//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24147 SUBJECT: GRB 190422A: Swift detection of a burst DATE: 19/04/22 23:15:41 GMT FROM: David Palmer at LANL M. J. Moss (George Washington University), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 22:55:29 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190422A (trigger=899979). Swift did not slew until ~T+8 min due to an observing constraint. The BAT on-board calculated location is RA, Dec 182.124, -60.238 which is RA(J2000) = 12h 08m 30s Dec(J2000) = -60d 14' 15" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of at least 220 sec, where data are currently available. The peak count rate based on the available data was ~2000 counts/sec (15-350 keV), at ~175 sec after the trigger. The XRT began observing the field at 23:04:18.5 UT, 529.3 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 182.03650, -60.22311 which is equivalent to: RA(J2000) = 12h 08m 08.76s Dec(J2000) = -60d 13' 23.2" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 165 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 (8.59 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 1.1 (+1.25/-0.89) x 10^22 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 531 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 mag. No correction has been made for the large, but uncertain, extinction expected. This source lies within the current (Sector 11) field-of-view of TESS camera 2. Burst Advocate for this burst is M. J. Moss (mikejmoss3 AT gmail.com). 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24148 SUBJECT: Fermi GRB190422.67 Global MASTER-Net observations report DATE: 19/04/22 23:46:22 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, Moscow State University A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) 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, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB190422.67 ( 12h 36m 55.20s , -54d 57m 00.00s, R=7.96) errorbox 22200 sec after trigger time at 2019-04-22 22:15:04 UT, with upper limit up to 17.1 mag. The observations began at zenit distance = 85 deg. The sun altitude is -33.1 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB190422.67 errorbox 24752 sec after trigger time at 2019-04-22 22:57:37 UT, with upper limit up to 17.6 mag. Observations started at twilight. The observations began at zenit distance = 50 deg. The sun altitude is -11.4 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1000359 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 22290 | 2019-04-22 22:15:04 | MASTER-IAC | ( 13h 8m 49.48s , -49d 50m 04.89s) | C | 180 | 16.5 | 22290 | 2019-04-22 22:15:04 | MASTER-IAC | ( 13h 21m 27.24s , -49d 53m 16.96s) | C | 180 | 16.1 | 22518 | 2019-04-22 22:18:52 | MASTER-IAC | ( 13h 8m 49.73s , -49d 49m 45.20s) | C | 180 | 16.6 | 22518 | 2019-04-22 22:18:52 | MASTER-IAC | ( 13h 21m 27.30s , -49d 52m 57.18s) | C | 180 | 16.3 | 22973 | 2019-04-22 22:26:27 | MASTER-IAC | ( 13h 21m 25.93s , -49d 53m 15.20s) | C | 180 | 16.7 | 22973 | 2019-04-22 22:26:27 | MASTER-IAC | ( 13h 8m 48.45s , -49d 50m 06.11s) | C | 180 | 17.0 | 23202 | 2019-04-22 22:30:16 | MASTER-IAC | ( 13h 8m 50.02s , -49d 50m 08.74s) | C | 180 | 17.1 | 23202 | 2019-04-22 22:30:16 | MASTER-IAC | ( 13h 21m 27.28s , -49d 53m 16.75s) | C | 180 | 16.8 | 24763 | 2019-04-22 22:57:37 | MASTER-OAFA | ( 12h 7m 16.02s , -60d 7m 13.60s) | C | 20 | 16.4 | 24792 | 2019-04-22 22:58:01 | MASTER-IAC | ( 12h 6m 27.16s , -53d 7m 29.24s) | P- | 30 | 15.2 | 24792 | 2019-04-22 22:58:01 | MASTER-IAC | ( 12h 7m 33.15s , -53d 9m 58.65s) | P| | 30 | 15.1 | 24832 | 2019-04-22 22:58:36 | MASTER-OAFA | ( 12h 7m 16.20s , -60d 7m 15.15s) | C | 40 | 16.7 | 24863 | 2019-04-22 22:59:07 | MASTER-IAC | ( 12h 7m 00.67s , -53d 8m 05.99s) | P- | 40 | 15.3 | 24863 | 2019-04-22 22:59:07 | MASTER-IAC | ( 12h 8m 06.57s , -53d 10m 34.27s) | P| | 40 | 15.4 | 24915 | 2019-04-22 22:59:54 | MASTER-OAFA | ( 12h 7m 16.40s , -60d 7m 16.70s) | C | 50 | 16.8 | 24948 | 2019-04-22 23:00:22 | MASTER-IAC | ( 12h 7m 00.38s , -53d 45m 45.99s) | P- | 60 | 15.7 | 24948 | 2019-04-22 23:00:22 | MASTER-IAC | ( 12h 8m 07.13s , -53d 48m 13.24s) | P| | 60 | 15.7 | 25017 | 2019-04-22 23:01:26 | MASTER-OAFA | ( 12h 7m 16.48s , -60d 7m 17.62s) | C | 70 | 17.0 | 25060 | 2019-04-22 23:02:04 | MASTER-IAC | ( 12h 7m 01.44s , -53d 46m 23.47s) | P- | 80 | 15.9 | 25060 | 2019-04-22 23:02:04 | MASTER-IAC | ( 12h 8m 08.15s , -53d 48m 49.88s) | P| | 80 | 15.9 | 25136 | 2019-04-22 23:03:15 | MASTER-OAFA | ( 12h 7m 16.59s , -60d 7m 18.78s) | C | 90 | 17.2 | 25184 | 2019-04-22 23:03:58 | MASTER-IAC | ( 12h 7m 01.70s , -53d 47m 24.89s) | P- | 100 | 16.0 | 25184 | 2019-04-22 23:03:58 | MASTER-IAC | ( 12h 8m 08.38s , -53d 49m 50.58s) | P| | 100 | 16.0 | 25280 | 2019-04-22 23:05:24 | MASTER-OAFA | ( 12h 7m 16.57s , -60d 7m 19.33s) | C | 120 | 17.4 | 25334 | 2019-04-22 23:06:13 | MASTER-IAC | ( 12h 7m 02.22s , -53d 46m 22.39s) | P- | 130 | 16.0 | 25334 | 2019-04-22 23:06:13 | MASTER-IAC | ( 12h 8m 08.81s , -53d 48m 47.66s) | P| | 130 | 16.0 | 25455 | 2019-04-22 23:08:04 | MASTER-OAFA | ( 12h 7m 16.54s , -60d 7m 19.63s) | C | 150 | 17.5 | 25512 | 2019-04-22 23:08:56 | MASTER-IAC | ( 12h 7m 02.44s , -53d 31m 39.33s) | P- | 160 | 16.1 | 25512 | 2019-04-22 23:08:56 | MASTER-IAC | ( 12h 8m 08.63s , -53d 34m 04.09s) | P| | 160 | 16.2 | 25658 | 2019-04-22 23:11:12 | MASTER-OAFA | ( 12h 7m 16.45s , -60d 7m 19.73s) | C | 180 | 17.6 | 25716 | 2019-04-22 23:12:10 | MASTER-IAC | ( 12h 7m 03.58s , -53d 50m 03.12s) | P- | 180 | 15.9 | 25716 | 2019-04-22 23:12:10 | MASTER-IAC | ( 12h 8m 09.30s , -53d 52m 19.78s) | P| | 180 | 16.0 | 25876 | 2019-04-22 23:14:50 | MASTER-OAFA | ( 12h 7m 16.30s , -60d 7m 19.71s) | C | 180 | 17.6 | 25948 | 2019-04-22 23:16:02 | MASTER-IAC | ( 12h 7m 05.40s , -53d 49m 25.20s) | P- | 180 | 15.7 | 25952 | 2019-04-22 23:16:06 | MASTER-IAC | ( 12h 8m 11.03s , -53d 51m 41.65s) | P| | 180 | 15.9 | 26184 | 2019-04-22 23:19:58 | MASTER-IAC | ( 12h 8m 10.96s , -53d 55m 24.75s) | P| | 180 | 15.9 | 26184 | 2019-04-22 23:19:58 | MASTER-IAC | ( 12h 7m 05.11s , -53d 53m 08.62s) | P- | 180 | 15.8 | 26413 | 2019-04-22 23:23:47 | MASTER-IAC | ( 12h 8m 11.60s , -53d 47m 46.13s) | P| | 180 | 16.0 | 26413 | 2019-04-22 23:23:47 | MASTER-IAC | ( 12h 7m 05.87s , -53d 45m 30.02s) | P- | 180 | 15.9 | 26647 | 2019-04-22 23:27:41 | MASTER-IAC | ( 12h 7m 07.09s , -53d 44m 51.54s) | P- | 180 | 16.0 | 26648 | 2019-04-22 23:27:42 | MASTER-IAC | ( 12h 8m 12.93s , -53d 47m 07.24s) | P| | 180 | 16.0 | 26889 | 2019-04-22 23:31:43 | MASTER-IAC | ( 12h 8m 14.25s , -54d 1m 56.91s) | C | 180 | 15.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24150 SUBJECT: Swift GRB190422.96 Global MASTER-Net observations report DATE: 19/04/23 00:31:21 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, Moscow State University A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) 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, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB190422.96 ( 12h 8m 29.76s , -60d 14m 16.80s, R=0.05) errorbox 128 sec after trigger time at 2019-04-22 22:57:37 UT, with upper limit up to 17.7 mag. Observations started at twilight. The observations began at zenit distance = 47 deg. The sun altitude is -11.4 deg. The galactic latitude b = -60 deg., longitude l = 98 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1000655 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 138 | MASTER-OAFA | C | 20 | 16.4 | 207 | MASTER-OAFA | C | 40 | 16.7 | 290 | MASTER-OAFA | C | 50 | 16.8 | 392 | MASTER-OAFA | C | 70 | 17.0 | 512 | MASTER-OAFA | C | 90 | 17.2 | 656 | MASTER-OAFA | C | 120 | 17.4 | 830 | MASTER-OAFA | C | 150 | 17.5 | 1034 | MASTER-OAFA | C | 180 | 17.6 | 1252 | MASTER-OAFA | C | 180 | 17.6 | 1471 | MASTER-OAFA | C | 180 | 17.7 | 1690 | MASTER-OAFA | C | 180 | 17.7 | 1909 | MASTER-OAFA | C | 180 | 17.7 | 2130 | MASTER-OAFA | C | 180 | 17.7 | 2348 | MASTER-OAFA | C | 180 | 17.7 | 2567 | MASTER-OAFA | C | 180 | 17.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24151 SUBJECT: GRB 190422A: Enhanced Swift-XRT position DATE: 19/04/23 02:43:14 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1699 s of XRT Photon Counting mode data and 1 UVOT images for GRB 190422A, 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 = 182.03450, -60.22425 which is equivalent to: RA (J2000): 12h 08m 8.28s Dec (J2000): -60d 13' 27.3" 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24155 SUBJECT: GRB 190422A: Swift-XRT refined Analysis DATE: 19/04/23 14:32:12 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), A. Tohuvavohu (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (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) and M.J. Moss report on behalf of the Swift-XRT team: We have analysed 6.8 ks of XRT data for GRB 190422A (Moss et al. GCN Circ. 24147), from 536 s to 31.0 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 24151). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=3.7 (+1.8, -1.2). At T+895 s the decay flattens to an alpha of -0.4 (+0.4, -0.5) before breaking again at T+3926 s to a final decay with index alpha=0.54 (+/-0.15). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.04 (+0.18, -0.17). The best-fitting absorption column is 1.66 (+0.25, -0.23) x 10^22 cm^-2, in excess of the Galactic value of 8.6 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 5.5 x 10^-11 (1.2 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.66 (+0.25, -0.23) x 10^22 cm^-2 Galactic foreground: 8.6 x 10^21 cm^-2 Excess significance: 5.7 sigma Photon index: 2.04 (+0.18, -0.17) If the light curve continues to decay with a power-law decay index of 0.54, the count rate at T+24 hours will be 0.11 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.3 x 10^-12 (1.4 x 10^-11) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00899979. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24157 SUBJECT: GRB 190422A: Swift-BAT refined analysis DATE: 19/04/23 15:19:18 GMT FROM: Amy Lien at GSFC T. Sakamoto (AGU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), M. J. Moss (GWU), D. M. Palmer (LANL), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (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 190422A (trigger #899979) (Moss et al., GCN Circ. 24147). The BAT ground-calculated position is RA, Dec = 182.126, -60.167 deg which is RA(J2000) = 12h 08m 30.3s Dec(J2000) = -60d 10' 02.6" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 82%. The mask-weighted light curve shows a multi-peaked structure. The emission started before the source entered the BAT FOV, and lasted until ~T+360 s. The main peak occurred at ~ T+175 s. We cannot determine T90 since the available data do not cover the entire burst emission. The time-averaged spectrum from T+6.39 to T+359.48 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.76 +- 0.08. The fluence in the 15-150 keV band is 6.5 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+174.47 sec in the 15-150 keV band is 2.6 +- 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/899979/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24159 SUBJECT: GRB 190422A: Swift/UVOT Upper Limits DATE: 19/04/23 17:30:19 GMT FROM: Kira Simpson at PSU GRB 190422A: Swift/UVOT Upper Limits K. K. Simpson (PSU) and M. J. Moss (George Washington University) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 190422A 532 s after the BAT trigger (Moss et al., GCN Circ. 24147). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 24151) 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 532 682 147 >18.8 white 532 7906 647 >18.8 v 689 6879 352 >17.2 b 788 7700 352 >18.3 u 763 7495 352 >18.9 w1 738 7289 352 >19.1 m2 713 7084 352 >19.1 w2 838 7995 438 >19.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.58 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 24161 SUBJECT: GRB 190422A: Fermi GBM detection DATE: 19/04/23 22:20:03 GMT FROM: Rachel Hamburg at UAH R. Hamburg (UAH), C. Fletcher (USRA), and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 22:58:24.00 UT on 22 April 2019, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 190422A (trigger 577666709 / 190422957) which was also detected by the Swift/BAT (Moss et al. 2019, GCN 24147). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 71 degrees. The GBM light curve shows a complex lightcurve with one main peak preceded and followed by weaker bursts of emission. A duration (T90) is calculated to be about 212 s (50-300 keV). The time-averaged spectrum from T0-21.5 s to T0+42.0 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.67 +/- 0.09 and the cutoff energy, parameterized as Epeak, is 58 +/- 7 keV. A Band function fits the spectrum equally well with Epeak = 50 +/- 9 keV, alpha = -1.57 +/- 0.14 and beta = -2.42 +/- 0.27. The event fluence (10-1000 keV) in this time interval is (4.8 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.54 s in the 10-1000 keV band is 4.84 +/- 0.17 ph/s/cm^2." The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/