Gamma-ray Burst 220926B

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN Notice

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Mon 26 Sep 22 10:38:34 UT
NOTICE_TYPE:    INTEGRAL Wakeup
TRIGGER_NUM:    10042,   Sub_Num: 0
GRB_RA:         273.9650d {+18h 15m 52s} (J2000),
                274.3522d {+18h 17m 25s} (current),
                273.1131d {+18h 12m 27s} (1950)
GRB_DEC:        -37.2473d {-37d 14' 49"} (J2000),
                -37.2381d {-37d 14' 16"} (current),
                -37.2645d {-37d 15' 51"} (1950)
GRB_ERROR:      2.93 [arcmin, radius, statistical only]
GRB_INTEN:      11.23 [sigma]
GRB_TIME:       38299.75 SOD {10:38:19.75} UT
GRB_DATE:       19848 TJD;   269 DOY;   22/09/26
SC_RA:          266.25 [deg] (J2000)
SC_DEC:         -32.46 [deg] (J2000)
SUN_POSTN:      183.06d {+12h 12m 14s}   -1.32d {-01d 19' 24"}
SUN_DIST:        90.23 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:     190.17d {+12h 40m 41s}   -1.13d {-01d 07' 59"}
MOON_DIST:       84.68 [deg]
GAL_COORDS:     355.83, -9.58 [deg] galactic lon,lat of the burst
ECL_COORDS:     273.25,-13.85 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=2.0000 and Time_Error=2.0000.  
COMMENTS:       Possibly real GRB event

GCN Notice

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Mon 26 Sep 22 10:38:38 UT
NOTICE_TYPE:    INTEGRAL Refined
TRIGGER_NUM:    10042,   Sub_Num: 1
GRB_RA:         273.9546d {+18h 15m 49s} (J2000),
                274.3418d {+18h 17m 22s} (current),
                273.1027d {+18h 12m 25s} (1950)
GRB_DEC:        -37.2428d {-37d 14' 33"} (J2000),
                -37.2336d {-37d 14' 00"} (current),
                -37.2599d {-37d 15' 35"} (1950)
GRB_ERROR:      2.58 [arcmin, radius, statistical only]
GRB_INTEN:      24.58 [sigma]
GRB_TIME:       38305.75 SOD {10:38:25.75} UT
GRB_DATE:       19848 TJD;   269 DOY;   22/09/26
SC_RA:          266.25 [deg] (J2000)
SC_DEC:         -32.46 [deg] (J2000)
SUN_POSTN:      183.06d {+12h 12m 14s}   -1.32d {-01d 19' 25"}
SUN_DIST:        90.22 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:     190.17d {+12h 40m 42s}   -1.13d {-01d 08' 00"}
MOON_DIST:       84.67 [deg]
GAL_COORDS:     355.83, -9.57 [deg] galactic lon,lat of the burst
ECL_COORDS:     273.24,-13.85 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=5.0000 and Time_Error=5.0000.  
COMMENTS:       Possibly real GRB event

GCN Notice

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Mon 26 Sep 22 10:41:34 UT
NOTICE_TYPE:    INTEGRAL Refined
TRIGGER_NUM:    10042,   Sub_Num: 2
GRB_RA:         273.9542d {+18h 15m 49s} (J2000),
                274.3414d {+18h 17m 22s} (current),
                273.1023d {+18h 12m 25s} (1950)
GRB_DEC:        -37.2427d {-37d 14' 33"} (J2000),
                -37.2335d {-37d 14' 00"} (current),
                -37.2598d {-37d 15' 34"} (1950)
GRB_ERROR:      2.58 [arcmin, radius, statistical only]
GRB_INTEN:      24.64 [sigma]
GRB_TIME:       38305.75 SOD {10:38:25.75} UT
GRB_DATE:       19848 TJD;   269 DOY;   22/09/26
SC_RA:          266.25 [deg] (J2000)
SC_DEC:         -32.46 [deg] (J2000)
SUN_POSTN:      183.06d {+12h 12m 14s}   -1.32d {-01d 19' 27"}
SUN_DIST:        90.22 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:     190.20d {+12h 40m 47s}   -1.15d {-01d 08' 44"}
MOON_DIST:       84.65 [deg]
GAL_COORDS:     355.83, -9.57 [deg] galactic lon,lat of the burst
ECL_COORDS:     273.24,-13.85 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=10.0000 and Time_Error=10.0000.  
COMMENTS:       Possibly real GRB event

GCN Notice

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Mon 26 Sep 22 11:24:07 UT
NOTICE_TYPE:    INTEGRAL Offline
TRIGGER_NUM:    10042,   Sub_Num: 3
GRB_RA:         273.9353d {+18h 15m 44s} (J2000),
                274.3225d {+18h 17m 17s} (current),
                273.0834d {+18h 12m 20s} (1950)
GRB_DEC:        -37.2413d {-37d 14' 28"} (J2000),
                -37.2322d {-37d 13' 55"} (current),
                -37.2584d {-37d 15' 29"} (1950)
GRB_ERROR:      1.00 [arcmin, radius, statistical only]
GRB_INTEN:      24.64 [sigma]
GRB_TIME:       38305.75 SOD {10:38:25.75} UT
GRB_DATE:       19848 TJD;   269 DOY;   22/09/26
SC_RA:          266.25 [deg] (J2000)
SC_DEC:         -32.46 [deg] (J2000)
SUN_POSTN:      183.08d {+12h 12m 20s}   -1.34d {-01d 20' 09"}
SUN_DIST:        90.18 [deg]   Sun_angle= -6.1 [hr] (East of Sun)
MOON_POSTN:     190.54d {+12h 42m 10s}   -1.32d {-01d 19' 25"}
MOON_DIST:       84.25 [deg]
GAL_COORDS:     355.83, -9.56 [deg] galactic lon,lat of the burst
ECL_COORDS:     273.23,-13.85 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Time_Scale=10.0000 and Time_Error=10.0000.  
COMMENTS:       refined_coordinates_after_offline_analysis

GCN Circular #32586
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
GCN Circular #32587
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.
GCN Circular #32592
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.
GCN Circular #32781
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.

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Jochen Greiner, last update: 17-Oct-2022 [Disclaimer]