//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7903 SUBJECT: GRB 080625: Gamma Ray Burst Localization by SuperAGILE DATE: 08/06/25 15:34:22 GMT FROM: Marco Feroci at IASF/INAF L. Pacciani, I. Donnarumma, E. Del Monte, M. Feroci, Y. Evangelista, E. Costa, I. Lapshov, F. Lazzarotto, L. Pacciani, M. Rapisarda, P. Soffitta, (INAF/IASF Rome), A. Giuliani, S. Vercellone, A. Chen, S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, M. Fiorini, P. Caraveo, A. Zambra (INAF/IASF Milan), A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi, M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V. Vittorini, A. Argan, A. Trois (INAF/IASF Rome), G. Barbiellini, F. Longo (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2), M. Prest, E. Vallazza (Universita` dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), and P. Giommi, C. Pittori, (ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report: "SuperAGILE detected and localized a gamma ray burst on June 25th 2008, at 12:28:31 UT. The event was approximately 22 degrees off-axis. The observed duration in the 20-60 keV energy range is about 80 seconds, with a single peak structure. The burst was triggered and localized on ground. The burst position was reconstructed as (RA, Dec) (298.4423 deg, 56.2653 deg), which is: RA(J2000) = 19h 53m 46.14s Dec(J2000) = 56d 15' 55.1" with an uncertainty of 3' radius. The given uncertainty accounts for both the statistical and systematic errors. An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7904 SUBJECT: GRB 080625: Observations at OSN DATE: 08/06/25 22:27:30 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo (ESO), F. Aceituno, A.J. Castro-Tirado, J. Gorosabel (IAA-CSIC) report on behalf of a larger collaboration: We have observed the field of GRB080625, detected by SuperAGILE (Pacciani et al. GCN 7903), from the 1.5m OSN telescope starting at June 25.8591 (8.14 hours after the burst). Preliminary analysis does not show any evident new source within the 3' error box as compared with the DSS2 IR frame. We note, however, that our combined 4x300s I-band frame yields a limit of I < 21.5, significantly deeper than the catalogue. Further imaging is scheduled in order to determine if any of the objects that we detect at or beyond the limit of the catalogue is the afterglow of GRB 080625. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7905 SUBJECT: GRB 080625: Swift/UVOT Detection of an Optical Afterglow DATE: 08/06/26 02:09:08 GMT FROM: Stefan Immler at NASA/GSFC S. Immler (NASA/CRESST/GSFC) reports on behalf of the Swift/UVOT team: The Swift Ultra-Violet/Optical Telescope (UVOT) started observing GRB 080625 (Pacciani et al., GCN Circ. 7903) ~5.0 hours after the AGILE trigger. A candidate afterglow is found in UVOT White, v, and b filter images which cover the entire AGILE error circle. The preliminary Swift/UVOT position of the optical afterglow candidate is: RA(J2000) = 19:53:37.06 = 298.4044 DEC(J2000) = +56:16:40.5 = 56.2779 with a 1-sigma error radius of about 0.5 arcsec. The following table gives the measured magnitudes: Filter T_start [s] T_stop [s] Exp [s] Magnitude White 18769 19567 799 20.3 +/- 0.1 White 24551 25179 1427 20.6 +/- 0.1 V 19575 20350 776 19.6 +/- 0.1 B 17964 18762 799 20.1 +/- 0.1 B 23746 24544 799 20.7 +/- 0.2 U 17880 23741 240 >20.4 (3-sigma UL) The values quoted above are in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627). No correction has been made for the expected extinction corresponding to E(B-V) of 0.44 mag in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7906 SUBJECT: GRB 080625:Swift-XRT detection of the afterglow DATE: 08/06/26 02:25:11 GMT FROM: Michael Stroh at PSU/Swift M.C. Stroh, C. Pagani and L. Vetere (PSU) report on behalf of the Swift-XRT team The Swift-XRT began observations of the SuperAGILE burst GRB 080625 (Pacciani et al., GCN Circ 7903) ~5 hours after the trigger. The data consist of 3.9 ks observed in Photon Counting mode. We detect an X-ray counterpart at position: RA, Dec = 298.40420, 56.27747 which is equivalent to: RA (J2000): 19 53 37.0 Dec (J2000): +56 16 38.9 with an uncertainty of 4 arcsec (radius, 90% confidence). This is consistent with the UVOT position (Immler, GCN 7905). We are unable to determine whether the source is decaying at this time. Observations are continuing and further analysis regarding the fading nature of this source will be issued as the data become available. The spectrum can be fitted with a powerlaw with an intrinsic absorbing column of (2.5+/-0.9) e21 cm-2 and photon index 2.31+/- 0.17. The observed (unabsorbed) 0.3-10 keV flux is 2.91 (3.00) e-12 erg cm-2 s-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7907 SUBJECT: GRB 080625: Further observations from OSN DATE: 08/06/26 07:25:24 GMT FROM: Antonio Deugarte at IAA-CSIC A. de Ugarte Postigo (ESO), F. Aceituno, A.J. Castro-Tirado, J. Gorosabel (IAA-CSIC) report on behalf of a larger collaboration: We have observed again the field of GRB 080625 (Pacciani et al. GCN 7903) using the 1.5m OSN telescope at Sierra Nevada Observatory (Granada, Spain) at a mean epoch of 14.76h after the burst. The object identified by Immler et al. (GCN 7905) is well detected in this and in our previous epoch (GCN 7904). A preliminary photometry against USNO-B1.0 stars shows the object decaying, as seen in the following table: t-t0 (hours) Exp (s) I mag 8.325 4x300 19.3+/-0.2 14.769 3x300 20.0+/-0.2 //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7908 SUBJECT: GRB 080625: Swift/UVOT Follow-Up Observations DATE: 08/06/27 19:17:20 GMT FROM: Stefan Immler at NASA/GSFC S. Immler (NASA/CRESST/GSFC) reports on behalf of the Swift/UVOT team: Swift Ultra-Violet/Optical Telescope (UVOT) follow-up observations of GRB 080625 (Pacciani et al., GCN Circ. 7903), starting ~25.9 hrs after the AGILE trigger, confirm the fading of the optical afterglow (Immler et al., GCN Circ. 7905; de Ugarte Postigo et al., GCN Circ. 7907). The following magnitude is measured in the co-added image obtained in the White filter: Filter T_start [s] T_stop [s] Exp [s] Magnitude White 93,092 162,754 5,776 21.3 +/- 0.1 The magnitude quoted above is in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627). No correction has been made for the expected extinction corresponding to E(B-V) of 0.14 mag in the direction of the burst (Schlegel et al. 1998). Note the corrected value for the extinction compared to Immler 2008 (GCN Circ. 7905). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 7930 SUBJECT: GRB 080625: Suzaku WAM observation of the prompt emission DATE: 08/07/03 03:43:57 GMT FROM: Takeshi Uehara at Hiroshima U T. Uehara, Y. Hanabata, Y. Fukazawa, T. Takahashi, C. Kira (Hiroshima U.), M. Ohno, M. Kokubun, M. Suzuki, T. Takahashi (ISAS/JAXA), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), K. Onda, M. Tashiro, Y. Terada, Y. Urata, A. Endo, N. Kodaka, K. Morigami, T. Sugasahara, W. Iwakiri (Saitama U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), T. Enoto, K. Nakazawa, K. Makishima (Univ. of Tokyo), E. Sonoda, M. Yamauchi, H. Tanaka, R. Hara (Univ. of Miyazaki), S. Hong (Nihon U.), on behalf of the Suzaku WAM team, report: The long GRB 080625 (SuperAGILE ; Marco et al., GCN 7903) was detected by the the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 12:28:41 UT on 25 July 2008 (=T0). The observed light curve shows a single peak, starting at T0s, ending at T0+62s with a duration (T90) of about 62 seconds. The fluence in 100 - 1000 keV was 2.3(+1.3/-0.7) E-6 erg/cm^2. The 1-s peak flux measured from T0+33s was 0.4(+0.2/-0.3) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-15s to T0+50s is well fitted by a single power-law with a photon index of 1.7 (+1.2/-0.8) (chi^2/d.o.f = 9.6/8) at the 120 - 500 keV bandpass. All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves with 1-sec time resolution for this burst will be appeared at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/untrig/grb_table.html