GRB 240204A
GCN Circular 35922
Subject
GRB240204A: VIRT optical upper limit
Date
2024-03-14T00:11:58Z (2 years ago)
From
Priya Gokuldass at ERAU <gokuldap@my.erau.edu>
Via
Web form
K. Smith (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), D. Morris (NASA), T. Lombardi (Eckerd College), K. Noonan (UVI), R. Querrard (UVI), D. Smith (UVI) report:
We observed the field of GRB240204A (Cenko et al., GCN 35666) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 02-05-2024 starting at 00:36:35 (T+10.04 hrs). We performed a series of exposures in an R filter with a total exposure of 4000s. The weather conditions were clear during the hours of observation with an average airmass of 1.08.
We do not detect any source within the enhanced XRT position (Beardmore et al. GCN 35671). This non-detection is consistent with the upper limits and detections of the faint optical transient reported by Master (Lipunov et al., GCN 35668), Mondy (Pozanenko et al., GCN 35670), Montarrenti Observatory (Leonini et al., GCN 35672), LCOGT (Perez-Fournon and Poidevin, GCN 35673), Osservatorio Nastro Verde (Ruocco et al., GCN 35677), Liverpool Telescope (Bochenek et al., GCN 35678), and Observatoire de Haute-Provence (Adami et al., GCN 35690). We report the following 3-sigma upper limit:
T_mid ||Exposure ||Filter ||Limit
T+ 10.04 hrs || 4000s || R || >20.9
The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. The VIRT is still in the commissioning phase.
We acknowledge financial support from NASA MUREP MIRO award 80NSSC21M0001 and NASA EPSCoR award 80NNSC22M0063. R.Q and N.B.O also acknowledge financial support from South Carolina Space Grant award 80NSSC20M0054. This message can be cited.
GCN Circular 35714
Subject
Konus-Wind detection of GRB 240204A
Date
2024-02-11T19:46:09Z (2 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
Via
legacy email
D. Svinkin, D. Frederiks, M. Ulanov, A. Tsvetkova,
A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 240204A
(Fermi-GBM detection: The Fermi GBM team, GCN 35664;
Swift-BAt detection: Cenko et al., GCN 35666;
AstroSat-CZTI detection: Joshi et al., GCN 35692)
triggered Konus-Wind at T0=54473.519 s UT (15:07:53.519).
The burst light curve shows a single pulse
which starts at ~T0-4.5 s and has a total duration of ~21.5 s.
The emission is seen up to ~1 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240204_T54473/
As observed by Konus-Wind, the burst
had a fluence of 1.37(-0.07,+0.07)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.448 s,
of 4.22(-1.15,+1.15)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.29(-0.16,+0.17)
and Ep = 81(-6,+6) keV (chi2 = 87/83 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.9
(chi2 = 86/82 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 35705
Subject
GRB240204A: Swift/UVOT Upper Limits
Date
2024-02-08T15:37:24Z (2 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
Via
Web form
M. H. Siegel (PSU) and and S. B Cenko (GSFC) report on behalf of the
Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240204A
4.8 ks after the BAT trigger (Cenko et al., GCN Circ 35666). No optical
afterglow consistent with either the optical (Pozanenko et al., GCN
Circ. 35670) or X-ray (Beardmore et al., GCN Circ. 35671) position is
detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures of
the candidate afterglow field are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 5887 6087 196 >20.70
v 4862 6498 393 >19.32
b 5683 5882 196 >19.98
u 5477 28539 1048 >20.54
uvw1 5272 5472 196 >19.26
uvm2 5067 6669 360 >19.36
uvw2 6093 6293 196 >19.42
The magnitudes in the table are not corrected for the Galactic extinction
due to the high but uncertain reddening in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 35692
Subject
GRB 240204A: AstroSat CZTI detection
Date
2024-02-06T14:39:17Z (2 years ago)
From
Varun Bhalerao at IIT Bombay <varunb@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 240204A which was also detected by Fermi-GBM (Fermi GBM Team, GCN Circ. 35664), and Swift (Cenko et al., GCN Circ. 35666).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-02-04 15:07:49.50 UTC. The measured peak count rate associated with the burst is 201 (+40 -25) counts/s above the background in the combined data of four quadrants, with a total of 1125 (+193 -176) counts. The local mean background count rate was 308 (+5 -6) counts/s. Using cumulative rates, we measure a T90 of 10.5 (+1.1 -2.5) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-02-04 15:07:49.4 UTC. The measured peak count rate associated with the burst is 388 (+65, -60) counts/s above the background in the combined data of all quadrants, with a total of 2008 (+336, -351) counts. The local mean background count rate was 1276 (+6, -6) counts/s. We measure a T90 of 8.5 (+3.1, -2.1) 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 35691
Subject
GRB 240204A: Mondy optical afterglow observations
Date
2024-02-06T07:50:17Z (2 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
S. Belkin (IKI, HSE), N. Pankov (HSE, IKI), E. Klunko (ISTP), A. Pozanenko (IKI) report on behalf of IKI-GRB-FuN:
We observed the GRB 240204A (Fermi-GBM team GCN 35664, Cenko et al. GCN 35666, Pozanenko et al. GCN 35670, Leonini et al. GCN 35672, Pérez-Fournon et al. GCN 35673, Dainotti et al. GCN 35677, Bochenek et al. GCN 35678; Adami et al. GCN 35690) with AZT-33IK telescope of Mondy observatory starting on 2024-02-04 (UT) 16:05:26 and 2024-02-05 (UT) 13:10:09. Preliminary photometry of the afterglow based on USNO-B1.0 (R2) nearby stars is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2024-02-04 16:05:26 0.04292 R 480 19.90 0.10 21.9
2024-02-04 16:13:26 0.04847 R 480 20.01 0.11 21.8
2024-02-04 16:21:26 0.05403 R 480 19.93 0.10 21.9
2024-02-04 16:29:27 0.05959 R 480 19.85 0.09 21.8
2024-02-04 17:31:00 0.11345 R 2400 20.55 0.10 22.5
2024-02-05 13:10:09 0.96772 R 8400 22.4 0.2 23.1
GCN Circular 35690
Subject
GRB 240204A : OHP/T193/T120 optical afterglow fading detection
Date
2024-02-06T05:05:24Z (2 years ago)
From
Christophe Adami at LAM <christophe.adami@lam.fr>
Via
Web form
C. Adami, D. Russeil, H. LeCoroller (Pythéas/LAM), E. Abdo, M. Carta, T. Chehab, M. Colliaux, A. Gharibi-Ziarati, E. Pouyer,
A. Jacquet, F. Malaval, S. Aftis (AMU), J. Balcaen, Y. Degot-Longhi, (OHP/Pythéas), E. Le Floc'h, D. Götz, F. Schüssler (CEA
Paris-Saclay), B. Schneider (MIT), S. Basa (Pytheas/OHP/LAM), A. Saccardi, S. D. Vergani (GEPI, Obs. de Paris),
M. Dennefeld (IAP), report on behalf of a larger collaboration
We observed the field of GRB 240204A (Fermi-GBM team GCN 35664, Cenko et al. GCN 35666, Pozanenko et al. GCN 35670,
Leonini et al. GCN 35672, Pérez-Fournon et al. GCN 35673, Dainotti et al. GCN 35677, Bochenek et al. GCN 35678) using the
T193cm telescope equiped with the MISTRAL instrument and with the T120cm telescope at Observatoire de Haute-Provence
(France). On the night of 04 February 2024, we made 9 sets of observations with MISTRAL in r band (30min each) and two sets
of observations with the T120 telescope (V and i bands: 135min each). On the night of 05 February 2024, we made an
additional single set of observations with MISTRAL in r band during 97.5min. Details are given in the table below.
All magnitudes were calibrated against the PanStarrs catalog (mean Kron magnitudes), extracted in a radius of 1arcmin around
the GRB position. Magnitudes were not corrected for galactic extinction.
Our results in r-band show a fading behaviour of typically 0.09+/-0.03 mag/hour over the 10 first hours and of 0.06+/-0.01 mag/hours over the 31 first hours.
-----------------------------------------------
T-T0 (in hours) | mag | filter | Telescope
-----------------------------------------------
+4.09 | 21.82+/-0.21 | r | MISTRAL@T193
+4.70 | 21.88+/-0.15 | r | MISTRAL@T193
+5.29 | 21.86+/-0.11 | r | MISTRAL@T193
+5.89 | 21.92+/-0.12 | r | MISTRAL@T193
+6.64 | 21.77+/-0.10 | r | MISTRAL@T193
+7.22 | 21.98+/-0.10 | r | MISTRAL@T193
+7.99 | 21.88+/-0.12 | r | MISTRAL@T193
+8.69 | 22.10+/-0.13 | r | MISTRAL@T193
+9.32 | 22.51+/-0.31 | r | MISTRAL@T193
+30.72 | 23.37+/-0.31 | r | MISTRAL@T193
+6.02 | 22.69+/-0.17 | g | T120
+6.02 | 20.33+/-0.13 | i | T120
We acknowledge OHP staff for its excellent support during the AMU M2-Physics 2024 observationnal internship. This work
received support from the French government under the France2030 investment plan, as part of the initiative d’Excellence
d’Aix-Marseille Universit´e- A*MIDEX (AMX-19-IET-008). We were also supported by the IPhU Graduate School program at
Aix-Marseille University. We also acknowledge the support by Master Erasmus Mundus Europhotonics
(599098-EPP-1-2018-1-FR-EPPKA1-JMD-MOB) financed by EACEA (European Education and Culture Executive Agency).
GCN Circular 35688
Subject
GRB 240204A: Swift-BAT refined analysis
Date
2024-02-06T02:39:23Z (2 years ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
Via
email
T. Sakamoto (AGU),S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
M. J. Moss (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC), M. Stamatikos (OSU)
(i.e. the Swift-BAT team):
Swift-BAT triggered on GRB 240204A at 15:07:50.63 UT on 2024-02-04.
Swift slewed immediately, but didn’t have initial BAT information due to a telemetry gap.
Using the data set from T-239 to T+346 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 240204A (trigger #1212898)
(Cenko, et al., GCN Circ. 35666). The BAT ground-calculated position is
RA, Dec = 104.290, 1.078 deg which is
RA(J2000) = 06h 57m 09.6s
Dec(J2000) = +01d 04' 41.5"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 9%.
The BAT light curve shows a complex structure with a duration of ~ 20 sec.
T90 (15-350 keV) is 18.93 +- 2.06 sec (estimated error including systematics).
The time-averaged spectrum from T-22.96 to T+8.96 sec is best fit by a power law
with an exponential cutoff. This fit gives a photon index 1.21 +- 0.28,
and Epeak of 67.8 +- 12.6 keV (chi squared 41.34 for 56 d.o.f.). For this
model the total fluence in the 15-150 keV band is 1.0 +- 0.0 x 10^-05 erg/cm2
and the 1-sec peak flux measured from T+0.08 sec in the 15-150 keV band is
22.1 +- 1.5 ph/cm2/sec. A fit to a simple power law gives a photon index
of 1.80 +- 0.06 (chi squared 55.74 for 57 d.o.f.). All the quoted errors
are at the 90% confidence level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1212898/BA/
GCN Circular 35680
Subject
GRB 240204A: Fermi GBM Observation
Date
2024-02-05T21:17:16Z (2 years ago)
From
Lorenzo Scotton at UAH <lscottongcn@outlook.com>
Via
Web form
L. Scotton (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 15:07:38.68 UT on 04 February 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240204A (trigger 728752063/240204630),
which was also detected by Swift XRT (S. B. Cenko et al. 2024, GCN 35666).
The Fermi GBM on-ground location is consistent with the Swift XRT position.
The angle from the Fermi LAT boresight is 101 degrees.
The GBM light curve consists of a single emission episode with a duration (T90)
of about 15.9 s (50-300 keV). The time-averaged spectrum
from T0-6.5 to T0+34.5 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.03 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 84 +/- 2 keV.
The event fluence (10-1000 keV) in this time interval is
(1.69 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+12 s in the 10-1000 keV band is 32.9 +/- 0.5 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 79 +/- 2 keV, alpha = -0.97 +/- 0.04 and beta = -3.0 +/- 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 35678
Subject
GRB 240204a: Liverpool Telescope optical afterglow detection
Date
2024-02-05T20:01:51Z (2 years ago)
From
A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk>
Via
Web form
A. Bochenek, J. Wise, D. A. Perley (LJMU) report:
We observed the field of GRB 240204A (Fermi-GBM team, GCN 35664; Cenko et al., GCN 35666; Pozanenko et al., GCN 35670) with the IO:O optical camera on the 2m robotic Liverpool Telescope. We conducted two sets of observations, the first starting at 2024-02-04 22:39:16 UT (approx. 7.5h after the burst), and the second starting at 2024-02-04 23:57:25 UT (approx. 9h after the burst). Both consisted of 2x60s exposures in the SDSS g, r, i, and z filters. Conditions were generally good throughout.
The afterglow is detected in the i and z bands in both epochs, and in the r-band in the first epoch. We measure the following magnitudes:
MJD Time since burst Filter Mag. (AB)
60344.94386 7.52 hours g > 22.72
60344.94585 7.57 hours r 21.37 ± 0.20
60344.94783 7.62 hours i 20.98 ± 0.21
60344.94981 7.66 hours z 20.74 ± 0.20
60344.99812 8.82 hours g > 22.29
60345.00012 8.87 hours r > 22.08
60345.00210 8.92 hours i 20.85 ± 0.12
60345.00408 8.97 hours z 20.34 ± 0.13
The photometry was obtained using nearby PanSTARRS secondary standards and was not corrected for extinction.
The source was detected at a position consistent with previous detections.
GCN Circular 35677
Subject
GRB 240204A: Osservatorio Astronomico Nastro Verde upper limit
Date
2024-02-05T18:30:30Z (2 years ago)
From
Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>
Via
Web form
Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
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 image the field of GRB 240204A (Swift triggered on the Fermi/GBM, GCN 35664; Cenko et al., GCN 35666; Pozanenko et al., GCN 35670)
with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. Member of:
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione
The observations started at 18:16 UT of 2024/02/04, after about 3 hours after the GRB trigger, at the end of twilight
with principal telescope SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 104 image of 60 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker and Astrometrica software
We have not detected any clearly visible sources, up to 20th magnitude with clear skies.
Start T0+ End T0+ Rlim
18:16:19 UT 21:15:19 UT 19.5
We did not found any optical counterpart in the error box of the XRTcandidate.
Magnitudes were estimated with the Gaia DR2 cat. and
are not corrected for galactic dust extinction.
The message may be cited.
GCN Circular 35673
Subject
GRB 240204A: optical afterglow detection with LCOGT 1m telescopes at Sutherland and Teide Observatories
Date
2024-02-05T02:47:44Z (2 years ago)
From
Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf@iac.es>
Via
Web form
I. Pérez-Fournon and F. Poidevin (IAC and ULL) report
We observed the field of GRB 240204A, detected by FERMI GBM (Fermi GBM team, GCN 35664) and by Swift XRT (Cenko et al., GCN 35666), centred at the enhanced Swift-XRT position reported by Beardmore et al. (GCN 35671) with LCOGT 1m telescopes at Sutherland and Teide Observatories. We detect a source, not visible in PanSTARRS imaging, at the position RA (J2000) = 06:56:43.367, Dec (J2000) = +01:01:38.06 (+/- 0.5" in both coordinates). We measure the following magnitudes in SDSS filters: r' = 21.10 +/- 0.15 on 2024-02-04 20:37:30 UT (Sutherland Observatory) and i' = 20.79 +/- 0.15 on 2024-02-04 21:29:56 UT (Teide Observatory), calibrated using the Gaia DR3 synthetic photometry catalog generated from the Gaia BP/RP mean spectra (Gaia Collaboration, 2022), uncorrected for interstellar extinction.
The reported position agrees within the errors with the enhanced Swift-XRT position and with the positions of the optical source detected by Pozanenko et al. (GCN 35670) and Leonini et al. (GCN 35672).
The flux is clearly decreasing in the red bands.
GCN Circular 35672
Subject
GRB 240204A: Montarrenti Observatory optical observations
Date
2024-02-04T23:54:13Z (2 years ago)
From
Simone Leonini at Montarrenti Observatory (Siena, Italy) <s.leonini@iol.it>
Via
Web form
S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez, L. Bellizzi (Montarrenti Observatory, Siena, Italy, part of UAI/SSV-GRB section), M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy) and B. De Simone (Universita' degli Studi Di Salerno) report:
We observed the field of GRB 240204A (Swift triggered on the Fermi/GBM, GCN 35664; Cenko et al., GCN 35666; Pozanenko et al., GCN 35670) with the automated and remoted 0.53m Ritchey-Chretien telescope at Montarrenti Observatory (Siena, Italy, IAU code C88).
The observations were started under good weather conditions at 2024-02-04 18:58:44 UT (approximately 4 hours after burst) stacking 30x40s Rc-band CCD images.
The OT was detected at the following position:
RA (J2000.0) 06h 56m 43.39s +/-0.11
Decl. (J2000.0) +01° 01' 38.5" +/-0.14
Preliminary photometry was obtained using nearby PanSTARRS stars as follows:
MJD Filter Mag. Err.
60345.30597 Rc 21.02 +/-0.21
Magnitudes were converted using Lupton (2005) equations and were not corrected for galactic dust extinction.
GCN Circular 35671
Subject
GRB 240204A: Enhanced Swift-XRT position
Date
2024-02-04T19:44:55Z (2 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1322 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 240204A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 104.18139, +1.02693 which is equivalent
to:
RA (J2000): 06h 56m 43.53s
Dec (J2000): +01d 01' 36.9"
with an uncertainty of 2.5 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 35670
Subject
GRB 240204A: Mondy optical afterglow candidate
Date
2024-02-04T18:05:52Z (2 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
A. Pozanenko (IKI), E. Klunko (ISTP), N. Pankov (HSE, IKI), S. Belkin (IKI, HSE) report on behalf of IKI-GRB-FuN:
We observed the field of Swift localization of GRB 240204A (Cenko et al., GCN 35666) which is also detected be GMB/Fermi (Fermi GBM team GCN 35664) with AZT-33IK telescope of Mondy observatory starting on 2024-02-04 (UT) 16:05:26. In the first images of 60 s exposure we detected the object in coordinates of (J2000) 06:56:43.36, +01:01:37.7 with uncertainties of 0.2 arcsec in both coordinates. The position of the object is within XRT afterglow localization (Cenko et al., GCN 35666). The object is absent in PS1 catalogue. Preliminary photometry of the object is R ~ 20.6 based on USNO-B1.0 (R2) nearby stars.
We suggest the source is an afterglow of GRB 240204A.
GCN Circular 35668
Subject
Fermi GRB 240204A: Global MASTER-Net observations report
Date
2024-02-04T16:15:52Z (2 years 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 240204A ( Fermi GBM team, GCN 35664) errorbox 818 sec after notice time and 854 sec after trigger time at 2024-02-04 15:21:52 UT, with upper limit up to 20.8 mag. The observations began at zenith distance = 54 deg. The sun altitude is -48.0 deg.
The galactic latitude b = -2 deg., longitude l = 216 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2371241
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
884 | 2024-02-04 15:21:52 | MASTER-Tunka | (06h 45m 43.71s , -03d 13m 03.5s) | C | 60 | 19.9 |
944 | 2024-02-04 15:21:52 | MASTER-Tunka | (06h 45m 43.71s , -03d 13m 03.5s) | C | 180 | 20.4 | Coadd
1154 | 2024-02-04 15:21:52 | MASTER-Tunka | (06h 45m 43.71s , -03d 13m 03.5s) | C | 600 | 20.8 | Coadd
947 | 2024-02-04 15:22:56 | MASTER-Tunka | (06h 45m 43.78s , -03d 13m 01.1s) | C | 60 | 19.9 |
1011 | 2024-02-04 15:23:59 | MASTER-Tunka | (06h 45m 43.83s , -03d 12m 59.8s) | C | 60 | 19.9 |
1074 | 2024-02-04 15:25:02 | MASTER-Tunka | (06h 45m 43.88s , -03d 12m 57.8s) | C | 60 | 19.9 |
1134 | 2024-02-04 15:25:02 | MASTER-Tunka | (06h 45m 43.88s , -03d 12m 57.9s) | C | 180 | 20.4 | Coadd
1201 | 2024-02-04 15:27:09 | MASTER-Tunka | (06h 45m 44.01s , -03d 12m 54.0s) | C | 60 | 19.8 |
1264 | 2024-02-04 15:28:12 | MASTER-Tunka | (06h 45m 44.05s , -03d 12m 52.5s) | C | 60 | 19.9 |
1327 | 2024-02-04 15:29:15 | MASTER-Tunka | (06h 45m 44.14s , -03d 12m 50.2s) | C | 60 | 19.9 |
1387 | 2024-02-04 15:29:15 | MASTER-Tunka | (06h 45m 44.14s , -03d 12m 50.2s) | C | 180 | 20.4 | Coadd
1454 | 2024-02-04 15:31:22 | MASTER-Tunka | (06h 45m 44.31s , -03d 12m 46.5s) | C | 60 | 19.8 |
1522 | 2024-02-04 15:32:30 | MASTER-Tunka | (06h 45m 49.39s , -03d 12m 38.6s) | C | 60 | 19.9 |
1585 | 2024-02-04 15:33:33 | MASTER-Tunka | (06h 45m 49.44s , -03d 12m 36.0s) | C | 60 | 20.0 |
1645 | 2024-02-04 15:33:33 | MASTER-Tunka | (06h 45m 49.44s , -03d 12m 36.0s) | C | 180 | 20.5 | Coadd
1648 | 2024-02-04 15:34:37 | MASTER-Tunka | (06h 45m 49.50s , -03d 12m 34.2s) | C | 60 | 20.0 |
1712 | 2024-02-04 15:35:40 | MASTER-Tunka | (06h 45m 49.57s , -03d 12m 32.2s) | C | 60 | 20.0 |
1775 | 2024-02-04 15:36:43 | MASTER-Tunka | (06h 45m 49.60s , -03d 12m 30.7s) | C | 60 | 20.0 |
1835 | 2024-02-04 15:36:43 | MASTER-Tunka | (06h 45m 49.61s , -03d 12m 30.8s) | C | 180 | 20.5 | Coadd
1838 | 2024-02-04 15:37:46 | MASTER-Tunka | (06h 45m 49.68s , -03d 12m 29.1s) | C | 60 | 20.1 |
1901 | 2024-02-04 15:38:50 | MASTER-Tunka | (06h 45m 49.73s , -03d 12m 27.3s) | C | 60 | 20.0 |
1965 | 2024-02-04 15:39:53 | MASTER-Tunka | (06h 45m 49.77s , -03d 12m 25.3s) | C | 60 | 20.0 |
2028 | 2024-02-04 15:40:56 | MASTER-Tunka | (06h 45m 49.82s , -03d 12m 23.8s) | C | 60 | 20.0 |
2091 | 2024-02-04 15:41:59 | MASTER-Tunka | (06h 45m 49.86s , -03d 12m 21.8s) | C | 60 | 20.0 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 35666
Subject
GRB 240204A: Swift detection of a burst
Date
2024-02-04T15:33:54Z (2 years ago)
From
K.L. Page at U Leicester <klp5@leicester.ac.uk>
Via
email
S. B. Cenko (GSFC), C. Gronwall (PSU), J.D. Gropp (PSU),
J. A. Kennea (PSU) and K. L. Page (U Leicester) report on behalf of
the Neil Gehrels Swift Observatory Team:
Swift/BAT triggered on the Fermi/GBM reported long GRB 240204A (GCN #35664).
Due to a telemetry outage, no realtime BAT data are available.
The XRT began observing the field at 15:10:12.2 UT, 154 seconds
after the Fermi/GBM trigger. Using promptly downlinked data we find an
uncatalogued X-ray source located at RA, Dec 104.18190, 1.02767 which
is equivalent to:
RA(J2000) = 06h 56m 43.66s
Dec(J2000) = +01d 01' 39.6"
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This
position may be improved as more data are received; the latest position
is available at https://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 6.45
x 10^21 cm^-2 (Willingale et al. 2013).
Due to a telemetry outage, there are no UVOT data available at this time.
Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)
GCN Circular 35664
Subject
GRB 240204A: Fermi GBM Final Real-time Localization
Date
2024-02-04T15:18:07Z (2 years 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 15:07:38 UT on 4 Feb 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240204A (trigger 728752063.677018 / 240204630).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 101.5, Dec = -3.4 (J2000 degrees, equivalent to J2000 06h 46m, -3d 23'), with a statistical uncertainty of 1.6 degrees.
The angle from the Fermi LAT boresight is 102.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240204630/quicklook/glg_skymap_all_bn240204630.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/bn240204630/quicklook/glg_healpix_all_bn240204630.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240204630/quicklook/glg_lc_medres34_bn240204630.gif