GRB180904A

This page lists all entries on GRB180904A in GRBweb

Summary IPN Swift GCN 23194 GCN 23195 GCN 23196 GCN 23197 GCN 23198 GCN 23199 GCN 23200 GCN 23203 GCN 23204 GCN 23205 GCN 23206 GCN 23209

Summary table
Variable Value Source
T0 21:28:32 UTC GCN_circulars,Swift Det
ra 274.2498° Swift
decl 46.6298° Swift
pos_error 1.94e-04° Swift
T90 5.4 s Swift
T90_start 21:28:32 UTC Swift
fluence 2.40e-07 erg/cm² Swift
T100 5.4 s
GBM_located False
mjd 58365.89481481481 GCN_circulars,Swift Det
IPN table
GRB_name GRB180904A
ra 274.2500°
decl 46.6167°
pos_error 5.00e-02°
Swift table
GRB_name GRB180904A
t_trigger 21:28:32 UTC
ra 274.2498°
decl 46.6298°
pos_error 1.94e-04°
T90 5.4 s
fluence 2.40e-07 erg/cm²
GCN 23194 table
GRB_name GRB180904A
GCN_number 23194
Detection_method Swift Det
t_trigger 21:28:32 UTC
ra 274.2500°
decl 46.6230°
Circular_text TITLE: GCN CIRCULAR NUMBER: 23194 SUBJECT: GRB 180904A: Swift detection of a burst DATE: 18/09/04 21:42:57 GMT FROM: David Palmer at LANL A. D'Ai (INAF-IASFPA), J.D. Gropp (PSU), J. A. Kennea (PSU), S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC), M. J. Moss (George Washington University), D. M. Palmer (LANL), B. Sbarufatti (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 21:28:32 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180904A (trigger=859282). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 274.250, +46.623 which is RA(J2000) = 18h 17m 00s Dec(J2000) = +46d 37' 24" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 20 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger. The XRT began observing the field at 21:30:35.3 UT, 123.0 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source with an enhanced position: RA, Dec 274.2495, 46.6298 which is equivalent to: RA(J2000) = 18h 16m 59.87s Dec(J2000) = +46d 37' 47.4" with an uncertainty of 2.3 arcseconds (radius, 90% containment). This location is 24 arcseconds from the BAT onboard position, within the BAT error circle. 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (3.37 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.3 (+3.26/-2.80) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 4.47e-10 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 131 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 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 0.04. Burst Advocate for this burst is A. D'Ai (antonino.dai AT ifc.inaf.it). 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.)
GCN 23195 table
GRB_name GRB180904A
GCN_number 23195
Detection_method Optical
ra 274.2489°
decl 46.6298°
Circular_text TITLE: GCN CIRCULAR NUMBER: 23195 SUBJECT: GRB 180904A: NOT optical observations, candidate host galaxy DATE: 18/09/04 23:04:27 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst Daniele Malesani (DAWN/NBI and DARK/NBI), Kasper Elm Heintz (Univ. Iceland and DAWN/NBI), Sune Dyrbye (NOT), report on behalf of a largert collaboration: We observed the field of GRB 180904A (D'Ai' et al., GCN 23194) with the Nordic Optical Telescope (NOT) equipped with the AlFOSC camera. In an image of 300 s exposure taken with the SDSS r filter and commencing on Sep 4.9057 UT (15.6 min after the GRB), we detect a single object consistent with the currently available XRT position (http://www.swift.ac.uk/xrt_positions/). Its coordinates are (J2000): RA = 18:16:59.74 Dec = +46:37:47.1 Compared to nearby stars from the Pan-STARRS survey, we measure for this object a magnitude r = 22.56 +- 0.08 AB. We note that the same object is visible in the archival Pan-STARRS image of this field, with a measured magnitude r = 22.84 +- 0.15 AB. There is thus only marginal indication of excess flux in the NOT image. If this object is related to GRB 180904A, as suggested by the spatial coincidence with the X-ray position, it is largely or entirely dominated by the host galaxy. Further observations are planned.
GCN 23196 table
GRB_name GRB180904A
GCN_number 23196
Detection_method Swift-XRT Det
ra 274.2498°
decl 46.6297°
Circular_text TITLE: GCN CIRCULAR NUMBER: 23196 SUBJECT: GRB 180904A: Enhanced Swift-XRT position DATE: 18/09/04 23:19:01 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 468 s of XRT Photon Counting mode data and 1 UVOT images for GRB 180904A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 274.24978, +46.62971 which is equivalent to: RA (J2000): 18h 16m 59.95s Dec (J2000): +46d 37' 46.9" with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 23197 table
GRB_name GRB180904A
GCN_number 23197
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 23197 SUBJECT: GRB 180904A: OSN observations DATE: 18/09/05 00:16:23 GMT FROM: Luca Izzo at IAA-CSIC L. Izzo, D. A. Kann, A. de Ugarte Postigo, C.C. Thoene (all HETH/IAA-CSIC), and F. Aceituno (IAA-CSIC) report: We observed the field of GRB 180904A (D’Ai et al., GCN #23194) with the 1.5-m OSN telescope in Granada, Spain. We obtained 12 x 300 s images in the Ic band centered at 1.23 hours after the GRB. At the enhanced XRT position of the GRB (Osborne et al., GCN #23196), we find no source inside the Swift-XRT error circle down to a limit of Ic (AB) > 22.4. We note, however, that the object reported in Malesani et al., GCN #23195, lies just outside the XRT position reported by Osborne et al., and may therefore be unrelated to the GRB. The calibration was performed using i-band magnitudes of nearby stars in the Pan-STARRS catalog, transformed into Ic magnitudes according to the Lupton (2005) transformations.
GCN 23198 table
GRB_name GRB180904A
GCN_number 23198
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 23198 SUBJECT: GRB 180904A: SAO RAS optical observations DATE: 18/09/05 00:46:37 GMT FROM: Moskvitin Alexander at SAO RAS Moskvitin, A. S., Spiridonova O. I., Maslennikova O. A. (SAO RAS), report on behalf of larger GRB follow-up team. We observed the field of the GRB 180904A (D'Ai et al., GCNC 23194) with the Zeiss-1000 telescope of SAO RAS (+ CCD UBVRcIc photometer) on the 2018 September, 4.926 (mid. time). The observations started since 7.2 minutes after the Swift trigger (21:35:44--22:46:03 UT). 12 x 300 sec. exposures in Rc band were obtained. We can not see any object inside the XRT enhanced 1".8 error circle (Osborne et al., GCNC 23196) down to the limiting magnitude of R_lim = 22.7, but at the edge of the circle we detected the object mentioned by Malesani et al. (GCNC 23195). The preliminary magnitude of the object is R = 21.9 +/- 0.2 (Vega system) compared to nearby USNO-B1 stars. The finding chart can be found at ftp://ftp.sao.ru/pub/grb/GRB/GRB180904A_SAORAS.png
GCN 23199 table
GRB_name GRB180904A
GCN_number 23199
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 23199 SUBJECT: GRB 180904A: LT early observations DATE: 18/09/05 09:57:11 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) on behalf of a large collaboration report: The 2-m robotic Liverpool Telescope automatically began observing Swift GRB 180904A (D'Ai et al. GCN 23194) with the polarimeter RINGO3 and the IO:O camera on September 04, 21:32:12 UT (219 seconds from the GRB trigger time). Within the enhanced Swift-XRT error circle (Osborne et al. GCN 23196) we do not detect any object down to a limit of r' > 21.2 mag in a 6x10s exposure at a mid time of 37 minutes post burst, as calibrated against nearby Pan-STARRS objects, in agreement with previous reports (Malesani et al. GCN 23195; Izzo et al. GCN 23197; Moskvitin et al. GCN 23198).
GCN 23200 table
GRB_name GRB180904A
GCN_number 23200
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 23200 SUBJECT: GRB 180904A: Swift-XRT refined Analysis DATE: 18/09/05 13:04:23 GMT FROM: Phil Evans at U of Leicester K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU), P.A. Evans (U. Leicester) and A. D'Ai report on behalf of the Swift-XRT team: We have analysed 6.5 ks of XRT data for GRB 180904A (D'Ai et al. GCN Circ. 23194), from 129 s to 45.0 ks after the BAT trigger. The data comprise 91 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 23196). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.9 (+0.4, -0.6). At T+179 s the decay steepens to an alpha of 7.84 (+0.16, -1.21) before breaking again at T+247 s to a final decay with index alpha=1.19 (+/-0.15). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.61 (+0.24, -0.22). The best-fitting absorption column is 4.6 (+1.0, -0.9) x 10^21 cm^-2, in excess of the Galactic value of 3.4 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.19 (+0.26, -0.24) and a best-fitting absorption column of 4.3 (+1.2, -1.1) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.3 (+1.2, -1.1) x 10^21 cm^-2 Galactic foreground: 3.4 x 10^20 cm^-2 Excess significance: 6.0 sigma Photon index: 2.19 (+0.26, -0.24) If the light curve continues to decay with a power-law decay index of 1.19, the count rate at T+24 hours will be 7.3 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.6 x 10^-14 (4.6 x 10^-14) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00859282. This circular is an official product of the Swift-XRT team.
GCN 23203 table
GRB_name GRB180904A
GCN_number 23203
Detection_method Swift-BAT Det
ra 274.2600°
decl 46.6400°
Circular_text TITLE: GCN CIRCULAR NUMBER: 23203 SUBJECT: GRB 180904A: Swift-BAT refined analysis DATE: 18/09/05 15:28:50 GMT FROM: Amy Lien at GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), 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 180904A (trigger #859282) (D'Ai et al., GCN Circ. 23194). The BAT ground-calculated position is RA, Dec = 274.260, 46.640 deg which is RA(J2000) = 18h 17m 02.4s Dec(J2000) = +46d 38' 23.3" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 56%. The mask-weighted light curve shows a weak structure that starts at ~T0 and ends at ~T+6 s. T90 (15-350 keV) is 5.40 +- 0.89 sec (estimated error including systematics). The time-averaged spectrum from T+0.28 to T+6.18 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.02 +- 0.30. The fluence in the 15-150 keV band is 2.4 +- 0.4 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+5.14 sec in the 15-150 keV band is 0.5 +- 0.2 ph/cm2/sec. 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/859282/BA/
GCN 23204 table
GRB_name GRB180904A
GCN_number 23204
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 23204 SUBJECT: GRB 180904A: RATIR Optical and NIR Observations DATE: 18/09/05 15:49:17 GMT FROM: Nat Butler at Az State U Nat Butler (ASU), Alan M. Watson (UNAM), 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 180904A (D'Ai, et al., GCN 23194) 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 2018/09 5.13 to 2018/09 5.32 UTC (5.66 to 10.26 hours after the BAT trigger), obtaining a total of 2.91 hours exposure in the r and i bands and 1.33 hours exposure in the Z, Y, J, and H bands. Within the XRT error circle (Osborne, et al., GCN 23196), we detect the source reported by Malesani, et al. (GCN 23195) at a consistent brightness level. In comparison with the USNO-B1 and 2MASS catalogs, we obtain the following detections and upper limit (3-sigma): r = 22.61 +/- 0.08 i = 22.06 +/- 0.05 Z = 22.13 +/- 0.16 Y = 21.64 +/- 0.18 J = 21.72 +/- 0.21 H > 21.86 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.
GCN 23205 table
GRB_name GRB180904A
GCN_number 23205
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 23205 SUBJECT: GRB 180904A: Swift/UVOT Upper Limits DATE: 18/09/05 15:58:34 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and A. D'Ai (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 180904A 131 s after the BAT trigger (D'Ai et al., GCN Circ. 23194). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 23196) is detected in the initial UVOT exposures, consistent with the non-detections of Malesani et al. (GCN Circ. 23195), Izzy et al. (GCN Circ 23197), Moskvitin et al. (GCN Circ. 23198) and Guidorzi et al. (GCN Circ. 23199). Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 131 281 147 >21.1 u_FC 289 539 246 >20.1 white 131 589 167 >21.1 v 620 640 19 >20.1 b 545 565 19 >19.4 u 289 539 246 >20.1 w1 670 690 19 >18.1 w2 595 615 19 >18.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 23206 table
GRB_name GRB180904A
GCN_number 23206
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 23206 SUBJECT: GRB 180904A: AbAO optical upper limit DATE: 18/09/05 16:18:22 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Pozanenko (IKI), R. Inasaridze (AbAO), E. Mazaeva (IKI), V. Ayvazian (AbAO), O. Kvaratskhelia (AbAO), G. Kapanadze (AbAO), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 180904A (D'Ai et al., GCN 23194) with AS-32 (0.7m) telescope of Abastumani Observatory starting on September 04 (UT) 21:52:23. We do not detect any object within enhanced XRT position (Osborne et al., GCN 23196). Preliminary photometry of the field is following: Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2018-09-04 21:52:23 0.05731 CR 70*60 n/d n/d 21.5 The photometry is based on nearby USNO-B1.0 stars (R2 magnitude) USNO-B.1_id R2 1366-0296056 14.72 1366-0296068 15.43 1365-0287325 15.62 1366-0296106 15.21 1366-0296088 14.95 1366-0296093 14.37
GCN 23209 table
GRB_name GRB180904A
GCN_number 23209
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 23209 SUBJECT: GRB 180904A: BOOTES-2/TELMA early observations DATE: 18/09/05 22:11:32 GMT FROM: Youdong HU at IAA-CSIC, UGR C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), Y.-D. Hu, E. Fernandez-Garcia, J. C. Tello, A. Ayala, A. J. Castro-Tirado (IAA-CSIC), and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report: The 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Spain) automatically responded in 56s (and 116s after the GRB onset) to the Swift trigger of GRB 180904A (D'Ai et al. GCNC 23194). The first image (11s exposure, unfiltered) was obtained at 21:30:28 UT. At the position of the enhanced Swift X-ray afterglow (Osborne et al. GCNC 23196), no optical afterglow is detected down to 19 mag at a mid time of 6 minutes post burst. This is consistent with the limits reported by Malesani et al. (GCNC 23195), Izzo et al. (GCNC 23197), Moskvitin et al. (GCNC 23198, Guidorzi et al. (GCNC 23199), Butler et al. (GCNC 23204), Siegel et al. (GCNC 23205), Volnova et al. (GCNC 23206).