Gamma-ray Burst 241120A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 20 Nov 24 05:54:20 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     753774843
GRB_RA:          194.133d {+12h 56m 32s} (J2000),
                 194.415d {+12h 57m 40s} (current),
                 193.566d {+12h 54m 16s} (1950)
GRB_DEC:         +47.383d {+47d 22' 60"} (J2000),
                 +47.249d {+47d 14' 57"} (current),
                 +47.654d {+47d 39' 13"} (1950)
GRB_ERROR:       8.82 [deg radius, statistical plus systematic]
GRB_INTEN:       165 [cnts/sec]
DATA_SIGNIF:     11.70 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20634 TJD;   325 DOY;   24/11/20
GRB_TIME:        21238.54 SOD {05:53:58.54} UT
GRB_PHI:          88.00 [deg]
GRB_THETA:        35.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.71
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      97%  GRB
2nd_MOST_LIKELY:   2%  Generic Transient
DETECTORS:       0,1,0, 0,0,0, 0,0,0, 0,1,0, 0,0,
SUN_POSTN:       236.16d {+15h 44m 39s}  -19.80d {-19d 48' 03"}
SUN_DIST:         76.83 [deg]   Sun_angle= 2.8 [hr] (West of Sun)
MOON_POSTN:      118.59d {+07h 54m 22s}  +25.73d {+25d 43' 46"}
MOON_DIST:        62.06 [deg]
MOON_ILLUM:      77 [%]
GAL_COORDS:      120.44, 69.72 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      167.88, 47.81 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_lc_medres34_bn241120246.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 33.98,-14.62 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL event (trignum=10982).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 20 Nov 24 05:54:26 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      60
TRIGGER_NUM:     753774843
GRB_RA:          195.050d {+13h 00m 12s} (J2000),
                 195.320d {+13h 01m 17s} (current),
                 194.506d {+12h 58m 02s} (1950)
GRB_DEC:         +53.617d {+53d 37' 00"} (J2000),
                 +53.483d {+53d 28' 59"} (current),
                 +53.886d {+53d 53' 09"} (1950)
GRB_ERROR:       4.33 [deg radius, statistical plus systematic]
GRB_INTEN:       943 [cnts/sec]
DATA_SIGNIF:     45.10 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        20634 TJD;   325 DOY;   24/11/20
GRB_TIME:        21238.54 SOD {05:53:58.54} UT
GRB_PHI:          94.00 [deg]
GRB_THETA:        40.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.53
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,1,0, 0,0,0, 0,0,0, 0,1,0, 0,0,
SUN_POSTN:       236.16d {+15h 44m 39s}  -19.80d {-19d 48' 03"}
SUN_DIST:         81.30 [deg]   Sun_angle= 2.7 [hr] (West of Sun)
MOON_POSTN:      118.59d {+07h 54m 22s}  +25.73d {+25d 43' 45"}
MOON_DIST:        61.84 [deg]
MOON_ILLUM:      77 [%]
GAL_COORDS:      120.02, 63.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      162.65, 53.12 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_lc_medres34_bn241120246.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 33.98,-14.62 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL event (trignum=10982).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 20 Nov 24 05:55:12 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     753774843
GRB_RA:          192.460d {+12h 49m 50s} (J2000),
                 192.743d {+12h 50m 58s} (current),
                 191.889d {+12h 47m 33s} (1950)
GRB_DEC:         +49.650d {+49d 38' 60"} (J2000),
                 +49.515d {+49d 30' 53"} (current),
                 +49.922d {+49d 55' 20"} (1950)
GRB_ERROR:       1.36 [deg radius, statistical only]
DATA_SIGNIF:     28.10 [sigma]
DATA_INTERVAL:   3.072 [sec]
GRB_DATE:        20634 TJD;   325 DOY;   24/11/20
GRB_TIME:        21238.54 SOD {05:53:58.54} UT
GRB_PHI:          92.00 [deg]
GRB_THETA:        36.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       236.16d {+15h 44m 39s}  -19.80d {-19d 48' 04"}
SUN_DIST:         79.28 [deg]   Sun_angle= 2.9 [hr] (West of Sun)
MOON_POSTN:      118.60d {+07h 54m 24s}  +25.73d {+25d 43' 39"}
MOON_DIST:        60.66 [deg]
MOON_ILLUM:      77 [%]
GAL_COORDS:      123.61, 67.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      164.53, 49.01 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_lc_medres34_bn241120246.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_753774843.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL event (trignum=10982).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 20 Nov 24 05:54:36 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      59
TRIGGER_NUM:     753774843
GRB_RA:          196.380d {+13h 05m 31s} (J2000),
                 196.649d {+13h 06m 36s} (current),
                 195.837d {+13h 03m 21s} (1950)
GRB_DEC:         +51.620d {+51d 37' 12"} (J2000),
                 +51.487d {+51d 29' 14"} (current),
                 +51.887d {+51d 53' 15"} (1950)
GRB_ERROR:       1.93 [deg radius, statistical only]
DATA_SIGNIF:     47.30 [sigma]
DATA_INTERVAL:   1.024 [sec]
GRB_DATE:        20634 TJD;   325 DOY;   24/11/20
GRB_TIME:        21238.54 SOD {05:53:58.54} UT
GRB_PHI:          91.00 [deg]
GRB_THETA:        39.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       236.16d {+15h 44m 39s}  -19.80d {-19d 48' 04"}
SUN_DIST:         79.23 [deg]   Sun_angle= 2.6 [hr] (West of Sun)
MOON_POSTN:      118.59d {+07h 54m 23s}  +25.73d {+25d 43' 44"}
MOON_DIST:        62.88 [deg]
MOON_ILLUM:      77 [%]
GAL_COORDS:      117.68, 65.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      165.76, 52.08 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_lc_medres34_bn241120246.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_753774843.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL event (trignum=10982).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 20 Nov 24 06:03:19 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     753774843
GRB_RA:          192.460d {+12h 49m 50s} (J2000),
                 192.743d {+12h 50m 58s} (current),
                 191.889d {+12h 47m 33s} (1950)
GRB_DEC:         +49.650d {+49d 38' 60"} (J2000),
                 +49.515d {+49d 30' 53"} (current),
                 +49.922d {+49d 55' 20"} (1950)
GRB_ERROR:       1.17 [deg radius, statistical only]
GRB_DATE:        20634 TJD;   325 DOY;   24/11/20
GRB_TIME:        21238.54 SOD {05:53:58.54} UT
GRB_PHI:          92.00 [deg]
GRB_THETA:        36.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       236.17d {+15h 44m 40s}  -19.80d {-19d 48' 08"}
SUN_DIST:         79.28 [deg]   Sun_angle= 2.9 [hr] (West of Sun)
MOON_POSTN:      118.68d {+07h 54m 43s}  +25.71d {+25d 42' 40"}
MOON_DIST:        60.62 [deg]
MOON_ILLUM:      77 [%]
GAL_COORDS:      123.61, 67.48 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      164.53, 49.01 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_lc_medres34_bn241120246.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_locplot_all_bn241120246.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL event (trignum=10982).

GCN Circular #38279
The Fermi GBM team reports the detection of a likely LONG GRB
At 05:53:58 UT on 20 Nov 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241120A (trigger 753774843.543556 / 241120246).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 192.5, Dec = 49.7 (J2000 degrees, equivalent to J2000 12h 50m, 49d 42'), with a statistical uncertainty of 1.2 degrees.
The angle from the Fermi LAT boresight is 36.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_skymap_all_bn241120246.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_healpix_all_bn241120246.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241120246/quicklook/glg_lc_medres34_bn241120246.gif
GCN Circular #38280
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 4 s has been detected by IBAS in the IBIS/ISGRI data at 05:53:58 UT of 2024 November 20.
The refined coordinates (J2000) are:
```
R.A.=  194.2908 deg,
DEC.=  52.1504 deg
```
with an uncertainty of 1 arcmin (90% c.l.).
A preliminary analysis gives a peak flux of about 2 ph/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 1.3e-06 erg/cmsq.
This burst has also been detected by Fermi/GBM (GCN 38279), and its position is at 2.7=C2=B0 from the Fermi reported position.
A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html
GCN Circular #38285
R. Hamburg (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 05:53:58.54 UT on 20 November 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241120A (trigger 753774843/241120246), which was also detected by INTEGRAL/IBAS (Gotz et al. 2024, GCN 38280). The Fermi GBM on-ground location is consistent with the INTEGRAL position.
The angle from the Fermi LAT boresight is about 39 degrees.
The GBM light curve consists of a single emission episode with a duration (T90) of about 3.2 s (50-300 keV). The time-averaged spectrum from T0-0.5 to T0+3.3 s is best fit by a Band function with Epeak = 181 +/- 13, alpha = -0.3 +/- 0.1, and beta = -2.4 +/- 0.2.
The event fluence (10-1000 keV) in this time interval is (3.6 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.7 s in the 10-1000 keV band is 12.3 +/- 0.3 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/"
GCN Circular #38291
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), R. Ya. Inasaridze (AbAO), V. Aivazyan (AbAO) report on behalf of IKI-GRB-FuN:
We observed the field of GRB 241120A detected (The Fermi GBM team, GCN 38279; Gotz et al., GCN 38280) with AZT-33IK telescope of Sayan (Mondy) observatory, and AS-32 telescope of Abastumani observatory (AbAO). The observations started at Mondy on 2024-11-20 at 20:01 UT, i.e. ~0.6 days since trigger. Within the localization circle of INTEGRAL (Gotz et al., GCN 38280) we do not find any evident candidates in comparison with known catalogues. However, there is a source in our observations at the coordinates of (J2000) RA=12:57:04.3 Dec=+52:08:45.8 with uncertainty of 0.2 arcses in both coordinates for which it can be assumed that the source is showing marginal decreasing of brightness. The source is presented at least in PS1, SDSS and DESI. Preliminary photometry of the source is as follows:
```
Date       UT_start Exp_time t-T0      Filter OT Err    UL     
                      (s)   (mid, days)                 (3sigma)
2024-11-20 20:01:27 28*120   0.60798   R   19.85 0.10   22.6   AZT-33IK
2024-11-20 23:12:31 56*60    0.74066   R   20.1  0.3    20.6   AS-32
```
The magnitudes were calibrated with nearby USNO-B1.0 stars (R2 magnitudes) and not corrected for the Galactic extinction.
The source is 53 arcsec from the centre of IBIS/ISGRI localization. The catalogued source is a galaxy with estimated photo-z = 0.36 and brightness of r=20.2 (SDSS DR16), and photo-z = 0.38 (DESI). The source brightness in PS1 is r = 20.69. We may suggest the source is a possible candidate in the afterglow of GRB 241120A.
GCN Circular #38295
M. L. Cherry (LSU), A. Yoshida, T. Sakamoto, S. Sugita, Y. Kawakubo (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
The long GRB 241120A (Fermi GBM Final Real-time Localization: Fermi GBM team, GCN Circ. 38279; a long GRB detected by INTEGRAL: Gotz et al., GCN Circ. 38280; Fermi GBM Observation, Hamburg et al., GCN Circ. 38285) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 05:54:00.493 UTC on 20 November 2024 (https://cgbm.calet.jp/cgbm_trigger/flight/1416117245/index.html).
The burst signal was seen by all CGBM detectors. Because of a problem with the ground alert processing script, the GCN notice was not distributed automatically for this event.
The burst light curve shows a single emission episode that starts at T-3.0 sec, peaks at T+0.1 sec, and ends at T+0.8 sec. The T90 and T50 durations measured by the SGM data are 2.9 =C2=B1 0.5 sec and 0.8 =C2=B1 0.3 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
https://cgbm.calet.jp/cgbm_trigger/ground/1416117245/
The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.
GCN Circular #38296
C. Adami (LAM/Pytheas/AMU), M. Dennefeld (IAP), S. Basa (LAM/OHP/Pytheas/AMU) report on behalf of a larger collaboration:
We observed the field of GRB241120A (Gotz et al., GCN 38280; Fermi GRM team, GCN 38279; Hamburg et al., GCN 38285; Pankov et al., GCN 38291; Cherry et al., GCN 38295) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. Four exposures were obtained in the r-band (300s + 3x420s) from 2024 21 November 04:39 UT to 2024 21 November 05:05 UT (~+23h after detection) with two positions on the sky (position "1" for exposures 1 and 4, and position "2" for exposures 2 and 3) separated by a dithering of ~10arcsec. The moon was at an illumination of ~68% and at a distance of 56deg from target.
The combined frame has a detection upper limit of r~22.5+/-0.6 (5sigma limit). The photometric calibration was performed using objects from the PanSTARRS catalog. The magnitudes are not corrected for Galactic extinction.
There is no clear additional objects in the MISTRAL image as compared with the PanStarrs r-band image except a source at 12:57:06.0 +52:08:26.6 (r~22.2+/-0.2). This source (apparently extended) is however only present in two of the four exposures we performed (position "2" exposures) and is possibly an internal reflection within the instrument due to the intense Moon illumination. More observations are requested to check this point.
We also checked the candidate of Pankov et al. We clearly detect this object and measured a magnitude of r~20.40+/-0.08 23h after the original detection. This object is also present in the PanStarrs r-band catalog at r~20.39+/-0.02. If this was the transient, it was back to its initial magnitude 0.96 days after detection. This would be in good agreement with the light curve proposed by Pankov et al.
We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Pierre Troncin and the SOPHIE observer Aleyna Adamson.
GCN Circular #38297
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long-duration GRB 241120A (Fermi-GBM detection: Fermi GBM team, GCN 38279; Hamburg & Meegan, GCN 38285; INTEGRAL (IBIS/ISGRI) detection: Gotz et al., GCN 38280; CALET (CGBM) detection: Cherry et al., GCN 38295) triggered Konus-Wind at T0=21240.717 s UT (05:54:00.717).
The burst light curve shows a single pulse, which starts at ~T0-1.9 s and has a total duration of ~2.9 s. The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241120_T21240/
As observed by Konus-Wind, the burst had a fluence of 3.55(-0.48,+0.59)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.372 s, of 4.98(-1.17,+1.30)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.91(-0.29,+0.34) and Ep = 267(-56,+95) keV (chi2 = 80/78 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.6 (chi2 = 80/77 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #38307
A. Pal (Konkoly Observatory), M. Dafcikova, J. Ripa, M. Kolar, N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, 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 241120A (Fermi/GBM detection: GCN 38279; INTEGRAL/SPI-ACS detection: GCN 38280; CALET/CGBM detection: GCN 38295; Konus/Wind detection: GCN 38297) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abst= ract).
The detection was confirmed at the peak time 2024-11-20 05:54:00.1 UTC. The T90 duration measured by GRBAlpha is 3 s and the overall significance during T90 reaches 8 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB241120A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/. GRBAlpha, launched on 2021 March 22, is a demonstration mission for a futur= e CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GR= BAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM ar= ray, covering the energy range from ~50 keV to ~1000 keV. To increase the d= uty cycle and the downlink rate, the upgrade of the on-board data acquisiti= on software stack is in progress. 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: 25-Nov-2024 [Disclaimer]