//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23295 SUBJECT: GRB 181003A: Swift detection of a burst DATE: 18/10/03 05:25:47 GMT FROM: David Palmer at LANL A. P. Beardmore (U Leicester), M. J. Moss (George Washington University), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 05:11:03 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 181003A (trigger=865179). Swift did not slew immediately to the burst due to an observing constraint. The BAT on-board calculated location is RA, Dec 52.569, -34.023 which is RA(J2000) = 03h 30m 17s Dec(J2000) = -34d 01' 23" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 30 sec. The peak count rate was ~600 counts/sec (15-350 keV), at ~0 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+46.3 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is A. P. Beardmore (apb AT star.le.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23296 SUBJECT: GRB 181003A: Swift-XRT observations DATE: 18/10/03 06:56:48 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), M. Perri (ASDC) and G. Tagliaferri (INAF-OAB) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 181003A at 06:02:32.6 UT, 3089.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 52.52910, -33.96445 which is equivalent to: RA(J2000) = 03h 30m 06.98s Dec(J2000) = -33d 57' 52.0" with an uncertainty of 4.5 arcseconds (radius, 90% containment). This location is 242 arcseconds from the BAT onboard position. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. As this position is significantly outside the BAT error circle, it is probably unrelated to the trigger. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.24 x 10^20 cm^-2 (Willingale et al. 2013). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23299 SUBJECT: GRB 181003A: MASTER optical observation DATE: 18/10/03 13:57:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa,A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institute R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias D. Buckley, South African Astronomical Observatory A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory O. Gres, N.M. Budnev, Yu.Ishmuhametova Applied Physics Institute of Irkutsk State University V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to Swift GRB181003A (Beardmore et al. GCN 23295, Evans et al. GCN 23296) 4 sec after notice time and 59 sec after trigger time at 2018-10-03 05:12:02 UT, with upper limit up to 19.1 mag. The observations started on zenit distance = 65 deg. The sun altitude was -23.8 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) was pointed to the GRB181003A 10 sec after notice time and 64 sec after trigger time at 2018-10-03 05:12:08 UT, with upper limit up to 20.3 mag. The observations started on zenit distance = 27 deg. The sun altitude was -53.3 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. We obtained the following upper limits: Tmid-T0 | MASTER observatory |Filt.| Exp.,s| m_lim | Comment _________|_____________________|_____|_______|_______|________ 89 | MASTER-IAC | P- | 10 | 16.29 | 89 | MASTER-IAC | P- | 50 | 17.38 | Coadd 89 | MASTER-IAC | P- | 710 | 19.12 | Coadd 96 | MASTER-OAFA | C | 10 | 16.88 | 96 | MASTER-OAFA | C | 70 | 18.69 | Coadd 96 | MASTER-OAFA | C | 550 | 19.83 | Coadd 131 | MASTER-IAC | P- | 20 | 16.75 | 176 | MASTER-OAFA | C | 20 | 17.54 | 185 | MASTER-IAC | P- | 20 | 16.75 | 242 | MASTER-IAC | P- | 30 | 17.31 | 242 | MASTER-IAC | P- | 120 | 17.94 | Coadd 272 | MASTER-OAFA | C | 40 | 18.17 | 312 | MASTER-IAC | P- | 40 | 17.05 | 393 | MASTER-OAFA | C | 50 | 18.4 | 393 | MASTER-OAFA | C | 210 | 19.3 | Coadd 399 | MASTER-IAC | P- | 50 | 17.53 | 500 | MASTER-IAC | P- | 70 | 17.66 | 500 | MASTER-IAC | P- | 250 | 18.41 | Coadd 531 | MASTER-OAFA | C | 70 | 18.7 | 632 | MASTER-IAC | P- | 80 | 17.66 | 701 | MASTER-OAFA | C | 90 | 18.81 | 774 | MASTER-IAC | P- | 100 | 17.92 | 900 | MASTER-OAFA | C | 120 | 19.05 | 900 | MASTER-OAFA | C | 450 | 19.72 | Coadd 951 | MASTER-IAC | P- | 130 | 17.92 | 1145 | MASTER-OAFA | C | 150 | 19.18 | 1170 | MASTER-IAC | P- | 160 | 17.92 | 1434 | MASTER-OAFA | C | 180 | 19.31 | 1434 | MASTER-OAFA | C | 1800 | 20.16 | Coadd 1436 | MASTER-IAC | P- | 180 | 18.15 | 1436 | MASTER-IAC | P- | 1800 | 19.11 | Coadd 1749 | MASTER-IAC | P- | 180 | 18.16 | 1749 | MASTER-IAC | P- | 540 | 19 | Coadd 1764 | MASTER-OAFA | C | 180 | 19.26 | 1764 | MASTER-OAFA | C | 540 | 19.84 | Coadd 2070 | MASTER-IAC | P- | 180 | 18.16 | 2097 | MASTER-OAFA | C | 180 | 19.27 | 2382 | MASTER-IAC | P- | 180 | 18.16 | 2429 | MASTER-OAFA | C | 180 | 19.3 | 2709 | MASTER-IAC | P- | 180 | 18.14 | 2709 | MASTER-IAC | P- | 540 | 18.97 | Coadd 2760 | MASTER-OAFA | C | 180 | 19.26 | 2760 | MASTER-OAFA | C | 540 | 19.81 | Coadd 3027 | MASTER-IAC | P- | 180 | 18.14 | 3093 | MASTER-OAFA | C | 180 | 19.26 | 3428 | MASTER-OAFA | C | 180 | 19.25 | 3761 | MASTER-OAFA | C | 180 | 19.3 | 3761 | MASTER-OAFA | C | 540 | 19.9 | Coadd 3887 | MASTER-IAC | P- | 180 | 17.93 | 4094 | MASTER-OAFA | C | 180 | 19.27 | 4203 | MASTER-IAC | P- | 180 | 17.89 | 4203 | MASTER-IAC | P- | 540 | 18.43 | Coadd 4428 | MASTER-OAFA | C | 180 | 19.3 | 4515 | MASTER-IAC | P- | 180 | 17.73 | 4758 | MASTER-OAFA | C | 180 | 19.3 | 4758 | MASTER-OAFA | C | 540 | 19.85 | Coadd 4758 | MASTER-OAFA | C | 1800 | 20.26 | Coadd 4835 | MASTER-IAC | P- | 180 | 17.45 | 5093 | MASTER-OAFA | C | 180 | 19.3 | 5151 | MASTER-IAC | P- | 180 | 17.08 | 5151 | MASTER-IAC | P- | 540 | 17.39 | Coadd Filter C is unfiltred band (clear), calibrated by USNO B1 thousands field stars as 0.2B+0.8R. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23300 SUBJECT: GRB 181003A: LCO Cerro Tololo observations DATE: 18/10/03 14:56:21 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi, R. Martone (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU), A. Cucchiara, D. Morris (U. of Virgin Islands) on behalf of a large collaboration report: We automatically observed Swift GRB 181003A (Beardmore et al. GCN 23295) with one LCO 1-m unit at Cerro Tololo from October 03, 05:26:07 UT (corresponding to 15 minutes from the GRB trigger time) with the SDSS r' filter. Within the Swift-XRT error circle (Evans et al. GCN 23296) we marginally detect an uncatalogued source with r'=22.11 +- 0.25 mag from a 9x60s exposure at a mid time of 0.35 hours post GRB, as calibrated against nearby Pan-STARRS objects, at the following position: RA(J2000) =  03:30:06.86 DEC(J2000)= -33:57:54.2 with an error radius of about 1". //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23303 SUBJECT: GRB 181003A: Swift/UVOT Upper Limits DATE: 18/10/03 17:47:56 GMT FROM: Sam LaPorte at PSU GRB 181003A: Swift/UVOT Upper Limits S. J. LaPorte (PSU) and A. P. Beardmore (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 181003A 3095 s after the BAT trigger (Beardmore et al., GCN Circ. 23295). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 23296) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag b 5040 5240 196 >20.83 uvm2 3452 3652 196 >19.46 u 3862 3902 39 >19.19 v 3427 3447 196 >19.79 uvw1 3658 3857 196 >19.85 uvw2 5451 5597 144 >19.37 white 3091 3240 294 >21.73 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23305 SUBJECT: GRB 181003A: Swift-XRT afterglow detection DATE: 18/10/03 18:08:13 GMT FROM: Andy Beardmore at U Leicester A. Tohuvavohu (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), S. J. LaPorte (PSU), J.A. Kennea (PSU) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Swift/BAT-detected burst GRB 181003A (Beardmore et al. GCN Circ. 23295), collecting 8.6 ks of Photon Counting (PC) mode data between T0+3.1 ks and T0+34.3 ks. Six uncatalogued X-ray sources are detected consistent with being within 296 arcsec of the Swift/BAT position, of which one ("Source 1") is fading with 3-sigma significance, and is therefore likely the GRB afterglow. Using 1905 s of PC mode data and 1 UVOT image, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 52.52869, -33.96466 which is equivalent to: RA (J2000): 03h 30m 06.89s Dec(J2000): -33d 57' 52.8" with an uncertainty of 6.3 arcsec (radius, 90% confidence). This position is 4.0 arcmin from the Swift/BAT position. The source is fading with alpha >0.8. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00865179. The results of the full analysis of the XRT observations are available at http://www.swift.ac.uk/ToO_GRBs/00865179. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23306 SUBJECT: GRB 181003A: Swift-BAT refined analysis DATE: 18/10/03 22:34:55 GMT FROM: Amy Lien at GSFC H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), A. P. Beardmore, J. R. Cummings (CPI), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 181003A (trigger #865179) (Beardmore et al., GCN Circ. 23295). The BAT ground-calculated position is RA, Dec = 52.481, -33.991 deg which is RA(J2000) = 03h 29m 55.4s Dec(J2000) = -33d 59' 25.8" with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The mask-weighted light curve shows a weak structure that starts at ~T-10 s and ends at ~ T+20 s. The burst went out of the BAT field of view at ~T+97 s. T90 (15-350 keV) is 21.5 +- 4.8 sec (estimated error including systematics). The time-averaged spectrum from T-11.20 to T+18.01 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index -0.20 +- 1.12, and Epeak of 56.5 +- 14.4 keV (chi squared 52.40 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.2 +- 0.7 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T+1.86 sec in the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.54 +- 0.19 (chi squared 63.13 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/865179/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 23307 SUBJECT: GRB 181003A: RATIR Optical and NIR Observations DATE: 18/10/04 19:27:17 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM), Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report: We observed the field of GRB 181003A (Beardmore et al., GCN Circ. 23295) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2018/10 4.32 to 2018/10 4.46 UTC (26.59 to 29.89 hours after the BAT trigger), obtaining a total of 1.41 hours exposure in the r and i bands and 0.58 hours exposure in the Z, Y, J, and H bands. For a source within the Swift-XRT error circle (Tohuvavohu et al., GCN Circ. 23305), in comparison with the USNO-B1 and 2MASS catalogs, we obtain the following 3-sigma upper limits: r > 23.40 i > 23.15 Z > 22.01 Y > 21.53 J > 21.19 H > 20.73 These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.