//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3360 SUBJECT: Swift-BAT detection of GRB050505 DATE: 05/05/06 00:15:29 GMT FROM: Scott Barthelmy at NASA/GSFC C. Hurkett (U. Leicester), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), P. Shady (MSSL), J. Osborne (U. Leicester), J. Kennea, D. Burrows (PSU) for the Swift-team: At 23:22:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050505 (trigger #117504). The BAT on-board calculated location is RA, Dec 141.782, +30.255 (J2000) with an uncertainty of 4 arcmin (radius, 3-sigma, including estimated systematic uncertainty, 90% containment). The BAT light curve showed a multipeak structure with a duration of about 45 seconds. The peak count rate measured by BAT was about 1500 counts/sec in the 15 - 350 keV band, occurring at the trigger. The Swift spacecraft did not make an immediate slew because of the Earth observing constraint. [GCN OPS NOTE(05May05): The author list was changed to include authors that were accidentally left out.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3364 SUBJECT: GRB050505 Swift-BAT refined analysis DATE: 05/05/06 02:12:32 GMT FROM: Hans Krimm at NASA-GSFC D. Hullinger (UMD), L. Barbier (GSFC), S. Barthelmy (GSFC), L. Cominsky (Sonoma State), J. Cummings (GSFC/NRC), E. Fenimore (LANL), R. Fink (GSFC), M. Galassi (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS), M. Suzuki (Saitama), M. Tashiro (Saitama U.), J. Tueller (GSFC), on behalf of the Swift/BAT team: At 23:22:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB050505 (trigger=117504) (GCN Circ 3360, Hurkett et al.). The refined BAT ground position is (RA,Dec) = 141.787, +30.245, [deg; J2000] +- 3 arcmin, (95% containment). The burst was 49 degrees off the Swift boresight, which is ~30% coded. The BAT mask-weighted light curve shows a multi-peaked structure with a total duration T90 (15-350 keV) 60 +- 2 seconds (estimated error including systematics). The initial peak began ~15 seconds before the trigger and extended to 10 seconds after the trigger. There were three further short peaks beginning at T+20 seconds, T+31 seconds, and T+49 seconds. The spectrum is well fit by a simple power law with photon index of 1.5 +- 0.1. The fluence in the 15-350 keV band is (4.1 +- 0.4) x 10^-6 erg/cm2. The 1-second peak photon flux in the 15-350 band is (2.2 +- 0.3) ph/cm2/s recorded at 1 second after the trigger. All the quoted errors are at the 90% confidence level. We note that this burst appears to be well-suited for ground follow-up observations, as it is located 90 degrees from the Sun, 120 degrees from the Moon, close to the ecliptic, and away from the Galactic plane. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3365 SUBJECT: GRB 050505: Swift XRT Position DATE: 05/05/06 02:53:21 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT J. A. Kennea, D. N. Burrows (PSU), C. P. Hurkett, J. P. Osbourne (U. Leicester) and N. Gehrels (NASA/GSFC) report on behalf of the Swift XRT team: The Swift BAT instrument detected a GRB at 23:22:21 UT on 5th May 2005 (GCN Circ 3360). The observatory executed an automated slew to the BAT position and the XRT began taking data at 00:09:23 UT on 6th May 2005. The XRT was in Auto state but was not able to centroid on the afterglow due to low source brightness. From downlinked data we find a uncatalogued X-ray source located at: RA(J2000) = 9:27:03.2, Dec(J2000) = +30:16:21.5 We estimate an uncertainty of about 6 arcseconds radius (90% containment). This position is 124 arcseconds from the BAT position reported in GCN 3364. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3366 SUBJECT: GRB050505: Optical Afterglow Candidate DATE: 05/05/06 07:25:58 GMT FROM: S. Bradley Cenko at Caltech S. Bradley Cenko, Chuck Steidel, Naveen Reddy, and Derek B. Fox report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: We have imaged the field of GRB050505 (GCN 3360) with the Keck Low Resolution Imaging Spectrometer (LRIS) mounted on the 10-m Keck I Telescope. Observations in imaging mode consisted of 2 x 300 s simultaneous exposures in the g' and I filters. The mean epoch of our observations is approximately 5:45 UT 6 May 2005 (~ 6.1 hours after the burst). In the XRT error circle reported in GCN 3365, we find one bright source, with coordinates (J2000.0): RA: 09:27:03.3 Dec: +30:16:23.7 We tentatively identify this source as the afterglow of GRB050505. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3367 SUBJECT: GRB 050505 UVOT DATE: 05/05/06 08:22:11 GMT FROM: Simon Rosen at MSSL-UCL S. Rosen (MSSL), C. Hurkett (Leicester), W. Landsman (GSFC), P. Roming (PSU), T. Poole (MSSL), N. Gehrels (GSFC), K. Mason (MSSL), J. Nousek (PSU), on behalf of the Swift UVOT team The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of GRB050505 on May 06, 2005 at 00:09:08 UT, ~48 minutes after the initial Swift BAT trigger (Hullinger et al, GCN 3364) (the delay in observations was due to the Earth-limb constraint, which prevented an immediate slew). Initial data is limited to one 100s exposure in each of four filters. We detect no source at the Swift XRT position (Kennea et al, GCN 3365) in any filter. The limiting magnitudes (5-sigma in 6" radius apertures) in each of the UVOT filters are as follows: Filter Lim_Mag Duration (s) T_start (s) V ~17.7 100 T + 2870 U ~18.4 100 T + 3180 UVW1 ~18.9 100 T + 3080 UVM2 ~19.7 100 T + 2970 The magnitudes are based on preliminary zero-points, measured in orbit, and will require refinement with further calibration. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3368 SUBJECT: GRB 050505: Keck absorption spectrum and redshift (z=4.27) DATE: 05/05/06 08:36:50 GMT FROM: Edo Berger at Carnegie Obs Edo Berger (Carnegie Observatories), S. Bradley Cenko, Chuck Steidel, Naveen Reddy, and Derek B. Fox (Caltech) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We obtained a 900-sec spectrum of the optical candidate (GCN 3366) of GRB 050505 (GCN 3360) with LRIS on the Keck I 10-m telescope on 2005, May 6.27 UT. We find very strong absorption over the range of 6200-6500 A, corresponding to Ly alpha absorption around z = 4.1 to 4.3. In addition, we find several metal absorption lines, including SiIV (1393,1402), at a redshift of 4.27. At this redshift, the second highest measured for any GRB, the isotropic equivalent gamma-ray energy is 7.7e53 erg." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3370 SUBJECT: GRB050505: AAVSO observations DATE: 05/05/06 13:31:30 GMT FROM: Arne A. Henden at AAVSO D. Hohman (Stone Edge Observatory), A. Henden (AAVSO) and A. Price (AAVSO) report on behalf of the AAVSO International High Energy Network on optical observations of GRB050505 (GCN #3360, Hurkett et al.): No afterglow candidate is found in the field or at the location of the afterglow reported by Cenko et al. (GCN 3366) to a limiting unfiltered (R-like) magnitude of 18.5 using USNO-A2.0 reference stars. Observation midpoint time was 02:19 UT on May 6, 2005 (2.9hrs after burst). Details of the observation are below along with a link to the FITS image. The unfiltered observations have significant Rc/Ic contribution and so are complementary to the UVOT observations reported by Rosen, et al. (GCN 3367). Name: Dennis Hohman email: dennishohman@adelphia.net Observer: Dennis Hohman Site: Stone Edge Observatory Location: Orchard park, NY LatitudeLongitude: -78.75, 42.76 Elevation: 950 ft Scope: C8 ScopeFocalRatio: 6.1 CCDVendor: ST7XME CCDDetector: KAF401E CCDSize: 382x255 CCDPixelScale: 3.0 CCDFOV: 12.9x19.4 Object: GRB050505 ObsDate: 05/06/05 ObsMidPointTime: 02:19 TimePerFrame: 240 sec NumberOfFrames: 7 Filters: CR Processing: Flatfield,Dark sub, avg Seeing: 3.8 LimitingMag: 18.7 Sky: Clear, some high clouds afterglowmag: afterglowerr: compstars: Report: Entire error circle covered. No new object visible to estimated mag 18.5 comments: A FITS image has been uploaded to ftp://ftp.aavso.org/grb/DennisHohman_GRB050505_2453496.67896_.fits The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3371 SUBJECT: GRB 050505: Further Swift UVOT observations. DATE: 05/05/06 14:17:46 GMT FROM: Simon Rosen at MSSL-UCL S. Rosen (MSSL), C. Hurkett (Leicester), S. Holland (GSFC), P. Roming (PSU), A. Blustin (MSSL), N. Gehrels (GSFC), K. Mason (MSSL), J. Nousek (PSU), on behalf of the Swift UVOT team Further to the initial Swift UVOT results (Rosen et. al. 3367) we report the results of co-added, deeper exposures of GRB 050505 with the Swift Ultra-Violet/Optical Telescope (UVOT) on May 06, 2005. We detect no source at the Keck determined location (Cenko et al, GCN 3366) in any of the UVOT filters with the following 5 sigma and 3 sigma limits (in 6" radius apertures) Filter Lim_Mag Lim_mag Total duration (s) T_range (s) 5sigma 3sigma V 19.82 20.35 2527 2807 - 28543 B 20.50 21.04 1999 3236 - 26917 U 20.26 20.84 2890 3132 - 22757 UVW1 20.81 21.36 1999 3029 - 22040 UVM2 21.13 21.68 2422 2924 - 21132 UVW2 21.27 21.83 1997 3342 - 27826 T_range is since the BAT trigger time (Hullinger et al. 3364). The magnitudes are based on preliminary zero-points, measured in orbit, and will require refinement with further calibration. We note that for the estimated redshift of 4.1 - 4.3 (GCN 3368), the Lyman limit lies between the UVOT B and V filters - the lack of a UVOT detection in V may be significant, depending on the brightness of the source detected by Keck and the true redshift. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3372 SUBJECT: GRB050505: Infrared observations DATE: 05/05/06 14:58:07 GMT FROM: Evert Rol at U.Leicester E. Rol (U. of Leicester), N. Tanvir (U. of Hertfordshire), A. Levan (U. of Leicester), A. Adamson, L. Fuhrman (JAC), R. Priddey, R. Chapman (U. of Hertfordshire) report: We have observed the error circle of GRB050505 (GCN 3360) in K-band with the WFCAM instrument on UKIRT. At the position of the optical candidate (GCN 3366), we clearly detect a point-like source, presumably the infrared counterpart. Relative to 2MASS stars in the frame we measure a provisional magnitude of K = 18.1 +/- 0.2 (error includes allowance for possible systematics), 6.82 hours after the burst trigger (mid-exposure time). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3373 SUBJECT: GRB 050505, simultaneous optical observation DATE: 05/05/06 20:11:23 GMT FROM: Javier Gorosabel at LAEFF-INTA, Madrid M. Jelinek, A. J. Castro-Tirado, J. Gorosabel, A. de Ugarte Postigo, S. Guziy (IAA-CSIC Granada), P. Kubanek, R. Hudec (Astronomical Institute of the Academy of Sciences, Ondrejov), and S. Vitek (Czech Technical University), report: "The BOOTES-1 very wide field camera, located at Estacion de Sondeos Atmosfericos (INTA-CEDEA) in Huelva (Spain), observed the region of the sky containing the SWIFT/BAT error box for GRB 050505 (Hurkett et al. GCN 3360) as part of its routine observing schedule. A 30 s exposure started at 23:22:00 UT (21 s prior to the onset of the 90 s long burst), with the following frame starting at 23:23:00 UT (i.e. covering the late part of the event). A limiting (unfiltered, airmass 1.6) magnitude of 9.2 is derived for any prompt optical flash arising from this event." This message can be quoted. [GCN OPS NOTE(07may05): Per author's request, the second time was changed to 23:22:30.] [GCN OPS NOTE(08may05): Per author's request, the second time was changed to 23:23:00. The Hurkett reference was changed to 3360.] //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3375 SUBJECT: GRB 050505 - Faulkes Telescope North observations DATE: 05/05/06 21:07:47 GMT FROM: Nial Tanvir at IofA U.Cambridge R. Chapman, N. Tanvir (U. of Hertfordshire), E. Rol, A.Levan (U. of Leicester), R. Priddey (U. of Hertfordshire), I. Steele, R. Smith, C. Mundell and M. Bode (Liverpool John Moores University) report on behalf of the ROBONET collaboration: The Swift/BAT error circle of GRB 050505 (GCN3360) was observed in R-band starting May 6.30 UT with the 2m Faulkes Telescope North on Haleakala. Several short exposures were combined and reveal a source at the position of the candidate optical counterpart from GCN3366. Preliminary photometry relative to USNO-B1 stars in the frame provides a magnitude of R = 21.5 +/- 0.2 for this source. Further observations are planned. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3376 SUBJECT: GRB 050505: early time observations DATE: 05/05/07 22:28:55 GMT FROM: Alberto Castro-Tirado at LAEFF-INTA A. de Ugarte Postigo, M. Jelinek, J. Gorosabel (IAA-CSIC Granada), P. Kubanek, R. Hudec (ASU-CAS Ondrejov), T. J. Mateo Sanguino (Univ. de Huelva), S. Castillo, S.Guziy and A. J. Castro-Tirado (IAA-CSIC), report: "Following the detection by SWIFT/BAT of GRB 050505 (Herkett et al., GCN 3360), the pair of 0.2m BOOTES-1B telescopes at INTA-CSIC's Observatorio de Arenosillo responded automatically at 23:32:30 UT (i.e. 70 s after the alert which was received 9.5 min after the onset of the event). A co-addition of the first V- and I-band images taken do not reveal the optical afterglow at the position given by Bradley Cenko et al., (GCN 3366). On the other hand, the 0.6m telescope (+BOOTES-IR optical camera) at IAA's Observatorio de Sierra Nevada responded automatically at 23:31:57 UT (i.e. 37 s after the alert received 9.5 min after the onset of the event). Due to technical problems (the telescope is still in commissioning phase), the first image was acquired at 00:09 UT (47 min after the GRB). A preliminary analysis of our R-band observations (total exposure time = 1 hour) imposes a limit of R > 19 to the afterglow optical emission (Bradley Cenko et al., GCN 3366). Further analysis is in progress." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3377 SUBJECT: GRB 050505: Keck I-band Magnitude DATE: 05/05/07 23:02:43 GMT FROM: S. Bradley Cenko at Caltech S. Bradley Cenko, Chuck Steidel, Naveen Reddy, and Derek B. Fox report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: We have further analyzed the I band images of the afterglow of GRB 050505 reported in GCN 3366. Using the USNO-B1 star located at RA: 09:27:06.5667, Dec: +30:17:18.750 (I = 18.85) as a reference, we find the following magnitude for the afterglow: UT Time UT Date Time Since Burst (hr) Magnitude ------------------------------------------------------------------------ 5:45:47 May 6 6.4 20.66 +/- 0.1 //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3398 SUBJECT: GRB 050505: SARA Observations DATE: 05/05/09 19:03:38 GMT FROM: Autumn Homewood at Clemson U Autumn Homewood, Dieter H. Hartmann (Clemson), Matt Wood (FIT) Report on behalf of the Follow-Up-Network (FUN) GRB collaboration: We observed a 8x12 arcminute field centered on the optical afterglow (GCN 3366) of GRB 050505 discovered by Swift (GCN 3360) with the SARA 0.9 m Telescope at KPNO. Observations were carried out under good seeing conditions with the U55 CCD. We obtained 35 minutes of exposure in R. Observations started at UT 05/05/06 03:03:37, and ended 03:43:43. We do not detect the afterglow. Our R-band upper limit (1-sigma) is R(lim) = 19.7. The calibration was carried out using the USNO A2.0 catalog. The SARA home page can be found at http://www.astro.fit.edu/sara/sara.html This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3403 SUBJECT: GRB 050505, early TAROT observation DATE: 05/05/10 08:34:00 GMT FROM: Jean-Luc Atteia at Lab d Astrophys.,OMP,Toulouse Klotz, A., Boer M. (OHP), and Atteia, J.L. (LAT) report: We imaged the entire field of GRB 050505 (cf. Hurkett et al. GCNC 3360) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. Observations started at 23:31:49 UT, 7 seconds after the GCN notice, and 9.1 min after the GRB. The field had an elevation lower than 26 degrees above horizon at the begining of the observations. When we co-add series of 30s unfiltered images, we detect a source at the position mentioned by S. Bradley Cenko et al. (GCNC 3366) until 23h47 UT. As the redshift measured by Berger et al. (GCNC 3378) indicates a strong absorption over the range of 6200-6500 A, we compared the flux of TAROT images (clear filter) with the I band magnitudes of the USNO-B1 catalog. We find the following magnitudes: 2005-05-05T23:31:49 to 2005-05-05T23:39:25 I=18.2 +/- 0.2 2005-05-05T23:39:32 to 2005-05-05T23:47:08 I=18.4 +/- 0.2 2005-05-05T23:49:55 to 2005-05-05T23:59:39 I>18.8 The comparison with the I magnitude of 20.66 reported by Cenko et al. (GCN 3377) 6.4 hours after the GRB, indicate a slope of -0.7 for the temporal decay in I band. Further information can be found at http://www.cesr.fr/~klotz/grb050505/ //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4184 SUBJECT: Recent GRB UBVRcIc field photometry DATE: 05/10/31 16:31:02 GMT FROM: Arne A. Henden at AAVSO A. Henden (AAVSO/USNO) reports on behalf of the USNO GRB Team: We have acquired UBVRcIc all-sky photometry for 23x23arcmin fields centered on the coordinates of recent GRB localizations with the USNOFS 1.0-m telescope on 1 or 2 photometric nights. We are using a new CCD, and so place an additional zeropoint error of about 0.03mag that should be added in quadrature to the errors reported in the files listed below. Stars brighter than V=13.0 are saturated and should be used with care. We have placed the photometric data on our anonymous ftp site: ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb050505.dat ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb051021.dat ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb051022.dat ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb051028.dat Since these bursts had identified optical afterglows, we may improve the photometric calibration on subsequent observing runs. As always, you should check the dates on the .dat file prior to final publication to get the latest photometry. There is a README file on the ftp directory to give you information about the procedures used to calibrate these fields.