Gamma-ray Burst 240828A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 28 Aug 24 14:55:36 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     746549711
GRB_RA:          220.617d {+14h 42m 28s} (J2000),
                 220.893d {+14h 43m 34s} (current),
                 220.056d {+14h 40m 13s} (1950)
GRB_DEC:         +23.733d {+23d 43' 60"} (J2000),
                 +23.629d {+23d 37' 46"} (current),
                 +23.946d {+23d 56' 44"} (1950)
GRB_ERROR:       4.65 [deg radius, statistical plus systematic]
GRB_INTEN:       706 [cnts/sec]
DATA_SIGNIF:     31.20 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        20550 TJD;   241 DOY;   24/08/28
GRB_TIME:        53706.83 SOD {14:55:06.83} UT
GRB_PHI:         298.00 [deg]
GRB_THETA:        80.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.47
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       157.58d {+10h 30m 20s}   +9.39d {+09d 23' 11"}
SUN_DIST:         61.88 [deg]   Sun_angle= -4.2 [hr] (East of Sun)
MOON_POSTN:       93.81d {+06h 15m 14s}  +28.64d {+28d 38' 34"}
MOON_DIST:       107.02 [deg]
MOON_ILLUM:      27 [%]
GAL_COORDS:       31.43, 64.76 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      209.09, 37.32 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_lc_medres34_bn240828622.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 62.20,-5.68 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 28 Aug 24 14:55:45 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      60
TRIGGER_NUM:     746549711
GRB_RA:          226.000d {+15h 04m 00s} (J2000),
                 226.273d {+15h 05m 05s} (current),
                 225.447d {+15h 01m 47s} (1950)
GRB_DEC:         +23.617d {+23d 37' 00"} (J2000),
                 +23.522d {+23d 31' 18"} (current),
                 +23.811d {+23d 48' 40"} (1950)
GRB_ERROR:       5.32 [deg radius, statistical plus systematic]
GRB_INTEN:       681 [cnts/sec]
DATA_SIGNIF:     61.90 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        20550 TJD;   241 DOY;   24/08/28
GRB_TIME:        53706.83 SOD {14:55:06.83} UT
GRB_PHI:         293.00 [deg]
GRB_THETA:        80.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.47
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       157.58d {+10h 30m 20s}   +9.39d {+09d 23' 10"}
SUN_DIST:         66.81 [deg]   Sun_angle= -4.6 [hr] (East of Sun)
MOON_POSTN:       93.81d {+06h 15m 15s}  +28.64d {+28d 38' 34"}
MOON_DIST:       110.61 [deg]
MOON_ILLUM:      27 [%]
GAL_COORDS:       33.70, 59.94 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      214.98, 39.03 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_lc_medres34_bn240828622.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 62.20,-5.68 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 28 Aug 24 14:55:55 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      59
TRIGGER_NUM:     746549711
GRB_RA:          219.140d {+14h 36m 34s} (J2000),
                 219.394d {+14h 37m 35s} (current),
                 218.625d {+14h 34m 30s} (1950)
GRB_DEC:         +35.640d {+35d 38' 24"} (J2000),
                 +35.534d {+35d 32' 01"} (current),
                 +35.857d {+35d 51' 24"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     86.80 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        20550 TJD;   241 DOY;   24/08/28
GRB_TIME:        53706.83 SOD {14:55:06.83} UT
GRB_PHI:         299.00 [deg]
GRB_THETA:        92.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       157.58d {+10h 30m 20s}   +9.39d {+09d 23' 10"}
SUN_DIST:         61.70 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:       93.81d {+06h 15m 15s}  +28.64d {+28d 38' 34"}
MOON_DIST:        97.87 [deg]
MOON_ILLUM:      27 [%]
GAL_COORDS:       60.31, 66.10 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      200.76, 47.62 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_lc_medres34_bn240828622.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_746549711.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        Bright hard burst in the GBM.  
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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 28 Aug 24 14:57:03 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      3
TRIGGER_NUM:     746549711
GRB_RA:          219.140d {+14h 36m 34s} (J2000),
                 219.394d {+14h 37m 34s} (current),
                 218.625d {+14h 34m 30s} (1950)
GRB_DEC:         +35.660d {+35d 39' 36"} (J2000),
                 +35.554d {+35d 33' 13"} (current),
                 +35.877d {+35d 52' 36"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     101.50 [sigma]
DATA_INTERVAL:   8.192 [sec]
GRB_DATE:        20550 TJD;   241 DOY;   24/08/28
GRB_TIME:        53706.83 SOD {14:55:06.83} UT
GRB_PHI:         299.00 [deg]
GRB_THETA:        92.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       157.58d {+10h 30m 20s}   +9.39d {+09d 23' 09"}
SUN_DIST:         61.71 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:       93.82d {+06h 15m 18s}  +28.64d {+28d 38' 33"}
MOON_DIST:        97.85 [deg]
MOON_ILLUM:      27 [%]
GAL_COORDS:       60.35, 66.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      200.74, 47.64 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_lc_medres34_bn240828622.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_746549711.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
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_SPIACS event (trignum=10876).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 28 Aug 24 15:04:31 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     746549711
GRB_RA:          219.150d {+14h 36m 36s} (J2000),
                 219.403d {+14h 37m 37s} (current),
                 218.636d {+14h 34m 33s} (1950)
GRB_DEC:         +35.810d {+35d 48' 36"} (J2000),
                 +35.704d {+35d 42' 13"} (current),
                 +36.027d {+36d 01' 36"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
GRB_DATE:        20550 TJD;   241 DOY;   24/08/28
GRB_TIME:        53706.83 SOD {14:55:06.83} UT
GRB_PHI:         299.00 [deg]
GRB_THETA:        93.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       157.59d {+10h 30m 21s}   +9.38d {+09d 23' 03"}
SUN_DIST:         61.73 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:       93.90d {+06h 15m 36s}  +28.64d {+28d 38' 28"}
MOON_DIST:        97.71 [deg]
MOON_ILLUM:      27 [%]
GAL_COORDS:       60.71, 66.05 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      200.65, 47.77 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_lc_medres34_bn240828622.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_locplot_all_bn240828622.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:        Bright hard burst in the GBM.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=10876).

GCN Circular #37317
The Fermi GBM team reports the detection of a likely LONG GRB
At 14:55:06 UT on 28 Aug 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240828A (trigger 746549711.829992 / 240828622).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 219.1, Dec = 35.8 (J2000 degrees, equivalent to J2000 14h 36m, 35d 47'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 93.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_skymap_all_bn240828622.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/bn240828622/quicklook/glg_healpix_all_bn240828622.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240828622/quicklook/glg_lc_medres34_bn240828622.gif

GCN Circular #37321
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (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. Gress, N.M. Budnev, O.Ershova (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),
V. Yurkov, A. Gabovich (Blagoveschensk Educational State University)
MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 240828A ( Fermi GBM team, GCN 37317) errorbox 140 sec after notice time and 176 sec after trigger time at 2024-08-28 14:58:02 UT, with upper limit up to 15.9 mag. The observations began at zenith distance = 74 deg. The sun altitude is -30.0 deg.
The galactic latitude b = 66 deg., longitude l = 60 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2579196
We obtain a following upper limits.

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     196 | 2024-08-28 14:58:02 |         MASTER-Amur | (14h 39m 23.80s , +35d 19m 54.3s) |  P/ |    40 | 15.1 |        
     196 | 2024-08-28 14:58:03 |         MASTER-Amur | (14h 39m 04.59s , +35d 42m 17.2s) |  P\ |    40 | 15.0 |        
     257 | 2024-08-28 14:59:03 |         MASTER-Amur | (14h 39m 23.90s , +35d 19m 55.4s) |  P/ |    40 | 15.1 |        
     257 | 2024-08-28 14:59:03 |         MASTER-Amur | (14h 39m 04.69s , +35d 42m 19.9s) |  P\ |    40 | 15.3 |        
     329 | 2024-08-28 15:00:05 |         MASTER-Amur | (14h 39m 24.07s , +35d 19m 57.8s) |  P/ |    60 | 15.1 |        
     329 | 2024-08-28 15:00:05 |         MASTER-Amur | (14h 39m 04.80s , +35d 42m 23.7s) |  P\ |    60 | 15.2 |        
     417 | 2024-08-28 15:01:28 |         MASTER-Amur | (14h 39m 24.26s , +35d 20m 00.2s) |  P/ |    70 | 15.4 |        
     417 | 2024-08-28 15:01:28 |         MASTER-Amur | (14h 39m 04.89s , +35d 42m 27.4s) |  P\ |    70 | 14.5 |        
     519 | 2024-08-28 15:03:00 |         MASTER-Amur | (14h 39m 04.99s , +35d 42m 33.0s) |  P\ |    90 | 14.6 |        
     519 | 2024-08-28 15:03:00 |         MASTER-Amur | (14h 39m 24.53s , +35d 20m 04.7s) |  P/ |    90 | 14.5 |        
     640 | 2024-08-28 15:04:51 |         MASTER-Amur | (14h 39m 24.82s , +35d 20m 08.4s) |  P/ |   110 | 14.7 |        
     640 | 2024-08-28 15:04:51 |         MASTER-Amur | (14h 39m 05.09s , +35d 42m 38.4s) |  P\ |   110 | 14.9 |        
     787 | 2024-08-28 15:07:03 |         MASTER-Amur | (14h 39m 25.20s , +35d 20m 15.8s) |  P/ |   140 | 14.9 |        
     787 | 2024-08-28 15:07:03 |         MASTER-Amur | (14h 39m 05.32s , +35d 42m 47.3s) |  P\ |   140 | 15.0 |        
     962 | 2024-08-28 15:09:44 |         MASTER-Amur | (14h 39m 25.71s , +35d 20m 24.5s) |  P/ |   170 | 15.9 |        
     962 | 2024-08-28 15:09:44 |         MASTER-Amur | (14h 39m 05.65s , +35d 42m 57.7s) |  P\ |   170 | 15.7 |        
    1159 | 2024-08-28 15:12:56 |         MASTER-Amur | (14h 39m 26.35s , +35d 20m 34.9s) |  P/ |   180 | 15.5 |        
    1160 | 2024-08-28 15:12:56 |         MASTER-Amur | (14h 39m 06.13s , +35d 43m 10.6s) |  P\ |   180 | 15.6 |        
    1360 | 2024-08-28 15:16:16 |         MASTER-Amur | (14h 39m 26.92s , +35d 20m 46.7s) |  P/ |   180 | 15.5 |        
    1360 | 2024-08-28 15:16:16 |         MASTER-Amur | (14h 39m 06.57s , +35d 43m 23.0s) |  P\ |   180 | 15.6 |

The observation and reduction will continue. The message may be cited.

GCN Circular #37327
U.Quadri, L.Strabla and P.Madurini (Bassano Bresciano Astronomical Observatory),
Members of: GRB/UAI - Gamma ray Burst section of Unione Astrofili Italiani. AAVSO - American Association of Variable Star Observers. GAC - Gruppo Astrofili Cremonesi.
In a large collaboration with: M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno) report:
We performed optical follow-up observations of the GRB 240828A discovered by the Fermi satellite. We used the Baker-Schmidt telescope (Diam 250mm F/3) of the (IAU station 565) Bassano Bresciano Astronomical Observatory (Italy).
The single Field of the telescope is 41.2' x 30.7' To cover the uncertainty zone of the satellite position, we performed a mosaic of 9 images in order to cover a rectangle with sides of 2.1 x 1.5 degrees centered on the coordinates J2000 14h 36m, 35d 47'
We performed a total of 9 pointings to cover an area of 3.9 square degrees. For each pointing, 10 images were taken with duration of 20 seconds each.
The limiting magnitude is CR 17 (CR= Unfiltered with R zero point).
The sequence of pointing and the taking of images were automated by means of a telescope control software developed at our observatory.
The image analysis was performed using the subtraction method, with the template from POSS2/UKTSU Red images.
The observations started 4 hour after the GRB trigger.
For each field, we co-added 10 exposures of 20 sec each.
```
Start T0+      End T0+      CR lim
4.03 hour     4.81 hour     17
```
We did not found any credible optical counterpart in the error box of the Fermi Satellite.
Magnitudes were estimated with the pan-STARRS cat and are derived using Lupton (2005) equations. Not corrected for galactic dust extinction.
Reference: http://www.osservatoriobassano.org
The message may be cited.
GCN Circular #37328
S. Srijan (IITB), G. Waratkar (IITB), J. Joshi (IUCAA), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 240828A which was also detected by Fermi/GBM (Fermi GBM team, GCN Circ. 37317) and INTEGRAL/SPI-ACS (Trigger 10876).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-08-28 14:55:46 UTC. The measured peak count rate associated with the burst is 368 (+43, -46) counts/s above the background in the combined data of all quadrants, with a total of 4077 (+335, -387) counts. We caution that there is a 0.3 s readout dead time in CZT data during the burst which affects the calculated total counts. The local mean background count rate was 329 (+2, -3) counts/s. Using cumulative rates, we measure a T90 of 39.6 (+1.5, -1.0) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-08-28 14:55:45 UTC. The measured peak count rate is 1695 (+94, -66) counts/s above the background in the combined Veto data of all quadrants, with a total of 24765 (+699, -823) counts. The local mean background count rate was 1491 (+5, -6) counts/s. We measure a T90 of 39.6 (+0.5, -0.3) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 28 Aug 24 23:37:52 UT
NOTICE_TYPE:     Fermi-LAT Offline Position
TRIGGER_NUM:     1080646295
GRB_RA:          225.492d {+15h 01m 58s} (J2000),
                 225.735d {+15h 02m 56s} (current),
                 224.999d {+15h 00m 00s} (1950)
GRB_DEC:         +36.641d {+36d 38' 27"} (J2000),
                 +36.545d {+36d 32' 42"} (current),
                 +36.837d {+36d 50' 13"} (1950)
GRB_ERROR:       18.05 [arcmin radius, 90% containment, statistical only]
GRB_DATE:        20550 TJD;   241 DOY;   24/08/28
GRB_TIME:        53706.82 SOD {14:55:06.82} UT
TRIGGER_ID:      0x20000000
MISC:            0x40000000
SUN_POSTN:       157.91d {+10h 31m 39s}   +9.26d {+09d 15' 26"}
SUN_DIST:         66.73 [deg]   Sun_angle= -4.5 [hr] (East of Sun)
MOON_POSTN:       99.12d {+06h 36m 29s}  +28.45d {+28d 26' 48"}
MOON_DIST:        97.91 [deg]
MOON_ILLUM:      24 [%]
GAL_COORDS:       60.20, 60.87 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      207.08, 50.82 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi LAT Offline position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        It is the result of human-in-the-loop processing.  
COMMENTS:        This is a human generated position of a LAT ground detection. Fermi LAT detected a late time GeV emission fro
COMMENTS:        This source corresponds to GBM trigger.

GCN Circular #37329
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (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. Gress, N.M. Budnev, O.Ershova (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),
V. Yurkov, A. Gabovich (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 LAT GRB240828.62 (trigger No 1080646295,15h 01m 58.08s , +36d 38m 27.6s, R=0.300833) errorbox 8021 sec after trigger time at 2024-08-28 17:08:48 UT, with upper limit up to 18.1 mag. Observations started at twilight. The observations began at zenith distance = 75 deg. The sun altitude is -11.1 deg.
MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the LAT GRB240828.62 errorbox 17444 sec after trigger time at 2024-08-28 19:45:51 UT, with upper limit up to 18.0 mag. The observations began at zenith distance = 62 deg. The sun altitude is -30.3 deg.
The galactic latitude b = 61 deg., longitude l = 60 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2579813
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    8051 | 2024-08-28 17:08:48 |         MASTER-SAAO | (14h 53m 16.72s , +37d 14m 30.3s) |   C |    60 | 13.4 |        
    8552 | 2024-08-28 17:17:08 |         MASTER-SAAO | (15h 03m 20.23s , +37d 15m 11.4s) |   C |    60 | 17.4 |        
    9476 | 2024-08-28 17:32:33 |         MASTER-SAAO | (14h 53m 14.86s , +37d 15m 50.5s) |   C |    60 | 18.0 |        
    9555 | 2024-08-28 17:33:52 |         MASTER-SAAO | (15h 03m 19.09s , +37d 16m 15.9s) |   C |    60 | 18.1 |        
   10458 | 2024-08-28 17:48:54 |         MASTER-SAAO | (15h 03m 19.97s , +37d 16m 48.7s) |   C |    60 | 18.1 |        
   11211 | 2024-08-28 18:01:28 |         MASTER-SAAO | (15h 00m 13.36s , +35d 22m 55.7s) |   C |    60 | 14.0 |        
   17475 | 2024-08-28 19:45:51 |      MASTER-Tavrida | (14h 53m 21.53s , +36d 03m 58.8s) |   C |    60 | 18.0 |        
   18524 | 2024-08-28 20:03:20 |      MASTER-Tavrida | (14h 53m 24.35s , +36d 04m 05.1s) |   C |    60 | 17.7 |        
   19572 | 2024-08-28 20:20:48 |      MASTER-Tavrida | (14h 53m 27.59s , +36d 03m 37.4s) |   C |    60 | 17.8 |        
   22677 | 2024-08-28 21:12:34 |      MASTER-Tavrida | (14h 55m 41.91s , +37d 23m 27.8s) |   C |    60 | 17.6 |        
   23600 | 2024-08-28 21:27:56 |      MASTER-Tavrida | (14h 55m 41.63s , +37d 22m 39.0s) |   C |    60 | 17.6 |        
   24533 | 2024-08-28 21:43:29 |      MASTER-Tavrida | (14h 55m 46.76s , +37d 23m 38.0s) |   C |    60 | 13.5 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #37330
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the Fermi/LAT GRB 240828A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00127
Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the Fermi/LAT event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular #37331
R. Gupta (NASA GSFC), and N. Di Lalla (Stanford University) report on behalf of the Fermi-LAT Collaboration:
On Aug 28, 2024, Fermi-LAT detected high-energy emission from GRB 240828A, which was also detected by Fermi-GBM (trigger 746549711 / 240828622, GCN 37317), and AstroSat CZTI (GCN 37328).
The best LAT on-ground location is found to be:
RA, Dec = 225.49, 36.64 (J2000)
with an error radius of 0.30 deg (90 % containment, statistical error only).
This was 93 deg from the LAT boresight at the time of the GBM trigger: T0 = 14:55:06 UT.
The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 3500-6100 s after the GBM trigger is (8.2 +/- 3.8) E-7 ph/cm2/s. The estimated photon index above 100 MeV is -2.1 +/- 0.4.
The highest-energy photon is a 1.7 GeV event which is observed ~ 5400 seconds after the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst is Niccolo' Di Lalla ( niccolo.dilalla@stanford.edu).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #37337
A.P. Beardmore (U. Leicester), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), M. Ferro (INAF-OAB), J.A. Kennea (PSU), D.N. Burrows (PSU), M. A. Williams (PSU), J.P. Osborne (U. Leicester) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 240828A in a series of observations tiled on the sky. The total exposure time is 3.3 ks, distributed over 3 tiles; the maximum exposure at a single sky location was 2.3 ks. The data were collected between T0+42.1 ks and T0+60.2 ks, and are entirely in Photon Counting (PC) mode.
Six uncatalogued X-ray sources are detected, of which one ("Source 3") is above the RASS 3-sigma upper limit at this position, and is therefore likely the GRB afterglow. The position of this source is RA, Dec=225.5130, +36.5285 which is equivalent to:
```
RA (J2000): 15:02:3.12
Dec(J2000): +36:31:42.5
```
with an uncertainty of 3.9 arcsec (radius, 90% confidence). This position is 6.8 arcmin from the Fermi/LAT position.
The light curve can be modelled with a power-law decay with a decay index of alpha=3.043 (+0.027, -0.580).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.47 (+0.33, -0.24). The best-fitting absorption column is consistent with the Galactic value of 1.3 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (3.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.3 (+/-6.6) x 10^20 cm^-2
Galactic foreground: 1.3 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.47 (+0.33, -0.24)
```
If the light curve continues to decay with a power-law decay index of 3.043, the count rate at T+24 hours will be 0.014 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.3 x 10^-13 (5.3 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021707. The results of the full analysis of the tiled XRT observations are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00127.
This circular is an official product of the Swift-XRT team.
GCN Circular #37339
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, observed the field of GRB 240828A (The Fermi
GBM team, GCN 37317; Srijan et al., GCN 37328) around the
Fermi/LAT position (Gupta & Lalla, GCN 37331) starting at 03:32,
Aug. 29 UT, about 12.61 hours after the burst. Observations were
performed in 3 x 3 tiling mode, a set of clear (roughly R) filter
images were obtained. Within the XRT afterglow (Beardmore et al.,
GCN 37337) error circle, we detected a bright uncataloged optical
afterglow candidate at J2000 position of (error ~0.5"):
RA: 15:02:02.97
Dec: +36:31:43.93
We estimate the clear band magnitude to be ~17.9 mag at 12.69 hours
after the burst. Further observations are encouraged.
GCN Circular #37341
S. Dalessi (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 14:55:06.83 UT on 28 August 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240828A (trigger 746549711/240828622). which was also detected by AstroSat (S. Srijan et al. 2024, GCN 37328), Fermi-LAT (R. Gupta et al. 2024, GCN 37331), Swift-XRT (A.P. Beardmore et al. 2024, GCN 37337), and KAIT (W. Zheng et al. 2024 37339) The Fermi GBM on-ground location is consistent with the AstroSat, Fermi-LAT, Swift-XRT, and KAIT positions.
The angle from the Fermi LAT boresight is 97 degrees.
The GBM light curve multiple peaks with a duration (T90) of about 41.2 s (50-300 keV). The time-averaged spectrum from T0+0.002 to T0+44.225 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.96 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 850 +/- 30 keV.
The event fluence (10-1000 keV) in this time interval is (8.05 +/- 0.07)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+38.8 s in the 10-1000 keV band is 18.6 +/- 0.4 ph/s/cm^2.
A Band function fits the spectrum equally well with Epeak= 820 +/- 30 keV, alpha = -0.96 +/- 0.01 and beta = -2.9 +/- 0.2.
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 #37344
A. S. Moskvitin and O. I. Spiridonova (SAO RAS) report on behalf of the GRB follow-up team.
We observed the field of GRB 240828A (Fermi GBM team, GCN 37317; Srijan et al., GCN 37328; Gupta and Di Lalla, GCN 37331; Beardmore et al., GCN 37337; Dalessi and Meegan GCN 37341) with the SAO RAS 1-meter telescope Zeiss-1000 equipped with the CCD-photometer. We obtained 3 x 300 sec frames in each of BVRcIc filters on August 29.
The OT (Zheng and Filippenko; GCN 37339) is clearly detected in our images. The results are as follows.
```
Start    -- Stop, UT  t_mid - T0, d   filter  mag +/- err
18:14:38 -- 18:33:37  1.14515         B       20.54 +/- 0.05
18:34:12 -- 18:50:59  1.15798         V       20.16 +/- 0.05
17:38:50 -- 17:56:05  1.11969         Rc      19.73 +/- 0.03
17:56:52 -- 18:13:53  1.13213         Ic      19.36 +/- 0.07
```
Magnitudes were calibrated against nearby SDSS stars (converted with Lupton 2005 equations) and not corrected for the MW extinction.
GCN Circular #37349
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, continued observing the optical afterglow of
GRB 240828A (Zheng et al., GCN 37339; Moskvitin et al., GCN
37344) starting at ~1.54 days after the burst. A set of 31x60s
clear (roughly R) filter images were obtained. The afterglow
was clearly detected in our coadd image and we measure its
brightness has faded to be 20.2 +/- 0.2 mag.
GCN Circular #37370
A. S. Moskvitin and V. V. Vlasyuk (SAO RAS), report on behalf of the GRB follow-up team.
We observed the field of GRB 240828A (Fermi GBM team, GCN 37317; Srijan et al., GCN 37328; Gupta and Di Lalla, GCN 37331; Beardmore et al., GCN 37337; Dalessi and Meegan GCN 37341) with the AS-500(2) 0.5-m Ritchey-Chretien telescope of SAO RAS equipped with CCD-photometer and Andor iXon Ultra EM-CCD DU-897 camera with 512x512 pixels E2V chip. We obtained 40 x 90 sec. images in Rc band on August 31 (2024-08-31T18:44:29 -- 2024-08-31T19:59:08), t_mid - T0 = 3.1852 days.
The OT (Zheng and Filippenko, GCNs 37339, 37349; Moskvitin and Spiridonova, GCN 37344) is marginally detected in our stacked frame with the brightness of R = 21.8 +/- 0.3 calibrated against nearby SDSS stars (magnitudes converted with Lupton 2005 equations) and not corrected for the MW extinction.
GCN Circular #37377
Yan-Qiu Zhang (IHEP), Shao-Lin Xiong (IHEP), Chen-Wei Wang (IHEP) report on= behalf of the GECAM team:
GECAM-C was triggered on-ground by a long burst, GRB 240828A, at 2024-08-28= T14:55:07.150 UTC (T0), which was also detected by Fermi/GBM (Fermi GBM tea= m, GCN #37317; S. Dalessi et al., GCN #37341), AstroSat CZTI (S. Srijan et = al., GCN #37328), Fermi-LAT (R. Gupta et al., GCN #37331), Swift-XRT (A.P. = Beardmore et al., GCN #37337) and INTEGRAL/SPI-ACS (trigger #10876).
According to the GECAM-C light curves in about 6-6000 keV, this burst mainl= y consists of multiple pulses with a duration (T90) of about 41.41=EF=BC=88= +1.13,-1.05=EF=BC=89s. The time-averaged spectrum from T0+0.83 to T0+42.24 s could be fit by a pow= er law with high energy exponential cutoff function with a fluence of about= 7.77E-05 erg/cm^2 in 10-1000 keV.
The GECAM light curve could be found here: https://twikinew.ihep.ac.cn/pubgecam/Sandbox/GRB/GECAMC_lC_GRB240828A.png
The GECAM-C on-ground location (J2000) is:=20
```
Ra: 227.7 deg  =20
Dec: 39.9 deg
Err: 1.8 deg (1-sigma, statistical only)
```
GECAM location is consistent with the Fermi/LAT position within the error.
We note that these results are very preliminary. Refined analysis will be r= eported later.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor = (GECAM) mission originally consists of two microsatellites (GECAM-A and GEC= AM-B) launched in Dec. 2020. As the third member of GECAM constellation, GE= CAM-C was launched onboard SATech-01 experimental satellite in July 2022. G= ECAM mission is funded by the Chinese Academy of Sciences (CAS).
GCN Circular #37382
SVOM/GRM team: Yan-Qiu Zhang, Shi-Jie Zheng, Chen-Wei Wang, Wen-Jun tan, Yo= ng-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Ha= o-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming S= ong, You-Li Tuo, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie W= ang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-= Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Wen-Long Zhang, = Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao, Chao Zheng (IHEP), Maria-Grazi= a Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Ta= is Maiolino (LUPM), Fr=C3=A9d=C3=A9ric Piron (LUPM), St=C3=A9phane Schanne = (CEA), Jingwei Wang (IAP)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (I= HEP), St=C3=A9phane Basa (LAM), JeanLuc Att=C3=A9ia (IRAP), Arnaud Claret (= CEA), Zi-Gao Dai (USTC), Fr=C3=A9d=C3=A9ric Daigne (IAP), Jin-Song Deng (NA= OC), Andrea Goldwurm (APC), Diego G=C3=B6tz (CEA), Xu-Hui Han (NAOC), Cyril= Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs= .Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (= UNLV)
report on behalf of the SVOM team:
During the commissioning phase, the SVOM/GRM detected a long GRB 240828A at= 2024-08-28T14:55:07.200 UT (T0), which was also observed by Fermi/GBM (Fer= mi GBM team, GCN #37317; S. Dalessi et al., GCN #37341), AstroSat CZTI (S. = Srijan et al., GCN #37328), Fermi-LAT (R. Gupta et al., GCN #37331), GECAM = (Yan-Qiu Zhang et al., GCN #37377) and INTEGRAL/SPI-ACS (trigger #10876).
At the time of this burst ECLAIRs was not acquiring data.=20
With the event-by-event data downloaded through the X-band ground station, = the light curve shows that this burst consists of multiple pulses with a du= ration of about 45 s. The SVOM/GRM light curve can be found here: http://www.bursthub.cn//admin/static/svgrb240828A.png
The Space Variable Objects Monitor (SVOM) is a China-France joint mission l= ed by the Chinese National Space Administration (CNSA, China), National Cen= ter for Space Studies (CNES, France) and the Chinese Academy of Sciences (C= AS, China), which is dedicated to observing gamma-ray bursts and other tran= sient phenomena in the energetic universe. GRM is developed by the Institut= e of High Energy Physics (IHEP) of CAS.
The SVOM/GRM point of contact for this burst is: Yan-Qiu Zhang (IHEP)(zhang= yanqiu@ihep.ac.cn)

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