//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 430 SUBJECT: GRB ALERT: GRB991105 DATE: 99/11/05 19:56:27 GMT FROM: Luigi Piro at IAS/CNR Frascati Luigi Piro, BeppoSAX Mission Scientist, on behalf of the SAX team reports: On Nov.5, 16:40:44 UT a GRB (GRB991105) was detected simultaneously by the GRBM and WFC of BeppoSAX (also BATSE trigger #7841). Preliminary coordinates from WFC are: R.A.(2000)= 180.80 DEC(2000)= -66.76 with an error radius of about 5'. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 431 SUBJECT: BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd) DATE: 99/11/05 20:25:30 GMT FROM: Luigi Piro at IAS/CNR Frascati Luigi Piro, BeppoSAX Mission Scientist, on behalf of the SAX team reports refined position for GRB991105: Refined coordinates from WFC are: R.A.(2000)= 180.753 DEC(2000)= -66.814 with an error radius of about 3.6' On Nov.5, 16:40:44 UT a GRB (GRB991105) was detected simultaneously by the GRBM and WFC of BeppoSAX (also BATSE trigger #7841). //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 432 SUBJECT: GRB991105: SAX-GRBM/-WFC detection DATE: 99/11/05 21:55:09 GMT FROM: M.Smith. at SRON M.J.S. Smith, J.in't Zand, Space Research Organization of the Netherlands (SRON), Utrecht, G. Tarei, M. Dadina, BeppoSAX Scientific Operation Center (SOC), Rome, and L. Piro, Istituto di Astrofisica Spaziale/CNR, Rome report: "The BeppoSAX Gamma Ray Burst Monitor (GRBM) and Wide Field Camera (WFC unit 2) observed a gamma-ray burst triggered on November 5.6950 UT (BATSE trigger 7701). A preliminary analysis reveals a duration of 13 s in the GRBM, with a peak intensity of 970 cts/s in the 40-700 keV energy band. In the WFC, the duration is 40 s and the peak flux is 1.1 Crab (2-28 keV). The position of the X-ray counterpart is R.A. = 12h 03m 01s, Decl. = -66d 48' 49" (equinox 2000.0) with an 99% error radius of 3.6'. A BeppoSAX NFI follow-up observation will not be performed due to sun-angle constraints." //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 433 SUBJECT: Revised BeppoSAX WFC position of GRB991105 DATE: 99/11/06 15:49:47 GMT FROM: Luigi Piro at IAS/CNR Frascati Revised BeppoSAX WFC position of GRB991105 The refined position of GB991105 distributed in the BeppoSAX Mail n. 99/30 and GCN Circular 432 has been revised to: R.A. (2000) = 180.871 DEC. (2000) = -66.757 with the same error radius of 3.6' Luigi Piro BeppoSAX Mission Scientist //////////////////////////////////////////////////////////////////////// Circular No. 7303 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions) BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science) URL http://cfa-www.harvard.edu/iau/cbat.html ISSN 0081-0304 Phone 617-495-7244/7440/7444 (for emergency use only) GRB 991105 M. J. S. Smith et al. inform us that the position on IAUC 7301 requires correction by 4'.4 to R.A. = 12h03m29s, Decl. = -66o45'24" (equinox 2000.0). (C) Copyright 1999 CBAT 1999 November 6 (7303) Daniel W. E. Green //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 439 SUBJECT: GRB 991105, optical observations DATE: 99/11/08 18:34:21 GMT FROM: Alberto Castro-Tirado at Inst.de Astrofisica de Andaluciaajct@iaa.es GRB 991105, optical observations Alberto Castro-Tirado, LAEFF-INTA (Madrid) and IAA-CSIC (Granada) Javier Gorosabel and Celia Sanchez-Fernandez, LAEFF-INTA (Madrid) Pam Kilmartin and John Hearnshaw, University of Canterbury Ian Bond, Nick Rattembury and Phil Yock, University of Auckland K. Ohnishi, Nagano National College of Technology and Marco Feroci, IAS (Frascati), on behalf of the BSAX team report: "We have obtained six 10-minute exposures at the revised BeppoSAX WFC position for GRB 991105 (Piro et al. GCN 433) with the 0.61-m Mount John University Observatory (MJUO) telescope. The first set of images were taken on Nov 6.41 UT (17.1 hr after the GRB) through a broad band filter (R + I bandpass). The second one was obtained on Nov 7.37 UT with identical setup. After a visual comparison with the Digital Sky Survey and among the two co-added images, no sources varying by more than 0.3 mag were seen to the DSS limit (R about 21) within the BeppoSAX error box." This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 441 SUBJECT: IPN localization of GRB991105 DATE: 99/11/08 22:27:28 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and T. Cline, on behalf of the NEAR GRB team, and M. Feroci, on behalf of the BeppoSAX GRB team, report: Although GRB991105 (GCN 433) was too weak to be observed by Ulysses, it was observed by NEAR. The preliminary IPN annulus for it is centered at RA=187.6492 deg., Decl.=-7.9319 deg. (J2000), and has a radius of 58.9882 +/- 0.0607 deg. (3 sigma). The annulus width is therefore about equal to the WFC error circle diameter, but it intersects it at: RA(2000) Decl.(2000) 12 h 03 m 52 s -66 o 48' 13" 12 h 02 m 59 s -66 o 47' 30" and therefore reduces the WFC area slightly. A map may be found at ssl.berkeley.edu/ipn3/991105/. Some refinements to this annulus are expected which should further reduce the WFC error circle area. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 442 SUBJECT: GRB 991105: BATSE Observations DATE: 99/11/08 23:18:20 GMT FROM: R. Marc Kippen at BATSE/UAH/MSFC R. M. Kippen, S. Phengshamnan & T. Giblin (University of Alabama in Huntsville) report on behalf of the BATSE GRB team: GRB 991105 was detected by BATSE on 1999 November 5.694963 UT as trigger number 7841. The event consisted of a complex series of pulses with two major episodes and significant spectral evolution. The T50 and T90 durations are 12.35 (-/+ 1.90) s and 48.64 (-/+ 1.36) s, respectively. The burst's peak flux (50-300 keV; integrated over 1.024 s) and fluence (>20 keV) are 1.98 (-/+ 0.06) photons cmE-2 sE-1 and 4.01 (-/+ 0.79) x 10E-6 erg cmE-2, respectively---ranking it in the top 20% (38%) of the BATSE burst flux (fluence) distribution. The average spectral hardness of the burst, as estimated by the ratio of 100-300 keV counts to those in the 50-100 keV range, is H32 = 0.83 (-/+ 0.01), which is average for bursts of this duration. The BATSE burst location is consistent with those measured by BeppoSAX (GCN 430) and the IPN (SAX/NEAR; GCN 411). The lightcurve for this event will be available shortly at: http://gammaray/batse/grb/lightcurve/ //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 449 SUBJECT: Optical Observations of GRB991105 DATE: 99/11/30 16:50:17 GMT FROM: Nicola Masetti at ITeSRE,CNR,Bologna Optical Observations of GRB991105 E. Palazzi, E. Pian, N. Masetti, F. Frontera (ITESRE, CNR, Bologna), E. Rol, P.M. Vreeswijk (U. of Amsterdam), P. McCarthy, H.-W. Chen, B. Schommer, C. Smith, N. Suntzeff (CTIO), H. Pedersen, J. Hjorth (CUO, Copenhagen), C. Kouveliotou (NASA-MSFC/USRA), T. Augusteijn, and R. Athreya (ESO) on behalf of the BeppoSAX and Amsterdam/Huntsville GRB optical follow-up teams, report: "We have observed the revised BeppoSAX WFC error circle of GRB 991105 (Piro 1999, GCN 433) in the BRi bands at the ESO 2.2m telescope at La Silla (Chile) 15.8 and 39.9 hours after the burst. The field is very crowded as it lies on the Galactic plane. The reddening towards that direction is E(B-V) = 0.623 (Schlegel et al. 1998, ApJ 500, 525), implying a Galactic extinction of 2.7, 1.7 and 1.2 mag in B,R, and i, respectively. No galaxies are seen in the field, which is also indicative of considerable optical extinction. Photometric calibration was done using standard stars in the Landolt field SA98 (Landolt 1992, AJ 104, 340). The comparison between the two sets of images does not show any object with significant brightness variations larger than 0.5 mag down to the 3 sigma limiting magnitudes of R=23.5, B=22.5, i=22.0. We also observed the GRB field with the 4m telescope at CTIO (Chile), taking images in the R band over 4 nights starting 15 hours after the burst. SN search software has been applied to those images by N. Suntzeff and collaborators. No variables were detected in the field down to a 3 sigma limiting magnitude R=23.4, thus confirming the results from the ESO observations." This message is citeable.