kocevski (UC Berkeley) report: We slewed to the afterglow position with the Keck I telescope (+LRIS) and began taking imaging exposures at 12:50:58 UT, ten minutes after the trigger. By visual comparsion with the DSS we identify a faint candidate optical afterglow at the position: RA = 00:33:47.412 dec = +61:03:34.09 Further observations of the afterglow candidate are ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6886 SUBJECT: GRB 071011: NAYUTA Optical Observation DATE: 07/10/11 16:56:46 GMT FROM: Ryo Iizuka at NHAO R. Iizuka and S. Maeno report on behalf of NHAO. We observed the field of GRB 071011 (GCN 6882) with MINT on the 2.0-m NAYUTA telescope at Nishi-Harima Astronomical Observatory, Japan. We took images for a total of 3000 sec in R-band filter on 2007 Oct 11 13:36 UT (56 minutes after the burst). We detect the afterglow reported by GCN 6883 (Daniel Parley et al.). We estimate a preliminary magnitude of R~22 mag relative to USNO-B1.0 stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6887 SUBJECT: GRB 071011: Early Super-LOTIS Observations DATE: 07/10/11 17:36:50 GMT FROM: Grant Williams at Steward Observatory G. G. Williams (MMTO) and P. A. Milne (Steward Observatory), on behalf of the Super-LOTIS Collaboration, report: The robotic 0.6-m Super-LOTIS telescope began observing the error box of GRB 071011 (Swift Trigger 293924, Marshall et al. GCN 6882) at 12:40:53.4 UT, 40.4 seconds after the trigger. Our initial observations include 5 x 10s exposures, 5 x 20s exposures, and 30 x 60s exposures, all in the R-band. The observations occurred during morning twilight at a starting airmass of 2.16. In our earliest exposure, we do not detect the afterglow candidate reported by Perley (GCN 6883) and confirmed by Iizuka (GCN 6886) or any other candidates in the BAT error circle to the following 3-sigma limiting magnitude determined from nearby USNO-B1.0 stars: t_start (UT) exp t (s) t_start-t_0 (s) Limit -------------------------------------------------------- 12:40:53.4 10.0 40.4 R > 16.90 Subsequent exposures also do not reveal any additional candidates. Analysis is ongoing. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6889 SUBJECT: GRB 071011, Swift-BAT refined analysis DATE: 07/10/11 18:19:12 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC/UMBC), S.D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F.E. Marshall (GSFC), D. Palmer (LANL), 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-119 to T+183 sec from the recent telemetry downlink, we report further analysis of BAT GRB 071011 (trigger #293924) (Marshall, et al., GCN Circ. 6882). The BAT ground-calculated position is RA, Dec = 8.395, 61.132 deg which is RA(J2000) = 0h 33m 34.8s Dec(J2000) = 61d 07' 57" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 37%. The mask-weighted light curve shows two roughly symmetric peaks. The first starts at ~T-10 sec, peaks at ~T+1 sec, and reachs a minimum at ~T+30 sec. The second picks up at the minimum at ~T+30 sec, peaks at ~T+46 sec, and ends at ~T+90 sec. T90 (15-350 keV) is 61 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-9.5 to T+63.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.41 +- 0.12. The fluence in the 15-150 keV band is 2.2 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+45.98 sec in the 15-150 keV band is 1.7 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6891 SUBJECT: GRB 071011: XRT afterglow detection DATE: 07/10/11 18:24:21 GMT FROM: Boris Sbarufatti at INAF-IASF-Pa B. Sbarufatti, V. La Parola, E. Troja, V. Mangano (INAF-IASFPA), J. Kennea (PSU), F.E. Marshall (GSFC) report on behalf of the Swift-XRT team. We have analyzed the first orbit of XRT data of the Swift observation of GRB 071011 (Marshall et al., GCN 6882), started at 13:28:40 UT. We have a 1600 sec exposure in PC mode. We detect a single uncatalogued bright source within the XRT field of view, across an hot column, at position RA, Dec= 8.3887, +61.1325 deg which is RA(J2000)= 0h 33m 33.30s Dec(J2000)= +61d 07' 57.3" with an uncertainty of 4.4 arcsec (90% containment radius). This is 11 arcsec from the BAT refined position (Sakamoto et al, GCN 6889). We remark that the new BAT error circle excludes the optical afterglow candidate reported by Perley et al. (GCN 6883). A quick look to the XRT light curve gives a flat behavior at the level of 0.3 counts/sec. We wait for more data to improve our analysis. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6894 SUBJECT: GRB 071011: MARGE Optical Limits DATE: 07/10/11 21:17:44 GMT FROM: Heather Swan at U.of Michigan/ROTSE H. Swan (U Mich), I. Smith (Rice), C. Akerlof (U Mich), and M. Skinner (Boeing) report on behalf of the MARGE collaboration: The AEOS Burst Camera (ABC) on the AEOS telescope, located at the Maui Space Surveillance System on Haleakala, observed the field of GRB071011 (Swift trigger 293924 (F. E. Marshall et al, GCN 6882)). The images are unfiltered 10s exposures which started ~6 minutes after the trigger and ended ~ 1 hour later. We see the OT candidate observed by Perley et al (GCN 6883), but it does not fade (between 6-60 minutes). The first image which contains the XRT position (B. Sbarufatti et al, GCN 6891) occurred at 20 minutes after the Swift trigger. We coadded the ABC images into sets of 10 and observe three distinct closely spaced stellar objects within 7 arc-seconds of the XRT coordinates given in GCN 6891. These appear to be consistent with a set of unresolved stars in the DSS plates (second epoch) suggesting that no new sources have been found within the 3-sigma XRT error circle. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6895 SUBJECT: GRB 071011: P60 Optical Afterglow Candidate DATE: 07/10/11 23:17:00 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (Caltech) reports on behalf of a larger collaboration: We have imaged the field of GRB071011 (Marshall et al.; GCN 6882) with the automated Palomar 60-inch telescope (P60). Observations began at 12:43:38 UT on October 11 (205 s after the burst) and we were able to obtain 3 x 60 s images in the R, i', and z' filters before closing due to twilight. Based on comparison with the Digital Sky Survey plates, we do not find any new sources inside the XRT error circle (Sbarufatti et al.; GCN 6891), as was reported by Swan et al. (GCN 6894). However, slightly outside the XRT error circle (~ 8" away), we detect a stationary, fading source at coordinates (J2000.0): RA: 00:33:32.74 Dec: +61:08:04.4 In our initial R-band exposure, we measure a magnitude of R=17.92, using several stars from the USNO-B catalog for photometric calibration. The source fades by over a magnitude in each filter over the duration of our observations. We therefore consider this likely to be the optical afterglow of GRB071011. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6896 SUBJECT: GRB 071011: Kanazawa Optical limits DATE: 07/10/12 01:22:20 GMT FROM: Daisuke Yonetoku at Kanazawa U T. Kidamura, S. Tanabe, Y. Okuma, S. Yokota, T. Nashimoto, T. Fujinaga, H. Fujimoto, R. Edamura A. Wada, T. Murakami and D. Yonetoku (Kanazawa Univerasity) report on behalf of the Kanazawa GRB team The robotic Kanazawa 0.4-m telescope imaged the field of GRB 071011 (Marshall et al. GCN 6882) at 190 seconds after the burst trigger. We observed the field in unfiltered 10x 30s exposure. Based on comparison of our initial image with the DSS plate, we do not detect any source inside the XRT error circle (Sbarufatti et al. ; GCN 6891, Swan et al. 6894), and also we do not detect the source reported by Cenko (GCN 6895) . Our upper limit is ~17.6 under the poor sky condition. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6898 SUBJECT: GRB 071011: Confirmation of P60 optical afterglow DATE: 07/10/12 01:57:39 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, D. Kocevski, D. Poznanski, J. S. Bloom, and M. Modjaz (UC Berkeley) report: We have performed further analysis of our LRIS imaging of GRB 071011 (Marshall et al., GCN 6882). The afterglow candidate we reported previously (GCN 6883) does not vary by more than 0.1 magnitude between 13:01 and 14:22 UT, and is therefore unlikely to be the optical afterglow of GRB 071011. Our earliest-time LRIS images do not cover the position of the X-ray source reported by Sbarufatti et al. (GCN 6891) due to the large offset between the initial BAT position and XRT position. We returned to the field starting at 14:10:52 UT and acquired 2x120s in R-band and 2x120s in the RG850 filter through high airmass. No new objects are detected within the XRT error circle to an approximate limiting magnitude (3 sigma) of R~24.5. We do detect a source at the location reported by Cenko et al. Our position of this source (J2000), relative to the USNO B1.0 catalog, is: RA = 00:33:32.731 dec = +61:08:04.57 The relative astrometric uncertainty is <0.5". We calculate a preliminary magnitude of R = 20.4 +/- 0.1 relative to five nearby USNO stars. Comparison to the magnitude reported by Cenko et al. (GCN 6895) indicates that the source has faded significantly and confirms that this is the optical afterglow of GRB071011. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6899 SUBJECT: GRB 071011, Optical afterglow DATE: 07/10/12 07:10:43 GMT FROM: Shashi Bhushan Pandey at ARIES, INDIA S. B. Pandey, K Misra and Rupak Roy (ARIES, NainiTal, India, on behalf of l= arger Indian GRB collaboration) We observed Swift GRB 071011 with 1.04m telescope NainiTal starting ~ 4.0 hours after the burst (Marshall et al. GCN 6882). Observations were performed in R_c and I_c filters. Photometry of the co-added I_c frames (300 sec x 6) marginally detects the afterglow candidate (I_c ~ 20.0) reported by Cenko S. B. (GCN 6895) in comparison to nearby USNO stars. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6900 SUBJECT: GRB 071011: NAYUTA Optical Observation, correction to GCN6886 DATE: 07/10/12 12:30:17 GMT FROM: Ryo Iizuka at NHAO R. Iizuka and S. Maeno report on behalf of NHAO. We observed the field of GRB 071011 (GCN 6882) with MINT on the 2.0-m NAYUTA telescope at Nishi-Harima Astronomical Observatory, Japan. We took images in R-band on 2007 Oct 11 13:36 UT (56 minutes after the burst). We detect a source at the position reported by Cenko et al. (GCN 6895). We estimate a preliminary magnitude relative to the USNO B1.0 catalog. The source fades over our observations, as was reported by Perley et al. (GCN 6898). start(UT) exp(sec) R-mag err -------------------------------------------- 13:36:23 300 20.3 0.2 14:37:37 300 21.0 0.2 -------------------------------------------- //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6902 SUBJECT: GRB 071011: Swift-XRT refined analysis DATE: 07/10/12 15:07:59 GMT FROM: Boris Sbarufatti at INAF-IASF-Pa B. Sbarufatti, V. Mangano, V. La Parola, E. Troja (INAF-IASFPA), P. Evans, A. Beardmore (U Leicester), D. N. Burrows (PSU), F. E. Marshall (NASA/GSFC) report on behalf of the Swift-XRT team We have analysed the first orbits of Swift-XRT data obtained for GRB 071011 (trigger=293924, GCN 6882). The observation consists of 6.6 ks exposure in Photon Counting (PC) mode, starting 2.7 ks after the trigger. The GRB afterglow is clearly detected inside the XRT field of view (FoV) at a large off axis angle only in the initial 1.6 ks. During the following 5 ks the source was outside the FoV because of an incorrect spacecraft pointing. Using an improved algorithm that takes into account the presence of the underlying hot column we obtain a refined position of: RA, Dec= 8.38816, 61.13327 (degrees) RA(J2000)= 00h 33m 33.1s Dec(J2000)= +61d 07' 59.77" with an estimated uncertainty radius of 4.1 arcsec (90% containment radius). This is 2.7 arcsec away from the previous XRT position (GCN 6891) and 5.5 arcsec away from the optical afterglow reported by Cenko (GCN 6895) and Perley et al. (GCN 6898). We note that the position uncertainty of 4.1 arcseconds includes both systematic and statistical uncertainty, but the systematic component may be underestimated for a source this close to the edge of the field of view. The light curve shows a behavior consistent with a powerlaw decay with slope -1 +/- 0.7. Due to the large uncertainty we need more data to constrain the afterglow evolution. The spectrum extracted from the initial 1.6 ks PC data can be modelled with an absorbed power-law with photon index Gamma = 2.6 +/- 0.5, and an absorbing column of NH = (1.5 +/- 0.7)E22 cm-2, in excess with respect to the Galactic value of 5.18E21 cm-2. The observed (unabsorbed) flux is 1.26 (6.00)E-11 ergs cm-2 s-1. All errors are quoted at 90% confidence level. Additional X-ray observations planned for Oct 14-15 should help improve both the counterpart position accuracy and the measurement of the decay rate and spectral parameters. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6904 SUBJECT: GRB 071011: Xinglong TNT Optical afterglow observations DATE: 07/10/12 19:51:41 GMT FROM: L.P. Xin at NAOC L.P. Xin, M.Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, Y. Urata, and W.K. Zheng on behalf of EAFON report: We have observed GRB 071011 beginning at 12:46:05.3 UT, 353s after the burst with TNT 80cm and EST 1m telescopes at xinglong Observatory, A series of Whiete, R and V band images were obtained, preliminary analysis shows the optical afterglow reported by S. B. Cenko (GCN 6895), faded continuly. Derived from USNO-A2.0 R magnitude, We find the early time White band magnitude: --------------------------------------------------- (sec after the burst ) magnitude merr 363.053 17.88143 0.08 407.981 18.02971 0.09 498.701 18.28329 0.10 657.677 18.52271 0.10 834.797 19.55457 0.08 Further analysis is under going. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6905 SUBJECT: GRB 071011: Optical Limit after 13.95hrs DATE: 07/10/13 01:54:53 GMT FROM: Myungshin Im at Seoul Nat U M. Im, I. Lee (Seoul National University), and Y. Urata (Saitama University) on behalf of the EAFON team: Using the Mt. Lemmon (Arizona, US) 1.0m telescope operated by the Korea Astronomy Space Science Institute, we observed the field of GRB071011 (GCN 6882, Barthelmy et al.) beginning at 02:37:30 UT on Oct 12, or 13.95 hrs after the trigger. A stacked image of 11, 5 min frames in the R-band does not show the OT reported by Cenko et al. (6895), Perley et al. (6898), Pandey et al. (6899), Iizuka et al. (6900), and Xin et al. (6904). Using USNO B1.0 R2mag of stars for photometric calibration, we place the upper limit of the OT as R > 21.9 mag (3-sigma, 6" aperture mag) 13.95 hrs after the trigger. It appears that the OT faded beyond the R limit. t_start (UT) Filter exp (sec) R-mag ----------------------------------------------------- 02:37:30 R 11x300 > 21.9mag (3-sigma) We will report later, a more careful analysis of the BVRI images taken during the same period. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6914 SUBJECT: VLA non-detection of GRB 071011 DATE: 07/10/14 17:45:25 GMT FROM: Poonam Chandra at U Virginia/NRAO P. Chandra (UVA/NRAO) and D. A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We observed the field centered on the P60 position (GCN#6895) of the Swift burst GRB 0701011 (GCN#6882) using the VLA at a frequency of 8.46 GHz and starting at 4.03 UT on Oct 13, 2007. We do not detect any radio emission at P60 position of the afterglow (GCN#6895). The flux density at afterglow position is -14 ± 60 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: 6922 SUBJECT: GRB 071011: MITSuME Optical Observations DATE: 07/10/16 14:41:48 GMT FROM: Nobuyuki Kawai at Tokyo Tech D. Kuroda, K. Yanagisawa, M. Yoshida (NAOJ), T. Ishimura, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB071011 (Marshall et al., GCN 6882) with the 3-color 50cm MITSuME Telescope at Okayama Astrophysical Observatory, and 3-color 105cm Telescope at Ishigakijima Astronomical Observatory. The observations started at 12:50:06 Oct.11 (9m53s after the trigger) at Okayama, and at 13:04:15 Oct.11 (24m02s after the trigger) at Ishigakijima. In the co-added images of Ic and Rc bands (Okayama), and Ic, Rc, and V bands (Ishigakijima), we detected the optical afterglow reported by Cenko et al. (GCN 6895). We estimate the magnitudes relative to the USNO B1.0 catalog. The results are followings. ### Results at Okayama ### start end Exposure Ic mag Rc mag ------------------------------------------------------- 12:50:06 13:00:06 10 x 60 s 18.2 +/- 0.4 19.0 +/- 0.3 13:02:48 13:12:48 10 x 60 s 19.2 +/- 0.4 19.5 +/- 0.4 13:15:26 13:25:26 10 x 60 s 19.3 +/- 0.4 -- ------------------------------------------------------- ### Results at Ishigakijima ### start end Exposure Ic mag Rc mag V mag ----------------------------------------------------------------------- 13:04:15 13:19:14 5 x 60 s 18.6 +/- 0.2 20.1 +/- 0.2 -- 13:25:17 13:58:09 5 x 60 s 19.1 +/- 0.4 19.9 +/- 0.2 -- 13:04:15 13:58:09 10 x 60 s -- -- 21.0 +/- 0.5 ------------------------------------------------------------------------