EP241213a, GRB 241213A
GCN Circular 39685
Subject
GRB 241213A: VIRT Optical Upper Limit
Date
2025-03-12T13:11:33Z (9 months 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), B. Gendre (UVI), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), D. Smith (UVI), R. Querrard (UVI), and C. Watson (UVI) report:
We observed the field of GRB241213A (Gupta et al., GCN 38547) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 2024-12-14 starting at 7:34:05 UT (T-mid ~ T0 + 20.3 hrs). We performed a series of exposures in an R filter with a total exposure of 740s. The weather conditions were partly cloudy during the hours of observation with an average airmass of 1.1.
We do not detect any source within the enhanced XRT position (Osborne et al. GCN 38552). This non-detection is consistent with reported detections (Qiu et al., GCN 38566) and upper limits (Spiridonova et al., GCN 38550; Shilling et al., GCN 38564; Brivio et al., GCN 38553; Strausbaugh et al., GCN 38558; and Qiu et al., GCN 38566). We report the following 3-sigma upper limit:
T_mid ||Exposure ||Filter ||Limit
T+20.3 h || 740 s || R || > 20.3
The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction.
We acknowledge financial support from NASA EPSCoR award 80NNSC22M0063, NSF PAARE award 2319415, and NASA EPSCoR award 80NSSC24M0112. This message can be cited.
GCN Circular 38590
Subject
GRB 241213A (EP241213a): GRBAlpha detection
Date
2024-12-17T15:41:39Z (a year ago)
From
Marianna Dafčíková at Masaryk University <500025@mail.muni.cz>
Via
Web form
M. Dafcikova, J. Ripa, M. Kolar (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Duriskova, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 241213A (Swift/BAT detection: GCN 38547; EP/WXT detection: GCN 38554; INTEGRAL/SPI-ACS detection: GCN 38556; Konus/Wind detection: GCN 38581) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract).
The detection was confirmed at the peak time 2024-12-13 02:19:00.5 UTC. The T90 duration measured by GRBAlpha is 4.5 s and the overall significance during T90 reaches 7.6 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB241213A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN Circular 38583
Subject
GRB 241213A: Swift-BAT refined analysis
Date
2024-12-16T20:57:10Z (a year ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Via
Web form
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), R. Gupta (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), D. Sadaula (GSFC/UMBC),
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 241213A (trigger #1274039)
(Gupta, et al., GCN Circ. 38547). The BAT ground-calculated position is
RA, Dec = 116.163, 35.269 deg which is
RA(J2000) = 07h 44m 39.2s
Dec(J2000) = +35d 16' 06.7"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 44%.
The mask-weighted light curve shows a single bright episode that starts
at ~T-11 s, peaks at ~T+1 s and ends at ~T+16 s.
T90 (15-350 keV) is 10.3 +- 3.1 sec (estimated error including systematics).
The time-averaged spectrum from T-10.79 to T+16.54 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.26 +- 0.06. The fluence in the 15-150 keV band is 4.1 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.24 sec in the 15-150 keV band
is 10.3 +- 0.5 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1274039
GCN Circular 38581
Subject
Konus-Wind detection of GRB 241213A (EP 241213a)
Date
2024-12-16T15:00:39Z (a year ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Via
Web form
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long-duration GRB 241213A
(Swift-BAT detection: Gupta et al., GCN 38547;
INTEGRAL-SPI-ACS detection: Barria et al., GCN 38556),
associated with the fast X-ray transient EP241213a
(Zhou et al., GCN 38554; Barria et al., GCN 38556),
triggered Konus-Wind at T0=8344.058 s UT (02:19:04.058).
The burst light curve shows a single pulse,
which starts at ~T0-3.1 s and has a total duration of ~7.6 s.
The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB241213_T08344/
As observed by Konus-Wind, the burst
had a fluence of 1.04(-0.07,+0.07)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.056 s,
of 4.78(-1.05,+1.06)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 = -0.88(-0.17,+0.18)
and Ep = 236(-24,+30) keV (chi2 = 74/77 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.6
(chi2 = 73/76 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 38566
Subject
GRB 241213A: SVOM/VT optical candidate
Date
2024-12-14T04:24:28Z (a year ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
SVOM/VT commissioning team: Y. L. Qiu, H. L. Li (NAOC), Y. Wang (PMO), R.-Z. Li (YNAO), L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, D. H. Zhao (NAOC), J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV)
report on behalf of the SVOM team:
The SVOM/VT conducted follow-up observations of the Swift-triggered GRB 241213A (Gupta et al., GCN 38547) in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously, from 10.636 hours to 15.7 hours after the burst.
With the X band downlinked data, an uncatalogued optical source was detected within the errorbox of XRT (Osborne et al., GCN 38552) in VT_R stacked image, compared to the PanSTARRS catalog. The brightness of the source was estimated to be 23.8 ± 0.3 mag in AB magnitude in VT_R image at the mid time of 13.6 hours post the burst, with a total exposure time of 135*50 seconds. The source can not be detected in VT_B stacked image with 3 sigma upper limit of ~24.0 mag in AB magnitude.
The source is located at RA, Dec = 116.17031, 35.27805, which is equivalent to:
RA (J2000) : 07:44:40.87
Dec (J2000): +35:16:40.99
with an uncertainty of 0.5 arcsec.
We proposed that this source is the candidate for the gamma-ray burst. Further follow-ups with SVOM/VT are scheduled to confirm the nature of the source.
More deep follow-ups are encouraged.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC), CAS.
GCN Circular 38564
Subject
GRB 241213A: Swift/UVOT Upper Limits
Date
2024-12-13T22:54:19Z (a year ago)
From
Sam Shilling at Lancaster University <shilling.sam@gmail.com>
Via
Web form
S.P.R. Shilling (Lancaster) and R. Gupta (NASA GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 241213A
106 s after the BAT trigger (Gupta et al., GCN Circ. 38547).
No optical afterglow consistent with the enhanced XRT position
(Osborne et al., GCN Circ. 38552) 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 first
finding chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 106 256 147 >20.6
u_FC 318 568 246 >19.8
white 106 945 259 >20.7
v 648 4786 236 >19.2
b 573 766 39 >19.0
u 318 742 265 >19.9
w1 698 5045 67 >18.7
m2 673 4991 216 >19.5
w2 624 4581 236 >19.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.060 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 38562
Subject
GRB 241213A: Swift-XRT refined Analysis
Date
2024-12-13T16:21:52Z (a year ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
We have analysed 4.5 ks of XRT data for GRB 241213A, from 106 s to 33.0
ks after the BAT trigger. The data comprise 275 s in Windowed Timing
(WT) mode with the remainder in Photon Counting (PC) mode.
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.59 (+0.07, -0.08), followed by a break at T+680 s to
an alpha of 1.20 (+0.16, -0.06).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.89 (+/-0.10). The
best-fitting absorption column is 3.3 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 6.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.85 (+/-0.14) and a
best-fitting absorption column of 3.9 (+0.8, -0.7) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 4.3 x 10^-11 (6.2 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 3.9 (+0.8, -0.7) x 10^21 cm^-2
Galactic foreground: 6.7 x 10^20 cm^-2
Excess significance: 7.4 sigma
Photon index: 1.85 (+/-0.14)
If the light curve continues to decay with a power-law decay index of
1.20, the count rate at T+24 hours will be 0.014 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.9 x
10^-13 (8.5 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01274039.
This circular is an official product of the Swift-XRT team.
GCN Circular 38558
Subject
GRB 241213A: LCOGT Optical Upper Limits
Date
2024-12-13T14:28:54Z (a year ago)
From
Robert Strausbaugh at Eastern Illinois University <rstrausbaugh@eiu.edu>
Via
email
R. Strausbaugh (Eastern Illinois University), A. Cucchiara (NASA) report on behalf of a larger collaboration:
We observed the Swift GRB 241213A field (Gupta et al., GCN 38547) with the LCOGT 1-meter Sinistro instrument at the McDonald Observatory USA site, on December 13, from 06:49 to 07:19 UT (corresponding to 4.50 to 5.00 hours after the GRB trigger time) with the sdss r and i filters.
We performed a series of 3x300s exposures in i-band and 2x300s in r-band. We do not detect a source within the Swift XRT enhanced error region (Osborne et al., GCN 38552) in either band, consistent with other optical upper limits (Lipunov et al., GCN 38548; Spiridonova et al., GCN 38550; Brivio et al., GCN 38553).
The following 5-sigma upper limits are calculated using the PanSTARRS catalog as reference:
r > 21.2
i > 21.5
These magnitudes are not corrected for galactic extinction.
GCN Circular 38556
Subject
EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
Date
2024-12-13T13:46:38Z (a year ago)
From
Aishwarya L Thakur at INAF-IAPS, Rome <aishth@outlook.com>
Via
Web form
Patrizia Barria(a,b), Giulia Gianfagna(a), James Craig Rodi(a), Aishwarya Linesh Thakur(a), Luigi Piro(a), Lorenzo Natalucci(a,b) report:
The fast X-ray transient, EP241213a, was discovered by the Einstein Probe/WXT (GCN 38554). This transient appears to be spatially coincident with GRB 241213A (BAT: GCN 38547, XRT: GCN 38552), as the XRT coordinates are consistent with the 2.8 arcmin WXT error circle. There is a temporal delay of ~ 100 s between the BAT and WXT detections. We searched for any corresponding emission in the INTEGRAL/SPI-ACS data.
In a light curve above 80 keV, we find a pulse temporally coincident with the BAT detection (thus occurring ~ 100 s after the EP/WXT detection, assuming they are the same event), with an approximate duration of 10 sec.
The approximate peak count rate is 80000 cts/s over a median background rate of 62500 cts/s.
This work is based on observations with INTEGRAL, an ESA project with instruments and a science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, and Spain), and with the participation of Russia and the USA. The SPI-ACS detector system has been provided by MPE Garching/Germany.
-----
(a) INAF/IAPS-Rome
(b) ICSC National Research Centre for High-Performance Computing
GCN Circular 38554
Subject
EP241213a: EP detection of An X-ray Transient
Date
2024-12-13T12:12:13Z (a year ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
X.-Y. Zhou (PRIC), R.-Z. Li (YNAO, CAS), D.-F. Hu (PMO, CAS), S.-X. Wen, H.-W. Pan (NAO, CAS) report on behalf of the Einstein Probe team:
We report on the detection of an X-ray transient by the Einstein Probe (EP), designated as EP241213a. The source was first detected by the Wide-field X-ray Telescope (WXT) on board EP in a single pointing observation (with an exposure time of 1.6 ks) at 2024-12-13T02:17:15 (UTC). The position of the transient is R.A. = 116.182 deg, Dec. = 35.271 deg, with an uncertainty of 2.8 arcmin. No previously known bright X-ray sources are found within the error circle around the transient position.
The WXT spectrum of the observation can be fitted by an absorbed power law with a photon index of 2.2+/-1.4, with the NH of (5.9+/-4.8) e21 cm^-2. The derived absorbed flux in 0.5-4 keV is ~5.2e-11 ergs/s/cm^2.
A Swift-XRT ToO proposal was submitted to observe the transient. Multi-wavelength follow-up observaitons are encouraged.
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES.
GCN Circular 38553
Subject
GRB 241213A: REM optical/NIR upper limits
Date
2024-12-13T12:02:01Z (a year ago)
From
Riccardo Brivio at INAF-OAB <riccardo.brivio@inaf.it>
Via
Web form
R.Brivio, M. Ferro, P. D’Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team:
We observed the field of GRB 241213A detected by Swift/BAT (Gupta et al., GCN 38547) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, J, H, K bands, starting on 2024 December 13 at 03:50:29 UT (i.e. 1.5 hours after the Swift trigger), and lasting for about 1 hour.
From preliminary photometry we do not detect any counterpart in the optical and NIR images at the enhanced Swift-XRT position (Osborne et al., GCN 38552) down to the following 3sigma magnitude upper limits:
r > 19.5 (AB; calibrated against the PanSTARRS catalogue)
at a mid-time of t - t0 = 2.1 hr after the trigger,
J > 17.8 (Vega; calibrated against the 2MASS catalogue)
at a mid-time of t - t0 = 2.2 hr after the trigger.
GCN Circular 38552
Subject
GRB 241213A: Enhanced Swift-XRT position
Date
2024-12-13T11:28:36Z (a year ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 433 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 241213A, 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 = 116.16998, +35.27882 which is equivalent
to:
RA (J2000): 07h 44m 40.80s
Dec (J2000): +35d 16' 43.8"
with an uncertainty of 3.4 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 38550
Subject
GRB 241213A: SAO RAS optical upper limit
Date
2024-12-13T09:16:58Z (a year ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
Via
Web form
O. I. Spiridonova and A. S. Moskvitin (SAO RAS),
report on behalf of the GRB follow-up team.
We observed the field of GRB 241213A (Gupta et al. GCN Circ. 38547)
with the 1-m telescope of SAO RAS, Zeiss-1000 + CCD-photometer
on December 12, 02:30:40--02:52:17 UT (t_mid - T0 = 1349 sec.),
observations started 700 seconds after the trigger. We obtained
4 x 300 sec images in Rc band under poor seeing and weather
conditions.
Inside the XRT error circle we did not detect any significant object
(as well as Lipunov et al., GCN Circ. 38548) down to the limiting
magnitude of R_lim = 21.0, calibrated against nearby PS1 stars
(magnitudes were converted with the Lupton 2005 equations
and not corrected for the MW extinction).
GCN Circular 38548
Subject
Swift GRB 241213A: Global MASTER-Net observations report
Date
2024-12-13T02:56:33Z (a year 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) was pointed to the Swift GRB 241213A ( R. Gupta et al., GCN 38547) errorbox 1183 sec after notice time and 1208 sec after trigger time at 2024-12-13 02:39:08 UT, with upper limit up to 17.8 mag. The observations began at zenith distance = 38 deg. The sun altitude is -20.1 deg.
The galactic latitude b = 26 deg., longitude l = 185 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2708197
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
1289 | MASTER-Kislovodsk | P- | 160 | 17.6 |
1469 | MASTER-Kislovodsk | P- | 520 | 17.8 | Coadd
1467 | MASTER-Kislovodsk | P- | 180 | 16.9 |
1667 | MASTER-Kislovodsk | P- | 180 | 16.4 |
The observation and reduction will continue.
The message may be cited.
GCN Circular 38547
Subject
GRB 241213A: Swift detection of a burst
Date
2024-12-13T02:39:47Z (a year ago)
From
K.L. Page at U Leicester <klp5@leicester.ac.uk>
Via
email
R. Gupta (NASA GSFC), C. Gronwall (PSU), K. L. Page (U Leicester) and
T. Sakamoto (AGU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 02:19:00 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 241213A (trigger=1274039). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 116.148, +35.280 which is
RA(J2000) = 07h 44m 35s
Dec(J2000) = +35d 16' 49"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a bright peak
with a duration of about 15 sec. The peak count rate
was ~9500 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 02:25:36.0 UT, 395.9 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 116.17145,
35.27944 which is equivalent to:
RA(J2000) = 07h 44m 41.15s
Dec(J2000) = +35d 16' 46.0"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This
location is 68 arcseconds from the BAT onboard position, within the BAT
error circle. 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 in excess of the Galactic value (6.66 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 5
(+2.07/-1.84) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 250 seconds with the U filter starting
318 seconds after the BAT trigger. No credible afterglow candidate has been
found in the initial data products. The 2.7'x2.7' sub-image covers none of the
XRT error circle. The 8'x8' region for the list of sources generated on-board
covers 100% of the XRT error circle. The list of sources is typically complete
to about 18.0 mag. No correction has been made for the expected extinction
corresponding to E(B-V) of 0.060.
Burst Advocate for this burst is R. Gupta (rahulbhu.c157 AT gmail.com).
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/)