This contains both the "A" and "B" 080603 bursts. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7788 SUBJECT: Possible GRB080603: Faulkes Telescope North optical afterglow candidate DATE: 08/06/03 12:01:54 GMT FROM: Andreja Gomboc at LT,ARI,Liverpool JMU A. Gomboc (U. Ljubljana), I.A. Steele (Liverpool JMU), E. Rol, P. O'Brien (U. Leicester), A, Melandri, D. Bersier, C.G. Mundell, R.J. Smith, D. Carter, S. Kobayashi, M. Burgdorf, M. Bode (Liverpool JMU), C. Guidorzi (INAF-OAB), N. Bannister, N. Tanvir (U. Leicester) report: The 2-m Faulkes Telescope North (Hawaii) automatically reacted to the INTEGRAL trigger 5283 and possible GRB 080603 and started observing the field at 1.3 min after the trigger. We detect an optical afterglow candidate at: RA 18:37:38.1, dec +62:44:39.4. We estimate the magnitude of the source (calibrated to USNO-B1.0 catalogue) to be I=20.3+-0.3 at t_0+5.93 min and R=19.6+-0.3 at t_0+7.37 min. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7789 SUBJECT: GRB 080603 OA candidate DATE: 08/06/03 12:02:13 GMT FROM: Ryan Chornock at UC Berkeley R. Chornock, D. Perley, W. Li, and A. V. Filippenko (UC Berkeley) report that: The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory slewed to the position of GRB 080603 and detected a new source not present in the DSS at coordinates: (J2000) 18:37:38.06 +62:44:39.3 The new source was first detected in a 60s image starting at 11:28:55 UT and is near magnitude 18.7 in unfiltered and I band images. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7790 SUBJECT: GRB 080603: A long GRB detected by INTEGRAL DATE: 08/06/03 13:04:48 GMT FROM: Sandro Mereghetti at IASF/CNR A.Paizis, S.Mereghetti (IASF-Milano), D.Gotz (CEA-Saclay), M. Turler, V.Beckmann, M. Beck (ISDC, Versoix), and J. Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: A GRB lasting about 180 s has been detected by IBAS in IBIS/ISGRI data at 11:18:11 UT of June 3. The coordinates (J2000) are: RA: 279.409 [degrees] DEC: +62.735 [degrees] with an uncertainty of 2 arcmin (90% c.l.). A preliminary analysis gives a peak flux in the 20-200 keV range of about 0.5 ph/cmq/s (1-s integration time) and a fluence over the same energy range of about 10e-6 erg/cmq. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7791 SUBJECT: GRB 080603: Gemini-North redshift DATE: 08/06/03 15:29:48 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, J. S. Bloom (UC Berkeley), and J. X. Prochaska (UCO/Lick) report on behalf of a larger collaboration: Following the KAIT detection (Chornock et al., GCN 7789) of the afterglow candidate of GRB 080603 (Paizis et al., GCN 7790; Gomboc et al., GCN 7788) we began a spectroscopic sequence at Gemini-North using GMOS. We acquired 2x1200s longslit exposures starting at UT 13:24. We detect very strong resonance lines of MgII and FeII and the fine-structure transitions of FeII which establish the redshift of the GRB to be z=1.6880. In addition, we identify intervening MgII absorption systems at z=1.5635 (90% c.l.) and z=1.271 (100% c.l.) In addition, in a single acquisition exposure starting at UT 13:05:05 (107 minutes after the trigger) the object has a magnitude (relative to USNO B1.0) of R~19.7, suggesting it has not faded significantly since the observations of Gomboc et al. (GCN 7788). We thank Richard McDermid and the Gemini staff and for support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7792 SUBJECT: GRB 080603B: ROTSE-III Detection of Optical Counterpart DATE: 08/06/03 19:55:01 GMT FROM: Wiphu Rujopakarn at U AZ/Steward W. Rujopakarn (Steward), T. Guver (U Arizona), D.A. Smith (Guilford), report on behalf of the ROTSE collaboration: ROTSE-IIId, located at the Turkish National Observatory at Bakirlitepe, Turkey, responded to GRB 080603B (Swift trigger 313087). The first image was at 19:38:36.2 UT, 22.9 s after the burst (8.3 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a new, rapidly fading object, not visible in the DSS (second epoch), with coordinates: 11:46:07.8 +68:03:39.9 (J2000), with positional uncertainty of 1" or better start UT mag mlim(of image) ---------------------------------- 19:38:36.2 14.1 14.9 A jpeg image is available at http://www.rotse.net/images/gsb313087_3d00_img.jpg (OT circled in yellow and blue) [GCN OPS NOTE(03jun08): Per author's request, the "B" was added to the GRB name.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7793 SUBJECT: GRB080603: Super-LOTIS detection of Optical Counterpart DATE: 08/06/03 19:58:42 GMT FROM: Peter A. Milne at Super-LOTIS P.A. Milne (U Arizona) and A. Updike (Clemson U) report on behalf of the Super-LOTIS team: The 0.6m Super-LOTIS telescope began R-band observations of the error region of GRB080603 at 11:19:04 UT. The OT detected by Gomboc et al. (GCN 7788) and Chornock et al. (GCN 7789) is not apparent in the initial images, but is clearly visible in subsequent images. Using a stack of 10 x 60sec images obtained between 11:22:44 -> 11:33:46, we estimate the magnitude of the source to be R=19.3 +/- 0.3. We used the USNO-B star at RA=18:37:55, Dec=+62:44:32 to derive the R2 magnitude. Analysis continues to better characterize the rise of the emission from the OT. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7794 SUBJECT: GRB 080603B: Swift detection of a burst with optical afterglow DATE: 08/06/03 19:59:18 GMT FROM: Scott Barthelmy at NASA/GSFC V. Mangano (INAF-IASFPA), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), P. J. Brown (PSU), G. Cusumano (INAF-IASFPA), N. Gehrels (NASA/GSFC), C. Guidorzi (INAF-OAB), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (MSSL), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), K. M. McLean (GSFC/UMD), P. T. O'Brien (U Leicester), C. Pagani (PSU), D. M. Palmer (LANL), A. M. Parsons (GSFC), J. L. Racusin (PSU), T. Sakamoto (NASA/UMBC), B. Sbarufatti (INAF-IASFPA), M. Stamatikos (NASA/ORAU), T. N. Ukwatta (GSFC/GWU), D. E. Vanden Berk (PSU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 19:38:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080603B (trigger=313087). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 176.528, +68.076 which is RA(J2000) = 11h 46m 07s Dec(J2000) = +68d 04' 33" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows three main peaks with a duration of about 70 sec. The peak count rate was ~8000 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 19:39:55 UT. XRT found a bright, uncatalogued X-ray source located at: RA(J2000) = 11h 46m 07.7s Dec(J2000) = +68d 03' 35.2" with an uncertainty of 4.7 arcseconds (radius, 90% containment). UVOT took a finding chart exposure of nominal 100 seconds with the White (160-650 nm) filter starting 72 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at RA(J2000) = 11:46:07.70 = 176.5321 DEC(J2000) = +68:03:40.0 = 68.0611 with a 1-sigma error radius of about 0.5 arc sec. This position is 4.9 arc sec. from the center of the XRT error circle. The estimated magnitude is 15.9 with a 1-sigma error of about 0.5 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01. Burst Advocate for this burst is V. Mangano (vanessa AT ifc.inaf.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: 7795 SUBJECT: GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve DATE: 08/06/03 21:54:31 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 080603 detected by SWIFT (trigger 313087) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 62 min after the GRB trigger (burst occured at the sunset). The elevation of the field decreased from from 63 degrees above horizon and weather conditions were good. We detected the candidate couterpart mentioned by Rujopakarn et al. (GCNC 7792). We note that the afterglow stays at about the same magnitude between 68 to 109 minutes. Magnitudes derived from two R filtered images are: t0+68 min to t0+ 71 min R=17.4 t0+106 min to t0+109 min R=17.5 The afterglow seems to exhibit a plateau phase in its optical light curve. We continue the follow-up. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7797 SUBJECT: GRB080603B: NOT redshift DATE: 08/06/03 23:00:16 GMT FROM: Johan U. Fynbo at U.Copenhagen Johan Fynbo (DARK/NBI), Pierre-Olivier Quirion (Univ. Aarhus), Dong Xu, Daniele Malesani, C. C. Thoene, J. Hjorth, B. Milvang-Jensen (DARK/NBI), and Pall Jakobsson (Univ. Hertfordshire) report on behalf of a larger collaboration: We observed the field of GRB 080603B (Mangano et al., GCN 7794) with the NOT telescope. We obtained R-band imaging and a low resolution spectrum using the AlFOSC instrument. Based on the detection of Lyman-alpha and a number of relatively strong metal lines we infer a redshift of 2.69. [GCN OPS NOTE(04jun08): Per author's request, a "B" was added in the Subject. And Dong Xu was added to the author list.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7799 SUBJECT: GRB 080603B: TAROT Calern observatory confirmation of slow optical decay DATE: 08/06/04 00:41:39 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 080603B from 68 min to 240 min after the trigger with TAROT. The light curve displays a slow optical decay compatible with alpha=0.62 +/- 0.1. R~18.2 at t0+225 min. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7803 SUBJECT: GRB080603B: RTT150 optical observations, break in light curves DATE: 08/06/04 09:46:50 GMT FROM: Irek Khamitov at TUG R. Zhuchkov, I.Bikmaev, N. Sakhibullin (KSU/AST), I. Khamitov, Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.) R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), report: The optical counterpart (GCN7792, 7793, 7794, 7795, 7796, 7797, 7799) of GRB 080603B (GCN 7794, SWIFT trigger=313087) was observed with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), starting at 03 June, 20:55 UT, i.e. ~1.3 hours after the burst, using Andor CCD. A series of 70 frames with 60sec exposure in the R and V bands were taken for a time span ~ 4.5 hours. The afterglow is clearly detected in all images. Using RTT150 preliminary calibrated magnitudes for USNO-A2 1575-03195804 star R.A. = 11 46 09.53, Dec. = +68 01 51.3, V=14.2, R=13.8 mag, the brightness of the OT was estimated on each frame. V,R light curves are shown at: http://www.tug.tubitak.gov.tr/~irekk/grb/grb080603B/GRB080603B_lc.jpg Higher dispersion at (T-T0) > 4 hours must be due to high airmass ( Z ~ 65-70 degrees). The VR-light curves are well fitted with two power law decay functions with a break about 3 hours after the burst. A power law decay indices were estimated in OT VR-light curves as follow: before the break alpha_R=-0.59+/-0.03 alpha_V=-0.60+/-0.03 after the break alpha_R=-1.14+/-0.09 alpha_V=-1.03+/-0.07 The alpha indices before the break are in good agreement with Klotz et al. (GCN7799) calculated for the time span between 1 and 4 hours after the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7804 SUBJECT: GRB 080603A: Swift/UVOT detection of the afterglow DATE: 08/06/04 11:39:42 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (MSSL/UCL), and V. Mangano (INAF), report on behalf of the Swift UVOT team The Swift UltraViolet/Optical Telescope (UVOT) began observations of INTEGRAL burst GRB080603A (INTEGRAL trigger number 5283, Paizis et al., GCN Circ. 7790), on June 3, 2008, at 14:11:20 UT, 173 minutes after the initial trigger in the UVOT v filter. We detect a fading source at position : RA=18:37:38.21 Dec=+62:44:38.40 (279.40921 +62.74400 ddeg (J2000)). The initial magnitude observed for GRB080603A is given below for the first observation in the UVOT v filters: Filter Tstart(s) Tstop(s) Exp(s) Magnitude v 10389 10499 109. 19.16 +/- 0.35 The magnitude decrease observed was 1.2 magnitudes per hour. The values quoted above are on the UVOT Photometric System (Poole et al, 2008, MNRAS 383,627). They are not corrected for the expected galactic reddening of E(B-V) = 0.044 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7806 SUBJECT: GRB 080603B, Swift-BAT refined analysis DATE: 08/06/04 12:32:40 GMT FROM: Scott Barthelmy at NASA/GSFC J. Tueller (GSFC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), V. Mangano (INAF-IASFPA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+470 sec from recent telemetry downlinks, we report further analysis of BAT GRB 080603B (trigger #313087) (Mongano, et al., GCN Circ. 7794). The BAT ground-calculated position is RA, Dec = 176.554, 68.061 deg, which is RA(J2000) = 11h 46m 13.0s Dec(J2000) = +68d 03' 40.5" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows three main clusters of peaks. The first starts at T-1 sec, peaks at T+1 sec, and ends at ~T+7 sec. The second starts at T+8 sec and ends at T+20 sec. The third starts at ~T+42 sec and ends at ~T+80 sec. T90 (15-350 keV) is 60 +- 4 sec (estimated error including systematics). The time-averaged spectrum from T-0.1 to T+68.6 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.21 +- 0.30, and Epeak of 71.0 +- 16.0 keV (chi squared 63.16 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+0.96 sec in the 15-150 keV band is 3.5 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.78 +- 0.07 (chi squared 75.18 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/313087/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7808 SUBJECT: GRB 080603B: Swift/UVOT detection of the afterglow DATE: 08/06/04 13:57:29 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (MSSL/UCL), and V. Mangano (INAF-IASFPA), report on behalf of the Swift UVOT team The Swift UltraViolet/Optical Telescope (UVOT) began observations of GRB 080603A, on June 3, 2008, at 19:39:07 UT, 63 seconds after the initial Swift BAT trigger (Mangano et al., GCN Circ. 7794).. The refined uvot position is RA = 11:46:07.66 = 176.5316 DEC =+68:03:39.99 = 68.061105 with an error or 0.3". The first finding chart in the wh filter has problems due to the brightness of the image, and needs detailed analysis. We start our report with the second finding chart. The magnitudes with 1-sigma errors for GRB080603B are given below for the initial observation sequence. Filter Tstart(s) Tstop(s) Exp(s) Magnitude v 187.8 393.1 202 16.48 +/- 0.06 uvm2 5778.0 5977.8 197 > 19.51 (3-sigma UL) uvw1 5983.9 6183.7 197 20.02 +/- 0.56 u 6188.8 6388.6 197 18.80 +/- 0.23 b 6395.3 12274.3 643 19.34 +/- 0.14 The absence of a detection in the uvm2 filter is consitent with the reported redshift of 2.69 (Fynbo et al., GCN Circ. 7797). Magnitude variation in the b observations shor evidence of flaring or rebrightening.. The values quoted above are on the UVOT Photometric System (Poole et al, 2008, MNRAS 383,627). They are not corrected for the expected galactic reddening of E(B-V) = 0.013 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7810 SUBJECT: GRB 080603A: Swift-XRT detection of the afterglow DATE: 08/06/04 16:08:03 GMT FROM: Boris Sbarufatti at INAF-IASF-Pa B. Sbarufatti, V. Mangano, V. La Parola (INAF-IASF Pa) report on behalf of the Swift-XRT team The Swift XRT began observations of the INTEGRAL burst GRB 080603A (Paizis et al., GCN Circ 7790) on June 3, 14:11 UT, 173 minutes after the trigger. The data consist of 3.9 ks observed in Photon Counting mode. We detect an X-ray counterpart at position (astrometrically corrected using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 279.40858, 62.74446 which is equivalent to: RA (J2000): 18 37 38.06 Dec (J2000): +62 44 40.1 with an uncertainty of 1.9 arcsec (radius, 90% confidence). The light curve is dominated by a flare-like structure which covers all the observed time interval, making it impossible to estimate the behaviour of the underlying continuum and to predict the evolution of the source. The spectrum can be fitted with a powerlaw with an intrinsic absorbing column of (8+/-5)e21 cm-2 at z=1.688 (Perley et al., GCN Circ 7791) and photon index 2.4 ±0.3. The observed (unabsorbed) 0.3-10 keV flux is 3.23 (3.57)e-12 erg cm-2 s-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7811 SUBJECT: GRB 080603B: Swift-XRT refined analysis DATE: 08/06/04 16:37:24 GMT FROM: Boris Sbarufatti at INAF-IASF-Pa V. Mangano, V. La Parola, B. Sbarufatti (INAF-IASF PA) report on behalf of the Swift-XRT team: The Swift-XRT observed GRB 080603B (trigger 313087, Mangano et al. GCN Circ 7794) for three orbits which consisted of 200 s of Windowed Timing mode data starting 68 s after the trigger and 990 s of Photon Counting mode data, 274 s after the trigger. We obtained a refined XRT position at RA, Dec = 176.53312 68.06058 which is equivalent to: RA (J2000): 11 46 07.95 Dec (J2000): 68 03 38.11 with an uncertainty of 3.7 arcsec (radius, 90% confidence). The position is 3.2 arcsec from the on-board position reported in GCN Circ. 7794 and 0.7 arcsec from the refined UVOT position (Kuin et al. GCN Circ 7808). The X-ray light curve shows an initial steep decay with a slope of 3.4 ± 0.1, breaking to a shallower decay of 0.8 ± 0.1 at a time of 161 ± 6 s after the trigger. A spectrum of the Windowed Timing data can be well fit by an absorbed power-law, with a photon index Gamma = 1.68 ± 0.06 and a column density Nh = (7.9 ± 0.2) e21 cm-2 in excess with respect to the Galactic column density in this direction of 1.2e20 cm-2. The observed (unabsorbed) 0.3-10 keV flux is 7.0e-10 (7.7e-10) erg cm-2 s-1. The Photon Counting mode spectrum is also well fit by an absorbed powerlaw, with an Nh = (1.3 ± 0.2) e22 cm-2 and Gamma = 2.0 ± 0.2. The observed (unabsorbed) 0.3-10 keV flux is 1.55 e-11 (1.91e-11) erg cm-2 s-1. The predicted XRT count rate after 24 hours from burst is 6.0e-2 counts/s This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7812 SUBJECT: Konus-Wind observation of GRB 080603B DATE: 08/06/04 17:04:26 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 080603B (Swift-BAT trigger #313087: Mangano et al., GCN 7794, Tueller et al., GCN 7806) triggered Konus-Wind at T0=70692.383 s UT (19:38:12.383). The burst light curve shows several pulses with a total duration of ~70s. As observed by Konus-Wind the burst had a fluence of 4.50(-0.90, +1.53)x10^-6 erg/cm2, and a 256-ms peak flux measured from T0+0.624 s of 1.51(-0.38, +0.40)x10^-6 erg/cm2/s (both in the 20 keV - 1 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+73.984 s) can be fitted (in the 20-500 keV range) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.23(-0.54, +0.75), and Ep = 102(-28, +119) keV (chi2 = 50.5/42 dof). Fitting by GRBM (Band) model yields: the low-energy photon index is alpha = -0.94(-0.75, +1.21), the high energy photon index beta < -1.96, the peak energy Ep = 85(-30, +91) keV (chi2 = 49.7/41 dof). The spectrum of the most intense part (from T0 T0+16.640 s) is well fitted (in the 20 keV - 1 MeV range) by a power law with exponential cutoff model with alpha = -1.20(-0.32, +0.26) and Ep = 200(-56, +131) keV (chi2 = 63.5/56 dof). The fluence of this part is 3.51(-0.58, +0.69)x10^-6 erg/cm2. All the quoted errors are at the 90% confidence level. Assuming z = 2.69 (Fynbo et al., GCN 7797) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_\Lambda = 0.73, the isotropic energy release is E_iso ~7.7x10^52 erg, the maximum luminosity is (L_iso)_max ~9.4x10^52 erg/s, and Ep_rest ~350 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080603_T70692/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7813 SUBJECT: GRB 080603B : Liverpool Telescope Observations DATE: 08/06/04 17:13:50 GMT FROM: Andrea Melandri at Liverpool John Moores U A. Melandri, (Liverpool JMU), A. Gomboc (U. Ljubljana), C. Guidorzi (INAF-OAB), R.J. Smith, I.A. Steele, D. Bersier, C.G. Mundell, D. Carter, S. Kobayashi, M. Burgdorf, M. Bode (Liverpool JMU), E. Rol, P. O'Brien, N. Bannister, N. Tanvir (U. Leicester) report: On 2008 Jun 03 at 21:32:57UT we observed the Swift GRB 080603B (trigger=313087, Mangano et al., GCN 7794) with the Liverpool Telescope using SDSS-I, SDDS-R and Bessell-B filters. The OT reported by Rujopakarn et al. (GCN 7792), Mangano et al. (GCN 7794), Klotz et al. (GCN 7795, 7799), Castro-Tirado et al. (GCN 7796) and Zhuchkov et al.(GCN 7803) is well detected in all our single 300s exposures. We calibrated the afterglow magnitude using B, R and I magnitudes of few USNO B1 stars in the field of view. Our observations started soon after the plateau phase reported by Klotz et al. (GCN 7795) and Castro-Tirado et al. (GCN 7796) but our I-band and R-band images were acquired before and after the optical break reported by Zhuchkov et al.(GCN 7803). We found alpha_I= 0.55 +/- 0.03 before the optical break and alpha_R= 1.03 +/- 0.02 after the break, confirming the values found by Zhuchkov et al.(GCN 7803). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7814 SUBJECT: GRB 080603B : Xinglong EST observations DATE: 08/06/04 17:43:05 GMT FROM: W.K. Zheng at NAOC L.P.Xin, Q.C.Feng, M.Zhai, Y.L.Qiu, J.Y.Wei, J.Y.Hu, J.S.Deng, J.Wang, Y.Urata and W.K.Zheng on behalf of EAFON report: Xinglong EST started to observe the GRB080603B (Mangano et al., GCN 7794) from 14:42 UT Jun 04 with R and V filters. with the same calibration star as used in GCN7803 (Zhuchkov et al.) USNO-A2 1575-03195804 R=13.8 mag, we estimated the brightness of OT R ~ 20.3 +/- 0.15, which is consistent with the powler decay after the break given it GCN7803. Observation is still under going. This message may be cited For more information about Xinglong GRBs Follow-up observations, please visit the website: http://www.xinglong-naoc.org/grb/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7815 SUBJECT: GRB 080603B: Hobby-Eberly Telescope redshift confirmation DATE: 08/06/04 17:51:00 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara and D. B. Fox (Penn State) report: "Starting on 2008 June 4.13 UT we used the Marcario LRS spectrograph on the Hobby-Eberly Telescope (R ~ 230) to obtain 2 x 900s spectra of the optical afterglow of GRB 080603B (GCN 7792, GCN 7794). The spectrum covers the wavelength range 4500 to 10,000 Angstrom. We clearly detect the Lyman break and several metal absorption features corresponding to a redshift z = 2.69. No other systems are detected and our result confirms the redshift determination by Fynbo et al. (GCN 7797). We thank the HET staff for performing this challenging observation, in particular Matthew Shetrone." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7822 SUBJECT: GRB 080603A: TLS Afterglow Observation DATE: 08/06/05 15:22:40 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, U. Laux and S. Ertel (TLS Tautenburg) report: We observed the field of the INTEGRAL GRB 080603A (Paizis et al., GCN 7790) with the TLS 1.34m Schmidt telescope in mediocre observing conditions (low airmass but high humidity and moderate transparency). We obtained a total of 6 x 600 sec images at mid-time June 5.023368. The afterglow (Gomboc et al., GCN 7788; Chornock et al., GCN 7789) is faintly visible in each image. We stacked all six images. Assuming the USNOB1.0 star with ID 1527-0313986 at RA = 18:37:55.186, Dec. +62:45:32.28 to have R1 = 16.74 mag, we measure for the afterglow: dt Rc dRc 1.55241 21.39 0.03 (statistical only) We note the presence of a fainter source several arcseconds east of the OT which may slightly influence the photometry. In comparison to the magnitude measured by Perley et al. (GCN 7791), this implies a slow decay of alpha ~ 0.5. Further observations are warranted. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7823 SUBJECT: GRB 080603B: TLS Afterglow Observation DATE: 08/06/05 15:24:14 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, U. Laux and S. Ertel (TLS Tautenburg) report: We observed the field of the Swift GRB 080603B (Mangano et al., GCN 7794) with the TLS 1.34m Schmidt telescope in mediocre observing conditions (low airmass but high humidity and moderate transparency). We obtained a total of 6 x 600 sec images at mid-time June 4.980179. The afterglow (Rujopakarn, Guver, & Smith, GCN 7792) is faintly visible in each image. We stacked all six images. Assuming the USNOB1.0 star with ID 1580-0163070 at RA = 11:46:29.297, Dec. +68:03:23.43 (USNOB1.0 catalog value) to have R1 = 17.97 mag, we measure for the afterglow: dt Rc dRc 1.16197 21.32 0.04 (statistical only) In comparison to the magnitude measured by Xin et al. (GCN 7814) 0.8 days after the GRB, this implies a steep decay of alpha ~ 2.5. It is unclear if this is due to a break or to the use of different comparison stars. The comparison star used by Zhuchkov et al. GCN 7803, and Xin et al., GCN 7814, is saturated in our images. Further observations are warranted. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7824 SUBJECT: GRB 080603A: Xinglong R band observation DATE: 08/06/05 16:23:07 GMT FROM: W.K. Zheng at NAOC X.M. Meng, Y.N. Zhu, L.P. Xin, Q.C. Feng, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, J. Wang, Y. Urata and W.K. Zheng on behalf of EAFON report: We observed GRB080603A (Paizis et al., GCN 7790), with Xinglong 2.16m telescope + BFOSC on Jun 4, 1.321 Days after the burst. We marginally detected the OT (Gomboc et al., GCN 7788; Chornock et al., GCN 7789; Kuin et al., GCN 7804 Kann et al. GCN 7822) at 3 sigma level. With the same calibration star as used in GCN 7822 (Kann et al.) USNOB1.0 1527-0313986 at RA = 18:37:55.186, Dec. +62:45:32.28 R1 = 16.74, we estimated the OT brightness was R ~ 21.3 +/- 0.3. We also detected the faint star at east side of OT noted by Kann et al. This message may be cited. For more information about Xinglong GRBs Follow-up observations, please visit the website: http://www.xinglong-naoc.org/grb/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7826 SUBJECT: GRB 080603A: PAIRITEL infrared detection DATE: 08/06/05 22:02:45 GMT FROM: Daniel Perley at U.C. Berkeley A. A. Miller, J. S. Bloom, and D. A. Perley (UC Berkeley) report: We observed the optical afterglow of GRB080603A (Paizis et al., GCN 7790; Gomboc et al., GCN 7788; Chornock et al; GCN 7789) with the 1.3m Peters Automated Infrared Imaging Telescope (PAIRITEL) starting 18.89 hours post trigger on June 04, 2008 UT. We detected the afterglow in a 2927 sec mosaic of simultaneous 7.8 sec exposures in the J, H, and Ks filters. Preliminary photometry for the afterglow in exposures beginning on Jun 04.26 UT yields J = 18.9 +- 0.15, H = 17.9+- 0.15, and Ks = 16.8 +- 0.15, calibrated to the 2MASS system. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7827 SUBJECT: GRB 080603B: PAIRITEL infrared detection DATE: 08/06/05 22:02:59 GMT FROM: Daniel Perley at U.C. Berkeley A. A. Miller, J. S. Bloom, and D. A. Perley (UC Berkeley) report: We observed the optical afterglow of GRB080603B (Mangano et al., GCN 7794) with the 1.3m Peters Automated Infrared Imaging Telescope (PAIRITEL) starting 7.66 hours post trigger on June 04, 2008 UT. We detected the afterglow in a 2291 sec mosiac of 7.8 sec simultaneous exposures in the J, H, and Ks filters. Preliminary photometry for the afterglow in exposures beginning on Jun 04.14 UT yields J = 17.9 +- 0.1, H = 17.2 +- 0.1, and Ks = 16.7 +- 0.15, calibrated to the 2MASS system. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7840 SUBJECT: GRB 080603B: VLA radio upper limit DATE: 08/06/06 17:38:37 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 080603B (GCN 7794) at a frequency of 8.46 GHz on 2008 June 05.16 UT. The GRB radio afterglow is undetected and the peak radio flux at the SWIFT-UVOT position (GCN 7794) is 11 ± 41 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: 7843 SUBJECT: Possible VLA radio detection on INTEGRAL burst GRB 080603A DATE: 08/06/06 18:06:15 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 INTEGRAL GRB 080603A (GCN 7790) at a frequency of 8.46 GHz on 2008 June 05.39 UT. We detect a possible radio afterglow at KAIT optical afterglow position (GCN 7789) at a flux density level of 116 +/- 41 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: 7855 SUBJECT: VLA detection of INTEGRAL burst GRB 080603A DATE: 08/06/07 16:36:25 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 re-observe the field of view toward INTEGRAL GRB 080603A (GCN 7790) at a frequency of 8.46 GHz on 2008 June 07.42 UT. We clearly detect a radio afterglow at KAIT optical afterglow position (GCN 7789) at a flux density level of 154 ± 28 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: 7860 SUBJECT: GRB 080603A: optical observations DATE: 08/06/07 22:52:28 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed a field of INTEGRAL GRB 080603A (Paizis et al., GCN 7790) in R-band on June 06 between (UT) 22:32 - 23:55 with Zeiss-1000 (Simeiz) telescope of CrAO observatory. Extended object is found ~1" south from the position of optical afterglow (Gomboc et al., GCN 7788; Chornock et al., GCN 7789), and the position of the extended object is consistent with coordinates reported by Kuin et al. (GCN 7804). Therefore, we suggest it as a host galaxy of 080603A. Based on USNOB1.0 star with ID 1527-0313986 at RA = 18:37:55.186, Dec. +62:45:32.28 (R1 = 16.74) we estimated brightness of the extended object: UT, Exposure, R_mag, UL (mid time) 3.496 41x120 21.90 +/- 0.17 22.85 If the extended source is the host galaxy then contamination by the host can explain slow decay of light curve noted by Kann et al. (GCN 7822). A combined image can be found at http://grb.rssi.ru/GRB080603A/GRB080603A_2080606.gif The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7869 SUBJECT: GRB 080603b: optical observation DATE: 08/06/11 23:29:52 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 field of Swift GRB 080603b (Mangano et al., GCN 7794) on June 06 betwen (UT) 19:20:31 - 20:27:07 with Zeiss-1000 (Simeiz) telescope of CrAO observatory with favorable weather conditions. We do not detect optical afterglow (Rujopakarn, et al., GCN 7792) in a combined image of R-band up to 22.5 (3sigma). A photmetry is obtained in comparison with nearby USNOB-1.0 stars: UT, Exposure, UL (mid time) 3.011 d 33x120 s 22.5 (3sigma) The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7870 SUBJECT: GRB 080603A: Late-time Keck imaging and spectroscopy DATE: 08/06/13 00:28:58 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, J. S. Bloom, A. A. Miller, J. Shiode, J. Brewer, D. Starr, and R. Kennedy (UC Berkeley) report: On the night of 2008-06-07 (UT) we re-observed the location of GRB 080603A (GCN 7790, Paizis et al.) with Keck I / LRIS in g and R filters for 785s and 690s respectively, starting at 12:30 UT. The optical afterglow (Gomboc et al., GCN 7788; Chornock et al., GCN 7789) is well-detected as the northern member of a complex of sources. Calibrating relative to four nearby USNO B1.0 stars we estimate an afterglow magnitude of R = 23.7 +/- 0.1 (t = 4.05 days) The extended source reported by Rymyantsev et al. (GCN 7860) is clearly detected and is well-resolved into the afterglow plus two extended sources in the g-band frame, with the southern source significantly redder than the afterglow and the faint western source. A color image of the field is posted to: http://lyra.berkeley.edu/~dperley/080603a/080603a_color.png Given the very strong absorption lines reported in our spectroscopic observations (Perley et al., GCN 7791), this complex may be a bright host galaxy of this burst, as suggested by Rumyantsev et al. However, the sources above are offset significantly from the afterglow (which itself is not obviously extended), suggesting instead that they may represent one or both of the intervening absorbers. Later the same night, we acquired 2x900s spectra using a slit covering the northern (afterglow) source and southern source, and an additional 1x600 spectrum using a slit covering the faint western source and the bright, clearly separated eastern source noted by Kann et al. (GCN 7822). No obvious emission lines are evident in any spectrum. At any of the host and absorber redshifts of z=1.688, z=1.563 and z=1.271 respectively, the bright potential emission features (Ly-alpha, OII) are expected to fall outside our wavelength coverage, on top of sky lines, or be strongly attenuated by the atmosphere, so this result is mildly supportive of an association of these sources with the host and/or absorbers. However, the integrations were relatively short, and further follow-up is warranted. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7883 SUBJECT: GRB 080603A: optical observations on June 04 DATE: 08/06/14 11:28:28 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed a field of INTEGRAL GRB 080603A (Paizis et al., GCN 7790) in R-band on June 04 between (UT) Jun.04 23:18:41 - Jun.05 00:12:41 with Zeiss-1000 (Simeiz) telescope of CrAO observatory. At the place of the optical afterglow (Gomboc et al., GCN 7788; Chornock et al., GCN 7789) we detect an object with coordinates RA(J2000): 18 37 38.02 Dec(J2000): +62 44 39.44 Within uncertainties (0.5" or better ) the coordinates of the object are consistent with reported early (Gomboc et al., GCN 7788; Chornock et al., GCN 7789) and one can consider the object as afterglow of GRB 080603A. A group of two extended sources (Perley et al., GCN 7870) is not resolved in our later observation on 3.496 d (Rumyantsev et al. GCN 7860). The unresolved source (Rumyantsev et al. GCN 7860) lies ~1.8" south from the afterglow position. And tentatively one can consider the upper limit of the observation on 3.496 days R=22.85 (3sigma) as an upper limit of the afterglow brightness. Based on USNOB1.0 star with ID 1527-0313986 at RA = 18:37:55.186, Dec. +62:45:32.28 (R1 = 16.74) we estimated brightness of the afterglow on 1.521 days: UT, Exposure, R_mag, UL (mid time) 1.521 d 27x120 s 22.2 +/- 0.2 22.9 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7890 SUBJECT: GRB 080603b: optical observation DATE: 08/06/21 11:40:18 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Klunko (ISTP), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed afterglow (Rujopakarn, et al., GCN 7792) of Swift GRB 0800603b (Mangano et al., GCN 7794) with 1.5 m telescope of Sayan observatory (Mondy) on Jun.04 between (UT) 18:35 - 19:11. The afterglow is detected in a combined image of 8x120 s exposure. A photometry of the afterglow obtained against several USNO-A2.0 stars is following: T0+ Exposure R_mag (mid) 0.9686 d 8x120 s 21.10 +/- 0.10 This photometry confirms the steep decay of a light curve (alpha ~ 2.5) suggested by Kann et al. (GCN 7824). The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7974 SUBJECT: GRB 080603B: optical observations in CrAO DATE: 08/07/12 08:53:15 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, K. Antoniuk (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the afterglow (Rujopakarn, et al., GCN 7792) of the Swift GRB 080603B (Mangano et al., GCN 7794) on June 04 between (UT) 19:49:07 - 20:49:27 with AZT-11 (Nauchny) telescope of CrAO observatory in R-band. In a combined image we detect the afterglow. A photometry is obtained in comparison with nearby USNOB-1.0 stars: T0+ Exposure R_mag UL (mid) 1.0087 d 19x180 21.30 +/- 0.25 21.8 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7975 SUBJECT: GRB 080603B: optical observations in MAO DATE: 08/07/12 08:57:45 GMT FROM: Alexei Pozanenko at IKI, Moscow M. Ibrahimov, R. Karimov (MAO), V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the afterglow (Rujopakarn, et al., GCN 7792) of the Swift GRB 080603B (Mangano et al., GCN 7794) on June 04 between (UT) 16:12:24 - 16:34:23 with AZT-22 (Maidanak) telescope of MAO observatory in R-band. The afterglow is well detected in each individual frame. A photometry of the two combined images is obtained in comparison with nearby USNOB-1.0 stars: T0+ Exposure R_mag (mid) 0.8571 d 2x300 20.49 +/- 0.07 0.8703 d 3x300 20.71 +/- 0.08 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7976 SUBJECT: GRB 080603A: CrAO optical observations DATE: 08/07/12 15:18:05 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev, K. Antoniuk (CrAO), E. Klunko (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of INTEGRAL GRB 080603A (Paizis et al., GCN 7790) in R-band on June 03 between (UT) 19:16:25 - 19:43:54 with AZT-11(Nauchny) telescope of CrAO observatory. We detect optical afterglow (Gomboc et al., GCN 7788; Chornock et al., GCN 7789) in coordinates RA(J2000): 18 37 37.97 Dec(J2000): +62 44 38.9 with uncertanitie is 0.5". Based on USNOB1.0 star with ID 1527-0313986 at RA = 18:37:55.186, Dec. +62:45:32.28 (R1 = 16.74) we estimated brightness of the afterglow in a combined image at 0.3424 days: T0+, Exposure, R_mag, UL (mid time) 0.3424 d 10x180 s 20.62 +/- 0.13 21.8 This message may be cited.