GRB180402A

This page lists all entries on GRB180402A in GRBweb

Summary Fermi GBM IPN Swift GCN 22580 GCN 22581 GCN 22582 GCN 22583 GCN 22584 GCN 22585 GCN 22586 GCN 22587 GCN 22588 GCN 22600 GCN 22617

Summary table
Variable Value Source
GRB_name_Fermi GRB180402406
T0 9:44:59 UTC GCN_circulars,Swift Det
ra 251.9336° Swift
decl -14.9686° Swift
pos_error 2.72e-04° Swift
T90 0.448 s Fermi_GBM
T90_error 0.326 s Fermi_GBM
T90_start 9:44:59.047 UTC Fermi_GBM
fluence 1.31e-06 erg/cm² Fermi_GBM
fluence_error 2.78e-08 erg/cm² Fermi_GBM
T100 0.495 s
GBM_located False
mjd 58210.40623842592 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB180402406
trigger_name bn180402406
ra 251.9050°
decl -14.9631°
pos_error 4.53e+00°
datum 2018-04-02
t_trigger 9:44:59.367 UTC
T90 0.448 s
T90_error 0.326 s
T90_start 9:44:59.047 UTC
fluence 1.31e-06 erg/cm²
fluence_error 2.78e-08 erg/cm²
flux_1024 3.16e+00 erg/cm²/s
flux_1024_error 3.07e-01 erg/cm²/s
flux_1024_time -6.40e-01 erg/cm²/s
flux_64 1.75e+01 erg/cm²/s
flux_64_error 1.40e+00 erg/cm²/s
IPN table
GRB_name GRB180402A
ra 251.9042°
decl -14.9667°
pos_error 5.00e-02°
Swift table
GRB_name GRB180402A
t_trigger 9:44:59 UTC
ra 251.9336°
decl -14.9686°
pos_error 2.72e-04°
T90 0.18 s
fluence 1.40e-07 erg/cm²
GCN 22580 table
GRB_name GRB180402A
GCN_number 22580
Detection_method Swift Det
t_trigger 9:44:59 UTC
ra 251.9050°
decl -14.9630°
Circular_text TITLE: GCN CIRCULAR NUMBER: 22580 SUBJECT: GRB 180402A: Swift detection of a possibly short burst DATE: 18/04/02 10:08:54 GMT FROM: Jamie A. Kennea at PSU/Swift-XRT A. Y. Lien (GSFC/UMBC), A. P. Beardmore (U Leicester), J.D. Gropp (PSU) and K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift Observatory Team: At 09:44:59 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180402A (trigger=821103). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 251.905, -14.963 which is RA(J2000) = 16h 47m 37s Dec(J2000) = -14d 57' 48" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a short peak with a duration of about 0.3 sec. The peak count rate was ~9000 counts/sec (15-350 keV), at ~0 sec after the trigger. There are some additional variation in the light curve, however, this variation is also consistent with the presence of the currently-active black hole transient MAXI J1820+070 in the FOV. Further analysis of the full downlinked data will be required to determine the cause of the variation. The XRT began observing the field at 09:46:19.2 UT, 79.9 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 251.9335, -14.9683 which is equivalent to: RA(J2000) = 16h 47m 44.05s Dec(J2000) = -14d 58' 05.8" with an uncertainty of 2.1 arcseconds (radius, 90% containment). This location is 100 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. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.94 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 250 seconds with the U filter starting 139 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 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 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.77. Burst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). 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 22581 table
GRB_name GRB180402A
GCN_number 22581
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 22581 SUBJECT: GRB 180402A: LCO McDonald observations DATE: 18/04/02 12:25:42 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 LCO 1-m unit at McDonald Observatory (Texas) began observing Swift possibly short GRB 180402A (Lien et al. GCN 22580) on April 2, 10:02 UT (17.3 minutes since the GRB) with the SDSS-I filter. Within the XRT error circle we do not detect any uncatalogued optical afterglow down to i'>19.3 mag (5x120 s exposure, at a mid time of 23.7 min post GRB) as calibrated against nearby Pan-STARRS objects.
GCN 22582 table
GRB_name GRB180402A
GCN_number 22582
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 22582 SUBJECT: GRB 180402A: RATIR Upper Limits DATE: 18/04/02 15:51:46 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 180402A (Lien, et al., GCN 22580) 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 2018/04 2.41 to 2018/04 2.50 UTC (1.8 minutes to 2.33 hours after the BAT trigger), obtaining a total of 1.76 hours exposure in the r and i bands. For a source within the Swift-XRT error circle, in comparison with the USNO-B1 catalog, we obtain the following upper limits (3-sigma): r > 23.3 i > 23.3 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 22583 table
GRB_name GRB180402A
GCN_number 22583
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 22583 SUBJECT: GRB 180402A: KAIT Optical Upper Limit DATE: 18/04/02 17:40:39 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 180402A (Lien et al., GCN 22580 starting at 09:47:14 UT, 135 s after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. We do not detect any optical afterglow candidate within the XRT position error circle (Lien et al., GCN 22580). The typical limiting magnitude of our single clear image is about 18.5 mag calibrated to the APASS catalog.
GCN 22584 table
GRB_name GRB180402A
GCN_number 22584
Detection_method Swift-BAT Det
ra 251.9230°
decl -14.9280°
Circular_text TITLE: GCN CIRCULAR NUMBER: 22584 SUBJECT: GRB 180402A, Swift-BAT refined analysis DATE: 18/04/02 19:58:51 GMT FROM: Amy Lien at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180402A (trigger #821103) (Lien et al., GCN Circ. 22580). The BAT ground-calculated position is RA, Dec = 251.923, -14.928 deg which is RA(J2000) = 16h 47m 41.6s Dec(J2000) = -14d 55' 41.6" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 37%. The mask-weighted light curve shows a single short pulse that starts at ~T0, peaks at ~0.1 s, and ends at ~0.3 s T90 (15-350 keV) is 0.18 +- 0.03 sec (estimated error including systematics). The ground analysis confirmed that the additional variation seen in the raw light curve are indeed from MAXI J1820+070 (Lien et al., GCN Circ. 22580). The time-averaged spectrum from T+0.05 to T+0.26 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.52 +- 0.30. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.34 sec in the 15-150 keV band is 1.8 +- 0.3 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/821103/BA/
GCN 22585 table
GRB_name GRB180402A
GCN_number 22585
Detection_method Fermi GBM Det
t_trigger 9:44:59.370 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 22585 SUBJECT: GRB 180402A: Fermi GBM detection DATE: 18/04/02 21:52:22 GMT FROM: Christian Malacaria at U of Alabama/MSFC C. Malacaria (NASA-MSFC/USRA) reports on behalf of the Fermi GBM Team: "At 09:44:59.37 UT on 02 April 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 180402A (trigger 544355104 / 180402406). The event was also detected by the Swift/BAT (Lien et al. 2018, GCN 22580). The GBM on-ground location is consistent with the Swift position. The LAT boresight angle is 90 degrees. The duration (T90) is 0.448 +/- 0.326 s (8-1000 keV). The time-averaged spectrum from T0-0.1 s to T0+0.2 s is best fit by a Band function. The best-fit parameters are: Alpha = 2.23 +/- 2.03, Beta = -1.35 +/- 0.04, Epeak = 123.80 +/- 44.00 keV. The event fluence (8-1000 keV) in this time interval is (8.69 +/- 0.62)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0 s in the 10-1000 keV band is 17.5 +/- 1.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 22586 table
GRB_name GRB180402A
GCN_number 22586
Detection_method Swift-XRT Other
ra 251.9336°
decl -14.9686°
Circular_text TITLE: GCN CIRCULAR NUMBER: 22586 SUBJECT: GRB 180402A: Swift-XRT refined Analysis DATE: 18/04/03 10:09:03 GMT FROM: Phil Evans at U of Leicester V. D'Elia (ASDC), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and A.Y. Lien report on behalf of the Swift-XRT team: We have analysed 5.4 ks of XRT data for GRB 180402A (Lien et al. GCN Circ. 22580), from 83 s to 18.3 ks after the BAT trigger. The data comprise 24 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The best available XRT position (using the promptly downlinked event data, the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 251.9336, -14.9686 which is equivalent to: RA (J2000): 16 47 44.06 Dec(J2000): -14 58 06.9 with an uncertainty of 2.1 arcsec (radius, 90% confidence). The light curve can be modelled with a power-law decay with a decay index of alpha=1.94 (+/-0.10). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.46 (+0.28, -0.26). The best-fitting absorption column is 4.6 (+2.2, -1.7) x 10^21 cm^-2, consistent with the Galactic value of 2.9 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.6 x 10^-11 (7.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.6 (+2.2, -1.7) x 10^21 cm^-2 Galactic foreground: 2.9 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.46 (+0.28, -0.26) If the light curve continues to decay with a power-law decay index of 1.94, the count rate at T+24 hours will be 1.3 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.3 x 10^-16 (9.1 x 10^-16) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00821103. This circular is an official product of the Swift-XRT team.
GCN 22587 table
GRB_name GRB180402A
GCN_number 22587
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 22587 SUBJECT: GRB 180402A: Swift/UVOT Upper Limits DATE: 18/04/03 15:38:17 GMT FROM: Sam Emery at MSSL-UCL S.W.K. Emery (UCL-MSSL) and A. Y. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 180402A 140 s after the BAT trigger (Lien et al., GCN Circ. 22580). No optical afterglow consistent with the XRT position (D'Elia et al., GCN Circ. 22586) 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 first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 4328 4478 147 >20.8 u_FC 140 390 246 >19.7 white 4328 6805 407 >20.6 v 423 5916 286 >19.2 b 5101 6736 393 >20.2 u 140 6531 845 >20.3 w1 4691 6326 393 >20.4 w2 5512 5712 197 >19.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.77 in the direction of the burst (Schlegel et al. 1998).
GCN 22588 table
GRB_name GRB180402A
GCN_number 22588
Detection_method Konus-Wind Det
t_trigger 9:45:00.353 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 22588 SUBJECT: Konus-Wind observation of GRB 180402A DATE: 18/04/03 16:59:32 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, report: The short-duration, hard-spectrum GRB 180402A (Swift-BAT detection: Lien et al., GCN Circ. 22580; Fermi-GBM detection: Malacaria, GCN Circ. 22585) triggered Konus-Wind at T0=35100.353 s UT (09:45:00.353). The burst light curve shows bright, multi-peaked emission episode, which starts at T0-64 ms and has a total duration of ~180 ms, preceded by a weaker pulse at ~T0-340 ms. As observed by Konus-Wind, the burst had a fluence of 2.14(-0.33,+0.53)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0+0.086 s, of 2.03(-0.45,+0.60)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). Since the most intense part of the burst was detected before the trigger, the spectral analysis was performed using the KW 3-channel light curve data. Modeling the KW 3-channel spectrum of the main episode (from T0-0.064 s to T0+0.116 s) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -0.01(-0.43,+0.64), and Ep = 703(-161,+276) keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180402_T35100 All the quoted errors are at the 68% confidence level. All the quoted values are preliminary.
GCN 22600 table
GRB_name GRB180402A
GCN_number 22600
Detection_method Fermi GBM Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 22600 SUBJECT: GRB 180402A: Fermi GBM refined spectral analysis DATE: 18/04/04 18:32:57 GMT FROM: Christian Malacaria at U of Alabama/MSFC C. Malacaria (NASA-MSFC/USRA) reports on behalf of the Fermi GBM Team: "We report the refined spectral analysis of the short-duration GRB 180402A (Swift-BAT detection: Lien et al., GCN Circ. 22580; Fermi-GBM detection: Malacaria, GCN Circ. 22585; Konus-Wind observation: Svinkin, GCN Circ. 22588). The time-averaged spectrum from T0-0.064 s to T0+0.192 s is well fit by a power-law function with an exponential high-energy cutoff. The best-fit parameters are: Alpha = -0.36 +/- 0.10, Epeak = 1319 +/- 161 keV. The fluence (10-1000 keV) in this time interval is (1.21 +/- 0.06)E-06 erg/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 22617 table
GRB_name GRB180402A
GCN_number 22617
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 22617 SUBJECT: GRB 180402A: ISON-NM early optical limits DATE: 18/04/08 20:40:42 GMT FROM: Alexei Pozanenko at IKI, Moscow E. Mazaeva (IKI), L. Elenin (KIAM), A. Pozanenko (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift short burst GRB 180402A (Lien et al., GCN 22580) with 0.4-m telescope of ISON-NM observatory starting on Apr., 02 (UT) 09:45:39, i.e. 40 seconds after the burst trigger. We obtained 4 unfiltered images of 30 s exposure each. We do not detect any source within XRT error circle (Lien et al., GCN 22580). Upper limits are following. Date start (Ut) t-T0 Exp. UL (3sigma) (mid.,sec) (s) 2018-04-02 09:45:39 55 1*30 14.5 2018-04-02 09:45:39 133 4*30 15.0 The photometry is based on nearby USNO-B1.0 stars (R2 magnitudes).