//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32585 SUBJECT: GRB 220926A: Swift detection of a burst DATE: 22/09/26 10:04:24 GMT FROM: Kim Page at U.of Leicester M. J. Moss (GWU), R. Brivio (INAF-OAB), S. Dichiara (PSU), M. Ferro (INAF-OAB), N. P. M. Kuin (UCL-MSSL), K. L. Page (U Leicester), T. M. Parsotan (GSFC/UMBC/CRESSTII), T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team: At 09:22:50 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 220926A (trigger=1125354). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 245.011, -16.043 which is RA(J2000) = 16h 20m 03s Dec(J2000) = -16d 02' 32" 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 40 sec. The peak count rate was ~400 counts/sec (15-350 keV), at ~5 sec after the trigger. The source is not well identified in the rate data which is typical of an image trigger. The XRT began observing the field at 09:25:04.4 UT, 134 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 245.0022, -16.0438 which is equivalent to: RA(J2000) = 16h 20m 0.53s Dec(J2000) = -16d 02' 37.7" with an uncertainty of up to 2 arcmin (radius, 90% containment). Given the star tracker loss of lock at the time of the trigger, it is unclear how accurate this localisation is, hence the large uncertainty listed. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the White filter starting 143 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image processing FAILED because of no aspect solution. Results from the list of sources generated on-board are not available at this time. No correction has been made for the expected extinction corresponding to E(B-V) of 0.269. Note that this trigger occurred during an interval when the star trackers had lost lock. However, we believe this to be a real GRB. 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: 32586 SUBJECT: GRB 220926B DATE: 22/09/26 11:24:44 GMT FROM: Diego Gotz at CEA D. Gotz (CEA Saclay), S.Mereghetti (INAF, IASF-Milano), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: a gamma-ray burst lasting about 20 s has been detected by IBAS in the IBIS/ISGRI data at 10:38:11 UT of 2022 September 26. The refined coordinates (J2000) are: R.A. = 273.9353 deg DEC. = -37.2414 deg with an uncertainty of 1.0 arcmin (90% c.l.). A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32587 SUBJECT: Analysis of long GRB 220926B detected by INTEGRAL DATE: 22/09/26 15:46:31 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC, Versoix) and J.Borkowski (CAMK, Torun) report: GRB 220926B detected by IBAS in the IBIS/ISGRI (Gotz et al. GCN 32586) had a peak flux > 2 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range greater than 7e-7 erg/cmq (20 s integration time). Due to telemetry saturation we can provide only lower limits to these quantities. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32588 SUBJECT: Swift GRB 220926A: Global MASTER-Net observations report DATE: 22/09/26 17:58:14 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 220926A ( M. J. Moss et al., GCN 32585) errorbox 29605 sec after notice time and 29694 sec after trigger time at 2022-09-26 17:37:44 UT, with upper limit up to 18.3 mag. Observations started at twilight. The observations began at zenith distance = 44 deg. The sun altitude is -13.6 deg. The galactic latitude b = 23 deg., longitude l = 359 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2101458 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 29785 | MASTER-SAAO | C | 180 | 18.0 | 29997 | MASTER-SAAO | C | 180 | 18.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32589 SUBJECT: Swift GRB220926.34: Global MASTER-Net observations report DATE: 22/09/26 18:02:41 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB220926.34 (trigger No 1125350,16h 19m 42.00s , -15d 50m 13.6s, R=0.05) errorbox 33953 sec after notice time and 34030 sec after trigger time at 2022-09-26 17:37:44 UT, with upper limit up to 18.3 mag. Observations started at twilight. The observations began at zenith distance = 44 deg. The sun altitude is -13.6 deg. The galactic latitude b = 23 deg., longitude l = 359 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2101427 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 34121 | MASTER-SAAO | C | 180 | 18.0 | 34333 | MASTER-SAAO | C | 180 | 18.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32590 SUBJECT: Swift Trigger 1125354 (GRB 220926A) is not a GRB DATE: 22/09/26 19:58:18 GMT FROM: Jamie Kennea at Penn State U J. A. Kennea (PSU), K. J. Page (Leicester), S. Dichiara (PSU) and M. J. Moss (GWU) report on behalf of the Neil Gehrels Swift Observatory Team: The Swift reported GRB 220926A (GCN #32585) is not a GRB. The trigger was caused by the combination of a star tracker outage and a trigger on Sco X-1. Therefore we formally retract this GRB. We apologize for this error. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32592 SUBJECT: Integral GRB220926.44: Global MASTER-Net observations report DATE: 22/09/26 23:19:08 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Integral GRB220926.44 (trigger No 10042,18h 15m 51.53s , -37d 14m 49.8s, R=0.0488333) errorbox 25573 sec after notice time and 25590 sec after trigger time at 2022-09-26 17:44:49 UT, with upper limit up to 17.0 mag. Observations started at twilight. The observations began at zenith distance = 16 deg. The sun altitude is -15.0 deg. The galactic latitude b = -10 deg., longitude l = 356 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2101504 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 25680 | MASTER-SAAO | C | 180 | 17.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32781 SUBJECT: GRB 220926B: Detection by GRBAlpha DATE: 22/10/17 13:39:57 GMT FROM: Jakub Ripa at Masaryk University <245487@mail.muni.cz> M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), F. Munz, N. Husarikova, J.-P. Breuer, M. Topinka, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 220926B (INTEGRAL IBIS/ISGRI detection: Gotz et al., GCN 32586) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The subthreshold 4.7 sigma detection was confirmed at the peak time 2022-09-26 10:38:21.2 UTC. The light curve obtained by GRBAlpha is temporally consistent with the light curve obtained by INTEGRAL IBIS/ISGRI. The GOES X-ray flux does not show any excess, so we exclude this detection being a solar flare. Therefore, this event is consistent with being a GRB with a duration, as measured by GRBAlpha, of ~8 s. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB220926B_GCN.pdf GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, we are continuously upgrading the on-board data acquisition software stack. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.