GRB 241209C
GCN Circular 38482
Subject
GRB 241209C: Fermi GBM Final Real-time Localization
Date
2024-12-09T07:33:23Z (6 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 07:22:54 UT on 9 Dec 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241209C (trigger 755421779.595806 / 241209308).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 116.0, Dec = -1.0 (J2000 degrees, equivalent to J2000 07h 44m, -1d 00'), with a statistical uncertainty of 4.2 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/bn241209308/quicklook/glg_skymap_all_bn241209308.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/bn241209308/quicklook/glg_healpix_all_bn241209308.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241209308/quicklook/glg_lc_medres34_bn241209308.gif
GCN Circular 38490
Subject
GRB 241209C: AstroSat CZTI detection
Date
2024-12-09T12:29:50Z (6 months ago)
From
Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>
Via
Web form
J. Joshi (IUCAA), G. Waratkar (IITB), 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 241209C which was also detected by Fermi/GBM (Fermi-GBM Team, GCN Circ. 38482).
The source was clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-12-09 07:22:58.21 UTC. The measured peak count rate associated with the burst is 255 (+79, -35) counts/s above the background in the combined data of all quadrants, with a total of 1341 (+212, -365) counts. The local mean background count rate was 1635 (+16, -10) counts/s. We measure a T90 of 6.6 (+0.5, -0.9) 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 Circular 38497
Subject
Fermi GRB 241209C: Global MASTER-Net observations report
Date
2024-12-09T19:30:49Z (6 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
legacy email
V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko,
A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin,
V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 241209C ( Fermi GBM team, GCN 38482) errorbox 41800 sec after notice time and 41825 sec after trigger time at 2024-12-09 18:59:59 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 76 deg. The sun altitude is -57.6 deg.
The galactic latitude b = 12 deg., longitude l = 220 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2701134
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
41855 | 2024-12-09 18:59:59 | MASTER-Kislovodsk | (07h 45m 09.49s , -00d 33m 01.9s) | C | 60 | 16.5 |
41935 | 2024-12-09 19:01:19 | MASTER-Kislovodsk | (07h 53m 08.72s , -00d 32m 20.8s) | C | 60 | 16.9 |
42097 | 2024-12-09 19:04:01 | MASTER-Kislovodsk | (07h 45m 10.51s , -00d 34m 01.9s) | C | 60 | 17.3 |
42177 | 2024-12-09 19:05:21 | MASTER-Kislovodsk | (07h 53m 14.71s , -00d 34m 16.8s) | C | 60 | 16.9 |
42339 | 2024-12-09 19:08:03 | MASTER-Kislovodsk | (07h 45m 12.59s , -00d 33m 47.5s) | C | 60 | 16.8 |
42418 | 2024-12-09 19:09:22 | MASTER-Kislovodsk | (07h 29m 57.54s , -00d 32m 27.7s) | C | 60 | 17.3 |
42497 | 2024-12-09 19:10:42 | MASTER-Kislovodsk | (07h 37m 56.59s , -00d 31m 43.1s) | C | 60 | 17.5 |
42656 | 2024-12-09 19:13:21 | MASTER-Kislovodsk | (07h 37m 57.58s , -00d 33m 39.4s) | C | 60 | 17.5 |
42736 | 2024-12-09 19:14:40 | MASTER-Kislovodsk | (07h 30m 03.51s , -00d 33m 16.2s) | C | 60 | 17.3 |
42982 | 2024-12-09 19:18:46 | MASTER-Kislovodsk | (07h 53m 15.57s , -00d 32m 07.6s) | C | 60 | 16.9 |
43228 | 2024-12-09 19:22:52 | MASTER-Kislovodsk | (07h 53m 15.43s , -00d 32m 37.7s) | C | 60 | 16.8 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 38501
Subject
GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
Date
2024-12-09T21:29:41Z (6 months ago)
From
Jimmy DeLaunay at Penn State <delauj2@gmail.com>
Via
Web form
James DeLaunay (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:
Swift/BAT did not localize GRB 241209C onboard (T0: 2024-12-09T07:22:54.60 UTC, Fermi trig 755421779)
The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 24.5 in a 8.192 s analysis time bin, starting at T0 - 0.0 s.
Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2024. in prep)
The 90% credible area is 920 deg2 and the 50% credible area is 298 deg2.
The integrated probability inside the coded field of view is <1%.
The NITRATES skymap is consistent with the Fermi localization reported in the final position notice (GCN 38482). The combined Fermi/GBM+NITRATES 90% credible area is 162 deg2 and the 50% credible area is 46 deg2.
A plot of the probability skymap can be viewed here:
[skymap_plot](https://guano.swift.psu.edu/trigger_report?id=755421809/#:~:text=Probability%20Skymap)
The probability skymap file can be downloaded from the link here
[skymap_fits_file](https://guano.swift.psu.edu/files/755421809/0_n_PROBMAP)
Instructions on how to read and manipulate this map can be found here:
https://guano.swift.psu.edu/documentation
More details about this burst can be found on the trigger report page here:
https://guano.swift.psu.edu/trigger_report?id=755421809
GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be found at:
https://www.swift.psu.edu/guano/
GCN Circular 38524
Subject
GRB 241209C: Fermi GBM Observation
Date
2024-12-10T14:15:29Z (6 months ago)
From
Christian Malacaria at INAF-OAR <cmalacaria.astro@gmail.com>
Via
Web form
C. Malacaria (INAF-OAR) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 07:22:54.60 UT on 09 December 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 241209C (trigger 755421779/241209308),
which was also detected by AstroSat (J. Joshi et al. 2024, GCN 38490)
and Swift/BAT-GUANO (J. DeLaunay et al. 2024, GCN 38501).
The GBM Final Real-time Localization is reported in GCN 38482.
The angle from the Fermi LAT boresight is 36 degrees.
The GBM light curve consists of a single emission episode with a duration (T90)
of about 11 s (50-300 keV). The time-averaged spectrum
from T0-4.1 to T0+9.2 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.4 +/- 0.1 and the cutoff energy,
parameterized as Epeak, is 270 +/- 20 keV.
The event fluence (10-1000 keV) in this time interval is
(4 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+4.8 s in the 10-1000 keV band is 3.3 +/- 0.2 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/"