Contains both (what were once called 'A' and 'B'): //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3766 SUBJECT: Swift-BAT trigger 149118 is probably not a GRB DATE: 05/08/05 19:19:17 GMT FROM: Scott Barthelmy at NASA/GSFC J. Cummings (GSFC-NRC), S. Barthelmy (GSFC), D. Burrows (PSU), M. Chester (PSU), N. Gehrels (GSFC), M Goad (U. Leicester), O. Godet (U. Leicester), J. Kennea (PSU), A. Morgan (PSU), C. Pagani (PSU), D. Palmer (LANL) on behalf of the Swift team: The Swift-BAT trigger (trigger=149118) at 18:04:00 UT on 05 Aug 2005 is not likely to be due to a GRB. Although we detect an unknown source in the BAT FOV at RA,Dec=331.154,+29.902 (J2000, 3 arcmin, radius, 90%, sys+stat), we can not confirm that it is a GRB. And given that we have just come out of the gap in the data downlink passes and that there was a prior backlog of data to download, we will not have access to the full data set on this trigger for about 8 hours. At 18:06:00 UT XRT attempted to centroid on the BAT position, 120 secs after the BAT trigger. While the initial TRDSS lightcurve shows a marginal spike in the count rate, the instrument drops immediately into Photon-Counting mode with a very low count rate for the next 100 sec. Because of the low count rate, no position was acquired by the on-board software. We await ground analysis of the early XRT data following the first Malindi pass. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3767 SUBJECT: GRB050805a: MASTER optical candidat DATE: 05/08/05 20:48:55 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy, A.Krylov, G.Borisov, V.Vladimirov, Krushinski V. Sternberg Astronomical Institute, Moscow Union "Optic" MASTER (http://observ.pereplet.ru) responded to GRB 050801 (Swift trigger 149118). The first image was 35 sec after Notice Time and 113 sec after SWIFT probable GRB050805 detection (19:14:00.34 UT, GCN3766) under the evening sky near the horizont. The first image was saturated. The first not saturated image was at 720 sec after GRB time (exposition 1 s). Optical limit is about 12.5 (unfiltred close to R). On next images we see new variable faint source 14.5 inside Swift error box wich disapear after . alpha = 22 04 40.91 delta = +29 51 48.1 error is about 2''. The JPG-images are available at http://observ.pereplet.ru/images/GRB050805/1.jpg . This work is supported by RFFI 04-02-16411 grant. This message can be cited. Mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3768 SUBJECT: Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst DATE: 05/08/05 21:39:05 GMT FROM: Jay R. Cummings at NASA/GSFC/Swift J. Cummings (GSFC/NRC), S. Barthelmy (GSFC), D. Burrows (PSU), M. Chester (PSU), N. Gehrels (GSFC), M. Goad (U. Leicester), O. Godet (U. Leicester), J. Kennea (PSU), C. Markwardt (GSFC/UMD), A. Morgan (PSU), C. Pagani (PSU), K. Page (U. Leicester), D. Palmer (LANL), T. Sakamoto (GSFC/NRC) on behalf of the Swift team: At 20:41:26.7 UT, Swift-BAT triggered and located potential GRB 050805B (trigger=149131). The spacecraft slewed immediately. The BAT on-board calculated location is RA,Dec 306.005d, +37.213d {+20h 24m 01s, +37d 12' 46"} (J2000), with an uncertainty of 3 arcmin (radius, 90% containment, stat+sys). The trigger duration is 32 milliseconds, and the image significance was 6.3 sigma. At that level, we consider the BAT detection itself to be marginal. XRT began observing the burst at 20:42:40.8 UT, 74 seconds after the BAT trigger. The XRT was not able to centroid on a point source in the field, however the full field lightcurve shows a significant elevation above background, suggesting the presence of an X-ray source in the field. A catalogue search reveals no known X-ray sources in the field, suggesting this X-ray source is the X-ray afterglow. There is evidence of fading in the lightcurve, which will require ground processing to confirm. UVOT began observing the burst at 20:42:38.6 UT, 72 seconds after the BAT trigger. In a preliminary ground-processed 100-sec image, no new sources are found when compared to the DSS catalog down to a 5-sigma limiting magnitude of V > 19.0. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3769 SUBJECT: GRB050805b: MASTER optical observations DATE: 05/08/05 21:53:46 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy, A.Krylov, G.Borisov, V.Vladimirov, Krushinski V. Sternberg Astronomical Institute, Moscow Union "Optic" MASTER (http://observ.pereplet.ru) responded to GRB 050805b (Swift trigger 149131). The first image was 25 sec after Notice Time and 74 sec after SWIFT detection under the good weather condition. Optical limit is about 17.1 (30 sec exposition, unfiltred close to R). Ther is no new object in error box (GRB on Milky Way). The JPG-images are available at http://observ.pereplet.ru/images/GRB050805b/1.jpg . This work is supported by RFFI 04-02-16411 grant. This message can be cited. Mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3770 SUBJECT: GRB 050805b: TAROT optical limits DATE: 05/08/05 23:44:47 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 050805b detected by SWIFT (trigger 149131) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. First image was acquired 5.2s after the GCN notice (55.5s after GRB). The field had an elevation of 63 degrees above horizon and weather conditions were excellents. We detected no new source comparing our unfiltered images with the DSS2-R and 2MASS-K ones and comparing our succesive frames. From the first frame we give an early limit: T(sec since GRB) Exp(s) R-mag 55.5 - 70.5 15 >17.0 Limiting magnitude was estimated with the nearby USNO-B1 stars. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3771 SUBJECT: GRB 050805b: OHP optical limits DATE: 05/08/05 23:59:29 GMT FROM: Alain Klotz at CESR-CNRS Damerdji, Y. (CESR-OMP/OHP), Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report: We imaged the field of GRB 050805b detected by SWIFT (trigger 149131) with the 0.8m (F/15) telescope located at the Observatoire de Haute Provence Observatory (OHP), France. Camera is an Andor 47-40 equiped by a R band filter. First image was begined 16.4 min after the GRB. Weather conditions were excellents. We detected no new source comparing our succesive frames. From the first frame we give an limit: TMid(min since GRB) Exp(s) R-mag 18.87 300 >20.3 Limiting magnitude was estimated with the nearby USNO-B1 stars. This message can be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3772 SUBJECT: Retraction of Swift Trigger 149131 (GRB 050805B) DATE: 05/08/06 01:08:12 GMT FROM: Craig Markwardt at NASA/GSFC/UMD C. Markwardt (GSFC/UMD), S. Barthelmy (GSFC), J. Cummings (GSFC/NRC) J. Kennea (PSU), C. Pagani (PSU) on behalf Swift team: We report that trigger number 149131, previously designated GRB 050805B, is retracted. This trigger is consistent with a cosmic ray shower event in the detector, and a simultaneous random image fluctuation. Ground analysis of the XRT data does not show any X-ray source in the field. We therefore conclude from the XRT data that Trigger 149131 is not a GRB. As a separate note, the BAT position notice was delayed by ~42 seconds on board the spacecraft, due to a backlog of TDRSS telemetry caused by a commanded procedure. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3776 SUBJECT: GRB050805a : Null detection report DATE: 05/08/06 12:33:27 GMT FROM: Eran Ofek at Tel Aviv U. E. O. Ofek, Y. Lipkin (Wise observatory, TAU) report: We have observed the error box of the of the Swift trigger 149118 (Cummings et al. 2005, GCN 3766; designated as GRB 050805a by Lipunov et al. GCN 3767), using the Wise observatory 1m telescope + Tek CCD camera, starting at 2005, Aug 05th, 21:50 UTC. Comparing a 300 sec R-band image which we obtained (mid exposure time 0.15851 days after the Swift-BAT trigger) to the POSS2 R-band image, we did not detect any new source in the 2" error circle of the optical transient that was reported by Lipunov et al. (GCN 3767). The limiting magnitude of our image was R=19.5. If we understood correctly the message of Lipunov et al., then our observations took place 2.637 hrs after theirs. If Lipunov et al. indeed detected the OT, and further assuming a power-law decay, this time difference would imply a decay-rate index that is larger than 2.08. We note that according to GCN 3766, GRB050805a is probably not a real GRB. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3777 SUBJECT: GRB050805b: CrAO optical limit DATE: 05/08/06 16:36:32 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Pavlenko, Yu. Efimov, A. Shlyapnikov, A. Baklanov, V. Rumyantsev (CrAO), A.Pozanenko (IKI), M. Ibrahimov (MAO) on behalf of larger GRB follow up collaboration report: We observed the entire field of GRB 050805b detected by SWIFT (trigger 149131) with the Shain 2.6m telescope. The set of 300 seconds images in R filter were taken between August, 5 21:23:44 - 22:21:01 (UT). No fading source was detected as compared between single images. The typical limiting magnitude of the single image is 23.0m. This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3868 SUBJECT: GRB050805a: MASTER optical candidat DATE: 05/08/25 02:15:24 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, N.Tyurina, A.Belinski, E.Gorbovskoy, D.Kuvshinov, A.Krylov, G.Borisov, V.Vladimirov, Krushinski V. Sternberg Astronomical Institute, Moscow Union "Optic" MASTER (http://observ.pereplet.ru) responded to GRB 050824 (Swift trigger 151905). The first image was 764 sec after SWIFT GRB050824 detection under the not very good weather condition. We see OT J. Gorosabel (GCN 3865) with m = 17.5 (unfiltered close to R, exp. 45 sec) on 2-3 sigma level. On summ of 9 images from 19.5 up to 28.5 minut after GRB Time (23 12 16.00 UT) m= 18.0 on 5 sigma. UT After GRB time m 23 25 00 764s 17.9 23 31 44 19.5min - 28.5 min 18.3 23 31 44 19.5min - 37.75 min 18.8 The JPG-image of the summ will be available at http://observ.pereplet.ru/images/GRB050824/1.jpg . The reduction is continuing. This work is supported by RFFI 04-02-16411 grant. This message can be cited. Mailto: lipunov@sai.msu.ru //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4090 SUBJECT: GRB050805A: Rc optical observations DATE: 05/10/12 19:46:11 GMT FROM: Graziella Pizzichini at IASF/CNR,Bologna GRB050805A: optical observations D. Nanni, (INAF/Osservatorio di Roma), F. Terra (CRATI scrl, and Cosenza University), C. Bartolini, G. Greco, A. Guarnieri, A. Piccioni (Bologna University), S. Marinoni, A. De Blasi (INAF/Osservatorio di Bologna) and G. Pizzichini (INAF/IASF, Bologna) report: We observed the error box of possible GRB050805A (Swift trigger 149118) with the 152 cm Loiano Telescope and the BFOSC camera system in good sky conditions. We obtained the following images, all of them in the Rc filter: Start time (UT) Duration (min) 050805 22:24:05 10 050805 22:44:13 10 050805 23:09:17 20 050805 23:34:36 20 050806 02:07:02 20 050806 02:29:00 20 We do not detect the optical candidate cited by Lipunov et al., GCN 3767. At its location the 3 sigma magnitude limit in our coadded images is 22.5 . The coadded images and the observation log will be 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: GRB050805A. [GCN OPS NOTE(12oct05): The SUBJECT line was changed from "040825A" to "050805A".]