GRB 241008A
GCN Circular 37740
Subject
GRB 241008A: Fermi GBM Final Real-time Localization
Date
2024-10-08T22:10:36Z (8 months ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
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
Subject
GRB 241008A: BALROG localization (Fermi Trigger 750117609 / GRB 241008917)
Date
2024-10-08T22:34:56Z (8 months ago)
From
Jochen Greiner at MPE <jcgrog@mpe.mpg.de>
Via
email
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
Subject
Fermi GRB 241008A: Global MASTER-Net observations report
Date
2024-10-09T02:17:02Z (8 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
legacy email
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
Subject
GRB 241008A: Fermi-LAT detection
Date
2024-10-09T14:41:47Z (8 months ago)
From
Rahul Gupta at NASA GSFC <rahul.gupta@nasa.gov>
Via
Web form
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
Subject
GRB 241008A: Fermi GBM Observation
Date
2024-10-09T18:34:28Z (8 months ago)
From
Ava Myers at NASA GSFC <ava.myers@nasa.gov>
Via
Web form
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/"