This file contains both GRB 071010A and GRB 071010B. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6859 SUBJECT: GRB 071010: Swift detection of a burst DATE: 07/10/10 03:56:03 GMT FROM: David Palmer at LANL A. Moretti (INAF-OAB), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC), S. T. Holland (CRESST/USRA/GSFC), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team: At 03:41:12 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071010 (trigger=293707). The BAT on-board calculated location is RA, Dec 288.101, -32.379 which is RA(J2000) = 19h 12m 24s Dec(J2000) = -32d 22' 42" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a broad structure with a duration of about 30 sec. The peak count rate was ~600 counts/sec (15-350 keV), at ~2 sec after the trigger. Because Swift is in the process of returning to normal operations, automatic slewing to GRBs is currently disabled outside of business hours (US EDT). Therefore, there are no prompt XRT or UVOT observations of this burst. Burst Advocate for this burst is A. Moretti (moretti AT merate.mi.astro.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.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6860 SUBJECT: GRB 071010: TAROT La Silla observatory detection of the afterglow DATE: 07/10/10 04:09:00 GMT FROM: Alain Klotz at CESR-CNRS Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report: We imaged the field of GRB 071010 detected by SWIFT (trigger 293707) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile. The observations started 124.7s after the GRB trigger (70.5s after the notice). The elevation of the field decreased from from 26 degrees above horizon and weather conditions were good. We detect a new rsising source in the error box given by SWIFT at the following position (+/- 3 arcsec): RA(J2000.0) = 19h 12m 14.73s DEC(J2000.0) = -32d 24' 07.1" OT was R~15.6 at ~400s after GRB. We continue to observe. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon= 5.2380 lat=-18.2310 and the galactic extinction in R band is 1.3 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6861 SUBJECT: GRB 071010: Keck Observations of the Afterglow DATE: 07/10/10 05:37:15 GMT FROM: Josh Bloom at UC Berkeley J. S. Bloom, D. A. Perley, M. Modjaz, D. Poznanski (UC Berkeley), H.- W. Chen (U Chicago), and J. X. Prochaska (UCSC) report: "We have conducted preliminary imaging with the Keck I telescope (+LRIS) of the afterglow seen in TAROT (Klotz et al. GCN 6860) of GRB 071010 (Moretti et al. 6859). In the first set of short exposures (~100 sec) in R and G bands (starting at 04:48:34 UT) we detect a source near that position with a magnitude comparable to the faintest detectable DSS sources (corresponding to R~20 - 21 mag). We report a refined position (+/- 300 mas relative to USNO B1.0): ra= 19:12:14.624 dec= -32:24:07.16 J2000 The offset from the star at 19:12:17.121, -32:24:18.65 to the afterglow is 31.62" W, 11.49 "N. Spectroscopy is underway and reports from that analysis are forthcoming (the continuum is detected to the atmospheric cutoff in the blue, implying z<~2)." This message may be cited. We thank A. Klotz for helpful conversations regarding the TAROT afterglow detection. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6862 SUBJECT: GRB 071010: Rapid PROMPT Detections DATE: 07/10/10 06:45:21 GMT FROM: Josh Haislip at U.North Carolina J. Haislip, D. Reichart, M. Nysewander, A. LaCluyze, K. Ivarsen, J. A. Crain, A. Foster, M. Schubel, J. Styblova, T. Brennan, and A. Trotter report: Skynet observed the localization of GRB 071010 (Moretti et al., GCN 6859) with three of the 16" PROMPT telescopes at CTIO beginning 90 seconds after the burst (35 seconds after notification) in BVRI. We detect the afterglow (Klotz et al., GCN 6860) in all filters. At 2.6 minutes after the burst, we measure I ~ 17.5 mag. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6863 SUBJECT: GRB 071010: TAROT La Silla observatory photometry of the afterglow DATE: 07/10/10 07:35:34 GMT FROM: Alain Klotz at CESR-CNRS Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report: We derived accurate photometry of the afterglow of GRB 071010 (cf. Klotz et al. GCNC 6860) from TAROT, R and unfiltered images. We converted unfiltered magnitudes into R band using a simple offset assuming a low redshift (z<2) and a continuum spectrum as described by Bloom et al. (GCNC 6861). The afterglow is fainter than previously annonced in GCNC 6860. We observed a rise of brightness at a rate alpha=-0.9 (+/-0.5) until about 470s after the trigger (+/-60s) with a maximum brightness R=17.0. Then the afterglow has decreased at a rate alpha=+0.8 (+/-0.1) until at less 90 minutes after the trigger (R=19.1 at t_trig+90min). Observations are now finished in Chile due to the set of the GRB. This message may be cited.. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6864 SUBJECT: GRB 071010: Keck/LRIS Spectroscopy DATE: 07/10/10 07:56:39 GMT FROM: Jason Prochaska at UCO/Lick Obs Jason X. Prochaska (UCSC), D. A. Perley, M. Modjaz, J.S. Bloom, D. Poznanski (UC Berkeley), H.-W. Chen (U Chicago), report on behalf of GRAASP: "We observed the afterglow of GRB 071010 with the LRIS dual spectrometer for a series of 900s exposures starting at UT 05:00 under good conditions. Analysis of the blue side reveals a strong MgII absorber and corresponding FeII lines at z=0.98. The absence of strong features in the spectrum redward of 5700A suggests this is the redshift of the GRB. A more conservative upper limit is placed by the absence of IGM signatures at 3400A which indicates z_GRB < 1.8. Further analysis is in progress." This GCN may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6865 SUBJECT: GRB 071010 REM NIR observations DATE: 07/10/10 08:04:22 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, D. Fugazza, S. Covino, L.A. Antonelli, L. Calzoletti, S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini, V. D'Elia, F. Dalessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani, F. Vitali report on behalf of the REM team: We observed the field of the GRB 071010 (Moretti et al., GCN 6859) with the robotic 60-cm REM telescope located at La Silla (Chile). A set of observations was performed automatically in the Z, J, H, K NIR filters starting at 03:42:52 UT (about 100 sec after the burst) and lasted about 30 minutes due to visibility constraints. The analysis of the first set of H-band exposures clearly show the optical afterglow candidate reported by Klotz et al. (GCN 6860), Bloom et al. (GCN. 6861), Haislip et al. (GCN. 6862) at a level of H =14.3 ± 0.2 (calibrated against the 2MASS catalog). The afterglow is clearly detected in all bands. Futher analysis is in progress. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6868 SUBJECT: GRB 071010, Swift-BAT refined analysis DATE: 07/10/10 15:13:28 GMT FROM: Scott Barthelmy at NASA/GSFC H. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), C. Guidorzi (U.Bicocca&INAF-OAB), C. Markwardt (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), 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+394 sec from the recent telemetry downlink, we report further analysis of BAT GRB 071010 (trigger #293707) (Moretti, et al., GCN Circ. 6859). The BAT ground-calculated position is RA, Dec = 288.040, -32.385 deg which is RA(J2000) = 19h 12m 9.7s Dec(J2000) = -32d 23' 6" with an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 42%. The mask-weighted light curve shows a single peak starting at ~T-10 sec, peaking at ~T+1 sec, and ending at ~T+20 sec. T90 (15-350 keV) is 6 +- 1 sec (estimated error including systematics). The time-averaged spectrum from T-1.1 to T+5.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.33 +- 0.37. The fluence in the 15-150 keV band is 2.0 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.80 sec in the 15-150 keV band is 0.8 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6870 SUBJECT: GRB 071010: Swift-XRT observation DATE: 07/10/10 19:09:30 GMT FROM: Cristiano Guidorzi at INAF-OAB C. Guidorzi (Univ. Bicocca & INAF-OAB), V. Mangano (INAF-IASFPA) A. Moretti (INAF-OAB), P. Romano (Univ. Bicocca & INAF-OAB), report on behalf of the Swift-XRT team: Swift XRT observed the GRB 071010 (trigger=293707, Moretti et al., GCN Circ. 6859) beginning 34 ks after the BAT trigger. In 2.4 ks of Photon Counting mode data spanning 34-40 ks after the trigger we found the X-ray afterglow at RA,Dec =288.06008, -32.40172, which is RA(J2000) = 19 12 14.42 Dec(J2000)= -32 24 06.2 with error circles of radius 5.3 arcsec (90%, including boresight uncertainties). This lies 2.8 arcsec from the position given by the Keck observation (Bloom et al., GCN Circ. 6861) of the optical afterglow discovered by TAROT (Klotz et al., GCN Circ. 6860) and 84.8 arcsec from the BAT refined position (Krimm et al., GCN Circ. 6868). At present, due to the paucity of the observed events, we are unable to determine the fading rate. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6871 SUBJECT: GRB 071010B: Swift detection of a burst DATE: 07/10/10 21:09:02 GMT FROM: Craig Markwardt at NASA/GSFC/UMD C. B. Markwardt (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), C. Pagani (PSU), P. Romano (Univ. Bicocca & INAF-OAB), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA) and G. Stratta (ASDC) report on behalf of the Swift Team: At 20:45:47 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 071010B (trigger=293795). The BAT on-board calculated location is RA, Dec 150.530, +45.731 which is RA(J2000) = 10h 02m 07s Dec(J2000) = +45d 43' 53" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single FRED pulse with a duration of about 20 sec. The peak count rate was ~12,000 counts/sec (15-350 keV), at ~2 sec after the trigger. Because Swift is in the process of returning to normal operations, automatic slewing to GRBs is currently disabled outside of business hours (US EDT). Therefore, there are no prompt XRT or UVOT observations of this burst. Burst Advocate for this burst is C. B. Markwardt (craigm 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: 6872 SUBJECT: GRB 071010A: Keck/LRIS Photometry DATE: 07/10/10 21:16:37 GMT FROM: Josh Bloom at UC Berkeley D. A. Perley, J. S. Bloom, M. Modjaz, and D. Poznanski (UC Berkeley) report: "In addition to the spectroscopic followup reported by Prochaska et al. (GCN 6864), we acquired imaging of the GRB 071010A field in g and R band with the Keck I 10m telescope (+LRIS) starting in twilight and continuing until the object set. The fading afterglow reported by Klotz et al. (GCN 6860) is well-detected. Photometry, calculated relative to the USNO B1.0 catalog, is as follows: t_start(min) R err 67.497 18.025 +/- 0.03 71.041 18.080 +/- 0.03 189.225 18.784 +/- 0.02 194.482 18.806 +/- 0.02 199.457 18.827 +/- 0.02 201.544 18.846 +/- 0.02 203.794 18.873 +/- 0.02 This photometry supersedes the preliminary report in GCN 6861 (Bloom et al.). In addition, starting at 213 minutes after the trigger we obtained a rapid series of 26 simultaneous g+R integrations of typically 30 sec duration, lasting until 239 minutes after the trigger. Analysis is ongoing." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6873 SUBJECT: GRB 071010B possible optical transient DATE: 07/10/10 22:53:58 GMT FROM: AAVSO GRB Network at AAVSO A. Oksanen (Nyrola Observatory, Jyvaskyla, Finland) reports to the AAVSO International High Energy Network the following optical observations of GRB071010B (GCN #6871, Markwardt et al.): Arto Oksanen reports the detection of an optical transient located at RA 10:02:9.26, Dec +45:43:50.3 (J2000) at an initial unfiltered magnitude of 17.538 calibrated relative to USNOB R-band magnitudes. Midpoint of the exposures is 2007 Oct 10, 21:11:05 UTC, approximately 25 minutes after the trigger. There are no comparably bright stars within 0.5 arcminutes, and no minor planets in the area. Subsequent unfiltered images place the star fainter than 18th magnitude (unfiltered) indicating the object has faded since observations began. Analysis of additional unfiltered, Rc, Ic, and V images will be forthcoming. The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6876 SUBJECT: GRB 071010A: bright NIR afterglow DATE: 07/10/11 01:07:21 GMT FROM: Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center D. Malesani (DARK), V. D'Elia (INAF/OAR), S. Covino (INAF/OABr), G. Andreuzzi, A. Garcia de Gurtubai (INAF/TNG), and E. Maiorano (INAF/IASF Bo), report on behalf of a larger collaboration: We observed the optical afterglow of GRB 071010A (Moretti et al., GCN 6859; Klotz et al., GCN 6860) with the TNG telescope located in the Canary Islands. Observations were carried out with the NICS instrument equipped with the H filter, with mean time Oct 10.82 UT (15.7 hr after the GRB). At the position reported by Bloom et al. (GCN 6861), we clearly detect a pointlike object, with H = 16.62 +- 0.05. We note that this value is remarkably bright. Assuming typical afterglow colors (Fnu propto nu^-1), this corresponds to R ~ 19. When compared to the Keck photometry reported by Perley et al. (GCN 6872), this may suggest a flat segment or even a flaring behaviour. Alternatively, the afterglow may be very red. We thus encourage further observations to characterize the afterglow light curve and spectrum. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6877 SUBJECT: GRB 071010B, Swift-BAT refined analysis DATE: 07/10/11 01:12:33 GMT FROM: Scott Barthelmy at NASA/GSFC C. Markwardt (GSFC/UMD), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), 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 071010B (trigger #293795) (Markwardt, et al., GCN Circ. 6871). The BAT ground-calculated position is RA, Dec = 150.531, 45.733 deg which is RA(J2000) = 10h 2m 7.5s Dec(J2000) = 45d 44' 0" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 84%. The mask-weighted light curve shows a pretrigger pulse starting at ~T-45 sec, peaking at ~T-20 sec, and returning almost to background at ~T-8 sec. Then the main FRED pulse started at ~T-8 sec, peaked at ~T+2 sec, and ends around T+60 sec. Swift slewed to a preplanned target at T+130 sec at which point the burst location went out of the BAT FOV, so we have no more data about activity on this burst after that time. A small third peak starts at ~T+95 sec and is terminated by the spacecraft slew. T90 (15-350 keV) is at least 35.7 +- 0.5 sec (estimated error including systematics). The time-averaged spectrum from T-35.7 to T+24.1 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.53 +- 0.22, and Epeak of 52.0 +- 6.4 keV (chi squared 31.19 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.4 +- 0.1 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+1.40 sec in the 15-150 keV band is 7.7 +- 0.3 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.01 +- 0.05 (chi squared 46.71 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6878 SUBJECT: GRB071010B: Swift/XRT detection DATE: 07/10/11 02:20:08 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. A. Kennea (PSU), V. Mangano (INAF/IASF) and C. Markwardt (GSFC/UMD) report on behalf of the Swift/XRT team: At 22:29:34 UT on Oct 10th, 2007, Swift/XRT began observing the field of the BAT detected burst GRB071010B (Markwardt et al., GCN #6871). XRT took 807s of PC mode data, and detects an uncatalogued point source at the following coordinates: RA(J2000) = 10h 02m 09.2s, Dec(J2000) = +45d 43m 52.2s, with an estimated error of 5 arcseconds radius (90% confidence). This position lies 20 arcseconds from the refined BAT position (GCN #6877), and 1.9 arcseconds from the tentative optical counterpart reported by Oksanen et al. (GCN #6873). Due to the short observation, we are unable to determine if this X-ray source is fading. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6879 SUBJECT: Konus-Wind observation of GRB 071010B DATE: 07/10/11 11:23:47 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report: The long GRB 071010 (Swift-BAT trigger #293795: Markwardt et al., GCN 6871, 6877) triggered Konus-Wind at T0=74748.490 s UT (20:45:48.490). The burst light curve shows a single pulse with a duration of ~15 s, followed by a weak soft tail seen up to T-T0 ~50 s. There is a hint of the pretrigger pulse detected by BAT (Markwardt et al., GCN 6877) in the Konus-Wind soft energy band (18-70 keV). As observed by Konus-Wind the burst had a fluence of 4.78(-3.12, +0.95)x10^-6 erg/cm2, and a 64-ms peak flux measured from T0+1.6 s of 8.92(-5.99, +2.29)x10^-7 erg/cm2/s (both in the 20 keV - 1 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.640 s) can be fitted (in the 20 keV - 1 MeV range) by GRBM (Band) model for which: the low-energy photon index is alpha = -1.25 (-0.49, +0.74), the high energy photon index beta = -2.65(-0.49, +0.29), the peak energy Ep = 52 (-14, +10) keV (chi2 = 69.1/55 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB071010_T74748/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6880 SUBJECT: Optical observations: GRB 071010A DATE: 07/10/11 12:12:29 GMT FROM: Kuntal Mishra at ARIES,Nainital,India Rupak Roy, K. Misra, and S. B. Pandey (ARIES, NainiTal, India, on behalf of larger Indian GRB collaboration) We have imaged the field of Swift GRB 071010 (Moretti et al. GCN6859) with the 1.04m telescope at NainiTal ~ 0.5 days after the burst. Observations were performed in R and I bands in poor sky conditions. We observed the afterglow candidate in R and I bands reported by Klotz, A. et al. (GCN 6860). Magnitude of the OT is R ~ 20 in comparison to nearby USNO B1.0 stars. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6884 SUBJECT: GRB 071010B: Bright OT confirmed with TLS DATE: 07/10/11 14:56:36 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, C. Hoegner & R. Filgas (TLS Tautenburg) report: We observed the field of GRB 071010B (Markwardt et al., GCN 6871) with the TLS 1.34m Schmidt telescope under bad weather conditions (low transparency, passing clouds). We obtained 9 600 second integrations in the Rc Filter starting at UT 1:26:44 (0.2 days after the GRB). The afterglow (Oksanen, GCN 6873) is clearly detected on several frames, the others were lost to passing clouds. We measure a refined OT position (J2000) in comparison to the USNO-B1.0 catalog: RA = 10:02:09.24 Dec. = +45:43:49.7 with errors of 0".7. This is in accordance with the position of Oksanen (GCN 6873) and the Swift XRT detection (Kennea et al., GCN 6878). Preliminary photometry on raw images yields a decaying afterglow. Assuming the USNO-B1.0 star at RA = 10:02:06.71, Dec. = +45:42:34.2 (J2000) to have R2 = 17.26, we find the following magnitudes: Date Mid-Time Rc Rc error 11.06361 0.19848 18.61 0.07 11.07113 0.20600 18.73 0.05 11.07865 0.21352 18.87 0.06 11.13149 0.26637 19.21 0.05 Oksanen (GCN 6873) reported the OT to have R > 18 mag already in the first hour, therefore our bright detections may indicate a slow decay or a rebrightening. This GRB was a bright, soft FRED (Markwardt et al., GCN 6877; Golenetskii et al., GCN 6879) with a well determined peak energy. This may indicate an event at relatively low redshift. Further photometric and especially spectroscopic follow-up is encouraged. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6885 SUBJECT: GRB 071010A: Continued Keck Imaging DATE: 07/10/11 15:11:26 GMT FROM: Daniel Kocevski at UC Berkeley D. Kocevski, D. A. Perley, and M. Modjaz (UC Berkeley) report: Beginning at 04:47:42 UT (2007-10-11) we began a second series of imaging on the field of GRB 071010A (GCN 6733) using the Keck I telescope (+LRIS). We acquired 6 images with an effective exposure of 270s in R band and 360s in V band. The optical afterglow (GCN 6860) is still detected and has faded since our previous imaging epoch (GCN 6872). Preliminary aperture photometry of the source indicates that it has faded by 0.55 magnitudes since our previous imaging. Using the same calibration system as in our previous circular, we estimate a preliminary magnitude of R=19.42 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6888 SUBJECT: GRB 071010B: Gemini Spectroscopic Observations DATE: 07/10/11 17:52:12 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko (Caltech), A. Cucchiara, D. B. Fox (Penn State), E. Berger (Princeton), and P. A. Price (Hawaii) report on behalf of a larger collaboration: We have obtained a single 1800 s spectrum of the optical afterglow (Oksanen; GCN 6873) of GRB071010B (Markwardt et al.; GCN 6871) with the Gemini Multi-Object Spectrograph mounted on the Gemini North telescope. Our exposure began at 14:41 UT on October 11, and covered the wavelength range from 4000 - 8000 A. We find a strong absorption doublet at ~ 5450 A that we identify as Mg II 2796 / 2803 at z = 0.947. Weaker absorption features corresponding to Mg I 2852 and Fe II 2586 are also present at the same redshift. A preliminary inspection reveals no other absorption nor emission systems present. If the z=0.947 system is the host redshift, we calculate an isotropic energy release of ~ 1.1e52 erg in the 20 keV - 1 MeV observed frame (Golenetskii et al., GCN 6879). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6890 SUBJECT: GRB 071010B: Keck/LRIS Spectroscopy DATE: 07/10/11 18:21:41 GMT FROM: Jason Prochaska at UCO/Lick Obs Jason X. Prochaska (UCSC), D. A. Perley, M. Modjaz, J.S. Bloom, D. Poznanski (UC Berkeley), and C.C. Thoene (Dark Cosmology Center) report on behalf of GRAASP: "We observed the afterglow of GRB 071010B with the Keck/LRIS dual spectrometer for a series of 300s exposures starting at UT 15:08 under good conditions. We confirm the report of Cenko et al. (GCN 6888) of a strong MgII absorber at z=0.947 in the afterglow spectrum. Our data show corresponding FeII transitions at rest-frame wavelengths: 2344, 2382, 2586, and 2600. We do not identify any FeII* transitions and also set an upper limit to the rest equivalent width of ZnII 2026: EW<0.4A. Such weak ZnII 2026 absorption is rare for GRB host galaxies, but not unprecedented. A more conservative upper limit to the GRB redshift is set by the absence of IGM signatures at 3500A which indicates z_GRB < 1.9. Further analysis is in progress." This GCN may be cited. [GCN OPS NOTE(11oct07): Per the author's request, CCT was added to the list of authors.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6892 SUBJECT: GRB 071010B optical photometry DATE: 07/10/11 19:33:51 GMT FROM: AAVSO GRB Network at AAVSO A. Oksanen (Nyrola Observatory, Jyvaskyla, Finland), M. Templeton (AAVSO) and A. Henden (AAVSO) report further details on optical observations of GRB071010B (GCN #6871, Markwardt et al.; GCN #6873 Oksanen; GCN #6878 Kennea et al.; GCN #6884 Kann et al.): Further to the initial report given in GCN #6873, Arto Oksanen reports unfiltered photometry of the GRB 071010B afterglow spanning 2007 Oct 10 21:02:33 UT to 2007 Oct 11 03:24:27 UT (T0 + 17 minutes to T0 + 6 hours 39 minutes post-burst). The data are reasonably well fit by a single power law with index -1.14. The measured unfiltered magnitudes are approximately 0.3 magnitudes fainter than the Rc magnitudes reported by Kann et al (GCN #6884) taken at the same time, which is consistent with differences in zero-point calibration and bandpass. It should be noted that this field is covered by the SDSS, and that the AAVSO will obtain a BVRI calibration with the Sonoita Research Observatory, weather permitting. Oksanen also reports additional preliminary Ic and V-band magnitudes: 2007 Oct 10, 21:32 UT Ic = 17.64 +/- 0.05 2007 Oct 10, 21:52 UT V = 18.30 +/- 0.05 Both magnitudes are calibrated relative to the transformed SDSS ugriz magnitudes for the object at RA 10:01:54.62, Dec +45:40:29.0 (J2000). Further details of these observations, light curves, and analyses are in preparation for publication in the electronic Journal of the AAVSO. Full details of the observations are available at the following URL: ftp://ftp.aavso.org/grb/ArtoOksanen_GRB071010B_2454384.45422_.txt The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6893 SUBJECT: GRB 071010B: Super-LOTIS upper limit DATE: 07/10/11 20:35:13 GMT FROM: Adria C. Updike at Clemson U A. C. Updike (Clemson), P. A. Milne (Steward Observatory), G. G. Williams (MMTO), and D. H. Hartmann (Clemson) report on behalf of the Super-LOTIS Collaboration: The robotic 0.6m Super-LOTIS telescope observed the field of GRB 071010B (GCN 6871, Markwardt et al.) beginning at 10:24 UT on Oct 11, 13.6 hours after the trigger. We obtained 59 minutes in the R band and 19 minutes in the V band. We do not detect the OT (Oksanen GCN 6873, Kann et al. GCN 6884) in the stacked exposures. Limiting magnitudes were determined using 10 field stars calibrated to the USNO B1.0 catalog. t_start (UT) Filter exp (s) Limit ------------------------------------------------------------- 10:24:40 R 59x60 > 20.4 10:49:00 V 19x60 > 19.2 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6897 SUBJECT: GRB 071010B: Optical Detection DATE: 07/10/12 01:52:16 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 GRB071010B (GCN 6871, Markwardt et al.) beginning at 11:19:26 UT on Oct 11, or 14.3 hrs after the trigger. From a stacked image of four, 5 min frames in the R-band, we detect the OT (Oksanen GCN 6873, Kann et al. GCN 6884) with a high significance (S/N > 15) at the position they reported. Compared to the non-detection report at 13.6 hrs after the trigger (GCN 6893), our detection suggests re-brightening of OT. A preliminary photometry of the object using USNO B1.0 R2 mag of two stars near the OT is given below (aperture mag with 6" diameter circle). t_start (UT) Filter exp (sec) R-mag err ----------------------------------------------------- 11:19:26 R 4x300 19.8 0.08 (uncertain) We will report later, a more careful analysis of the BVR images taken during the same period. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6901 SUBJECT: VLA non-detection of GRB 071010A DATE: 07/10/12 14:46:05 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 BAT position of the Swift burst GRB 0701010A (GCN#6859) using the VLA at a frequency of 8.46 GHz and starting at 0.09 UT on Oct 12, 2007. We do not detect any radio emission Keck optical position of the afterglow (GCN#6861). The flux density at afterglow position is -4 ± 35 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: 6903 SUBJECT: GRB 071010B correction to GCN 6892 optical observations DATE: 07/10/12 17:58:30 GMT FROM: AAVSO GRB Network at AAVSO M. Templeton (AAVSO), D.A. Kann (TLS Tautenburg), A. Oksanen (Hankasalmi Observatory, Hankasalmi, Finland) and A. Henden (AAVSO) report the following correction to the decay rate for unfiltered optical photometry of GRB 071010B given in Oksanen et al. (GCN #6892): Due to a software error, the decay rate originally given in GCN #6892 (-1.14) is incorrect. The correct power-law for the optical decay is -0.482 +/- 0.064. This is consistent with an independent measure of -0.464 +/- 0.016 performed by D.A. Kann using additional data from the TLS Tautenburg 2-meter telescope. We also note the original data were obtained by A. Oksanen with the Hankasalmi Observatory 0.4-meter, rather than at Nyrola Observatory, and have corrected his affiliation accordingly. The corrected version of GCN #6892 follows: A. Oksanen (Hankasalmi Observatory, Hankasalmi, Finland), M. Templeton (AAVSO) and A. Henden (AAVSO) report further details on optical observations of GRB071010B (GCN #6871, Markwardt et al.; GCN #6873 Oksanen; GCN #6878 Kennea et al.; GCN #6884 Kann et al.): Further to the initial report given in GCN #6873, Arto Oksanen reports unfiltered photometry of the GRB 071010B afterglow spanning 2007 Oct 10 21:02:33 UT to 2007 Oct 11 03:24:27 UT (T0 + 17 minutes to T0 + 6 hours 39 minutes post-burst). The data are reasonably well fit by a single power law with index -0.482 +/- 0.064. The measured unfiltered magnitudes are approximately 0.3 magnitudes fainter than the Rc magnitudes reported by Kann et al (GCN #6884) taken at the same time, which is consistent with differences in zero-point calibration and bandpass. It should be noted that this field is covered by the SDSS, and that the AAVSO will obtain a BVRI calibration with the Sonoita Research Observatory, weather permitting. Oksanen also reports additional preliminary Ic and V-band magnitudes: 2007 Oct 10, 21:32 UT Ic = 17.64 +/- 0.05 2007 Oct 10, 21:52 UT V = 18.30 +/- 0.05 Both magnitudes are calibrated relative to the transformed SDSS ugriz magnitudes for the object at RA 10:01:54.62, Dec +45:40:29.0 (J2000). Further details of these observations, light curves, and analyses are in preparation for publication in the electronic Journal of the AAVSO. Full details of the observations are available at the following URL: ftp://ftp.aavso.org/grb/ArtoOksanen_GRB071010B_2454384.45422_.txt The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6906 SUBJECT: GRB 071010C Swift-BAT detection of a burst DATE: 07/10/13 02:59:07 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. R. Cummings (CRESST/NASA/GSFC) for the Swift-BAT team At 22:20:22 UT on October 10, the Swift Burst Alert Telescope (BAT) triggered on GRB 071010C (trigger #293804). The burst was on the edge of the field of view (3.5% coded) and no source was found automatically onboard. A source was found during later ground analysis at a location RA, Dec 338.054, +66.159 which is RA(J2000) = 22h 32m 13s Dec(J2000) = +66d 09' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single slow-rise slow-decay peak about 12 seconds long. The peak count rate was about 1000 counts/sec (15-350 keV), at ~1 sec after the trigger. Because the burst was detected on the ground, there are no prompt XRT or UVOT data. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6909 SUBJECT: GRB071010B, BVRcIc field calibration DATE: 07/10/13 15:46:46 GMT FROM: Arne A. Henden at AAVSO A. Henden (AAVSO) reports: While the field of GRB071010B has been observed by SDSS, we have also obtained a two-night BVRcIc field calibration using the 35cm robotic telescope at Sonoita Research Observatory. The calibration file has a limiting magnitude around V=18, with good standards brighter than V=16 or so. The file is available at ftp://ftp.aavso.org/public/calib/grb/grb071010b.dat This calibration is based on numerous Landolt standards, and has an external zeropoint error of about 0.02mag. We do not expect at this time to extend this calibration to fainter magnitudes. The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6915 SUBJECT: VLA detection of radio afterglow of GRB 071010B DATE: 07/10/14 18:12:15 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 Swift burst GRB 0701010B (GCN#6871) using the VLA at a frequency of 8.46 GHz and starting at 18.42 UT on Oct 13, 2007. We do not detect any radio emission at a position of (J2000): RA: 10 02 09.28 Dec: 45 43 49.07 The flux density at this position is 276 ± 49 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: 6916 SUBJECT: Correction to GCN circular no. # 6915 for GRB 071010B DATE: 07/10/14 18:46:26 GMT FROM: Poonam Chandra at U Virginia/NRAO P. Chandra (UVA/NRAO) reports: There was a typo in the text of GCN#6915 sent by me. The GRB 071010B is indeed detected in 8.46 GHz VLA radio band. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6918 SUBJECT: GRB 071010B: TLS 2nd Epoch, refined analysis DATE: 07/10/15 20:41:14 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, C. Hoegner & R. Filgas (TLS Tautenburg) report: We observed the afterglow (Oksanen, GCN 6873) of GRB 071010B (Markwardt et al., GCN 6871) with the Tautenburg 1.34m Schmidt telescope under good conditions, obtaining 16 600 second images in the Rc band at 3.2 to 3.3 days after the GRB. The afterglow is clearly detected in all frames. Using two USNO B1.0 stars (RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4, R2=16.80; RA (J2000) = 10:02:23.11, Dec. (J2000) = +45:41:41.1, R2=16.94), we revise our original photometry (Kann, Hoegner & Filgas, GCN 6884) using fully reduced images: Date Mid-Time Rc dRc 11.06361 0.19848 19.145 0.041 11.07113 0.20600 19.121 0.033 11.07865 0.21352 19.198 0.030 11.08617 0.22104 19.163 0.062 11.13149 0.26637 19.396 0.032 11.13902 0.27389 19.512 0.223 (Clouds) Using the same comparison stars, we derive the following magnitudes from our new images: Date Mid-Time Rc dRc 14.05372 3.18859 20.800 0.139 14.06126 3.19613 20.815 0.142 14.06878 3.20365 20.779 0.092 14.07630 3.21117 20.852 0.088 14.08382 3.21869 20.921 0.095 14.09133 3.22621 20.899 0.097 14.09885 3.23372 20.888 0.088 14.10638 3.24125 20.839 0.079 14.11389 3.24877 20.967 0.090 14.12141 3.25628 20.946 0.078 14.12892 3.26380 21.014 0.093 14.13644 3.27131 20.929 0.075 14.14395 3.27882 20.814 0.071 14.15146 3.28634 20.732 0.066 14.15899 3.29386 20.792 0.069 14.16650 3.30138 20.864 0.076 We note that the last data points seem to indicate a small rebrightening feature which was receding again when twilight stopped our observations. With Rc ~ 20.9 at 3.2 days after the GRB, the afterglow is among the brightest observed so far (Kann, Klose & Zeh 2006, ApJ, 641, 993; Kann et al., in preparation). Using data from Arto Oksanen (http://murtoinen.dyndns.org/ccd/grb/grb071010/) and Im, Lee & Urata (GCN 6897), we find that the afterglow can be fit with a broken power law with pre-break slope alpha_1 = 0.3 +/- 0.083, post-break slope alpha_2 = 0.575 +/- 0.009, and break time t_b = 0.049 +/- 0.019 days. The very shallow decay (Kann, Hoegner & Filgas, GCN 6884, Templeton et al., GCN 6903) is thus seen to continue, which is highly unusual. Further observations are planned and encouraged at other facitlities. This message may be cited. [GCN OPS NOTE(16oct07): Per author's request, the typo in the first line was changed from "071013" to "071010B".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6919 SUBJECT: GRB 071010B: Keck/LRIS Photometry DATE: 07/10/16 00:12:18 GMT FROM: Daniel Kocevski at UC Berkeley D. Kocevski, D. A. Perley, J. S. Bloom, M. Modjaz, and D. Poznanski (UC Berkeley) report: "In addition to the spectroscopic followup reported by Prochaska et al. (GCN 6890), we acquired a 90s exposure in R band and a 30s exposure in g and V bands of the field containing GRB 071010B with the Keck I 10m telescope (+LRIS), beginning at 15:01:21 UT on 2007-10-11. The optical afterglow at 10:02:9.26, +45:43:50.3 reported by Oksanen et al. (GCN 6871) and confirmed by Kann et al. (GCN 6884 ) was clearly detected. Using aperture photometry, we estimate the multi-color magnitudes of the afterglow to be: R = 19.62 V = 19.71 g = 19.10 when calibrated to Landolt standard star observations. We note that the afterglow had not faded considerably from the magnitude reported by Im et al. (GCN 6897) whose observations began approximately 4 hours earlier. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6920 SUBJECT: GRB 071010B: Photometry after 1.6 days DATE: 07/10/16 01:37:25 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 continued our observation of GRB071010B (GCN 6871, Markwardt et al.), beginning at 11:37:19 UT on Oct 12, or 1.62 days after the trigger. From a stacked image of nine, 5 min frames in the R-band, we detect the OT again (Oksanen GCN 6873, Kann et al. GCN 6884). A preliminary photometry of the object using the standard star data taken during the same day is given below (aperture mag with 6" diameter circle). Also given is a slightly revised R-band magnitude we reported earlier (Im et al., GCN 6897). t_start (UT) Filter exp (sec) R-mag err ----------------------------------------------------- Oct. 11, 11:19:47 R 4x300 19.81 0.08 Oct. 12, 11:37:19 R 9x300 20.54 0.10 Our result is consistent with the recent report that the GRB is fading rather slowly (GCN 6918, Kann et al.; GCN 6919 Kocevski et al.). However, compared with the magnitudes at Oct. 14 reported by Kann et al. (6918), our photometry suggests a very marginal decrease in the brightness between Oct. 12 - Oct. 14. We will report later, the BVRI photometry data taken during the same period. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6923 SUBJECT: GRB 071010B: TLS 3rd Epoch - finally a break?? DATE: 07/10/16 14:53:51 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, U. Laux & R. Filgas (TLS Tautenburg) report: We observed the afterglow (Oksanen, GCN 6873) of GRB 071010B (Markwardt et al., GCN 6871) with the Tautenburg 1.34m Schmidt telescope under mediocre conditions (low transparency), obtaining 12 600 second images in the Rc band at 5.3 days after the GRB. The afterglow is faintly detected in all frames. We create a stacked image and, using the same comparison stars as Kann, Hoegner & Filgas (GCN 6918), we derive the following magnitude: Date Mid-Time Rc dRc 16.09041 5.22528 21.293 0.045 In comparison with earlier data (see Kann, Hoegner & Filgas, GCN 6918, for references, and adding Kocevski et al., GCN 6919; Im, Lee & Urata, GCN 6920), we find the afterglow to be 0.3 magnitudes fainter than the extrapolation of the earlier decay. This may indicate that a break has occured. Inclement weather and an instrument switch will probably not allow us to obtain another epoch. Further follow-up at other northern facilities is strongly encouraged to check the validity of the break. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6924 SUBJECT: GRB 071010B: Optical observations of EST DATE: 07/10/16 16:03:33 GMT FROM: L.P. Xin at NAOC We observed the afterglow (Oksanen, GCN 6873) of GRB 071010B (Markwardt et al., GCN 6871) with the EST 1m telescope at Xinglong Observatory started from 19:07:59(UT) Oct.11. Totally 11*600s V-band images were obtained. With the calibration data reported by Henden (GCN 6909) we derived the afterglow had a magnitude V=20.75 +/- 0.05 with mid-time 23.314 hours after the burst. Compared with the V-band magnitude of Daniel Kocevski (GCN 6919), we found the V-band magnitude of the afterglow decayed deeply about 1 magnitude after about 5 hours. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6928 SUBJECT: GRB 071010B: Keck/DEIMOS emission-line redshift DATE: 07/10/17 04:47:44 GMT FROM: Daniel Perley at U.C. Berkeley D. Stern (JPL), D. A. Perley (UC Berkeley), N. Reddy (NOAO), J. X. Prochaska (UCSC), H. Spinrad (UCB) and M. Dickinson (NOAO) report: On the night of 2007 Oct. 11 we observed the afterglow of GRB 071010B (GCN 6871, Markwardt et al.; GCN 6873, Okansen et al.) with the Keck II 10m telescope + DEIMOS, for a total integration time of 1260 seconds, starting at 14:41 UT. The wavelength coverage was between 5230 and 10480 Angstroms. The detection of MgII previously reported by Cenko et al. (GCN 6888) and Prochaska et al. (GCN 6890) at a redshift of 0.947 is further confirmed, as is a weak detection of MgI 2852. In addition, the [OII] 3727 doublet emission feature is well-detected at the same redshift, superimposed on the continuum. [OIII] 5008 is also detected, as is (marginally) [OIII] 4960. These results strongly suggest that the redshift of GRB 071010B and its host galaxy is most likely 0.947. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6931 SUBJECT: GRB 071010B: Suzaku WAM observation of the prompt emission DATE: 07/10/18 02:57:14 GMT FROM: Masanori Ohno at Hiroshima U C. Kira, M. Ohno, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), Y. Terada, T. Tamagawa (RIKEN), K. Yamaoka, Y. E. Nakagawa, S. Sugita (Aoyama Gakuin U.), M. Tashiro, Y. Urata, A. Endo, K. Onda, M. Suzuki, N. Kodaka, K. Morigami (Saitama U.), T. Enoto, R. Miyawaki, K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M.Yamauchi, S. Maeno, H. Tanaka, R. Hara (Univ. of Miyazaki), M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report: The long GRB 071010B (Swift/BAT trigger #293795; C. B. Markwardt et al., GCN 6871, 6877) was triggered by the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 2007-10-10 20:45:49 UT (=T0). The observed light curve shows a single FRED-like peak, starting at T0-3s, ending at T0+10s, with a duration (T90) of about 5 seconds. There is no signal corresponding to the pre-trigger pulse and the weak soft tail detected by the Swift/BAT (GCN Report 92.1) and the Konus-Wind (GCN 6879) in the WAM energy band (50-5000 keV). The fluence in 100 - 1000 keV was (1.8 +/- 0.3)*10^-6 erg/cm^2. The 1-s peak flux measured from T0+1s was 1.1 +/- 0.3 photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-3s to T0+10s is well fitted by a single power-law with a photon index of 3.2 (-0.5, +0.7) (chi^2/d.o.f = 6/8 ). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6934 SUBJECT: GRB 071010A: Late-time Keck/LRIS photometry - possible host galaxy and jet break DATE: 07/10/18 21:59:38 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, A. V. Filippenko, J. M. Silverman, R. J. Foley, M. Modjaz, D. Kocevski, and J. S. Bloom report: We acquired an additional series of imaging observations of the field of GRB 071010A (Moretti et al., GCN 6859) with Keck I + LRIS starting at 5:01 UT, 2007-10-16 (6.05 days after the trigger), in g and R filters. The optical afterglow (Klotz et al. GCN 6860) has faded substantially. An object is observed at the GRB position, resolvable into two regions: a brighter, redder source to the east and a fainter, bluer source to the west. Comparison with our previous Keck imaging shows the afterglow position to be consistent only with the fainter, western source. The two sources may be a bright elongated host galaxy, a compact host galaxy with the afterglow offset from the center, or a foreground star with the afterglow coincidentally located very nearby. An image of the field is posted at: http://lyra.berkeley.edu/~dperley/071010a/071010a_keck.png Aperture photometry shows the combined complex of both sources to have a magnitude of R=22.5, using the same calibration system in previous circulars. The contribution from the afterglow is limited to R>23.3, depending on the uncertain contribution of a possible bright host galaxy. Refined photometry of our imaging starting at 2007-10-11 UT 04:47 (GCN 6885) shows the afterglow magnitude at that time to be R = 19.82+/-0.02. This indicates that the afterglow decay underwent a sharp break, from alpha < 0.5 between the first and second night to a minimum of alpha > 1.7 over the following five days. Comparison with the XRT light curve at http://astro.berkeley.edu/~nat/swift/00293707/bat_xrt.jpg shows the X-ray afterglow to have undergone a break at 10^5 seconds (roughly coincident with our measurement on 2007-10-11) from approximately flat evolution before this point to a rapidly decaying power law of alpha ~ 1.8 afterward. This suggests that this sharp break may be achromatic, and possibly indicative of a jet break. [GCN OPS NOTE(18oct07): The "and jet break" was added back on to the Subject-line of this circular. It was chopped off during processing because the mail sending/delivery system chopps wrapped Subject lines.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6935 SUBJECT: GRB 071010B: Light Curve Break Confirmed DATE: 07/10/18 22:28:48 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, U. Laux, R. Filgas (TLS Tautenburg), A. Oksanen (Hankasalmi Observatory, Hankasalmi, Finland), S. Covino (Brera), V. D'Elia (Rome), V. Lorenzi (INAF/TNG), R. Decarli (Como), and J. Kotilainen (Tuorla Observatory, University of Turku) report: At 7 days after the GRB, we obtained further Rc band imaging of the GRB 071010B (Markwardt et al., GCN 6871) afterglow (Oksanen, GCN 6873). We obtained a single 600 second image with the Tautenburg 1.34m Schmidt telescope under bad conditions (passing clouds, high humidity, wind). The afterglow is only faintly detected. Furthermore, we obtained 5 x 180 sec images with the TNG telescope in La Palma. The afterglow is clearly detected in each image and there is no evidence for underlying extended emission. Finally, at dawn, we obtained 4 x 100 sec Rc images with the NOT. Using the same comparison stars as Kann, Hoegner & Filgas (GCN 6918), we derive the following magnitude: Date Mid-Time Rc dRc Exposure Telescope 18.10966 7.24453 21.593 0.244 1 x 600 TLS 18.20581 7.34069 21.801 0.028 5 x 180 TNG 18.26479 7.39966 21.756 0.106 4 x 100 NOT These values confirm the light curve break first reported by Kann, Laux & Filgas (GCN 6923). Using all data available so far (see GCN 6918 and GCN 6923 for references), we find preliminary fit results for data after 0.05 days: alpha_1 = 0.56 +/- 0.01, alpha_2 = 1.46 +/- 0.10, t_b = 3.44 +/- 0.39 days. The post-break slope is still quite shallow, leaving open if this was a jet break or not. We note that the first break at 0.049 days (GCN 6918) has Delta alpha ~ 0.26 and therefore may be a cooling break. This message may be cited. [GCN OPS NOTE(19oct07): Per author's request, JK was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6945 SUBJECT: GRB071010b: optical observations DATE: 07/10/19 19:41:37 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Klunko, A. Marchenkov, M. Eselevich (ISTP), A. Shulga, A. Volnova (SAI MSU), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884) of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.12 ((UT) 19:44:42 - 20:45:06) and Oct. 13 ((UT)19:17:13 - 20:14:49) with 1.5m telescope of Sayan observatory. The optical afterglow is clearly visible in stacked images of both epochs. Based on two USNO B1.0 stars (Kann et. al GCN 6918) (RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4, R2=16.80; RA (J2000) = 10:02:23.11, Dec. (J2000) = +45:41:41.1, R2=16.94) we estimated brightness of the optical afterglow: T0+ , Exposure, R_mag (mid time) 1.9995 d 15x240 s 20.5 +/-0.1 2.979 d 20x180 s 20.8 +/-0.2 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6957 SUBJECT: GRB 071010B: Independent Confirmation of Break DATE: 07/10/20 23:45:41 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 continued our observation of GRB071010B (GCN 6871, Markwardt et al.), beginning at 10:53:09 UT on Oct 16, (5.58 days after the trigger), and at 10:54:39 on Oct 19 (8.58 days after the trigger). These observations reveal the optical afterglows again (GCN 6873, Oksanen et al.), and the Oct. 19 data confirms the break in the light curve reported earlier (GCN6935, Kann et al.). On the other hand, our Oct 16 photometry suggests that the break started around Oct. 16 or later. Photometry of the object is given below. t_start (UT) Filter exp (sec) R-mag err ----------------------------------------------------- Oct. 16, 10:53:09 R 17x300 21.2 0.1 Oct. 19, 10:54:39 R 8x300 22.0 0.3 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6969 SUBJECT: GRB 071010B: Fading quickly DATE: 07/10/22 01:03:04 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 continued our observation of GRB071010B (GCN 6871, Markwardt et al.), beginning at 11:00:20 UT on Oct 21. (10.59 days after the burst). Now, the optical afterglow (GCN 6873, Oksanen et al.) is very faint, and we have only a very marginal detection in our data. The faintness of the afterglow further confirms the light curve break (GCN6935, Kann et al.; GCN6957, Im, Lee, and Urata, et al.), and the GRB is quickly fading. Photometry of the object is given below. t_start (UT) Filter exp (sec) R-mag err ----------------------------------------------------- Oct. 21, 11:00:20 R 16x300 23.0 0.6 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6977 SUBJECT: GRB071010b: optical observation DATE: 07/10/22 18:22:00 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884) of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.19 between (UT) 01:39:50 - 02:54:14 with Zeiss-1000 (Simeiz) telescope of CrAO observatory. Based on USNO-A2.0 star RA (J2000) = 10 01 59.67, Dec. (J2000) = +45 46 12.80, R=18.30 we estimated brightness of the optical afterglow: T0+, Exposure, R_mag, err (mid time) 8.230 d 58x60 s 21.9 +0.37 -0.27 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7041 SUBJECT: GRB071010b: optical observation DATE: 07/11/03 14:35:44 GMT FROM: Alexei Pozanenko at IKI, Moscow K. Antonyuk, V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical afterglow (Oksanen GCN 6873, Kann et al. GCN 6884) of GRB071010b (Markwardt et al., GCN 6871) in R-band on Oct.12 between (UT) 01:01:50 - 02:03:27 with AZT-11 telescope of CrAO. Based on USNO-B1.0 star RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4, R2=16.80 we estimated brightness of the optical afterglow on a stacked image: T0+, Exposure, R_mag, err (mid time) 1.1989 d 12x300 s 20.70 +/-0.08 In comparison with the afterglow brightness obtained 2 and 3 days after burst (Klunko et al. GCN 6945), where photometry used the same calibration star, one can suggest either re-brightening between 1st and 3rd days, or at least plateau on the light curve. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7329 SUBJECT: GRB 071010B : Early optical brightening detected by TAOS DATE: 08/02/26 08:57:15 GMT FROM: Kuiyun Huang at ASIAA K. Y. Huang, M. E. Schwamb, J. H. Wang, C. Y. Wen, and TAOS team The 3 automatic 0.5-m telescopes of the TAOS (Taiwan American Occultation Survey, located at Lulin Observatory) started to observe GRB 071010B at 52s after the burst. The afterglow (Kann et al. GCN 6884) was detected in our 5s and 25s images. Due to twilight, the TAOS telescopes stopped taking images around 4 minutes after the burst. The afterglow, did not show significant decay but a mild increase during our observations. Our high resolution data and other measurements within 2 days indicate that GRB 071010B is composed of a slightly early brightening behavior and a shollow decay (Wang et al.). We note that special filter (5000-7200 A) was used in TAOS telescopes. This message may be cited.