//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7646 SUBJECT: GRB 080430: TAROT Calern observatory optical observations DATE: 08/04/30 20:09:33 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 080430 detected by SWIFT (trigger 310613) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. The observations started 18.8s after the GRB trigger (7.2s after the notice). The elevation of the field increased from from 82 degrees above horizon and weather conditions were good. We detect a new fading source in the error box given by SWIFT at the following position (+/- 3 arcsec): RA(J2000.0) = 11h 01m 14.2s DEC(J2000.0) +51d 41' 08" OT was R~16 at 18.8s after GRB. Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction. N.B. Galactic coordinates are lon=155.5591 lat=+57.8882 and the galactic extinction in R band is 0.0 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S. This message may be cited. 51°41'08" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7647 SUBJECT: GRB 080430: Swift detection of a burst with optical afterglow DATE: 08/04/30 20:16:10 GMT FROM: Scott Barthelmy at NASA/GSFC C. Guidorzi (INAF-OAB), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), W.L Landsman (GSFC), C. B. Markwardt (CRESST/GSFC/UMD), K. M. McLean (GSFC/UMD), P. T. O'Brien (U Leicester), D. M. Palmer (LANL), D. Perez (U Leicester), P. Romano (INAF-IASFPA), T. Sakamoto (NASA/UMBC), M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester), G. Tagliaferri (INAF-OAB), T. N. Ukwatta (GSFC/GWU), D. E. Vanden Berk (PSU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 19:53:02 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080430 (trigger=310613). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 165.322, +51.689 which is RA(J2000) = 11h 01m 17s Dec(J2000) = +51d 41' 22" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single FRED peak structure with a duration of about 20 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 19:53:50.9 UT, 48.9 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source with an enhanced position: RA, Dec 165.31041, 51.68546 which is equivalent to: RA(J2000) = 11h 01m 14.50s Dec(J2000) = +51d 41' 07.7" with an uncertainty of 2.7 arcseconds (radius, 90% containment). This location is 28 arcseconds from the BAT onboard position, within the BAT error circle. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (9.59e+19 cm^-2, Kalberla et al. 2005), with an excess column of 3 (+1.33/-1.17) x 10^21 cm^-2 (90% confidence). The relation of Grupe et al. (2007) implies that this burst has a redshift z<3.5, although high redshift fits to the absorbed XRT spectrum are possible if paired with an anomalously large column. A summary of the promptly downlinked data is given at http://www.swift.ac.uk/sper/310613/. The initial flux in the 2.5 s image was 1.26e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 400 seconds with the v filter starting 164 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 11:01:14.71 = 165.3113 DEC(J2000) = +51:41:08.5 = 51.6857 with a 1-sigma error radius of about 0.5 arc sec. This position is 2.2 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.6 with a 1-sigma error of about 0.5 mag. A white filter finding chart exposure was also taken before the v filter, showing that the afterglow is fading. No correction has been made for the expected extinction of about 0.04 magnitudes. Burst Advocate for this burst is C. Guidorzi (cristiano.guidorzi AT brera.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: 7648 SUBJECT: GRB 080430: Bootes observation DATE: 08/04/30 20:21:25 GMT FROM: Martin Jelinek at Inst.Astrophys.Andalucia,Granada M. Jelinek, P. Kubanek, J. Gorosabel, A. J. Castro-Tirado, F. Aceituno (IAA-CSIC Granada), L. Sabau-Graziati (INTA Madrid), A. de Ugarte Postigo (ESO Santiago), R. Hudec (ASU-CAS Ondrejov), P. Perez-Gonzalez and J. Zamorano (UCM Madrid) report on behalf of a larger collaboration: The BOOTES-1 0.3m telescope in South Spain observed GRB 080413A, starting at 19:53:36 UT (34 sec after the GRB). A sequence of preprogrammed 6 sec, 20 and 60 sec exposures was obtained. We find an optical counterpart at the coordinates (J2000) 11:01:14.777 +51:41:08.61 with an unfiltered magnitude ~17.0 at ~60s after the GRB. We continue observing the object with the 1.5m telescope at Observatorio Sierra Nevada, which confirms the reality of the object. -- Martin Jelinek, +420602105255, +34617840945, sirrah.cz/mates Instituto de Astrofisica de Andalucia, Granada //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7649 SUBJECT: GRB 080430 - SDSS Pre-Burst Observations DATE: 08/04/30 20:36:36 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 Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report: The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB080430 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/GRB080430 We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=165.322 (11:01:17.3), dec=51.6890 (51:41:20.4); Swift-BAT TRIGGER 310613), 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 GRB080430_sdss.calstar.dat, we report photometry and astrometry of 193 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 GRB080430_sdss.objects_flux.dat and GRB080430_sdss.objects_magnitudes.dat, we report photometry of 582 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 GRB080430_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB080430_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=0.061 mag, A_g=0.045 mag, A_r = 0.032 mag, A_i=0.025 mag, and A_z=0.017 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, PASP 118, 733). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr5. 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. (2007, ApJS, 172, 634), when using the data or referring to the technical documentation. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7650 SUBJECT: GRB 080430: Spectroscopy from CAHA DATE: 08/05/01 02:51:20 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo, L. Christensen (ESO), J. Gorosabel (IAA-CSIC), C. Thöne (Dark), D.A. Kann (TLS), A. Mora (UAM), T. Szeifert (ESO), M. Jelinek, A.J. Castro-Tirado (IAA-CSIC), S. Pedraz (CAHA), N. Cardiel, D. Montes (UCM). On behalf of a larger collaboration report: We have obtained spectroscopic observations of GRB 080430 from the 2.2m Calar Alto telescope (+CAFOS) starting at 21:11 UT (78 minutes after the burst). The observations consisted of 3x1200s integrations in low resolution. The signal to noise ratio is low but after a preliminary reduction we may conclude: 1) Continuum is clearly detected down to 3500 Angstroms, implying a redshift smaller than 1.9. 2) We detect an absorption feature at ~4900 Angstroms that we suggest to be the MgII doublet (2796.3, 2803.5), implying a most probable redshift of ~0.75. Further analysis is ongoing. Additional spectroscopic observations are encouraged. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7651 SUBJECT: GRB080430: Optical observation in AsU CAS Ondrejov & Brno DATE: 08/05/01 04:02:43 GMT FROM: Matus Kocka at Monteboo Obs,Masaryk U,Brno M. Kocka, M. Nekola, J. Strobl, R. Hudec, C. Polasek (AsU CAS - Ondrejov), M. Jelinek, P. Kubanek (IAA-CSIC - Granada), R. Novak (N. Copernicus Observatory - Brno) F. Munz (IASF/INAF - Bologna) The 0.5m D50 telescope in AsU CAS Ondrejov, Czech Republic observed GRB080430. Observation started at 20:57:02 UT. After 29 x 20 sec exposures we detected optical counterpart at the coordinates: (J2000) 11:01:14.7 +51:41:08.6 (M. Jelinek & al; GCN CIRCULAR 7648) Calibrated to near USNO et ESO star in R magnitude ~ 18.9mag (21:02:23 UT mid-time of exposure) http://physics.muni.cz/~koci/GRB080430/grb080430.jpg The 0.4m N. Copernicus Observatory telescope at Brno Czech Republic also observed same coordinates with the same results. http://ccder.blogspot.com/ Further analysis is in progress This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7652 SUBJECT: GRB 080430: Enhanced Swift-XRT position DATE: 08/05/01 04:40:50 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 18 s of overlapping XRT Photon Counting mode and UVOT data for GRB 080430, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 165.31109, +51.68539 which is equivalent to: RA (J2000): 11h 01m 14.66s Dec (J2000): +51d 41' 07.4" with an uncertainty of 1.7 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method. This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7653 SUBJECT: GRB 080430: Swift-XRT refined analysis DATE: 08/05/01 10:25:39 GMT FROM: Cristiano Guidorzi at INAF-OAB C. Guidorzi, J. Mao (INAF-OAB), P. Evans and K.L. Page (Leicester) report on behalf of the Swift-XRT team: The Swift-XRT began observing GRB 080430 (trigger=310613, Guidorzi et al., GCN Circ. 7647) in Window Timing mode, 55 s after the BAT trigger. Using 2 ks of overlapping XRT and UVOT data, we can improve the UVOT-enhanced XRT position given by Evans in al. (GCN Circ. 7652) to RA, Dec = 165.31104, +51.68558 which is equivalent to: RA (J2000): 11h 01m 14.65s Dec (J2000): +51d 41' 08.1" with an uncertainty of 1.4 arcsec (radius, 90% confidence). The light curve of the first five orbits, from 55 s to 24.7 ks, totalling 10.3 ks of exposure, can be modelled with a double broken power law with the following best-fitting parameters: alpha_1=2.34+/-0.16, t_break1=309 (-33,+58) s, alpha_2=0.38+/-0.06, t_break2=10.3 (-2.2,+3.8) ks, alpha_3=0.65+/-0.17 (chisq/dof=77/81). The WT mode spectrum spanning from 55 to 138 s can be fit by an absorbed power-law model, with a photon index of 2.42 (-0.14, +0.27) and column density of 4.6(-2.6, +3.2)e20 cm^-2, which is in excess of the average Galactic column density in this direction of 9.6e19 cm^-2. The PC mode spectrum of orbits 2 to 5, spanning from 5.6 to 24.7 ks, is fit with a higher column density, (2.0+/-0.4)e21 cm^-2 and a power-law index of 2.3+/-0.2. The corresponding observed (unabsorbed) 0.3-10 keV flux is 5.0e-12 (8.5e-12) erg cm^-2 s^-1. If the burst continues to decay at the same rate, we predict an XRT count rate of 3.8e-2 count/s at T+24 hours, which corresponds to an observed 0.3-10 keV flux of approximately 1.7e-12 erg cm^-2 s^-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7654 SUBJECT: GRB 080430: Hobby-Eberly Telescope Absorption Redshift DATE: 08/05/01 10:47:05 GMT FROM: Antonino Cucchiara at PSU A. Cucchiara and D. B. Fox (Penn State) report: "Starting on 2008 May 1.21 UT we used the Marcario LRS spectrograph on the Hobby-Eberly Telescope (R ~ 230) to obtain a 1200s spectrum of the optical afterglow of GRB 080430 (Guidorzi et al., GCN 7647). The spectrum covers the wavelength range 4100 to 10,500 Angstrom. We clearly observe metal absorption features corresponding to the MgII doublet (2796, 2803 A) and MgI (2852 A) at redshift z = 0.767. The spectrum does not show any other significant features, consistent with Calar Alto telescope observations (de Ugarte Postigo et al., GCN 7650). We thank the HET staff for performing this observation." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7655 SUBJECT: GRB080430: optical observations DATE: 08/05/01 12:01:37 GMT FROM: Alexei Pozanenko at IKI, Moscow M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy), Ju. Babina (CrAO), V. Petkov, A. Kurenya (BNO INR RAS), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the afterglow (Klotz et al. GCN 7646, Guidorzi et al. GCN 7647, Jelinek et al. GCN 7648) of GRB080430 (Guidorzi et al. GCN 7647) with Zeiss-600 of Mt.Terskol observatory on Apr.30. The fading afterglow is clearly detected in combined images. A photometry of the OT against USNO-B1.0 stars is following: UT, Exposure, R_mag (mid time) Apr.30.8906 15 x 60s 19.10 +/- 0.20 Apr.30.9014 15 x 60s 19.40 +/- 0.20 Apr.30.9130 15 x 60s 19.75 +/- 0.25 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7656 SUBJECT: GRB 080430, Swift-BAT refined analysis DATE: 08/05/01 13:19:08 GMT FROM: Scott Barthelmy at NASA/GSFC M. Stamatikos (GSFC/ORAU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), C. Guidorzi (INAF-OAB), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS), J. Tueller (GSFC), T. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 080430 (trigger #310613) (Guidorzi, et al., GCN Circ. 7647). The BAT ground-calculated position is RA, Dec = 165.331, 51.682 deg, which is RA(J2000) = 11h 01m 19.4s Dec(J2000) = +51d 40' 55.5" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single FRED peak starting at ~T-0.7 sec, peaking at ~T+1.5 sec, and ending at ~T+60 sec. T90 (15-350 keV) is 16.2 +- 2.4 sec (estimated error including systematics). The time-averaged spectrum from T-0.3 to T+21.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.73 +- 0.09. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+1.70 sec in the 15-150 keV band is 2.6 +- 0.2 ph/cm2/sec. 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/310613/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7657 SUBJECT: GRB 080430 optical observations DATE: 08/05/01 16:35:47 GMT FROM: AAVSO GRB Network at AAVSO Arto Oksanen (Muurame, Finland) and Veli-Pekka Hentunen (Varkaus, Finland) report to the AAVSO High Energy Network the following optical observations of GRB 080430 (Guidorzi et al., GCN Circular #7647): Arto Oksanen (Hankasalmi Obs., Hankasalmi, Finland) reports the detection of the optical counterpart of GRB 080430. Unfiltered observations were made using a 0.4-meter RC telescope with an SBIG STL-1001E CCD. The initial Swift XRT position was observed unfiltered with an initial set of 10 60-second exposures having a mid-point time of 2008 April 30, 20:08:54 UT; the afterglow was detected with a magnitude of 18.1 +/- 0.05 calibrated relative to GSC 3450-0639. Astrometry of the initial frames yields a position of RA 11:01:14.76 , Dec +51:41:08.9 (USNOA2.0 ref, +/- 0.4 arcseconds), which is within the stated uncertainties of the UVOT position (GCNCirc #7647). Images taken between April 30.839 and April 30.969 UT were reanalyzed and calibrated relative to two USNO-B1.0 stars of magnitude ~16.5. Photometry of combined frames yields a smoothly decaying light curve during the span of observations: obs midpoint CR error 2008 April 30.839 17.798 0.088 2008 April 30.849 18.329 0.120 2008 April 30.860 18.484 0.087 2008 April 30.875 18.751 0.076 2008 April 30.893 18.868 0.055 2008 April 30.911 18.956 0.052 2008 April 30.929 19.044 0.067 2008 April 30.949 19.012 0.064 2008 April 30.969 19.156 0.076 A detailed report of the initial observations is available at the following URL: ftp://ftp.aavso.org/grb/A.Oksanen_GRB080430_2454587.38588_.txt A FITS image of this observation is available at the following URL: ftp://ftp.aavso.org/grb/A.Oksanen_GRB080430_2454587.38588_.fits Markku Nissinen and Veli-Pekka Hentunen (Taurus Hill Observatory, Varkaus, Finland) also report the detection of the optical afterglow of GRB 080430. Observations were made using a Meade LX-200 0.3-meter telescope with an SBIG ST8-XME CCD; observations were made using both clear and R filters. A total of six 600-second exposures were obtained having an average midpoint time of 2008 April 30.943. Photometry of the combined clear and Rc frames yields magnitudes of CR=19.2+/-0.3 and R=19.5+/-0.5 calibrated relative to the GSC2.3 star N7JI005540. The observers noted the sky was not completely dark due to their high latitude and time of year. The AAVSO thanks the Curry Foundation for their continued support of the AAVSO International High Energy Network. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7658 SUBJECT: GRB 080430 - multicolor observations of the afterglow DATE: 08/05/01 21:03:39 GMT FROM: Christina Thoene at Niels Bohr Institute,DARK Cosmo Ctr Christina C. Thoene (DARK), Johan P. U. Fynbo (DARK), Antonio de Ugarte Postigo (ESO), D. Alexander Kann (TLS), Nicolaas E. Groeneboom, Øystein Rudjord, Jostein R. Kristiansen (Univ. Oslo) and Tapio Purismo (NOT) report: We observed the afterglow (GCN 7646, Klotz et al.) of GRB 080430 (GCN 7647, Guidorzi et al.) with MOSCA at the NOT/La Palma on Apr. 30 starting 1.21h after the burst. Observations in UBVRI filters with exposure times of 150s in each filter were acquired. The afterglow is clearly detected in all bands and we derive the following preliminary magnitudes based on the pre-burst SDSS calibrations (GCN 7649, Cool et al.) and standard transformations between SDSS and Bessell filters, times given are the start of the exposures. t-t0(h) band mag 1.92 U 19.9 +- 0.2 1.74 B 19.8 +- 0.1 1.56 V 19.3 +- 0.1 1.21 R 19.0 +- 0.1 1.38 I 18.7 +- 0.1 The blue colors and the detection down to the U band are consistent with the low redshift of that burst, z=0.767 as found by de Ugarte Postigo et al. (GCN 7650) and Cucchiara et al. (GCN 7654). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7659 SUBJECT: VLA radio upper limit on GRB 080430 DATE: 08/05/01 21:31:39 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 080430 (GCN 7647) at a frequency of 8.46 GHz at 2008 May 1.17 UT. We do not detect the GRB afterglow at the UVOT afterglow position (GCN 7647). The flux density at the GRB afterglow position is 68 ± 46 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: 7660 SUBJECT: GRB080430: Swift/UVOT observations DATE: 08/05/01 21:49:40 GMT FROM: Wayne Landsman at GSFC/SSAI W.B. Landsman (NASA/GSFC) and C. Guidorzi (INAF-OAB) report on behalf of the Swift/UVOT team The Swift/UVOT observed the field of GRB 080430 starting at 58s after the BAT trigger (Guidorzi et al., GCN 7647). We detect the afterglow in all seven UVOT filters at the position RA(J2000.0) = 11:01:14.66 DEC(J2000.0) = +51:41:08.4 with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence). This position is consistent with the enhanced XRT position (Guidorzi et al. GCN 7653) and the position reported from BOOTES obervations by Jelinek et al. (GCN 7648). The detection in the UVW2 (1950 A) filter is consistent with the redshift of ~0.76 determined from spectroscopic observations by Deugarte Postigo et al. (GCN 7650) and Cucchiara & Fox (GCN 7654). The temporal slope in the white filter out to 30400 seconds is approximately alpha = 0.23. UVOT photometry from early individual images is reported below. Filter Tmid(s) Expo(s) Magnitude ----------------------------------------------------- White 108 98 17.08 ± 0.03 White 928 98 18.23 ± 0.05 v 364 393 17.64 ± 0.06 v 1184 393 18.50 ± 0.09 b 5989 197 20.05 ± 0.21 u 5784 197 18.92 ± 0.12 w1 7014 197 18.89 ± 0.16 m2 6809 197 18.88 ± 0.22 w2 5684 197 19.24 ± 0.20 ----------------------------------------------------- These magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E{B-V} = 0.012 mag (Schlegel et al. 1998). The photometry is on the UVOT flight system described in Poole et al. (2008,MNRAS,383,627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7661 SUBJECT: GRB080430: RTT150 Optical Observations DATE: 08/05/02 00:18:18 GMT FROM: Irek Khamitov at TUG I. Khamitov (TUG), I. Bikmaev, R. Gumerov, A. Nemtinov, N. Sakhibullin (KSU/AST), R. Burenin, M. Pavlinsky, R. Sunyaev (IKI), Z. Eker (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.) report: The optical counterpart (GCN7646) of GRB 080430 (GCN 7647) was observed with Russian-Turkish 1.5-m telescope (RTT150, Bakirlitepe, TUBITAK National Observatory, Turkey), starting at May 01, 21:58 UT, i.e. ~26.08 hours after the burst, using Andor CCD. A series of frames 3*300s in R and 3*600s in B bands were made. The afterglow is clearly detected in all images. Using USNO-B1 star (416-022819, RA=11:01:16.86, DEC=+51:40:38.5, B2MAG=17.79, R2MAG=16.61) we estimated the following magnitudes for the OT on combined images: t-t0 (h) band mag err 26.25 R 21.3 0.1 27.98 B 22.3 0.1 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7662 SUBJECT: GRB 080430: Shallow decay DATE: 08/05/02 02:51:50 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo (ESO), C.C. Thöne (Dark), F. Aceituno (IAA-CSIC), Nicolaas E. Groeneboom, Øystein Rudjord, Jostein R. Kristiansen (Univ. Oslo) and Tapio Purismo (NOT) on behalf of a larger collaboration report: We are continuing with the monitoring of the afterglow (Klotz et al. GCN 7646) of GRB 080430 (Guidorzi et al., GCN 7647) with the 1.5m OSN telescope (Sierra Nevada Observatory) and the 2.5m NOT+MOSCA (Roque de los Muchachos Observatory) in I band. During the first day of observations we observe a steady decay with a shallow slope of alpha ~ 0.6 (f ~ t^-alpha), being at a magnitude of I ~ 20.5 one day after the burst. Further observations are encouraged. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7663 SUBJECT: GRB 080430: Optical observations DATE: 08/05/02 08:33:59 GMT FROM: Shashi Bhushan Pandey at ARIES, INDIA S. B. Pandey, Rupak Roy and Brijesh Kumar (ARIES, NainiTal, India, on behal= f of larger Indian GRB collaboration) We observed Swift GRB 080430 with 1.04m telescope NainiTal starting ~20.0 h= ours after the burst (Guidorzi et al. GCN 7647). Observations were performe= d in R_c and I_c filters. Photometry of one of the R_c frame (exposure time 1800s) shows theafterglow= around ~ 20.5 mag as reported in GCN 7646 and GCN 7648. The reported magni= tude is determined in comparison to nearby USNO stars. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7670 SUBJECT: GRB 080430 DATE: 08/05/03 17:54:03 GMT FROM: Francois Kugel at Obs.Chante-Perdix,04 Banon,Fr C.Rinner ; F.Kugel report: We imaged the field of GRB 080430 detected by SWIFT with the TEL 0.5-m f/3 reflector located at Observatoire Chante-Perdix - 04 Banon, France (A77 mpc station) The observations started at 21:33:18 (UT). 24 exposures of 120s were carried out and weather conditions were good. We observe a new source in the error box given by SWIFT at the following position: RA(J2000.0) = 11h 01m 14.76s DEC(J2000.0) +51d 41' 08.3" +/-0.3" magnitude = 18.6 +/-0.3 Astrometry and magnitudes were measured with the USNO-SA2.0 catalogue. No change magnitude was observed during the one hour observation. More information and pictures here : http://pagesperso-orange.fr/fkometes/pages/GRB080430.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7671 SUBJECT: GRB 080430 DATE: 08/05/03 18:03:09 GMT FROM: Francois Kugel at Obs.Chante-Perdix,04 Banon,Fr C.Rinner ; F.Kugel report: We are continuing with the monitoring of the afterglow (Klotz et al. GCN 7646) with the TEL 0.5-m f/3 reflector located at Observatoire Chante-Perdix - 04 Banon, France (A77 mpc station, N43.9997 E5.6475) The observations started at 20:39:12 (UT). 9 unfiltered exposures of 120s were carried out and weather conditions were good. We observe a weak reduction in magnitude RA(J2000.0) = 11h 01m 14.76s DEC(J2000.0) +51d 41' 08.3" ±0.3" magnitude = 19.6 ±0.3 one day after the burst. Astrometry and magnitudes were measured with the USNO-SA2.0 catalogue. More information and picture here : http://pagesperso-orange.fr/fkometes/pages/GRB080430.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7672 SUBJECT: GRB 080430 DATE: 08/05/03 18:14:17 GMT FROM: Francois Kugel at Obs.Chante-Perdix,04 Banon,Fr C.Rinner ; F.Kugel report: May 02 We are continuing with the monitoring of the afterglow (Klotz et al. GCN 7646) with the TEL 0.5-m f/3 reflector located at Observatoire Chante-Perdix - 04 Banon, France (A77 mpc station, N43.9997 E5.6475) The observations started at 20:21:42 (UT).36 unfiltered exposures of 120s were carried out; although weak the source is still visible (SNR = 4.4) on an addition of 28 exposuress (cloudy passages on the other images). Measured magnitude = 20.6 two day after the burst. Astrometry and magnitudes were measured with the USNO-SA2.0 catalogue. More information and picture here : http://pagesperso-orange.fr/fkometes/pages/GRB080430.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7681 SUBJECT: GRB 080430: TLS imaging one day after the GRB DATE: 08/05/05 20:00:39 GMT FROM: Alexander Kann at TLS Tautenburg D. A. Kann, F. Ludwig, R. Filgas and S. Klose (TLS tautenburg) report: We imaged the afterglow (Klotz et al., GCN 7646) of GRB 080430 (Guidorzi et al., GCN 7647) with the TLS Schmidt telescope one day after the GRB. Direct RRM observations a day earlier were unobtainable due to persistent bad weather. We obtained 22 180 second images starting with twilight under good conditions and at airmass 1. The afterglow is visible on all single images. From the SDSS photometry of the field (Cool et al., GCN 7649), we find that the bright star southeast of the afterglow, at R.A. = 11:01:16.88, Dec. = +51:40:38.6 has g = 17.111, r = 16.539 and i = 16.377. Using the transformations of Jester et al. 2005, we find Rc = 16.458 for this star. Using it as a comparison star, we derive for the afterglow from a stack of all images: time after burst Rc dRc 1.020536 days 21.20 0.06 This is in good agreement with the slightly later measurement of Khamitov et al. (GCN 7661) but significantly fainter than the magnitude reported by Pandey et al. (GCN 7663) for an observation a few hours earlier. Data analysis was delayed by access problems. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7717 SUBJECT: GRB 080430 DATE: 08/05/14 21:48:32 GMT FROM: Joel Nicolas at none J.Nicolas reports: Visible Obervation afterglow radiation of the start gamma GRB080430 TEL 0.28-m F/6.5 reflector Observatory:Vallauris 07:30:49 E 43:34:40 N B51 Composite of 26 images of 90s without filter Photometry at magnitude 19 Date 08/04/30 22h15 UT Using the USNO-A2 catalog, the source is located at: RA (J200O) = 11h 01m 14.76s DEC (J2000) = +51d 41' 08.46" The Image can be found at http://astrosurf.com/jnicolas/sursaut_gamma.htm //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7739 SUBJECT: GRB080430: optical observations DATE: 08/05/16 20:15:26 GMT FROM: Alexei Pozanenko at IKI, Moscow M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy), Ju. Babina (CrAO), V. Petkov, A. Kurenya (BNO INR RAS), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the afterglow (Klotz et al. GCN 7646, Guidorzi et al. GCN 7647, Jelinek et al. GCN 7648) of GRB080430 (Guidorzi et al. GCN 7647) with Zeiss-600 of Mt.Terskol observatory on May. 01. The afterglow is detected in a combined image. A photometry of the OT against USNO-B1.0 stars is following: UT, Exposure, R_mag (mid time) May.01.8795 15x90s 20.9 +/-0.3 The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7809 SUBJECT: GRB 080430: optical observations DATE: 08/06/04 15:58:14 GMT FROM: Graziella Pizzichini at IASF/CNR,Bologna F. Terra (Second University of Roma "Tor Vergata"), F. Munz (INAF/IASF Bologna) G. Greco, C. Bartolini, A. Guarnieri,A. Piccioni (Bologna University), D. Nanni (INAF/OAR and Second University of Rome "Tor Vergata"), G. Pizzichini(INAF/IASF Bologna), S. Galleti and S. Bernabei (Bologna Observatory) report: During the night between 08/04/30 and 08/05/01 we observed the OT of GRB080430 (Guidorzi et al., GCN 7647, Klotz, Boer & Atteia, GCN 7646) with the 1.52 cm telescope of the Bologna Observatory in Loiano in good weather conditons, airmass between 1 and 1.6, seeing less than 4". We obtained a total of 14 frames in Rc, V, B and I. Rc magnitudes went from 19.47 +- 0.11 at 2454587.40325 UT to 20.53 +- 0.10 at 2454587.54819 UT. Rc calibration was obtained from the NOMAD catalog. Our images 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 directory: /home/publicGRB/GRB080430/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8368 SUBJECT: GRB 080430: optical observations DATE: 08/10/13 15:39:36 GMT FROM: Graziella Pizzichini at IASF/CNR,Bologna F. Terra (Second University of Roma "Tor Vergata"), F. Munz (INAF/IASF Bologna) G. Greco, C. Bartolini, A. Guarnieri,A. Piccioni (Bologna University), D. Nanni (INAF/OAR and Second University of Rome "Tor Vergata"), G. Pizzichini(INAF/IASF Bologna), S. Galetti and S. Bernabei (Bologna Observatory) report: During the night between 08/04/30 and 080501 we observed the OT of GRB080430 (Guidorzi et al., GCN 7647, Klotz, Boer & Atteia, GCN 7646) in Rc, V, B AND I with the 1.52 cm telescope of the Bologna Observatory in Loiano in good weather conditons, airmass between 1 and 1.6, seeing less than 4". Calibration was obtained from the NOMAD catalog in the Rc filter and from the SDSS observations by Cool et al. in GCN 7649 for the other filters. We obtain the following magnitudes obs midpoint duration filter mag error seconds 2454587.40325 600 Rc 19,47 0,11 2454587.41120 600 V 19,20 0.12 2454587.42067 600 Rc 19,75 0,11 2454587.43274 1200 B 19,54 0,12 2454587.44788 600 Rc 19,60 0,15 2454587.45720 600 I 19,03 0,05 2454587.46673 600 Rc 19,75 0,11 2454587.47927 600 V 19,44 0,12 2454587.48806 600 Rc 19,96 0,10 2454587.51098 600 Rc 20,28 0,09 2454587.52303 600 Rc 20,01 0,09 2454587.53175 600 Rc 20,27 0,15 2454587.53946 600 I 19,14 0,06 2454587.54819 600 Rc 20,53 0,10 Our images 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 directory: /home/publicGRB/GRB080430/