//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8151 SUBJECT: GRB 080828: SuperAGILE GRB Localization DATE: 08/08/28 07:10:09 GMT FROM: Marco Feroci at IASF/INAF E. Del Monte, P. Soffitta, I. Donnarumma, Y. Evangelista, M. Feroci, F. Lazzarotto, L. Pacciani, E. Costa, I. Lapshov, M. Rapisarda (INAF/IASF Rome), A. Giuliani, S. Vercellone, A. Chen, S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, P. Caraveo (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, B. Preger, P. Santolamazza, F. Verrecchia (ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report: "SuperAGILE detected a gamma ray burst on 28 August 2008, at 03:14:45 UT. The event had a duration of about 25 s in the 20-60 keV energy range, with a single-peak structure. The burst position was reconstructed as (RA, Dec) (199.626 deg, -65.930 deg), which is: RA(J2000) = 13h 18m 30.32s Dec(J2000) = -65d 55' 48.2" 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: 8157 SUBJECT: GRB 080828: Swift-XRT detection of a possible X-ray afterglow DATE: 08/08/28 21:53:32 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore and R.L.C. Starling (U. Leicester) report on behalf of the Swift-XRT team: The Swift-XRT began observations of the field of the SuperAGILE detected GRB 080828 (Del Monte et al., GCN Circ 8151) at 2008-08-28 14:07:17UT, 39.15 ks after the burst. In 4.96 ks of photon counting mode data we detect a faint, uncatalogued X-ray source at RA, Dec 199.5871, -65.9405 which is RA (J2000) = 13:18:20.91 Dec (J2000) = -65:56:25.8 with an uncertainty of 4.2 arcsec (radius, 90% containment). This source is 1.1 arcmin away from the AGILE position and within its error circle. The measured XRT count rate is 0.008 +/- 0.001 count/s. At this stage we cannot tell whether the source is fading. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8161 SUBJECT: GRB080828: Swift/UVOT Upper Limits DATE: 08/08/29 17:08:41 GMT FROM: Paul Ward at MSSL P. Ward (MSSL-UCL) and W. Baumgartner (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT observed the field of GRB 080828 starting 39.15ks after the SuperAGILE detection (Del Monte et al., GCN Circ. 8151). We do not detect any afterglow at the Swift XRT position reported by Beardmore et al. (GCN Circ. 8157) in any of the following UVOT filters down to the given 3 sigma upper limits. Filter T_start(s) T_stop Exp(s) MagLimit White 46201 46561 355.8 > 21.40 u 44376 51948 1798.8 > 20.65 b 45289 52309 1250.3 > 21.33 w1 40064 51035 1615.6 > 21.05 m2 39156 40055 899.8 > 20.50 The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383,627). The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E(B-V) ~ 0.81 mag (Schlegel et al., 1998).