//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6393 SUBJECT: GRB 070509: ROTSE-III Optical Limits DATE: 07/05/09 03:14:54 GMT FROM: Eli Rykoff at U of Michigan/ROTSE E.S. Rykoff (U Mich), W. Rujopakarn (Steward), B. E. Schaefer (Louisiana State), report on behalf of the ROTSE collaboration: ROTSE-IIIc, located at the H.E.S.S. site at Mt. Gamsberg, Namibia, responded to GRB 070509 (Swift trigger 278903), producing images beginning 7.4 s after the GCN notice time. An automated response took the first image at 02:56:22.4 UT, 475.1 s after the burst, under fair conditions. We took 10 5-sec, 10 20-sec and continuing 60-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma BAT error circle or the XRT error circle, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 15.2-16.2; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 02:56:22.4 02:56:27.4 5 15.3 475.1 N 02:56:22.4 02:57:39.6 77 16.6 475.1 Y 02:57:53.8 03:02:39.5 285 17.2 566.5 Y //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6394 SUBJECT: GRB 070509: Swift detection of a burst DATE: 07/05/09 03:17:03 GMT FROM: David Palmer at LANL L. Vetere (PSU), S. D. Barthelmy (GSFC), M. M. Chester (PSU), D. Grupe (PSU), S. T. Holland (CRESST/GSFC/USRA), J. A. Kennea (PSU), C. B. Markwardt (GSFC/UMD), F. E. Marshall (NASA/GSFC), C. Pagani (PSU), D. M. Palmer (LANL), J. L. Racusin (PSU), M. Stamatikos (NASA/ORAU) and D. E. Vanden Berk (PSU) report on behalf of the Swift Team: At 02:48:27 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 070509 (trigger=278903). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 237.927, -78.681 which is RA(J2000) = 15h 51m 42s Dec(J2000) = -78d 40' 49" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single FRED-like peak with a duration of about 10 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began taking data at 02:49:35 UT, 68 seconds after the BAT trigger. XRT found a faint, uncatalogued X-ray source. The ground calculated location is RA, Dec 237.9592, -78.6511 which is RA(J2000) = 15h 51m 50.2s Dec(J2000) = -78d 39'04.0" with an uncertainty of 4.6 arcsec (radius, 90% containment, including systematic uncertainty). This location is 1.8 arcmin from the BAT on-board position, within the BAT error circle. UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 72 seconds after the BAT trigger, and a finding chart exposure of 400 seconds in V starting 177 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle; the 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.14. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6395 SUBJECT: GRB 070509: REM observations DATE: 07/05/09 04:02:46 GMT FROM: Stefano Covino at Brera Astronomical Observatory S. Piranomonte, S. Covino, L.A. Antonelli, A. Burzi, L. Calzoletti, S. Campana, G. Chincarini, M.L. Conciatore, S. Cutini, P. D'Avanzo, V. D'Elia, F. Dalessio, F. Fiore, D. Fugazza, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, D. Malesani, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, E. Pian, D. Rizzuto, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V. Testa, S.D. Vergani, F. Vitali report on behalf of the REM team: We observed the field of the GRB 070509 (Vetere et al., GCN 6394) with the robotic 60-cm REM telescope located at La Silla (Chile). A set of observations was performed automatically in the optical and near infrared filters (V, R, I and J, H, K, z) starting at 02:56:52 UT (33 sec after the Swift alert; more than 8 minutes after the burst). Preliminary analysis does not show any source down to the 2MASS limit in the XRT error circle (Vetere et al., GCN 6394). Further analyses are in progress. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6397 SUBJECT: GRB 070509, Swift-BAT refined analysis DATE: 07/05/09 13:32:02 GMT FROM: Scott Barthelmy at NASA/GSFC J. Cummings (GSFC/UMBC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), L. Vetere (PSU) on behalf of the Swift-BAT team: Using the data set from T-239 to T+963 sec from recent telemetry downlinks, we report further analysis of BAT GRB 070509 (trigger #278903) (Vetere, et al., GCN Circ. PSU). The BAT ground-calculated position is RA, Dec = 237.874, -78.657 deg, which is RA(J2000) = 15h 51m 29.8s Dec(J2000) = -78d 39' 24.0" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 92%. The mask-weighted lightcurve shows a single FRED-like pulse starting at T-2 sec, peaking at T_0, and ending at ~T+10 sec. T90 (15-350 keV) is 7.7 +- 0.3 sec (estimated error including systematics). The time-averaged spectrum from T-1.1 to T+7.9 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.33 +- 0.25. The fluence in the 15-150 keV band is 1.7 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.31 sec in the 15-150 keV band is 0.7 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. We note that the initial TDRSS messages for this burst were delayed ~6 min in transmission to the ground because the burst occurred during a Malindi downlink session. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6400 SUBJECT: GRB070509: Swift-XRT Refined Analysis DATE: 07/05/09 22:09:02 GMT FROM: Loredana Vetere at PSU L. Vetere, J. L. Racusin, D. Grupe, C. Pagani (PSU) and M. Perri (ASDC) report on behalf of the Swift Team: We have analysed the first 6.2ks of Swift XRT data from GRB 070509 (trigger number 278903, GCN 6394). The first orbit Photon Counting mode image (1.5ks) provides a refined XRT position at RA,DEC(J200) = 237.9588, -78.6508 which is RA(J2000) = 15h 51m 50.1s Dec(J2000) = -78d 39' 03.1" with an uncertainty of 4.1 arcsec (radius, 90% containment). This is 0.9 arcsec from the initial X-ray position (GCN 6394) and 1.0 arcmin from BAT refined position (Cummings et al. GCN 6397). The XRT light curve can be modeled with a broken power law with the following parameters: alpha1= -0.3 +/- 0.2 tbreak= 341 +/- 120 alpha2= -1.1 +/- 0.2 The X-ray spectrum of the first orbit PC data can be fitted with an absorbed power law (photon index = 0.8+/-0.2) with an absorbed column density fixed to the Galactic value (0.91e21 cm^-2; Dickey & Lockman, 1990). The absorbed (unabsorbed) 0.3-10.0keV flux for this spectrum was 8.8E-12 (9.1E-12) ergs cm^-2 s^-1. Assuming the source continues to decay at the same rate, we predict an XRT count rate of 3.5E-4 counts/s at T+24 hours, which corresponds to an observed (unabsorbed) flux of 5.1E-14 (5.3E-14) ergs cm^-2 s^-1. This circular is an official product of the Swift XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6404 SUBJECT: GRB 070509: Swift/UVOT Upper Limits DATE: 07/05/10 16:00:38 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC S. T. Holland (CRESST/GSFC/USRA) and L. Vetere (PSU) report on the behalf of the Swift UVOT team: The Swift/UVOT observed the field of GRB 070509 starting 73 s after the BAT trigger (Vetere et al. 2007, GCN Circ. 6394). We do not find any source, in any of the UVOT observations, inside the refined XRT error circle (Vetere et al., 2007 GCN Circ. 6400). The 3-sigma upper limits for detecting a source anywhere inside the refined XRT error circle in the co-added frames are: Filter T_start T_stop Exp(s) Mag (3-sigma upper limit) ----------------------------------------------------------------- V 179 6074 1003 20.6 B 657 1468 39 18.6 U 633 1443 58 18.4 UVW1 609 1419 58 18.0 UVM2 584 6085 65 17.5 UVW2 686 5869 236 19.3 White 73 1482 225 21.1 ----------------------------------------------------------------- The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.14 mag towards the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 6410 SUBJECT: GRB 070509: objects inside XRT error circle DATE: 07/05/16 22:08:24 GMT FROM: Daniele Malesani at Niels Bohr Inst,Dark Cosmology Center D. Malesani, C.C. Thoene (DARK), A. Williams (Perth Obs.), J.P.U. Fynbo (DARK), A.O. Jaunsen (Univ. Oslo) and P.M. Vreeswijk (ESO) report on behalf of a larger collaboration: We observed the field of GRB 070509 (Vetere et al., GCN 6394) with the ESO VLT UT2 equipped with the FORS1 instrument. Short BVRI observations were carried out between 2007 May 9.144 and 9.155 UT (starting 0.65 hr after the GRB). We detect three objects close to the XRT position, at the following coordinates (J2000, 0.5" error): A: RA = 15:51:49.29 Dec = -78:39:01.7 R = 23.48 +- 0.24 B: RA = 15:51:50.37 Dec = -78:39:06.4 R = 23.52 +- 0.25 C: RA = 15:51:50.91 Dec = -78:39:10.2 R = 22.71 +- 0.16 Objects A and B are inside the XRT error circle as reported by Vetere et al. (GCN 6400), while objects B and C are inside the XRT error circle as provided in Nat Butler's web page (revision 1.2, http://astro.berkeley.edu/~nat/swift/xrt_pos.html). Objects A and C are extended. Magnitudes are computed at the mean time 9.149 UT (0.78 hr after the GRB) and are calibrated against the USNO-B1 catalog. The 3-sigma limit is R = 23.8. A finding chart of the field can be seen here: http://www.astro.ku.dk/~malesani/GRB/070509/finder_VLT.jpg Further R-band observations were carried out with the 1.54m Danish telescope located in La Silla (Chile) and equipped with DFOSC on 2007 May 9.141 (4500 s) and May 13.134 UT (3000 s). Object C is marginally detected in both images, while objects A and B are below the detection limit. At this stage, we cannot claim association between the GRB and any of the above mentioned objects. We acknowledge excellent support from the observing staff in Paranal, in particular Alain Smette and Gael James. CT acknowledges Pisco and Bacardi support from the GROND staff at La Silla.