GRB 240306A
GCN Circular 35885
Subject
GRB 240306A: Fermi GBM Final Real-time Localization
Date
2024-03-06T06:56:45Z (a year 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 06:45:50 UT on 6 Mar 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240306A (trigger 731400355.209016 / 240306282).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 20.6, Dec = -42.0 (J2000 degrees, equivalent to J2000 01h 22m, -42d 00'), with a statistical uncertainty of 3.9 degrees.
The angle from the Fermi LAT boresight is 87.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240306282/quicklook/glg_skymap_all_bn240306282.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/bn240306282/quicklook/glg_healpix_all_bn240306282.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240306282/quicklook/glg_lc_medres34_bn240306282.gif
GCN Circular 35889
Subject
GRB 240306A: Swift/BAT-GUANO detection of a burst
Date
2024-03-06T17:04:09Z (a year ago)
From
Tyler Parsotan at NASA GSFC <tyler.parsotan@nasa.gov>
Via
email
Tyler Parsotan (NASA GSFC), James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU) report:
Swift/BAT did not localize GRB 240306A onboard (T0: 2024-03-06T06:45:49.58 UTC, Fermi/GBM trigger 731400355).
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 [-100,+100] 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 14 in a 2.048 s analysis time bin, starting at T0 + 0.512 s.
NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT coded FOV, with a DeltaLLHOut of 1.86.
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
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://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.swift.psu.edu%2Fguano%2F&data=05%7C02%7Ccirculars%40gcn.nasa.gov%7C887a752fe810456574d308dc3dff6823%7C7005d45845be48ae8140d43da96dd17b%7C0%7C0%7C638453414370014126%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=9uFWgjFqiTq7UwRwDR3jCnnbjlNCgpcAfpIrKYtWGmc%3D&reserved=0
GCN Circular 35891
Subject
Fermi GRB 240306A: Global MASTER-Net observations report
Date
2024-03-06T19:30:53Z (a year 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 240306A ( Fermi GBM team, GCN 35885) errorbox 41878 sec after notice time and 41910 sec after trigger time at 2024-03-06 18:24:20 UT, with upper limit up to 19.4 mag. Observations started at twilight. The observations began at zenith distance = 64 deg. The sun altitude is -16.8 deg.
The galactic latitude b = -74 deg., longitude l = 280 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2392907
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
41941 | 2024-03-06 18:24:20 | MASTER-SAAO | (01h 23m 00.92s , -38d 48m 51.7s) | C | 60 | 12.3 |
42840 | 2024-03-06 18:39:19 | MASTER-SAAO | (01h 36m 10.23s , -42d 27m 04.8s) | C | 60 | 13.2 |
42840 | 2024-03-06 18:39:19 | MASTER-SAAO | (01h 42m 50.95s , -42d 39m 23.8s) | C | 60 | 15.1 |
42920 | 2024-03-06 18:40:39 | MASTER-SAAO | (01h 30m 42.38s , -38d 40m 29.4s) | C | 60 | 14.5 |
42920 | 2024-03-06 18:40:39 | MASTER-SAAO | (01h 37m 00.55s , -38d 52m 46.6s) | C | 60 | 13.7 |
42999 | 2024-03-06 18:41:59 | MASTER-SAAO | (01h 20m 49.84s , -46d 15m 01.5s) | C | 60 | 16.2 |
42999 | 2024-03-06 18:41:59 | MASTER-SAAO | (01h 27m 56.71s , -46d 27m 27.1s) | C | 60 | 15.7 |
43079 | 2024-03-06 18:43:19 | MASTER-SAAO | (00h 54m 49.20s , -42d 27m 18.8s) | C | 60 | 17.2 |
43079 | 2024-03-06 18:43:19 | MASTER-SAAO | (01h 01m 28.21s , -42d 39m 44.6s) | C | 60 | 15.0 |
43159 | 2024-03-06 18:44:38 | MASTER-SAAO | (01h 39m 17.93s , -44d 20m 50.7s) | C | 60 | 15.4 |
43159 | 2024-03-06 18:44:38 | MASTER-SAAO | (01h 46m 10.88s , -44d 33m 13.0s) | C | 60 | 15.3 |
43238 | 2024-03-06 18:45:58 | MASTER-SAAO | (00h 56m 45.33s , -44d 21m 16.1s) | C | 60 | 18.3 |
43238 | 2024-03-06 18:45:58 | MASTER-SAAO | (01h 03m 37.12s , -44d 33m 43.9s) | C | 60 | 18.3 |
43318 | 2024-03-06 18:47:18 | MASTER-SAAO | (00h 53m 11.03s , -40d 34m 12.1s) | C | 60 | 19.2 |
43318 | 2024-03-06 18:47:18 | MASTER-SAAO | (00h 59m 38.30s , -40d 46m 36.9s) | C | 60 | 19.4 |
43398 | 2024-03-06 18:48:38 | MASTER-SAAO | (01h 15m 34.39s , -42d 28m 26.0s) | C | 60 | 19.4 |
43398 | 2024-03-06 18:48:38 | MASTER-SAAO | (01h 22m 13.76s , -42d 40m 50.0s) | C | 60 | 19.3 |
43477 | 2024-03-06 18:49:57 | MASTER-SAAO | (01h 13m 16.50s , -40d 32m 48.9s) | C | 60 | 19.3 |
43477 | 2024-03-06 18:49:57 | MASTER-SAAO | (01h 19m 43.99s , -40d 45m 11.2s) | C | 60 | 19.3 |
43557 | 2024-03-06 18:51:17 | MASTER-SAAO | (01h 18m 00.60s , -44d 22m 20.9s) | C | 60 | 19.4 |
43557 | 2024-03-06 18:51:17 | MASTER-SAAO | (01h 24m 52.76s , -44d 34m 46.7s) | C | 60 | 19.4 |
43637 | 2024-03-06 18:52:37 | MASTER-SAAO | (01h 33m 22.27s , -40d 32m 35.9s) | C | 60 | 19.3 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 35892
Subject
GRB 240306A: AstroSat CZTI detection
Date
2024-03-07T08:00:05Z (a year ago)
From
Gaurav Waratkar at IIT Bombay <gauravwaratkar24@gmail.com>
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 240306A which was also detected by Fermi-GBM (Fermi GBM team, GCN Circ. 35885), and Swift-BAT (Parsotan et al., GCN Circ. 35889).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-03-06 06:45:51.65 UTC. The measured peak count rate associated with the burst is 256 (+160, -4) counts/s above the background in the combined data of all quadrants, with a total of 633 (+225, -236) counts. The local mean background count rate was 301 (+7, -9) counts/s. We caution that there is a 0.3 s readout dead time in CZTI data during the burst which affects the calculated total count rate. Using cumulative rates, we measure a T90 of 7.1 (+1.6, -2.4) s.
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 35899
Subject
GRB 240306A: Fermi GBM observation
Date
2024-03-07T15:53:40Z (a year ago)
From
Elisabetta Bissaldi at Politecnico and INFN Bari <elisabetta.bissaldi@ba.infn.it>
Via
Web form
E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 06:45:50.21 UT on 06 March 2024, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 240306A (trigger 731400355 / 240306282),
which was also detected by the Swift/BAT GUANO (Parsotan et al. 2024, GCN 35889),
AstroSat CZTI (Joshi et al. 2024, GCN 35892) and INTEGRAL SPI-ACS (trigger 10616).
The GBM localization was reported in an earlier GCN (Fermi GBM Team, GCN 35885).
The angle from the Fermi LAT boresight at the GBM trigger time is 87 degrees.
The GBM light curve consists of single pulse
with a duration (T90) of about 9 s (50-300 keV).
The time-averaged spectrum from T0-1.7 s to T0+7.7 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.16 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 135 +/- 12 keV.
The event fluence (10-1000 keV) in this time interval is
(3.15 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux
measured starting from T0+0.6 s in the 10-1000 keV band
is 6.8 +/- 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 35930
Subject
GRID detection of GRB 240306A
Date
2024-03-16T12:53:36Z (a year ago)
From
GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>
Via
Web form
Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration:
GRID-03B reports the detection of the long-duration GRB 240306A, which was also detected by Fermi/GBM, Swift/BAT-GUANO and AstroSat CZTI (GCN Circular 35885, 35889 and 35892).
The event was triggered with GRID on 2024-03-06 at 06:45:48 UTC. The measured burst duration (T90) in the 30-2000 keV range is approximately 10.0 ± 1.0 seconds. Due to its proximity to Earth's atmosphere in the view of GRID-03B, the spectral data from GRID for this event may not be accurate.
The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB240306A/GRID_GRB240306A_ltcv.pdf.
GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.