//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4682 SUBJECT: GRB060206: Swift-BAT detection of a burst DATE: 06/02/06 05:36:23 GMT FROM: David Palmer at LANL D. Morris (PSU), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/ORAU), N. Gehrels (GSFC), S. Hunsberger (PSU), C. Markwardt (GSFC/UMd), D. Palmer (LANL), and E. Rol (U. Leicester) on behalf of the Swift team: At 04:46:53 UT, Swift-BAT triggered and located GRB060206 (trigger=180455). The spacecraft slewed immediately. The BAT on-board location is RA,Dec 202.946d,+35.075d {13h 31m 47s,+35d 04' 29"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The BAT light curve showed a single bright gaussian-peak structure from T-1 to T+10 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~2 seconds after the trigger. The XRT began taking data at 04:47:52, 58 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image and no prompt position is available. The burst occurred shortly before entry into the SAA, and therefore the count-rate lightcurve may be insensitive to a fading source. We are waiting for down-linked data to determine a position. UVOT took a finding chart exposure of 72 seconds with the V filter starting 58 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. No correction has been made for the expected extinction of about 0.04 magnitudes. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4683 SUBJECT: GRB060206: Optical afterglow DATE: 06/02/06 05:53:44 GMT FROM: Johan U. Fynbo at U.Copenhagen Johan P. U. Fynbo, Brian L. Jensen, José María Castro Cerón (DARK Cosmology Centre), Jyri Naeraenen (Helsinki Observatory) report on behalf of a larger collaboration: "Using ALFOSC on the Nordic Optical Telescope we have identified the likely afterglow of GRB060206 (GCN #4682) to the position: RA(2000), Dec(2000) = 13:31:43.4, +35:02:59.9 (+/-5 arcsec) Further observations are in progress" //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4684 SUBJECT: GRB060206 - Swift UVOT Confirmation of Optical Afterglow DATE: 06/02/06 07:19:12 GMT FROM: Sally Hunsberger at PSU/Swift P. Boyd (GSFC), S. Hunsberger (PSU), and C. Gronwall (PSU) on behalf of the Swift UVOT team: The list of sources from the first 72-second V UVOT finding chart exposure contains a bright, uncataloged optical source coincident with the position reported by Fynbo et al (GCN 4683). The UVOT source position is RA(2000) 202.9309 Dec(2000) 35.0510 The mean positional error between known sources in the field and catalog entries is 0.47". The V magnitude is estimated to be approximately 16.7. No correction has been made for the expected extinction of about 0.04 magnitudes. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4686 SUBJECT: GRB 060206: High redshift burst DATE: 06/02/06 07:39:47 GMT FROM: Johan U. Fynbo at U.Copenhagen Johan P. U. Fynbo, Brian L. Jensen, José María Castro Cerón (DARK Cosmology Centre), Jyri Naeraenen (Helsinki Observatory) report on behalf of a larger collaboration: "Using ALFOSC on the Nordic Optical Telescope we have obtained a spectrum of the afterglow of GRB 060206 (GCN #4682, 4683, #4684). The spectrum shows a rich Lyman-alpha forest as well as metal lines from the GRB host/environment. We still do not have a formal wavelength calibration, but a preliminary analysis indicates a redshift close to 5." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4687 SUBJECT: GRB 060206: RAPTOR observations of afterglow candidate variability. DATE: 06/02/06 08:55:58 GMT FROM: Przemyslaw R. Wozniak at LANL P.R. Wozniak, W.T. Vestrand, J. Wren, R. White, and S. Evans at Los Alamos National Laboratory on behalf of the RAPTOR team report: RAPTOR's autonomous system for locating optical counterparts to GRBs identified a variable object at position RA=202.931, DEC=35.0509 deg. At 2900 seconds after the trigger RAPTOR measured an R-band magnitude of ~17.3, followed by a brightening to ~16.3 mag over the next 700 seconds, where it remained for about 200 seconds before fading to ~16.9 mag over the next 45 min. The real time position was reported only to the RAPTOR rapid response team because of unusual photometric behavior of the object. This variable source has a location consistent with the position of the optical afterglow candidate found by Fynbo et al. (GCN 4683) and confirmed by Boyd et al. (GCN 4684). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4688 SUBJECT: GRB060206: SARA Detection DATE: 06/02/06 09:01:34 GMT FROM: Autumn Homewood at Clemson U A.L. Homewood, K.V. Garimella, D.H. Hartmann (Clemson University), R. Kaitchuck (BSU), and J.S. Shaw (UGA), report on behalf of the Clemson GRB Follow-Up Team: We began observations of the error box reported by Morris, et al (GCN 4682), beginning approximately 2.5 hours after the burst trigger. We confirm the afterglow reported by Fynbo, et al (GCN 4683). We derive a magnitude of R=17.77 +/- 0.26 mag after co-adding 10 300-second exposures and calibrating relative to the USNO A2.0 catalog. The image may be found at http://people.clemson.edu/~kgarime/burst/detections/grb060206/ No extinction corrections have been made. Observations are continuing. The Clemson Unversity GRB Response Site may be found at: http://people.clemson.edu/~kgarime/burst/index.php The SARA Homepage may be found at: http://www.saraobservatory.org This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4689 SUBJECT: GRB060206: Swift XRT Position DATE: 06/02/06 09:19:42 GMT FROM: David Morris at PSU/Swift-XRT D. Morris (PSU), D. Burrows (PSU), N. Gehrels (GSFC), P. Boyd (GSFC-UMBC), L. Angelini (GSFC-JHU) report on behalf of the Swift XRT team: We have analyzed the Swift XRT data from the first orbit observation of GRB 060206 (Morris et al., GCN4682), with a total exposure of 337 seconds. We find an uncataloged, fading source at: RA(J2000) = 13h 31m 43.4s Dec(J2000) = +35d 03' 02.0" This position is 99.0 arcseconds from the BAT position given in GCN 4682 and 1.8 arcseconds from the optical afterglow position reported in GCN 4683 (Fynbo et al) and refined in GCN 4684 (Boyd et al). We estimate an uncertainty of 4 arcseconds radius (90% containment). This circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4690 SUBJECT: GRB 060206: KAIT observations DATE: 06/02/06 09:22:29 GMT FROM: Weidong Li at UC Berkeley KAIT/LOSS W. Li, University of California, Berkeley, on behalf of the KAIT GRB team, report: We began observations of the error box of GRB 060206 reported by Morris et al. (GCN 4682) with the robotic 0.76-m Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory at about 3.9 hours after the burst, and the afterglow reported by Fynbo et al. (GCN 4683) was clearly detected in all the images. The afterglow is at magnitude 17.95 +/- 0.05 (calibrated to USNO B1.0) in a 120s unfiltered image started at 08:41:52 UT (3.92 hours after the burst). A finder chart of the afterglow can be found at http://astron.berkeley.edu/~weidong/grb060206.gif . //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4691 SUBJECT: GRB060206: P60 Optical Observations DATE: 06/02/06 09:31:48 GMT FROM: S. Bradley Cenko at Caltech E. O. Ofek, S. B. Cenko, A. M. Soderberg (Caltech), and D. B. Fox (Penn State) report on behalf of a larger collaboration: We have imaged the error circle of GRB060206A (Morris et al. GCN 4682), with the automated Palomar 60-inch telescope, starting 1.4 hours after the GRB trigger. Observations were taken under poor external conditions (cirrus clouds and below-average seeing). We find the afterglow reported by Fynbo et al. (GCN 4683) at J2000.0 coordinates: RA: 13:31:43.47 Dec: +35:03:03.3 The R-band magnitude of the afterglow, ~3.44 hours after the GRB trigger was about 17.2, assuming R=16.17 for the nearby USNO-B1 star 1250-0209088 (13:31:43.65 +35:02:31.4). A finding chart can be found at: http://astro.caltech.edu/~eran/GRB/060206/GRB060206_FC.jpg //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4692 SUBJECT: GRB 060206: Spectroscopic Redshift DATE: 06/02/06 09:34:16 GMT FROM: Johan U. Fynbo at U.Copenhagen Johan P. U. Fynbo, Marceau Limousin, José María Castro Cerón, Brian L. Jensen (DARK Cosmology Centre), Jyri Näränen (Helsinki Observatory) report on behalf of a larger collaboration: "From the calibrated ALFOSC spectrum of the afterglow of GRB 060206 (GCN #4682, #4683, #4684, #4686) we measure a redshift of z=4.045 based on Lyman-alpha, SiII, SiII*, OI, CII and SiIV among other lines. Our previous estimate was off due to a calculation error for which we apologise." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4693 SUBJECT: GRB060206: Liverpool Telescope observation DATE: 06/02/06 10:05:14 GMT FROM: Cristiano Guidorzi at ARI,Liverpool JMU C. Guidorzi, A. Monfardini, A. Gomboc, C.G. Mundell, A. Melandri, C.J. Mottram, R.J. Smith, I.A. Steele, D. Carter, M. Burgdorf, S. Kobayashi, D. Bersier, M.F. Bode (Liverpool JMU) report: "The 2-m Liverpool Telescope followed up the GRB060206 (Morris et al, GCN 4682) and started observing its position at 5.23 min after the GRB. We detect the optical afterglow in agreement with the candidate from Fynbo et al. (GCN 4683) and Boyd et al. (GCN 4684). The magnitude of the afterglow was R~16.5 (USNO-B1 calibrated) at ~5.2 min after the burst. After an initial fading, we confirm the rebrightening (Wozniak et al., GCN 4687) with R~16.3 at 60 min after the burst trigger time." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4694 SUBJECT: GRB060206: Swift XRT Refined Analysis DATE: 06/02/06 11:02:11 GMT FROM: David Morris at PSU/Swift-XRT D. Morris (PSU), D. Burrows (PSU), N. Gehrels (GSFC), J. Greiner (MPE), D. Hinshaw (GSFC-SPSYS) report on behalf of the Swift XRT team: We have analyzed the Swift XRT data from the first orbit of GRB 060206 (Morris et al., GCN4682), with a total exposure of 337 seconds. The refined XRT position is: RA(J2000) = 13h 31m 43.4s Dec(J2000) = +35d 03' 02" This position is 99.0 arcseconds from the BAT position given in GCN 4682 and 1.8 arcseconds from the optical afterglow position reported in GCN 4683 (Fynbo et al) and refined in GCN 4684 (Boyd et al). We estimate an uncertainty of 4 arcseconds radius (90% containment). The 0.2-10 keV light curve starts 65 seconds from the BAT trigger (T0). Due to the the spacecraft entry into the SAA, only a very small amount of data was collected during the first orbit. The available data suggest a decaying lightcurve but are too sparse to determine an accurate measure of the decay slope. A preliminary spectral fit to the PC data gives a spectral power law photon index of 2.0 ± 0.3 in the 0.2-10 keV band with NH of 4e20 +4e20/-3e20. The galactic NH value for this direction is 1e20. The unabsorbed 0.2-10 keV flux at the start of the XRT observation is estimated to be about 8E-11 erg/cm2/s. Due to the uncertain nature of the decay slope, we are currently unable to predict the expected flux at T+24hrs. Observations are ongoing and we will distribute further analysis as data become available. This circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4695 SUBJECT: GRB060206: SDSS Pre-Burst Observations DATE: 06/02/06 16:50:28 GMT FROM: Richard J. Cool at U.of AZ/Steward Obs Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann (APO), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report: The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB060206 prior to the burst. As these data should be useful as a pre-burst comparison and for calibrating photometry, we are supplying the images and photometry measurements for this GRB field to the community. Data from the SDSS, including 5 FITS images, 3 JPGS, and 3 files of photometry and astrometry, are being placed at http://mizar.as.arizona.edu/~grb/public/GRB060206 We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=202.946 (13:31:47.0), dec=35.0750 (35:04:30.0); GCN 4682), as well as 3 gri color-composite JPGs (with different stretches). The units in the FITS images are nanomaggies per pixel. A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS astrometric information. In the file GRB060206_sdss.calstar.dat, we report photometry and astrometry of 346 bright stars (r<20.5) within 15' of the burst location. The magnitudes presented in this file are asinh magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118, 1406). Beware that some of these stars are not well-detected in the u-band; use the errors and object flags to monitor data quality. In the files GRB060206_sdss.objects_flux.dat and GRB060206_sdss.objects_magnitudes.dat, we report photometry of 771 objects detected within 6' of the GRB position. We have removed saturated objects and objects with model magnitudes fainter than 23.0 in the r-band. The fluxes listed in GRB060206_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB060206_sdss.objects_magnitudes.dat are asinh magnitudes. All quantities reported are standard SDSS photometry, meaning that they are very close to AB zeropoints and magnitudes are quoted in asinh magnitudes. Photometric zeropoints are known to about 2% rms. None of the photometry is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis (1998) predictions for this region are A_U=0.054 mag, A_g=0.040 mag, A_r = 0.029 mag, A_i=0.022 mag, and A_z=0.015 mag. There are currently no objects within 6 arcminutes of the GRB position in the SDSS spectroscopic database. SDSS astrometry is generally better than 0.1 arcsecond per coordinate. Users requiring high precision astrometry should take note that the SDSS astrometric system can differ from other systems such as those used in other notices; we have not checked the offsets in this region. More detailed information pertaining to our SDSS GRB releases can be found in our initial data release paper (Cool et al. 2006, astro-ph/0601218). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr4. These data have been reduced using a slightly different pipeline than that used for SDSS public data releases. We cannot guarantee that the values here will exactly match those in the data release in which these data are included. In particular, we expect the photometric calibrations to differ by of order 0.01 mag. This note may be cited, but please also cite the SDSS data release paper, Adelman-McCarthy et al. (2006, ApJS, in press, astro-ph/0507711), when using the data or referring to the technical documentation. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4696 SUBJECT: GRB 060206 : Lulin optical observations DATE: 06/02/06 18:43:53 GMT FROM: Yuji Urata at RIKEN C.S. Lin, H.C. Lin, C.W. Chen, K.Y Huang W.H. Ip (NCU) Y. Urata (RIKEN), Y. Qiu (NAOC) on behalf of EAFON report: "We are observing GRB 060206 optical afterglow using 0.4-m and 1.0-m telescope at Lulin observatory, Taiwan. The imaging observation with B, V, R and I band were started at 15:49:15 UT (11.04 hours after the burst). The optical afterglow is detected in all bands. The stacked B-band image made from three 300 s exposures is available at http://cosmic.riken.go.jp/grb/eafon/GRB060206_Lulin-B.jpg MID Time(UT) Filter Exp. mag Telescope ----------------------------------------- 15.86 R 300s 18.8 LOT Further observations and analysis are in progress" //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4697 SUBJECT: GRB 060206: Swift-BAT refined analysis DATE: 06/02/06 21:16:50 GMT FROM: David Palmer at LANL D. Palmer (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC), M. Chester (PSU), J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), F. Marshall (GSFC), T. Mitani (ISAS), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (ISAS), M. Suzuki (Saitama), J. Tueller (GSFC), on behalf of the Swift/BAT team: Using the data set from T-60 to T+123 sec from the recent telemetry downlink, we report further analysis of BAT GRB 060206 (trigger # 180455) (GCN Circ 4682, Morris et al.). The BAT ground-calculated position is (RA,Dec) = 202.932, 35.050 deg {13h 31m 43.8s, 35d 2' 58.7"} (J2000) +- 1.0 arcmin, (radius, sys_stat, 90% containment). The partial coding was 98%. The 1-second binned light curve shows a single peak which extends out to around 8 seconds in the two lowest energy bins (15-25 and 25-50 keV), but is shorter in duration in the two highest energy bins (50-100 and 100-350 keV), extending out to only about 4 seconds. This could be an indication the burst is softening with time. The highest energy bin shows a possible double peak structure, with the first peak at T0-1 second. T90 (15-350 keV) is 7 +- 2 seconds (estimated error including systematics). The time-averaged spectrum from T-0.6 to T+13.7 is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.06 +- 0.34, and Epeak of 75.4 +- 19.5 keV (chi squared 57.88 for 56 d.o.f.). For this model the total fluence in the 15 - 150 keV band is (8.4 +- 0.4) x 10^-07 erg/cm2 and the 1-sec peak flux measured form T+2.11 sec in the 15-150 keV band is (2.8 +- 0.2) ph/cm2/sec. A fit to a simple power law gives a photon index of 1.69 +- 0.08 (chi squared 69.94 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. Using the best fit photon index and Epeak with a Band model with the high energy photon index fixed at beta = -2.5, and the redshift of 4.045 (Fynbo et al. GCN 4692), the isotropic-equivalent energy, Eiso, integrated from 1 to 1000 keV at the GRB rest frame is 5.8 x 10^52 ergs. This Eiso and the Epeak at the GRB rest frame ((1+z)*Epeak = 380 keV) are consistent with the Epeak-Eiso (Amati) relation (Amati et al, 2002). The Eiso in the BAT observed energy band (76 - 757 keV in the GRB rest frame) is 3.1 x 10^52 ergs. The estimated jet break time using the Eiso-Epeak-t_break relation (Liang & Zhang, ApJ, 633, 611) would be 8.6 days after the burst at the observer's frame (using the Band model). Using a cutoff power-law for the analysis (which is also consistent with the data) gives a 10.4 day estimate for the break time. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4699 SUBJECT: GRB 060206: Super-LOTIS observations DATE: 06/02/06 23:56:42 GMT FROM: Peter A. Milne at Super-LOTIS P.A.Milne (Steward Obs), G.G. Williams (MMTO), on behalf of the Super-LOTIS GRB team reports: We observed the optical afterglow of GRB 060206 (GCN 4682, GCN 4683) using the 60cm Super-LOTIS telescope at Kitt Peak, Arizona. Imaging began at 08:59:30 UT, 4.2 hours after the burst, and consisted of 20 one-minute exposures in both the R and V filters. The optical counterpart was detected at the following magnitudes: UT Start UT End FILTER Magnitude 08:59:30 09:25:50 R 17.87 +/- 0.12 09:27:00 09:52:20 V 18.37 +/- 0.22 Magnitudes are based upon comparison with 9 & 5 stars, respectively, from the Nomad-1 catalog, accessed through the USNO catalog service. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4701 SUBJECT: GRB 060206: Lick 3m Spectroscopy DATE: 06/02/07 02:47:37 GMT FROM: Ryan Foley at UC Berkeley J. X. Prochaska (UC Santa Cruz), D. S. Wong, S. H. Park, A. V. Filippenko, R. J. Foley, and W. Li (UC Berkeley) report: "We observed the afterglow of GRB 060206 with the Kast double spectrograph on the Shane 3-m reflector at Lick Observatory for 6000 s starting at UT 10:11 on 6 Feb., under poor observing conditions. We confirm the report from Fynbo et al. (GCN 4692) of strong metal-line features and a damped Lya profile centered at z = 4.048 +/- 0.001. The absence of a Lya forest redward of 6200 Ang marks this absorption system as the ISM of the host galaxy of GRB 060206. A Voigt profile analysis of the Lya profile gives log N(HI) = 20.90 +/- 0.15. The absence of a strong feature at SII 1253 places an upper limit to the metallicity of [S/H] < -0.9, while the detection of Fe II 1608 implies [Fe/H] > -1.7 dex. Finally, the rest EW of Si II 1526 (1.1 Ang) implies a velocity width for the low-ionization species greater than 200 km/s. This GCN may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4702 SUBJECT: GRB 060206: IR Detection of the Afterglow DATE: 06/02/07 06:41:10 GMT FROM: Daniel Perley at U.C. Berkeley K. Alatalo, D. Perley and J. S. Bloom (UCB) report: Starting at 2006-02-06 07:41:37 UT (2.91 hrs after the trigger) we began observing the field of GRB060206 (GCN 4682) with PAIRITEL. The transient reported by Fynbo et al. (GCN 4683, GCN 4689) is well detected in each of the 1800s mosaics simultaneously in JHKs bands, and is seen to fade between mosaics. The preliminary magnitude of the transient in the first epoch of imaging in each band, calibrated to the 2MASS catalog, is: J: 15.96 +- 0.03 H: 15.25 +- 0.03 Ks: 14.54 +- 0.04 This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4703 SUBJECT: GRB 060206: Subaru/FOCAS optical spectroscopy DATE: 06/02/07 07:05:05 GMT FROM: Nobuyuki Kawai at Tokyo Tech K. Aoki, T. Hattori (Subaru Telescope, NAOJ), K. S. Kawabata (Hiroshima University), and N. Kawai (Tokyo Tech) report on behalf of the Subaru GRB team: "We have obtained the optical spectra of the afterglow of GRB060206 (Morris et al., GCN 4682) with FOCAS attached to the Subaru 8.2 m Telescope on Mauna Kea. We have taken the spectra covering wavelength regions of 5000-10000 A at Feb 6.5 (UT) with a total exposure time of 4 hours. The spectral resolutions were about R=500-1000. The optical spectra clearly show rich absorption lines, with which we confirm the redshift of 4.05 (Fynbo et al. GCN 4692). We have detected C IV 1550, Fe II 1608, and Al II 1670 in addition to Si II, Si II*, O I, C II, and Si IV reported in GCN 4692. Besides the z=4.05 systems, we have found the z=2.26 and z=1.48 systems which show Mg II 2800 and Fe II absorption lines." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4706 SUBJECT: GRB 060206: optical observations at Asiago DATE: 06/02/07 17:08:28 GMT FROM: Daniele Malesani at SISSA-ISAS,Trieste,Italy D. Malesani (SISSA), H. Navasardyan (INAF/OApD), S. Piranomonte (INAF/OAR), N. Masetti (INAF/IASF Bo), report on behalf of a larger Italian collaboration: We observed the afterglow of GRB 060206 (Morris et al., GCN 4682, 4689; Fynbo et al., GCN 4683) with the AFOSC instrument at the Asiago observatory (Northern Italy). The observing conditions were awful (seeing of ~3.3"). Photometry was carried out in the R- and i- filters. Despite the bad sky conditions, the object was well detected in both filters (S/N~20). In particular, we find R = 19.65 +- 0.20 in comparison with several USNO-B1 stars (R1 magnitude). The error is mostly due to calibration. The mean time of the R-band observations (lasting 1 hr overall) is 2005 Feb 7.0037 (0.80 d after the GRB). This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4709 SUBJECT: GRB 060206: PROMPT Detections DATE: 06/02/07 22:45:49 GMT FROM: Josh Haislip at U.North Carolina J. Haislip, A. LaCluyze, C. MacLeod, M. Nysewander, D. Reichart, J. A. Crain, A. Foster, K. Ivarsen, and J. Kirshbrown report on behalf of the UNC team of the FUN GRB collaboration: We observed the localization of GRB 060206 (Morris et al., GCN 4682) with two of the PROMPT telescopes in Ur'i' between 1.63 and 3.36 hours after the burst under the automated control of Skynet. The afterglow (Fynbo et al., GCN 4683) faded from r' = 16.85 +/- 0.05 mag to r' = 17.83 +/- 0.12 mag over this period (calibrated to five SDSS stars; Cool et al., GCN 4695.) The best-fit temporal index is -1.0. PROMPT is currently being built and commissioned at CTIO. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4710 SUBJECT: GRB 060206: Tenagra II Observations DATE: 06/02/07 23:01:56 GMT FROM: Melissa Nysewander at UNC,Chapel Hill M. Nysewander, D. Reichart, A. Foster, M. Schwartz, P. Holvorcem report on the behalf of the UNC team of the FUN GRB Collaboration: We observed the localization of GRB 060206 (Morris et al., GCN 4682) with the 32-inch Tenagra II telescope in the Arizona Sonoran Desert in the V band beginning 26.5 hours after the burst. We do not detect the afterglow (Fynbo et al., GCN 4683) to V > 19.2 mag (3 sigma) at an effective time of 27.3 hours after the burst (calibrated to five NOMAD stars). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4712 SUBJECT: GRB 060206: More PROMPT Detections DATE: 06/02/08 07:05:32 GMT FROM: Aaron LaCluyze at U.North Carolina J. Kirshbrown, C. MacLeod, A. LaCluyze, J. Haislip, M. Nysewander, D. Reichart, J. A. Crain, A. Foster, and K. Ivarsen report on behalf of the UNC team of the FUN GRB collaboration: We continued to observe the localization of GRB 060206 (Morris et al., GCN 4682) with three of the PROMPT telescopes in Ui'I beginning 25.7 hours after the burst under the automated control of Skynet. We detect the afterglow (Fynbo et al., GCN 4683) at I = 18.79 +/- 0.16 mag at an effective time of 26.3 hours after the burst (calibrated to five SDSS stars; Cool et al., GCN 4695; using the transformation equations of Smith et al. 2002.) In the i' band, the afterglow continues to fade as a power law (Haislip et al., GCN 4709), with a best-fit temporal index of -1.05 between 1.63 and 26.3 hours after the burst. PROMPT is currently being built and commissioned at CTIO. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4713 SUBJECT: GRB 060206: TTT Observations DATE: 06/02/08 09:09:30 GMT FROM: Melissa Nysewander at UNC,Chapel Hill M. Nysewander, J. Harvey, A. Foster, D. Reichart, J. A. Crain, K. Ivarsen, and A. LaCluyze report on behalf of the UNC team of the FUN GRB Collaboration: We observed the localization of GRB 060206 (Morris et al., GCN 4682) with the 14.5-inch Trubble Terrestrial Telescope (TTT) in the mountains west of Fort Collins, Colorado, in red and green filters beginning 27.1 hours after the burst under the automated control of Skynet: Filter Start (UT) Stop (UT) Exposures Total (hr) Red 07:54:35 08:50:41 14 x 160s 0.62 Green 09:20:34 11:12:58 35 x 160s 1.56 TTT is the first non-PROMPT telescope on Skynet. Between 27.1 and 28.5 hours after the burst, these observations were taken in synch with PROMPT observations (Kirschbrown et al., GCN 4712). We do not detect the afterglow (Fynbo et al., GCN 4683) to R > 18.5 mag (3 sigma) at an effective time of 27.6 hours after the burst (calibrated to 5 USNO-B1.0 stars). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4715 SUBJECT: GRB 060206: WSRT Radio Observations DATE: 06/02/08 15:25:51 GMT FROM: Alexander van der Horst at U of Amsterdam A.J. van der Horst (University of Amsterdam) reports on behalf of a larger collaboration: "We observed the position of the GRB 060206 afterglow at 4.9 GHz with the Westerbork Synthesis Radio Telescope at February 7 21.89 UT to February 8 9.86 UT, i.e. 1.71 - 2.21 days after the burst (GCN 4682). We do not detect a radio source within the SWIFT/XRT error circle (GCN 4689), in particular at the position of the optical counterpart (GCN 4683, GCN 4684). The formal flux measurement for a point source at the position of the optical counterpart is 39 +/- 22 microJy. We note there is a bright radio source at RA 13h31m44.2s, Dec +35d03'04.6" (+/- 0.5 arcsec, J2000), i.e. 12 arcsec offset from the optical/X-ray counterpart position, with a flux of 738 +/- 28 microJy." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4716 SUBJECT: GRB 060206: near-infrared observations (JK' imaging) DATE: 06/02/09 07:08:47 GMT FROM: Hiroshi TERADA at Subaru Telescope,NAOJ H. Terada, T.-S. Pyo (Subaru Telescope, NAOJ), N. Kobayashi (University of Tokyo) and N. Kawai (Tokyo Tech) report: "Near-infrared photometry of the afterglow of GRB 060206 (Morris et al., GCN #4682) in the J, K'-bands was performed with IRCS (Infrared Camera and Spectrograph) on the SUBARU Telescope at February 7.5 UT. An average seeing was 0.5 arcsec in the J-band and 0.3 arcsec in the K'-band. The magnitude of the afterglow was J=18.77 +/ -0.04 at 10:38-11:04 UT (t=30.1 hr) and K'=17.78 +/ -0.01 at 13:37-14:30 UT (t=33.3 hr). The near-infrared decay index of the afterglow is estimated to be -1.11 in the J-band and -1.22 in the K'-band from comparison with the earlier report (J=15.96 and Ks=14.54 at t=2.9 hr, GCN #4702)." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4722 SUBJECT: GRB 060206: Swift/UVOT Observations DATE: 06/02/09 22:27:58 GMT FROM: Padi Boyd at GSFC P. Boyd (GSFC), D. Morris (PSU), F. Marshall (GSFC), N. Gehrels (GSFC) on behalf of the Swift/UVOT team report: The Swift/UVOT began observing the bright afterglow of GRB 060206 at 04:47:52 UT on 2006-02-06, approximately 57s after the BAT trigger (Morris et al., GCN 4682). The afterglow is well detected in the individual B and V exposures during the initial observation. The afterglow re-brightens in both filters between 2000 to 5000-s after the BAT trigger. After this event, the flux decays in both filters with a slope of ~1.15. Filter T_range(s) Exp(s) Average mag V 57-36588 2618 18.8 B 1662-34946 2911 21.3 Reported times are in seconds since BAT trigger. In a follow-up observation, beginning about 0.8 d after the BAT trigger, the source is not detected in B nor V down to the following 3-sigma magnitude upper limits: Filter T_range(s) Exp(s) mag upper limit V 69308-150688 5001 >21.7 B 69656-150353 4679 >22.6 The afterglow is not detected in any other UVOT filter down to the following 3-sigma magnitude upper limits: Filter T_range(s) Exp(s) mag U 1637-23385 1161 >21.5 UVW1 1757-5619 256 >20.6 UVM2 1733-30466 514 >21.3 UVW2 1686-35861 2638 >22.7 These magnitudes are uncorrected for Galactic extinction; E(B-V) = 0.013. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4732 SUBJECT: GRB060206, optical observations DATE: 06/02/10 13:12:12 GMT FROM: Adalberto Piccioni at Astronomy, Bologna U. G. Greco (Bologna University), F. Terra, D. Nanni, (Second University of Roma "Tor Vergata"), C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University), G. Pizzichini (INAF/IASF Bo) and R. Gualandi (INAF Bologna) report: During the night of February 6 -7, 2006 we observed the OT of GRB 060206 (Morris et al. GCN 4682; Fynbo et al. GCN 4683) with the 152 cm Loiano telescope equipped with the BFOSC camera system. The weather conditions were not photometric and the seeing was 2.5 arcsec. We obtained 3 images x 20 minutes in Rc filter, 2 x 30 minutes in V and 2 x 20 minutes in I. The 2 V frames have been co-added. We determined the following magnitudes derived from USNO-B1.0 (R1) catalogue for the Rc and I bands and NOMAD catalogue for V band: mean time (UT).......filter................ mag 6.960 ................ Rc ............ 19.78+/-0.15 6.976 ................ Rc ............ 19.70+/-0.11 6.990 ................ Rc ............ 19.79+/-0.12 7.025 ................ V ............. 20.06+/-0.17 7.054 ................ I ............. 19.16+/-0.11 7.069 ................ I ............. 19.19+/-0.10 We thank very much N. Masetti, who has obtained the images. Our RVI images, in which the comparison stars are marked, have been posted in our public directory from where they can be retrieved by sftp using hostname: ermione.bo.astro.it username: publicGRB password: GRB_bo. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4750 SUBJECT: GRB 060206: SOAR Detections DATE: 06/02/12 03:18:22 GMT FROM: Aaron LaCluyze at U.North Carolina A. LaCluyze, M. Nysewander, J. Haislip, A. de Oliveira, D. Reichart, J. Santos, A. Alvarez, S. Heathcote, J. C. Clemens, and A. Trotter report on behalf of the UNC team of the FUN GRB collaboration: We observed the localization of GRB 060206 (Morris et al., GCN 4682) with 4.1m SOAR at CTIO in VRI beginning 50.8 hours after the burst. We detect the afterglow (Fynbo et al., GCN 4683) at I = 20.70 +/- 0.04 mag at an effective time of 51.3 hours after the burst (calibrated to six SDSS stars; Cool et al., GCN 4695; using the transformation equations of Smith et al. 2002.) A more careful analysis of PROMPT's I-band detection from the night before (Kirschbrown et al., GCN 4712) yeilds I = 19.17 +/- 0.18 mag at an effective time of 27.0 hours after the burst. This implies a temporal index of -2.20 +/- 0.26 between 27.0 and 51.3 hours after the burst, which is significantly steeper than the temporal index that we measured with PROMPT on the first night (-1.0; Haislip et al., GCN 4709) This suggests that the jet is breaking, and at a significantly earlier time than estimated by Palmer et al. (GCN 4697). Continued monitoring is encouraged. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4764 SUBJECT: GRB060206: Swift XRT observations of an unbroken powerlaw decay DATE: 06/02/15 23:34:08 GMT FROM: David Morris at PSU/Swift-XRT D. C. Morris (PSU), C. Pagani (PSU), D. N. Burrows (PSU), J. A. Kennea (PSU) and K.Page (U. Leicester) report on behalf of the Swift XRT team: The Swift XRT has continued to monitor the light curve of GRB060206 with data taken as late as T+8 days. Our complete X-ray dataset from T+5ks to T+700ks remains consistent with a single unbroken powerlaw decay with alpha=1.35+/-0.15. We note that there is apparent variability, both positive and negative, on the timescale of days in the X-ray lightcurve somewhat larger than is implied by simple counting statistics. Our data are not consistent, however, with a break to a slope of -2.2 at T+27 hours and thus we cannot confirm the presence of the jet break reported in I-band observations by LaCluyze et al. (GCN 4750). The XRT data remain consistent with the prediction by Palmer et al (GCN 4597) of a jet break at 8.6 or 10.4 days (743ks or 899ks). The XRT countrate during the last observation, on February 14th, was 2e-3 cts/s, equivalent to a flux of approximately 1.5e-13 ergs/cm2/s. Observations are ongoing. The XRT lightcurve can be viewed at http://www.swift.psu.edu/images/GRB060206.jpg This circular is an official product of the Swift XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4768 SUBJECT: GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths DATE: 06/02/17 05:31:02 GMT FROM: Daniel E. Reichart at U.North Carolina D. Reichart, A. LaCluyze, M. Nysewander, and J. Haislip report on behalf of the UNC team of the FUN GRB collaboration: In addition to detecting the afterglow (Fynbo et al., GCN 4683) of GRB 060206 (Morris et al., GCN 4682) in I band 27.0 hours after the burst with PROMPT (Kirschbrown et al., GCN 4712; LaCluyze et al., GCN 4750) and 51.3 hours after the burst with SOAR (LaCluyze et al., GCN 4750), we detected the afterglow in i' band 26.0 hours after the burst with PROMPT, in V band 51.7 hours after the burst with SOAR, and in R band 51.9 hours after the burst with SOAR. At 26.0 hours after the burst, we measure i' = 19.83 +/- 0.22 mag. From our V and R photometry and a simple model of the Ly-alpha forest, we infer i' = 21.55 +/- 0.08 mag at 51.8 hours after the burst. (As a check, simple interpolation between our R and I photometry yeilds i' = 21.36 +/- 0.05 mag at 51.6 hours after the burst.) This implies a temporal index of -2.3 +/- 0.3 between 26.0 and 51.8 hours after the burst, which is consistent with and independent of our measurement of -2.20 +/- 0.26 between 27.0 and 51.3 hours after the burst in I band (LaCluyze et al., GCN 4750). PROMPT and SOAR light curves can be viewed at: http://www.physics.unc.edu/~reichart/grb060206.eps Continued monitoring is strongly encouraged, particularly given that no break is observed in X rays (Morris et al., GCN 4764). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4901 SUBJECT: GRB060206: optical observation DATE: 06/03/22 01:49:52 GMT FROM: Alexei Pozanenko at IKI, Moscow D. Sharapov (MAO, and NOT, La Palma), M. Ibrahimov, (MAO), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the localization of GRB 060206 (Morris et al., GCN 4682) with 1.5m telescope of Maidanak Astronomical Observatory in R-band between (UT) Feb. 07 23:26:38 and Feb. 08 00:36:06 (18x180 s) with a mean seeing 0.95". We detect the afterglow (Fynbo et al., GCN 4683) at R=20.78 +/- 0.03 at mean time (UT) Feb. 8.000. Calibration is based on SDSS stars; Cool et al., GCN 4695 using the transformation equations (Lupton, 2005). Combining this value with a light curve presented by Stanek et al. (astro-ph/0602495) one can suggest the jet brake later than 0.6 days. The value R=20.78 +/- 0.03 is also correlated with possible XRT light curve rebrightening (XRT light curve presented in the astro-ph/0602495). There is a tentative short time scale rebrightening within our observation; more detailed calibration is underway. The stacked image can be found in http://grb.rssi.ru/GRB060206/GRB060206_060207_AZT22_R.jpg The message may be cited.