Gamma-ray Burst 241008A

(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:     Tue 08 Oct 24 22:00:42 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      58
TRIGGER_NUM:     750117609
GRB_RA:          112.233d {+07h 28m 56s} (J2000),
                 112.513d {+07h 30m 03s} (current),
                 111.669d {+07h 26m 41s} (1950)
GRB_DEC:         -16.467d {-16d 28' 00"} (J2000),
                 -16.519d {-16d 31' 08"} (current),
                 -16.363d {-16d 21' 44"} (1950)
GRB_ERROR:       5.32 [deg radius, statistical plus systematic]
GRB_INTEN:       447 [cnts/sec]
DATA_SIGNIF:     39.00 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        20591 TJD;   282 DOY;   24/10/08
GRB_TIME:        79204.35 SOD {22:00:04.35} UT
GRB_PHI:          78.00 [deg]
GRB_THETA:        75.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.51
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      90%  GRB
2nd_MOST_LIKELY:   5%  Distant Particles
DETECTORS:       1,0,0, 0,0,0, 0,0,0, 1,0,0, 0,0,
SUN_POSTN:       194.84d {+12h 59m 23s}   -6.34d {-06d 20' 10"}
SUN_DIST:         80.88 [deg]   Sun_angle= 5.5 [hr] (West of Sun)
MOON_POSTN:      263.15d {+17h 32m 35s}  -28.50d {-28d 30' 09"}
MOON_DIST:       126.77 [deg]
MOON_ILLUM:      31 [%]
GAL_COORDS:      231.81,  0.56 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      117.34,-37.82 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 50.87,-24.53 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Oct 24 22:00:33 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      44
TRIGGER_NUM:     750117609
GRB_RA:          108.867d {+07h 15m 28s} (J2000),
                 109.087d {+07h 16m 21s} (current),
                 108.423d {+07h 13m 41s} (1950)
GRB_DEC:         -36.717d {-36d 43' 00"} (J2000),
                 -36.762d {-36d 45' 41"} (current),
                 -36.628d {-36d 37' 39"} (1950)
GRB_ERROR:       14.03 [deg radius, statistical plus systematic]
GRB_INTEN:       119 [cnts/sec]
DATA_SIGNIF:     7.40 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        20591 TJD;   282 DOY;   24/10/08
GRB_TIME:        79204.35 SOD {22:00:04.35} UT
GRB_PHI:          74.00 [deg]
GRB_THETA:        55.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.72
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      85%  GRB
2nd_MOST_LIKELY:  12%  Distant Particles
DETECTORS:       1,0,0, 0,0,0, 0,0,0, 1,0,0, 0,0,
SUN_POSTN:       194.84d {+12h 59m 23s}   -6.34d {-06d 20' 10"}
SUN_DIST:         82.82 [deg]   Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN:      263.15d {+17h 32m 35s}  -28.50d {-28d 30' 09"}
MOON_DIST:       110.33 [deg]
MOON_ILLUM:      31 [%]
GAL_COORDS:      248.51,-11.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      119.50,-58.24 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 50.87,-24.53 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Oct 24 22:00:51 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     750117609
GRB_RA:          108.940d {+07h 15m 46s} (J2000),
                 109.234d {+07h 16m 56s} (current),
                 108.347d {+07h 13m 23s} (1950)
GRB_DEC:         -10.300d {-10d 18' 00"} (J2000),
                 -10.345d {-10d 20' 41"} (current),
                 -10.211d {-10d 12' 39"} (1950)
GRB_ERROR:       2.48 [deg radius, statistical only]
DATA_SIGNIF:     42.10 [sigma]
DATA_INTERVAL:   2.048 [sec]
GRB_DATE:        20591 TJD;   282 DOY;   24/10/08
GRB_TIME:        79204.35 SOD {22:00:04.35} UT
GRB_PHI:          83.00 [deg]
GRB_THETA:        80.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       194.84d {+12h 59m 23s}   -6.34d {-06d 20' 11"}
SUN_DIST:         84.57 [deg]   Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN:      263.15d {+17h 32m 36s}  -28.50d {-28d 30' 10"}
MOON_DIST:       133.69 [deg]
MOON_ILLUM:      31 [%]
GAL_COORDS:      224.86,  0.64 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      112.20,-32.29 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_750117609.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
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:     Tue 08 Oct 24 22:01:38 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      1
TRIGGER_NUM:     750117609
GRB_RA:          108.630d {+07h 14m 31s} (J2000),
                 108.921d {+07h 15m 41s} (current),
                 108.042d {+07h 12m 10s} (1950)
GRB_DEC:         -11.330d {-11d 19' 47"} (J2000),
                 -11.374d {-11d 22' 27"} (current),
                 -11.242d {-11d 14' 32"} (1950)
GRB_ERROR:       1.81 [deg radius, statistical only]
DATA_SIGNIF:     38.60 [sigma]
DATA_INTERVAL:   5.120 [sec]
GRB_DATE:        20591 TJD;   282 DOY;   24/10/08
GRB_TIME:        79204.35 SOD {22:00:04.35} UT
GRB_PHI:          83.00 [deg]
GRB_THETA:        79.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       194.85d {+12h 59m 23s}   -6.34d {-06d 20' 11"}
SUN_DIST:         84.78 [deg]   Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN:      263.16d {+17h 32m 38s}  -28.50d {-28d 30' 11"}
MOON_DIST:       132.98 [deg]
MOON_ILLUM:      31 [%]
GAL_COORDS:      225.63, -0.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      112.02,-33.36 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_750117609.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Oct 24 22:02:00 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      3
TRIGGER_NUM:     750117609
GRB_RA:          112.860d {+07h 31m 26s} (J2000),
                 113.144d {+07h 32m 35s} (current),
                 112.286d {+07h 29m 09s} (1950)
GRB_DEC:         -14.530d {-14d 31' 47"} (J2000),
                 -14.584d {-14d 35' 01"} (current),
                 -14.423d {-14d 25' 22"} (1950)
GRB_ERROR:       1.61 [deg radius, statistical only]
DATA_SIGNIF:     62.70 [sigma]
DATA_INTERVAL:   13.312 [sec]
GRB_DATE:        20591 TJD;   282 DOY;   24/10/08
GRB_TIME:        79204.35 SOD {22:00:04.35} UT
GRB_PHI:          78.00 [deg]
GRB_THETA:        77.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       194.85d {+12h 59m 23s}   -6.34d {-06d 20' 12"}
SUN_DIST:         80.41 [deg]   Sun_angle= 5.4 [hr] (West of Sun)
MOON_POSTN:      263.16d {+17h 32m 38s}  -28.50d {-28d 30' 12"}
MOON_DIST:       128.06 [deg]
MOON_ILLUM:      31 [%]
GAL_COORDS:      230.40,  2.02 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      117.62,-35.80 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_750117609.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.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 08 Oct 24 22:09:24 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     750117609
GRB_RA:          112.870d {+07h 31m 29s} (J2000),
                 113.155d {+07h 32m 37s} (current),
                 112.296d {+07h 29m 11s} (1950)
GRB_DEC:         -14.480d {-14d 28' 47"} (J2000),
                 -14.534d {-14d 32' 01"} (current),
                 -14.373d {-14d 22' 22"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
GRB_DATE:        20591 TJD;   282 DOY;   24/10/08
GRB_TIME:        79204.35 SOD {22:00:04.35} UT
GRB_PHI:          78.00 [deg]
GRB_THETA:        77.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       194.85d {+12h 59m 24s}   -6.34d {-06d 20' 19"}
SUN_DIST:         80.41 [deg]   Sun_angle= 5.4 [hr] (West of Sun)
MOON_POSTN:      263.23d {+17h 32m 56s}  -28.51d {-28d 30' 28"}
MOON_DIST:       128.13 [deg]
MOON_ILLUM:      31 [%]
GAL_COORDS:      230.36,  2.05 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      117.62,-35.75 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_locplot_all_bn241008917.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:        This is likely a Long GRB.

GCN Circular #37740
The Fermi GBM team reports the detection of a likely LONG GRB
At 22:00:04 UT on 8 Oct 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241008A (trigger 750117609.348226 / 241008917).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 112.9, Dec = -14.5 (J2000 degrees, equivalent to J2000 07h 31m, -14d 30'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 77.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_skymap_all_bn241008917.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/bn241008917/quicklook/glg_healpix_all_bn241008917.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241008917/quicklook/glg_lc_medres34_bn241008917.gif
GCN Circular #37741
T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 750117609 at 22:00:04 on 08 Oct. 2024 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60).
The best-fit position is:
```
RA(2000.0) = 112.2 deg
Decl.(2000.0) = -9.2 deg
```
The 1 sigma statistical error radius is 2.7 deg. We estimate an additional systematic error of 2 deg.
Further details are available at: https://grb.mpe.mpg.de/grb/GRB241008917/
The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB241008917/healpix
The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB241008917/json
GCN Circular #37742
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) started inspect of the Fermi GRB 241008A ( Fermi GBM team, GCN 37740) errorbox 13231 sec after notice time and 13275 sec after trigger time at 2024-10-09 01:41:19 UT, with upper limit up to 16.1 mag. The observations began at zenith distance = 47 deg. The sun altitude is -29.8 deg.
The galactic latitude b = 2 deg., longitude l = 231 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2631173
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   13305 | 2024-10-09 01:41:19 |         MASTER-SAAO | (07h 30m 26.27s , -15d 51m 14.3s) |   C |    60 | 16.1 |        
   13385 | 2024-10-09 01:42:38 |         MASTER-SAAO | (07h 34m 40.78s , -13d 56m 06.3s) |   C |    60 | 13.6 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #37747
R. Gupta (NASA GSFC), C. Bartolini (UniTrento e INFN Bari), and J. Racusin (NASA GSFC) report on behalf of the Fermi-LAT Collaboration:
On Oct 08, 2024, Fermi-LAT detected high-energy emission from GRB 241008A, which was also detected by Fermi-GBM (trigger 750117609/ 241008917, GCN 37740).
The best LAT on-ground location is found to be:
RA, Dec = 112.84, -9.40 (J2000)
with an error radius of 0.23 deg (90 % containment, statistical error only).
This was 82 deg from the LAT boresight at the time of the GBM trigger: T0 = 22:00:04 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 0-2050 s after the GBM trigger is (2.1 +/- 0.7) E-6 ph/cm2/s. The estimated photon index above 100 MeV is -2.0 +/- 0.3.
The highest-energy photon is a 1.8 GeV event which is observed ~1667 seconds after the GBM trigger.
The Fermi-LAT point of contact for this burst is Rahul Gupta (rahul.gupta@nasa.gov).
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 #37748
A. Myers (NPP/GSFC) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 22:00:04.35 UT on 08 October 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241008A (trigger 750117609/241008917). which was also detected by Fermi-LAT (Gupta et al. 2024, GCN 37747). The Fermi GBM on-ground location is consistent with the Fermi-LAT position.
The angle from the Fermi LAT boresight is 75 degrees.
The GBM light curve consists of two peaks with a duration (T90) of about 53 s (50-300 keV). The time-averaged spectrum from T0 to T0+53.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.01 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 720 +/- 70 keV.
The event fluence (10-1000 keV) in this time interval is (2.46 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+11 s in the 10-1000 keV band is 10.7 +/- 0.3 ph/s/cm^2.
A Band function fits the spectrum equally well with Epeak= 500 +/- 100 keV, alpha = -0.96 +/- 0.04 and beta = -1.9 +/- 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/"

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Jochen Greiner, last update: 09-Oct-2024 [Disclaimer]