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GRB 241030A

GCN Circular 37955

Subject
GRB 241030A: Fermi GBM Final Real-time Localization
Date
2024-10-30T05:58:39Z (7 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 05:48:03 UT on 30 Oct 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241030A (trigger 751960088.32731 / 241030242).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 331.0, Dec = 77.8 (J2000 degrees, equivalent to J2000 22h 03m, 77d 47'), with a statistical uncertainty of 5.1 degrees.

The angle from the Fermi LAT boresight is 19.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241030242/quicklook/glg_skymap_all_bn241030242.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/bn241030242/quicklook/glg_healpix_all_bn241030242.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241030242/quicklook/glg_lc_medres34_bn241030242.gif



GCN Circular 37956

Subject
GRB 241030A: Swift detection of a burst with a bright optical counterpart
Date
2024-10-30T06:05:42Z (7 months ago)
From
Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>
Via
email
N. J. Klingler (GSFC/UMBC/CRESSTII), S. Dichiara (PSU),
R. Gupta (NASA GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 05:48:03 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 241030A (trigger=1263718).  Swift slewed immediately to the burst.
The BAT on-board calculated location is 
RA, Dec 343.033, +80.439 which is 
   RA(J2000) = 22h 52m 08s
   Dec(J2000) = +80d 26' 20"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of at least 180 sec.  The peak count rate
was ~12000 counts/sec (15-350 keV), at ~162 sec after the trigger.

The XRT began observing the field at 05:49:16.6 UT, 73.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 343.1400, 80.4482 which is equivalent to:
   RA(J2000)  = 22h 52m 33.60s
   Dec(J2000) = +80d 26' 53.5"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 72 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 82 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	22:52:33.57 = 343.13987
  DEC(J2000) = +80:26:59.9  =  80.44996
with a 90%-confidence error radius of about 0.61 arc sec. This position is 6.3
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.42 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.131.

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu).
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 37957

Subject
GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
Date
2024-10-30T08:19:57Z (7 months ago)
From
Alan Watson at UNAM <alan@astro.unam.mx>
Via
legacy email
Alan M. Watson (UNAM), S. Antier (OCA), Stéphane Basa (UAR Pytheas),
William H. Lee (UNAM), Dahlia Akl (AUS), Jean-Luc Atteia (IRAP), Nathaniel
R. Butler (ASU), Damien Dornic (CPPM), J.-G. Ducoin (CPPM), Francis Fortin
(IRAP), Simona Lombardo (LAM), Francesco Magnani (CPPM), and Margarita
Pereyra (UNAM)  report:

We imaged the field of GRB 241030A detected by Fermi/GBM, Swift/BAT, and
Swift/XRT (Fermi GBM Team, GCN Circ. 37955; Klingler et al., GCN Circ.
37956) during the commissioning of the COLIBRÍ (SVOM/F-GFT) telescope at
the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in
Mexico.

We observed with the engineering test camera in a red filter that
approximates SDSS r. We observed from 2024-10-30 07:33 to 07:43 UTC (1.8
hours after the trigger) and obtained 480 seconds of exposure. The data
were reduced using custom software and then analyzed and calibrated against
the PS1 catalog using the STDWeb service (Karpov et al., 2022).

We detect the optical counterpart at RA =343.13994 and Dec = 80.44994
(J2000) with an AB magnitude of:

    r = 16.68 +/- 0.01

Further observations are planned.

We warmly thank the COLIBRÍ engineering team and the staff of the
Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir.


GCN Circular 37958

Subject
GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
Date
2024-10-30T09:02:17Z (7 months ago)
From
Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf@iac.es>
Via
Web form
G. Fernández-Rodríguez, B. Armas-Chinea, F. Dobrindt, P. Escudero-Coca, Á. García Lozano, A. Huertas Ferrer, C. Méndez-Lapido, I. Ortega-Casas, M. Torreiro Martínez, G. Villa (all ULL), S.R. Berlanas (IAC and ULL), and I. Pérez-Fournon (IAC and ULL)

We report on optical follow-up observations of the likely long GRB 241030A detected by the Fermi Gamma-ray Burst Monitor (GBM) at 05:48:03 UT on 30 Oct 2024 (Fermi GBM team, GCN 37955) and by Swift BAT, XRT, and UVOT (Klinger et al., GCN 37956).

We observed the field of GRB 241030A with the Las Cumbres Observatory Global telescope network (LCOGT) Planewave Delta Rho 350 telescope and QHY600 CMOS camera located at the LCOGT node at McDonald Observatory (Texas, USA) in the SDSS g' and r' filters (600 sec exposures in both filters).
We detect a bright optical counterpart at a position consistent with the Swift UVOT coordinates (Klinger et al., GCN 37956) with magnitudes g' = 15.92 +/- 0.02 (starting at 06:25:11 UT  
on 30 Oct 2024, about 37 minutes after the Fermi trigger) and r'= 15.87 +/- 0.02 (starting at 06:35:19 UT on 30 Oct 2024, about 47 minutes after the Fermi trigger), calibrated against the PanSTARRS DR2 catalog and without corrections for Galactic extinction.


The bright optical counterpart has also been detected by COLIBRÍ (Watson et al., GCN 37957).

We encourage multiwavelength follow up.


These results are based on observations made with the Las Cumbres Observatory’s education network telescopes that were upgraded through generous support from the Gordon and Betty Moore Foundation, as part of a course on Astrophysical Techniques of the Master in Astrophysics of the Universidad de La Laguna, Tenerife, Spain (LCOGT observing programme IAC2024B-010, ULL-ASTRO-MASTER).



GCN Circular 37959

Subject
GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
Date
2024-10-30T09:46:53Z (7 months ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Via
legacy email
WeiKang Zheng, Thomas G. Brink, Alexei V. Filippenko (UC Berkeley), and Yi
Yang (Tsinghua Univ., Beijing), report on behalf of the KAIT GRB team:


Following the detection of GRB 241030A (Klingler et al., GCN 37956), we
observed its optical counterpart (Klingler et al., GCN 37956; Watson et
al., GCN 37957; Fernández-Rodríguez et al., GCN 37958) with the Low
Resolution Imaging Spectrometer (LRIS; Oke et al. 1995) on the Keck I 10 m
telescope. Observations started at 2024-10-30 06:47 UTC (about 1.0 hr after
the burst), and consisted of 3 x 200 s exposures with the 600/4000 grism
and 400/8500 grating. The spectrum shows a well-detected continuum
throughout the complete range (3400-10,200 Ang). Numerous narrow absorption
lines are present, including Mg II 2796, 2803 Ang doublets at redshifts of
0.456, 0.862, 1.302, and 1.411. We conclude that the redshift of the GRB is
likely to be 1.411, but perhaps larger if the highest-redshift doublet is
not associated with the interstellar medium in the host galaxy.

The data presented herein were obtained at the W. M. Keck Observatory,
which is operated as a scientific partnership among the California
Institute of Technology, the University of California, and the National
Aeronautics and Space Administration. The Observatory was made possible by
the generous financial support of the W. M. Keck Foundation. The authors
wish to recognize and acknowledge the very significant cultural role and
reverence that the summit of Maunakea has always had within the indigenous
Hawaiian community. We are most fortunate to have the opportunity to
conduct observations from this mountain.


GCN Circular 37960

Subject
GRB 241030A: TRT optical observations
Date
2024-10-30T09:54:50Z (7 months ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Via
Web form
J. An, S.Y. Fu (NAOC), S. Tinyanont, R. Anutarawiramkul, P. Butpan (NARIT), S.Q. Jiang, X. Liu, Z.P. Zhu, Z. Fan, W.X. Li, N.C. Sun, Y.N. Wang, D. Xu (NAOC) report on behalf of a large collaboration:

We observed the optical afterglow of GRB 241030A detected by Fermi/GBM (Fermi GBM team, GCN 37955) and Swift/BAT (Klingler et al., GCN 37956), using the 0.7-m telescope of the Thai Robotic Telescope network (TRT), located at Fresno, California, U.S.A.

Observations started at 06:14:49.0 UTC on 2024-10-30, i.e., 27 mins after the Swift/BAT trigger, and we obtained a series of 60 s, 90 s, and 180 s frames in the R-filter.

The optical afterglow was decaying during our observations, and had R = 14.77 +/- 0.01 mag at 0.45 hr post-trigger, calibrated with nearby Pan-STARRS stars and not corrected for Galactic extinction.

GCN Circular 37962

Subject
GRB 241030A: Enhanced Swift-XRT position
Date
2024-10-30T10:54:39Z (7 months 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 867 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 241030A, 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 = 343.13875, +80.44989 which is equivalent
to:

RA (J2000): 22h 52m 33.30s
Dec (J2000): +80d 26' 59.6"

with an uncertainty of 2.2 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 37963

Subject
GRB 241030A : MITSuME Akeno optical afterglow detection
Date
2024-10-30T11:31:39Z (7 months ago)
From
Narikazu Higuchi at Tokyo Tech <higuchi@hp.phys.titech.ac.jp>
Via
Web form
N. Higuchi, Y. Kubo, H. Hagio, I. Takahashi, M. Niwano, M. Sasada, S. Hayatsu, H. Seki, S. Joshima, Y. Yatsu and N. Kawai (Science Tokyo) report on behalf of the MITSuME collaboration:

We observed the field of GRB 241030A (Fermi GBM team GCN 37955, Dichiara et al. GCN 37956) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. 

The observation with a series of 60 sec exposures started at 2024-10-30 08:28:01.71 UT (2.67 hrs after the Fermi trigger). We stacked the images in good conditions. Then we detected a point source in the Rc-band image at the Swift/UVOT position (Dichiara et al. GCN 37956). Here we report the Rc-band magnitude as follows.

T0+[hours] | MID-UT | T-EXP[sec] | magnitude of aperture photometry
----------------------------------------------------------------------------------------------------------------
3.42 | 2024-10-30 09:13:32.41 | 1620 | Rc=17.59+/-0.05
----------------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the trigger
T-EXP: Total Exposure time

We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g'-, Rc- and Ic-band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ; https://github.com/MNiwano/Eclaire).

GCN Circular 37965

Subject
GRB 241030A: SVOM/VT optical afterglow observations
Date
2024-10-30T12:15:44Z (7 months ago)
Edited On
2024-10-30T13:26:16Z (7 months ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Via
Web form
SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, C. Wu, L. P. Xin, 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, (NAOC), J. Zhang, L. J.  Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO), S. L. Xiong(IHEP) 

SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Olivier Godet (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), 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), Bing Zhang (UNLV)

report on behalf of the SVOM team:

VT started to observe the field of GRB 241030A triggered by Fermi/GBM (Fermi GBM team, GCN 37955) and Swift/BAT (Klingler et al., GCN 37956) via ToO observations started at 2024-10-30T07:03:11 UTC, about 1.25 hours after the burst. The VT conducted observations simultaneously in two channels: VT_B (400nm-650nm) and VT_R (650nm-1000nm).

The counterpart (Dichiara et al. GCN 37956, Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963) was clearly detected in both bands with VT_B=17.00+/-0.01 mag and VT_R=16.25+/-0.01 mag at 6ks post the burst. 

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 37966

Subject
GRB 241030A: Multiband optical detection with Mephisto
Date
2024-10-30T13:14:05Z (7 months ago)
From
Brajesh Kumar at SWIFAR, YNU <brajesh@ynu.edu.cn>
Via
Web form
Weikang Lin (SWIFAR, YNU), Brajesh Kumar (SWIFAR, YNU), Guowang Du (SWIFAR, YNU), Yangwei Zhang (SWIFAR, YNU), Tao Wang (SWIFAR, YNU), Runnan Jiang (SWIFAR, YNU), Yaosong Yu (SWIFAR, YNU), Yu Pan (SWIFAR, YNU), Xingzhu Zou (SWIFAR, YNU), Xinlei Chen (SWIFAR, YNU), Jinghua Zhang (SWIFAR, YNU), Yuanpei Yang (SWIFAR, YNU), Yuan Fang (SWIFAR, YNU), Yehao Cheng (SWIFAR, YNU), Chenxu Liu (SWIFAR, YNU), Xuhui Han (NAOC), Pinpin Zhang (NAOC), Liping Xin (NAOC), Chao Wu (NAOC), Xiangkun Liu (SWIFAR, YNU), Xiaowei Liu (SWIFAR, YNU) report on behalf of the Mephisto Team:

We performed uvgriz band observations of the optical afterglow of GRB 241030A (Fermi GBM team, GCN 37955 and Swift/BAT, Klingler et al., GCN 37956), using the 1.6m Multi-channel Photometric Survey Telescope (Mephisto) of Yunnan University located at Lijiang Observatory. The observations were started at 11:32:55 2024/10/30  UT (~5.7 h after the trigger). Multiple frames with exposure time 180s, 79s and 50s were taken in uv, gr, iz bands, respectively. The OT (Dichiara et al. GCN 37956, Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al. GCN 37965) is clearly visible in the individual frames in all bands. The preliminary magnitudes are reported below which indicate the decay nature of the transient. The observations are continued.

Exp-start (UT)      Band Exp(s)  Mag (AB) 
2024/10/30 11:32:55  i    79     17.78 +/- 0.07
2024/10/30 11:32:55  g    50     18.71 +/- 0.10
2024/10/30 11:32:55  u   180     19.51 +/- 0.15
2024/10/30 11:37:54  z    79     17.72 +/- 0.14
2024/10/30 11:37:54  v   180     18.87 +/- 0.10
2024/10/30 11:37:54  r    50     18.13 +/- 0.05

--------------------------------------------------------------------------
Mephisto (Multi-channel Photometric Survey Telescope) is a 1.6m wide-field multi-channel telescope, the first of its type in the world, capable of imaging the same field of view in three optical bands simultaneously. It provides real-time, high-quality colors of stellar objects. The on-site telescope assemblage and commissioning were carried out in September 2022. The first light in all three channels was achieved on 2023 December 21. 
--------------------------------------------------------------------------

GCN Circular 37970

Subject
GRB 241030A: SVOM/C-GFT optical observations
Date
2024-10-30T13:50:02Z (7 months ago)
Edited On
2024-10-30T16:12:36Z (7 months ago)
From
Chao Wu at NAOC <cwu@nao.cas.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Chao Wu at NAOC <cwu@nao.cas.cn>
Via
Web form
SVOM/C-GFT team: Chao WU (NAOC), Zhe Kang (CHO), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC)

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)


We observed the field of GRB 241030A detected by Fermi/GBM (Fermi GBM team, GCN 37955) and Swift/BAT (Klingler et al., GCN 37956) on 2024-10-30T09:54:53 UT, ~ 4.09 hr after the trigger with C-GFT in the commissioning phase. A series of g, r and i band images were obtained with exposure time of 30s. The counterpart (Dichiara et al. GCN 37956, Watson et al., GCN 37957;  Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963, Qiu et al., GCN 37965, Lin et al. GCN 37966) was clearly detected in band g,r and i. The results are,

(T-T0)_mid(sec)      mag     mag_err  band
-------------------------------------
14825          17.50    +/- 0.07  i 
14935          18.01    +/- 0.12  g 
15143          17.84    +/- 0.09  r 

The photometry was calibrated with nearby PS1 star.

We thank the observation assistant Bowen Li and Guangsheng Zhang at Jilin observatory for their excellent support.


Chinese Ground Follow-up Telescope of SVOM mission is located at Jilin, Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope.


GCN Circular 37972

Subject
GRB 241030A: SVOM/GRM observation
Date
2024-10-30T14:05:37Z (7 months ago)
From
Yue Wang <m18509381757@163.com>
Via
Web form
SVOM/GRM team: Yue Wang, Chen-Wei Wang, Shi-Jie Zheng, Yong-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zhang, Wen-Jun Tan, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao, Chao Zheng (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP), JeanLuc Attéia (IRAP)

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:

During the commissioning phase, the SVOM/GRM was triggered in-flight by GRB 241030A at 2024-10-30T05:48:14 UT (T0), which was also observed by Fermi/GBM (Fermi GBM Team, GCN 37955) and Swift/BAT (Neil Gehrels Swift Observatory Team, GCN 37956).

The real-time alert data and light curves of SVOM/GRM were downlinked to the ground through the VHF system with low latency. With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses.

The GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb241030A.png

This burst is located at about 41.56 degrees from the SVOM optical axis. However, at the time of the burst ECLAIRs was not collecting data.

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. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.

The SVOM point of contact for this burst is: Yue Wang (IHEP)(yuewang@ihep.ac.cn)

GCN Circular 37974

Subject
GRB 241030A: Swift/UVOT Detection
Date
2024-10-30T15:42:42Z (7 months ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
Via
email
A.A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 241030A 83s after the BAT trigger (Klingler et al., GCN Circ. 37956) and Fermi/GBM trigger (Fermi GBM team, GCN Circ. 37955).
A fading source consistent with the XRT position (Beardmore et al., GCN Circ. 37962) and the optical counterpart (Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al., GCN 37965 and Wu et al., GCN 37970), is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  22:52:33.47 = 343.13946 (deg.)
    Dec (J2000) = +80:26:59.8  =  80.44995 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

Preliminary detections using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white               83          232          147         15.43 ± 0.02
white              575          595           19         13.80 ± 0.05
white              748          768           20         14.19 ± 0.04
v                  625          645           19         13.71 ± 0.05
b                  551          571           20         13.96 ± 0.04
u                  295          545          246         12.96 ± 0.02
w1                 674          694           20         14.09 ± 0.06
m2                 650          670           20         14.57 ± 0.10
w2                 601          621           20         15.34 ± 0.11

The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.131 in the direction of the burst (Schlegel et al. 1998).


GCN Circular 37975

Subject
Swift GRB 241030A: Global MASTER-Net observations report
Date
2024-10-30T16:05:02Z (7 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-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 241030A ( N. J. Klingler et al., GCN 37956) errorbox  36088 sec after notice time and 36349 sec after trigger time at 2024-10-30 15:53:52 UT, with upper limit up to  18.1 mag. Observations started at twilight.  The observations began at zenith distance = 38 deg. The sun  altitude  is -14.6 deg. 

The galactic latitude b = 19 deg., longitude l = 118 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2653521

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   36440 |      MASTER-Tavrida |   C |   180 | 18.0 |        
   36440 |      MASTER-Tavrida |   C |   180 | 18.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.



GCN Circular 37976

Subject
GRB 241030A: AKO Optical Afterglow Detection
Date
2024-10-30T16:05:15Z (7 months ago)
From
Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>
Via
legacy email
Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International
Astronomical Center in Abu Dhabi, UAE), and Shaikha Alshamsi, Nuha Manal
Pattani, and Nidhal Guessoum (American University of Sharjah, UAE), report:

 

We observed the field of GRB 241030A (Fermi GBM team, GCN 37955; Klingler et
al. & Neil Gehrels Swift Observatory Team GCN 37956; Beardmore et al. &
Swift-XRT Team GCN 37962) with our 0.36m f/7.7 robotic telescope. The
observation started on 30 October 2024 at 14:42 (UT), 8.9 hours after the
trigger.

 

We obtained 14x180s images using Ic filter at the position given by
Swift/XRT: 

R.A. (J2000): 22h 52m 33.30s

Dec. (J2000): +80d 26' 59.6"

 

We did detect an afterglow candidate at the above position at a magnitude of
Ic = 18.06 +/-0.15 for the stacked images. The magnitude was estimated using
the Atlas catalogue as a reference. The magnitude is not corrected for
galactic extinction.

 

Our observational result is consistent with those of Lin et al. (GCN 37966)
and those of the SVOM/C-GFT team (GCN 37970).



GCN Circular 37977

Subject
Fermi GRB 241030A: Global MASTER-Net observations report
Date
2024-10-30T17:00:59Z (7 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-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 241030A ( Fermi GBM team, GCN 37955) errorbox  36315 sec after notice time and 36349 sec after trigger time at 2024-10-30 15:53:52 UT, with upper limit up to  18.1 mag. Observations started at twilight.  The observations began at zenith distance = 38 deg. The sun  altitude  is -14.6 deg. 

The galactic latitude b = 18 deg., longitude l = 115 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2653574

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   36440 | 2024-10-30 15:53:52 |      MASTER-Tavrida | (22h 52m 47.54s , +80d 11m 32.7s) |   C |   180 | 18.0 |        
   36440 | 2024-10-30 15:53:53 |      MASTER-Tavrida | (22h 53m 03.69s , +80d 16m 00.2s) |   C |   180 | 18.1 |        
   36632 | 2024-10-30 15:57:05 |      MASTER-Tavrida | (22h 52m 52.55s , +80d 10m 19.5s) |   C |   180 | 13.8 |        
   36632 | 2024-10-30 15:57:05 |      MASTER-Tavrida | (22h 53m 07.57s , +80d 14m 46.7s) |   C |   180 | 13.7 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.



GCN Circular 37979

Subject
GRB 241030A: Fermi-LAT detection
Date
2024-10-30T18:34:51Z (7 months ago)
From
Roberta Pillera at Politecnico and INFN Bari <roberta.pillera@ba.infn.it>
Via
Web form
GRB 241030A: Fermi-LAT detection

R. Pillera (INFN Bari), R. Gupta (NASA GSFC), D. Kocevski (NASA/MSFC), and P. Loizzo (UniTrento and INFN Bari) report on behalf of the Fermi-LAT Collaboration:

On Oct 30, 2024, Fermi-LAT detected high-energy emission from GRB 241030A, which was also detected by Fermi-GBM (trigger 751960088 / 241030242, GCN 37955), Swift-BAT (Klingler et al., GCN 37956), and SVOM-GRM (Wang et al., GCN 37972).

The best LAT on-ground location is found to be:

RA, Dec = 343.0, 80.4 (J2000)

with an error radius of 0.2 deg (90 % containment, statistical error only).

This was 16 deg from the LAT boresight at the time of the GBM trigger: T0 = 05:48:03 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 0-800 s after the GBM trigger is (4.0 +/- 1.0) E-6 ph/cm2/s. The estimated photon index above 100 MeV is -2.13 +/- 0.27.

The highest-energy photon is a 2 GeV event which is observed ~ 470 seconds after the GBM trigger.

The Fermi-LAT point of contact for this burst is Roberta Pillera (roberta.pillera@ba.infn.it).

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 37982

Subject
Konus-Wind detection of GRB 241030A
Date
2024-10-30T19:00:59Z (7 months 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 241030A
(Fermi-GBM detection: Fermi GBM Team, GCN 37955;
Swift-BAT detection: Klingler et al., GCN 37956;
SVOM/GRM observation: Wang et al., GCN 37972;
Fermi-LAT detection: Pillera et al., GCN 37979)
triggered Konus-Wind at T0=20996.591 s UT (05:49:56.591).

The burst light curve shows a multipeaked structure
which starts at ~T0-112.7 s and has a total duration of ~210.4 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB241030_T20996/

As observed by Konus-Wind, the burst
had a fluence of 5.48(-1.28,+1.95)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+26.448 s,
of 3.45(-0.82,+0.89)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+103.168 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.99(-0.19,+0.40),
the high energy photon index beta = -2.26(-0.61,+0.30),
the peak energy Ep = 140(-43,+35) keV
(chi2 = 123/87 dof).

The spectrum near the maximum count rate
(measured from T0+22.016 to T0+28.160 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 = -0.91(-0.21,+0.23)
and Ep = 196(-35,+55) keV (chi2 = 91/88 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.2
(chi2 = 91/87 dof).

Assuming the redshift z=1.411 (Zheng et al., (GCN 37959))
and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,
and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is 2.84(-0.68,+1.04)x10^53 erg,
the peak luminosity L_iso is 4.47(-1.07,+1.15)x10^52 erg/s,
the rest-frame peak energy of the time-averaged spectrum
Ep,i,z is 339(-103,+84) keV and the spectrum near the maximum count rate
Ep,p,z is 473(-84,+133) keV.

With the obtained estimates, GRB 241030A is inside 68% prediction bands for
both 'Amati' and 'Yonetoku' relations derived for the sample of >300 long
KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021),
see http://www.ioffe.ru/LEA/GRBs/GRB241030_T20996/GRB241030A_rest_frame.pdf

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GCN Circular 37988

Subject
GRB 241030A: Swift-XRT refined Analysis
Date
2024-10-30T21:58:24Z (7 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
E. Ambrosi  (INAF-IASFPA) , M. A. Williams (PSU), S. Dichiara (PSU),
J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M.
Perri (SSDC & INAF-OAR) and P.A. Evans report on behalf of the
Swift-XRT team:

We have analysed 11 ks of XRT data for GRB 241030A, from 63 s to 45.7
ks after the  BAT trigger. The data comprise 859 s in Windowed Timing
(WT) mode (the first 9 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+4.5 ks) can be modelled with an
initial power-law decay with an index of alpha=0.87 (+0.17, -0.57),
followed by a break at T+10.4 ks to an alpha of 1.58 (+/-0.10).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.720 (+0.016, -0.011). The
best-fitting absorption column is  consistent with the Galactic value
of 1.8 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.95 (+0.08, -0.06) and a best-fitting absorption
column consistent with the Galactic value. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 3.6 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.8 x 10^21 cm^-2
Intrinsic column:    1.8 (+1.8, -0.0) x 10^21 cm^-2 at z=1.411
Photon index:	     1.95 (+0.08, -0.06)

If the light curve continues to decay with a power-law decay index of
1.58, the count rate at T+24 hours will be 0.034 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-12 (1.6 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01263718.

This circular is an official product of the Swift-XRT team.


GCN Circular 37993

Subject
GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
Date
2024-10-30T23:47:05Z (7 months ago)
From
Ismael Perez-Fournon at Instituto de Astrofisica de Canarias <ipf@iac.es>
Via
Web form
C. Méndez-Lapido, B. Armas-Chinea, F. Dobrindt, P. Escudero-Coca, G. Fernández-Rodríguez, Á. García Lozano, A. Huertas Ferrer, I. Ortega-Casas, M. Torreiro Martínez, G. Villa (all ULL), S.R. Berlanas (IAC and ULL), and I. Pérez-Fournon (IAC and ULL)

We have used the ATLAS forced photometry server (Shingles et al. 2021, Transient Name Server AstroNote 2021-7) to search for detections of the optical/UV counterpart (Klingler et al, GCN 37956;
Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959;
An et al.; GCN 37960; Higuchi et al., GCN 37963; SVOM/VT commissioning team and SVOM JSW, GCN 37965; 
Lin et al., GCN 37966; SVOM/C-GFT team and SVOM JSWG, GCN 37970; Breeveld and Klingler, GCN 37974; and Odeh et al., GCN 37976) of GRB 241030A, detected by Fermi GMB (Fermi GBM team, GCN 37955) and LAT (Pillera et al., GCN 37979), Swift BAT, XRT, and UVOT (Klingler et al., GCN 37956; Beardmore et al., GCN 37962; Breeveld and Klingler, GCN 37974; and Ambrosi et al., GCN 37988),
Konus-Wind (Ridnaia et al., GCN 37982), and SVOM/GRM (SVOM/GRM team and SVOM JSWG, GCN 37972). 


Using the ATLAS (Tonry et al. 2018, PASP 130 064505; Smith et al. 2020, PASP 132 085002) forced photometry server (Shingles et al. 2021, Transient Name Server AstroNote 2021-7) at the position of the Swift UVOT bright optical counterpart (Klingler et al., GCN 37956) reveals three strong detections in the ATLAS cyan filter with magnitudes 17.178 +/- 0.032, 17.258 +/- 0.031, and 17.332 +/- 0.035, at MJDs  60613.335407, 60613.338646, and 60613.344651, respectively, with a clear flux fading in these three epochs.

This work has made use of data from the Asteroid Terrestrial-impact Last Alert System (ATLAS) project. The Asteroid Terrestrial-impact Last Alert System (ATLAS) project is primarily funded to search for near earth asteroids through NASA grants NN12AR55G, 80NSSC18K0284, and 80NSSC18K1575; byproducts of the NEO search include images and catalogs from the survey area. This work was partially funded by Kepler/K2 grant J1944/80NSSC19K0112 and HST GO-15889, and STFC grants ST/T000198/1 and ST/S006109/1. The ATLAS science products have been made possible through the contributions of the University of Hawaii Institute for Astronomy, the Queen’s University Belfast, the Space Telescope Science Institute, the South African Astronomical Observatory, and The Millennium Institute of Astrophysics (MAS), Chile.
 


GCN Circular 38000

Subject
GRB 241030A: COLIBRI Continuing Detection of the Afterglow
Date
2024-10-31T08:36:14Z (7 months ago)
From
Alan Watson at UNAM <alan@astro.unam.mx>
Via
legacy email
S. Antier (OCA), Alan M. Watson (UNAM), Stéphane Basa (UAR Pytheas),
William H. Lee (UNAM), D. Akl (AUS), Jean-Luc Atteia (IRAP), Nathaniel R.
Butler (ASU), Damien Dornic (CPPM), J.-G. Ducoin (CPPM), Francis Fortin
(IRAP), Simona Lombardo (LAM), Francesco Magnani (CPPM), and Margarita
Pereyra (UNAM) report:

We imaged again the field of GRB 241030A detected by Fermi/GBM, Swift/BAT,
and Swift/XRT (Fermi GBM Team, GCN Circ. 37955; Klingler et al., GCN Circ.
37956) during the commissioning of the COLIBRÍ (SVOM/F-GFT) telescope at
the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in
Mexico.

We observed with the engineering test camera in a red filter that
approximates SDSS r. The data were reduced using custom software and then
analysed and calibrated against the PS1 catalog using the STDWeb service
(Karpov et al. 2022).

In 1200 seconds of exposure from 2024-10-31 01:46:50 to 02:10:56 UTC (0.83
to 0.85 days after the trigger), we detect the optical counterpart with an
AB magnitude of:

r = 19.95 +/- 0.06

This magnitude is consistent with the last optical observations reported
(GCN Circ. 37993, 37976, 37966 ).

Further observations are planned.

We warmly thank the COLIBRI engineering team and the staff of the
Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir


GCN Circular 38010

Subject
GRB 241030A: Swift-BAT refined analysis
Date
2024-10-31T13:57:08Z (7 months ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Via
legacy email
H. A. Krimm (NSF), S. D. Barthelmy (GSFC), R. Gupta (GSFC),
N. J. Klingler (GSFC/UMBC/CRESSTII), 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),
T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
 Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 241030A (trigger #1263718)
(Klingler, et al., GCN Circ. 37956).  The BAT ground-calculated position is
RA, Dec = 343.216, 80.438 deg which is
   RA(J2000)  =  22h 52m 51.9s
   Dec(J2000) = +80d 26' 18.2"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 80%.
 The mask-weighted light curve shows multiple emission periods. The initial episode
starts from T0 following four overlapping pulses, and ends around T+45 sec. Then,
the bright episode starts at T+105 sec, peaks at T+148 sec, and ends at T+230 sec.
T90 (15-350 keV) is 173.3 +- 5.0 sec (estimated error including systematics).
 The time-averaged spectrum from T-0.86 to T+276.48 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.64 +- 0.03.  The fluence in the 15-150 keV band is 2.73 +- 0.04 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T+147.45 sec in the 15-150 keV band
is 11.8 +- 0.3 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/1263718



GCN Circular 38015

Subject
GRB 241030A: Fermi GBM Observation
Date
2024-10-31T15:13:27Z (7 months ago)
From
Cuán de Barra at UCD <cuan.debarra@ucdconnect.ie>
Via
Web form
C. de Barra (UCD) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:

"At 05:48:03.33 UT on 30 October 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB241030A (trigger 751960088/241030242).
which was also detected by Swift-BAT (Klingler et al. 2024, GCN 37956), SVOM-GRM (Wang et al. 2024, GCN 37972), and Konus-Wind (Ridnaia et al. 2024, GCN 37982)
The Fermi GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 17 degrees.

The GBM light curve consists of multiple emission episodes with a duration (T90)
of about 166 s (50-300 keV). The time-averaged spectrum
from T0-21 to T0+217 s is best fit by
a Band function with Epeak = 129 +/- 7 keV,
alpha = -1.35 +/- 0.02, and beta = -2.31 +/- 0.08.

The event fluence (10-1000 keV) in this time interval is
(6.235 +/- 0.095)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+147 s in the 10-1000 keV band is 20 +/- 0.4 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 38016

Subject
GRB 241030A: SAO RAS optical observations
Date
2024-10-31T17:15:46Z (7 months ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
Via
legacy email
A. S. Moskvitin (SAO RAS) and V. P. Goranskij (SAI MSU)
report on behalf of the GRB follow-up team.

We observed the field of the GRB 241030A (Klingler et al., GCN 37956;
Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al.,
GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988;
Wu et al., GCN 37997) with the 1-m telescope of SAO RAS, Zeiss-1000
equipped with the CCD-photometer on October 30/31 night. We obtained
series of 300 and 600 sec. images in Rc band.

The OT (Klingler et al., GCN 37956; Watson et al., GCN 37957;
Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959;
An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al.,
GCN 37965; Lin et al., GCN 37966; Wu et al., GCN 37970;
Breeveld & Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993)
is clearly detected in our stacked frames. Preliminary photometry
calibrated against nearby Pan-STARRS stars (magnitudes converted
with Lupton 2005 equations) and not corrected by MW extinction:

date       UT_start--UT_end    t_mid-T0, h  exp., s   R_mag
Oct. 30    17:21:38--17:26:38  11.8392       6 x 300  18.72 +/- 0.04
Oct. 30    20:40:51--21:44:59  15.4145       6 x 600  19.09 +/- 0.06
Oct. 30/31 23:18:20--02:14:51  18.9756      15 x 600  19.36 +/- 0.04

list of used Pan-STARRS stars:
R.A. (J2000) Decl. (J2000)  R_mag (Lupton 2005)
343.156212740 80.434129340  14.119
343.189894620 80.452656920  17.502
343.155709870 80.466614280  16.501
343.372455850 80.465046470  14.448



GCN Circular 38019

Subject
GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
Date
2024-10-31T22:50:07Z (7 months ago)
From
Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann@physik.lmu.de>
Via
Web form
Malte Busmann (LMU), Daniel Gruen (LMU), Brendan O’Connor (Carnegie Mellon U.) and Antonella Palmese (Carnegie Mellon U.) report:

We observed the optical counterpart of GRB 241030A (Fermi GBM team, GCN 37955; Klingler et al., GCN 37956; Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959, An et al., GCN 37960, Higuchi at al., GCN 3763; Qui et al., GCN 37965; Lin et al., GCN 37966 and similar) which was also detected as an X-ray transient by Swift (Klingler et al., GCN 37956) and Einstein Probe (Wu et al., GCN 37997) as EP241030a with the Three Channel Imager (3KK) at the Fraunhofer
Telescope Wendelstein (FTW) in the r, i and J band simultaneously for 20 x 180 s starting at 2024-10-31T17:18:20 UT (1.48 days after the trigger). We detect the counterpart at

r = (20.89 +/- 0.02) mag
i = (20.62 +/- 0.02) mag
J = (20.11 +/- 0.04)  mag.

The r and i band magnitudes are calibrated against the PanSTARRS1 catalog and provided in the AB system. The J band magnitude is calibrated against the 2MASS catalog and converted to the AB system with Blanton and Roweis, 2007, doi:10.1086/510127. Magnitudes are not corrected for Galactic extinction.

We thank the staff of the Wendelstein Observatory for obtaining these observations.

GCN Circular 38021

Subject
GRB 241030A: Palomar 1-m telescope COSMOS optical observations
Date
2024-11-01T00:07:33Z (7 months ago)
From
Benjamin Schneider at MIT <bschn@mit.edu>
Via
Web form
Benjamin Schneider (MIT), Geoffrey Mo (MIT), Jill Juneau (MIT), Christopher Layden (MIT), Gustav Pettersson (MIT), Nathan Lourie (MIT), Robert Simcoe (MIT) report on behalf of a larger team:

We observed the field of GRB 241030A (Klingler et al., GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al., GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988; Wu et al., GCN 37997) with the Palomar 1-m telescope, equipped with the large format COSMOS-8k Teledyne camera currently under testing.

Our observations began at 2024-10-31T02:05:52 UTC (~20.4 hours after the GRB trigger) and consisted of 20x30s exposures in the r’ band. In the stacked image, we clearly detect the optical counterpart of GRB 241030A (Klingler et al., GCN 37956; Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al., GCN 37965; Lin et al., GCN 37966; Wu et al., GCN 37970; Breeveld & Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993, Moskvitin et al, GCN 38016; Busmann et al., GCN 38019).

The preliminary magnitude derived for the source is

r’ = 20.2 +/- 0.1 mag (AB)

The photometric calibration was performed using nearby stars from the PanSTARRS catalog and the magnitude is not corrected for Galactic extinction.


GCN Circular 38027

Subject
GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
Date
2024-11-01T09:10:37Z (7 months ago)
Edited On
2024-11-01T13:34:59Z (7 months ago)
From
Rui-Zhi Li at Yunnan Observatories, CAS <liruizhi@ynao.ac.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Rui-Zhi Li at Yunnan Observatories, CAS <liruizhi@ynao.ac.cn>
Via
email
R.-Z. Li, H. Lin, S.-S. Li, H.-C. Feng, B.-T. Wang, F.-F. Song, J. Mao and J.-M. Bai (YNAO, CAS) report:

We observed the optical counterpart of GRB 241030A (Klingler et al., GCN 37956; Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al., GCN 37965; Lin et al., GCN 37966; Wu et al., GCN 37970; Breeveld &amp; Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993; Moskvitin et al., GCN 38016; Busmann et al., GCN 38019; Schneider et al., GCN 38021), which was independently detected by Fermi/GBM (Fermi GBM Team, GCN 37955), Swift (Klingler et al., GCN 37956), SVOM/GRM (SVOM/GRM Team, GCN 37972), and Einstein Probe (Wu et al., GCN 37997; Liang et al., GCN 38026) as EP241030a.

The observation was conducted with the Gao-Mei-Gu (GMG) 2.4m telescope. Grism #3 was used, providing a wavelength coverage of 3400–9100 AA. A single 1-hour spectrum was obtained, with exposure beginning at 13:15:33 UT on 2024-10-30, about 7.46 hours after the Swift trigger.

Despite the low signal-to-noise ratio of the spectrum, we identified a strong absorption line of Al II at 1671 AA, along with weaker absorption lines of Fe II at 2374 AA, 2383 AA, 2587 AA, and 2600 AA, Mg II at 2800 AA, and Mg I at 2852 AA. These metal absorption features consistently indicate a redshift of z ~ 1.4, consistent with the Keck/LRIS result (Zheng et al., GCN 37959).

We acknowledge the staff at the Lijiang Observatory for conducting the observation.


GCN Circular 38031

Subject
GRB 241030A: Optical Observations via Virtual Telescope Project
Date
2024-11-01T11:24:15Z (7 months ago)
From
Gianluca Masi at Virtual Telescope Project <gianluca@bellatrixobservatory.org>
Via
Web form
Gianluca Masi, Virtual Telescope Project (Italy), reports:

We observed the field of GRB 241030A (Klingler et al., GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al., GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988; Wu et al., GCN 37997) with the 17”-432mm robotic unit available at the Virtual Telescope Project facility in Manciano, Italy, equipped with a KAF-6303E based CCD camera.

We collected 16, 300-second unfiltered exposures, then we averaged them. The central time of the resulting stack was 31 Oct. 2024, 18:27:50 UTC, that is about 36.8 hours after the burst.

We clearly detect the optical counterpart of GRB 241030A (Klingler et al., GCN 37956).

The position of the source is RA: 22 52 33.52; Decl.: +80 26 59.5 (J2000.0, mean residuals of 0.15”, reference stars from GaiaDR2) and the magnitude was estimated to be 19.9 (SNR=5, assuming R mags for the reference stars from GaiaDR2).

The image is available here:
https://www.virtualtelescope.eu/wordpress/wp-content/uploads/2024/11/GRB241030A_31oct2024_pw17_masi_vtp.jpg

GCN Circular 38032

Subject
GRB 241030A: further SAO RAS optical observations
Date
2024-11-01T11:48:47Z (7 months ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
Via
legacy email
A. S. Moskvitin (SAO RAS) and V. P. Goranskij (SAI MSU)
report on behalf of the GRB follow-up team.

We observed the field of GRB 241030A / EP241030a (Klingler et al.,
GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972;
Pillera et al., GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al.,
GCN 37988; Wu et al., GCN 37997; Liang et al., GCN 38026)
with the 1-m telescope of SAO RAS, Zeiss-1000 equipped
with the CCD-photometer on October 31, 17:49:28--18:22:41 UT
(t_mid - T0 = 1.5125 days = 36.3 hours).

The OT (Klingler et al., GCN 37956; Watson et al., GCN 37957;
Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959;
An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al.,
GCN 37965; Lin et al., GCN 37966; Wu et al., GCN 37970;
Breeveld & Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993;
Moskvitin & Goranskij, GCN 38016; Busmann et al., GCN 38019;
Schneider et al., GCN 38021; Li et al., GCN 38027; Masi, GCN 38031)
is clearly detected in our 3 x 600 sec stacked frame in Rc band
with the brightness of R = 20.31 +/- 0.06 (R_lim = 22.6),
calibrated against nearby Pan-STARRS stars (magnitudes converted
with Lupton 2005 equations) and not corrected by MW extinction.



GCN Circular 38035

Subject
GRB 241030A/EP241030a: TNOT observations of the optical counterpart
Date
2024-11-01T15:11:50Z (7 months ago)
Edited On
2024-11-01T16:14:39Z (7 months ago)
From
Xiaofeng Wang at Tsinghua University <wang_xf@mail.tsinghua.edu.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Xiaofeng Wang at Tsinghua University <wang_xf@mail.tsinghua.edu.cn>
Via
Web form
Y.S. Yan (THU), L. T. Wang (XAO), X.F. Wang(THU), A. Iskandar(XAO), J. L. Liu (THU),J. Mo (THU), A. Esamdin (XAO), S. Antier (OCA),and W. X. Li (NAOC) report the detection of the optical transient associated with GRB 241026A/EP241026a with a redshift of 1.41 (Klingler et al.,GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al., GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988; Wu et al., GCN 37997; Liang et al., GCN 38026; Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al.,GCN 37965; Lin et al., GCN 37966; Wu et al., GCN 37970; Breeveld & Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993; Moskvitin & Goranskij, GCN 38016; Busmann et al., GCN 38019; Schneider et al., GCN 38021; Li et al., GCN 38027; Masi, GCN 38031; Moskvitin et al., GCN 38032).

We obtained the CCD photometric observations on October 31 14:35--15:53 UT, with 100sx20 (~33.1 hrs from T0) exposure in the r band and 100sx20 (~33.7 hrs from T0) exposure in the i band, using the 0.8~m Tsinghua-Nanshan Optical Telescope (TNOT) located at Nanshan Station of Xinjiang Astronomy Observatory. The optical counterpart is clearly detected on the stacked images, with the following magnitudes:
 
r = 20.74 +- 0.14 mag (MJD = 60614.618)
i = 20.24 +- 0.20 mag (MJD = 60614.647)

The above photometric results are calibrated using the field stars from the Pan-STARRS1 catalog and are not corrected for the Galactic extinction.

GCN Circular 38041

Subject
GRB241030A: OHP/T193 optical observations
Date
2024-11-02T11:55:37Z (7 months ago)
From
Christophe Adami at LAM <christophe.adami@lam.fr>
Via
Web form
C. Adami (LAM), B. Schneider (MIT), report on behalf of a larger collaboration:

We observed the field of GRB241030A (at a redshift of z=1.41) (Fermi GBM Team, GCN 37955, 
Klingler et al., GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al., 
GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988; Wu et al., GCN 37997; Liang et 
al., GCN 38026; Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., 
GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al.,GCN 37965; Lin et al., 
GCN 37966; Wu et al., GCN 37970; Breeveld & Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993;
Moskvitin & Goranskij, GCN 38016; Busmann et al., GCN 38019; Schneider et al., GCN 38021; Li et 
al., GCN 38027; Masi, GCN 38031; Moskvitin et al., GCN 38032, Yan et al., GCN 38035, Liang et 
al., GCN38040) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped 
with the MISTRAL spectro-imager. A total of 70 min of exposure (7x600s) were obtained in the 
r-band starting at 03:46:29 UT on 2024-11-02 (~2.9 days after the trigger).

The optical counterpart is clearly detected on the stacked images, with the following 
preliminar magnitude: r = 21.9 +/- 0.1 mag (AB)

The photometric calibration was performed using nearby stars from the PanSTARRS catalog and 
the magnitude is not corrected for Galactic extinction.

We acknowledge the excellent support from Observatoire de Haute-Provence and in particular 
Stephane Favard for the MISTRAL observations.

GCN Circular 38042

Subject
Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
Date
2024-11-02T13:01:46Z (7 months ago)
From
Amar Aryan at National Central University, Institute of Astronomy (NCUIA) <amararyan941@gmail.com>
Via
Web form
A. Aryan (NCU), A. K. H. Kong (NTHU), W.-J. Hou, T.-W. Chen (both NCU), J. Gillanders (Oxford), S. J. Smartt (Oxford/QUB), Y. J. Yang, A. Sankar. K, Y.-C. Pan, C.-C. Ngeow, M.-H. Lee, H.-C. Lin, C.-H. Lai, H.-Y. Hsiao, C.-S. Lin, J.-K. Guo (all NCU), S. Yang, Z. N. Wang, L. L. Fan, G. H. Sun (all HNAS), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report: 

We observed the fields of the fast X-ray transients EP241021a (rebrightening; Quirola-Vasquez et al. GCN 37930, Freeburn et al. GCN 37942, Bochenek et al. 38030), EP241026b (Lian et al. GCN 37902, Lipunov et al. GCN 37905, Mohan et al. GCN 37920, Rossi et al. GCN 37938, Lian et al. GCN 37967, Bochenek et al. GCN 38018), and EP241030a/GRB241030A (Wu et al. GCN 37997, Fermi GBM Team, GCN 37955, Lipunov et al. GCN 38007, Busmann et al. GCN 38019, Liang et al. GCN 38026, Li et al. GCN 38027, Moskvitin et al. GCN 38032, Yan et al. GCN 38035, Liang et al. GCN 38040) using the 1m LOT at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al. 2024arXiv240609270C). 

We utilized the astroalign (Beroiz et al. 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al. 2022, ApJ, 935, 167) packages to align and stack the individual frames. Moreover, we utilized the Python-based package AutoPhOT (Brennan & Fraser, 2022, A&A, 667, A62) to perform the PSF photometry on our stacked frames. The details of the observations and measured photometry and 3-sigma limit (in the AB system) for each of the sources are as follows:

############################################################################
EP241021a: The first epoch of observations started at 2024-11-01, 15:44:21 UT.
Telescope | Filter | MJD (start) | t-t0 (d) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass
LOT | r | 60615.656 | 11.44 | 300 * 6 | 22.06 +/- 0.33 | 1".02 | 1.08

############################################################################
EP241026b: The first epoch of observations started at 2024-11-01, 16:19:08 UT.
Telescope | Filter | MJD (start) | t-t0 (d) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass
LOT | r | 60615.680 | 5.92 | 300 * 12 | > 23.4 | 1".08 | 1.05

############################################################################
EP241030a: The first epoch of observations started at 2024-11-01, 13:42:34 UT in r-band.
Telescope | Filter | MJD (start) | t-t0 (d) | Exposure (s) | Magnitude | avg. Seeing | med. Airmass
LOT | r | 60615.571 | 2.30 | 300 * 6 | 21.73 +/- 0.36 | 1".39 | 1.90
LOT | g | 60615.593 | 2.32 | 300 * 6 | 22.00 +/- 0.42 | 1".50 | 1.95

The presented magnitudes are calibrated using field stars from the Pan-STARRS1 catalog and are not corrected for the expected Galactic foreground extinction.


GCN Circular 38050

Subject
GRB 241030A: Rapid release of TESS data.
Date
2024-11-03T02:59:17Z (7 months ago)
From
Glen Petitpas at MIT <petitpas@mit.edu>
Via
Web form
From: The TESS Mission

The Transiting Exoplanet Survey Satellite (TESS) observed GRB 241030A during scheduled observations of Sector-85, and the GRB is contained within Camera 3 CCD 3. The window of observation encompasses the initial Fermi GCN trigger at UTC 05:48:03 on 30 Oct 2024 (GCN Circular 37955), as well as the entire error regions from the refined localizations by Swift (GCN Circular 37956).

The TESS Mission is making the TICA-processed full frame images (FFIs) for only Camera 3 CCD 3 in Sector 85 available to the public to accommodate rapid analysis by the community prior to the full data sets being available on MAST. Camera 3 CCD 3 FITS files will be available by approximately UTC 06 hours on 03 Nov 2024, and instructions for downloading are here:
https://tess.mit.edu/public/grb241030A/README.txt
Details and references regarding TICA  data products can be found at MAST (https://archive.stsci.edu/hlsp/tica). The FITS header timestamps are in TESS time and can be converted to UTC using the Astropy Time conversion from TDB to UTC.

The TESS Mission is also making SPOC calibrated FFIs for Sector-85 available for download at the following link by approximately UTC 13 hours 03 Nov 2024:
https://data.nas.nasa.gov/viz/vizdata/armichae/space/index.html
The SPOC data products are documented in the TESS Archive Manual at MAST (https://outerspace.stsci.edu/display/TESS/TESS+Archive+Manual). The SPOC FFI FITS header timestamps are provided in barycentric-corrected TESS Julian date : BTJD = BJD – 2457000.

The full TESS data set from the first orbit of Sector-85 (including full TICA and SPOC FFIs) should be available early this coming week, following the standard processing and release process.


GCN Circular 38055

Subject
GRB 241030A: Swift-UVOT observations of the optical prompt flare
Date
2024-11-03T09:57:36Z (7 months ago)
From
Hao Zhou at Purple Mountain Observatory, CAS <haozhou@pmo.ac.cn>
Via
Web form
Q. L. Wang, Y. Wang, H. Wang, H. Zhou, Z. P. Jin, Y. Z. Fan (PMO) reports:

Swift-UVOT began to observe the field of GRB 241030A about 83 seconds after the trigger in the event mode (Klingler et al. GCN [37956](https://gcn.nasa.gov/circulars/37956), Breeveld et al. GCN [37974](https://gcn.nasa.gov/circulars/37974)).

Similar to [Jin+2023](https://ui.adsabs.harvard.edu/abs/2023NatAs...7.1108J/abstract) and [Zhou+2023](https://ui.adsabs.harvard.edu/abs/2023ApJS..268...65Z/abstract), we construct white-band and U-band light curves with the time bin of 20 seconds, and the light curves clearly show two bumps peak around 135s and 405s.

The behavior of the first bump is similar to that of X-ray and Gamma-ray light curves, which implies the first bump seems to orginate from the prompt flare, and the second one could be the onset of the afterglow.

The multi-band light curve is avaliable at [https://postimg.cc/BX25wrFn](https://postimg.cc/BX25wrFn).


GCN Circular 38074

Subject
GRB 241030A: GRBAlpha detection
Date
2024-11-04T17:45:24Z (7 months ago)
From
Andras Pal at Konkoly Observatory <apal@szofi.net>
Via
Web form
A. Pal (Konkoly Observatory), M. Dafcikova, J. Ripa, M. Kolar, 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 241030A (Fermi/GBM detection: GCN 37955; Fermi/LAT detection: GCN 37979; Swift/BAT detection: GCN 37956; SVOM/GRM detection: GCN 37972; Konus/Wind detection: GCN 37982; INTEGRAL/SPI-ACS peak detection at 2024-10-30 ~05:50:21 UTC) 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 2024-10-30 05:50:20.9 UTC. The T90 duration measured by GRBAlpha is 208 s and the overall significance during T90 reaches 16 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB241030A_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 38105

Subject
GRB 241030A: Mondy optical observations
Date
2024-11-06T20:35:06Z (7 months ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP) report on behalf of IKI-GRB-FuN:

We continued observations of the optical afterglow (Klingler et. al, GCN 37956; Watson et. al, GCN 37957; Fernández-Rodríguez et. al, GCN 37958; An et. al, GCN 37960; Higuchi et. al, GCN 37963; SVOM/VT commissioning team, GCN 37965; Lin et. al, GCN 37966; SVOM/C-GFT team, GCN 37970; Breeveld & Klingler, GCN 37974; Odeh et. al, GCN 37976; Méndez-Lapido et. al, GCN 37993; Antier et. al, GCN 38000; Moskvitin & Goranskij, GCN 38016; Busmann et. al, GCN 38019; Schneider et. al, GCN 38021; Li et. al, GCN 38027; Masi, GCN 38031; Moskvitin & Goranskij, GCN 38032; Yan et. al, GCN 38035; The TESS Mission, GCN 38050; Wang et. al, GCN 38055;) of a likely long GRB 241030A (The Fermi GBM team, GCN 37955; Klingler et. al, GCN 37956; SVOM/GRM team, GCN 37972; R. Pillera et. al, GCN 37979; Liang et. al, GCN 38026; Pal et. al, GCN 38074;) at the redshift of z ~ 1.411 (Zheng et. al, GCN 37959, Li et. al, GCN 38027) with 1.5-meter AZT-33IK telescope of Sayan (Mondy) observatory. Four observa!
 tions were carried out since 2024-10-31 until 2024-01-04. All observations were taken in the R-filter using the CMOS-photometer Andor Neo. We clearyl detect the optical afterglow on the 2024-10-31 epoch, and tentatively detect a possible host galaxy of GRB 241030A on other epochs. The preliminary photometry is given below:


Date       UTstart  t-T0         Exp.    Filter    OT    Err       UL     
                    (mid, days)  (n*s)                          (3sigma)
2024-10-31 11:25:44 1.253254     27*120   R       20.43  0.09      22.3
2024-11-02 11:50:32 3.272567     30*120   R       22.8   0.4       22.7
2024-11-03 11:59:10 4.278553     30*120   R       22.7   0.3       22.7
2024-11-04 11:40:01 5.264565     29*120   R       22.6   0.4       22.5

The magnitudes were calibrated against stars of the PanSTARSS-PS1 catalog.
RA Dec R(Lupton transformations)
343.1048 +80.4430 17.287
343.2647 +80.4324 17.828

The reported magnitudes were not corrected for the Galactic extinction towards the GRB 241030A. From our observations we can suggest that photometry starting from 2024-11-02 could be the photometry of the host galaxy.







GCN Circular 38107

Subject
GRB 241030A: optical afterglow detection from the INAF Asiago Observatory
Date
2024-11-06T22:38:03Z (7 months ago)
From
Youdong HU at INAF-OAB <huyoudong072@hotmail.com>
Via
Web form
A. Reguitti (INAF-OAB / INAF-OAPd), Y.-D. Hu, M. Ferro, R. Brivio, P. D'Avanzo (INAF-OAB), L. Tomasella (INAF-OAPd), E. Cappellaro (INAF-OAPd), Paolo Ochner (UniPd) and Stefano Fiscale (UniParthenope), report on behalf of the CIBO and of the GRAWITA collaborations:

We carried out follow-up optical observations of GRB241030A by Fermi, Swift, SVOM and Konus-Wind (Fermi GBM team, GCNC 37955; Klingler et al., GCNC 37956; Beardmore et al., GCN 37962; SVOM/GRM team, GCNC 37972; Ridnaia et al., GCNC 37982; Pillera et al., GCNC 37979) from the INAF-Padova Astronomical Observatory located in Asiago (Italy) with the 67/92 Schmidt telescope starting on 2024-10-30 at 17:47:50UT (~12 hour after trigger) with SDSS-ri filters. In our single exposure, the optical afterglow (Watson et al., GCNC 37957;Fernández-Rodríguez et al., GCNC 37958; Zheng et al., GCNC 37959; An et al., GCNC 37960; Higuchi et al., GCNC 37963; SVOM/VT team, GCNC 37965; Lin et al., GCNC 37966; SVOM/C-GFT team, GCNC 37970; Breeveld et al., GCNC 37974; Lipunov et al., GCNC 37975 37977; Odeh et al., GCNC 37976; Moskvitin et al., GCNC 38016; Busmann et al. GCNC 38019; Schneider et al. GCNC 38021; Li et al. GCNC 38027; Masi et al. GCNC 38031; Moskvitin et al. GCNC 38032; Yan et al. GCNC 38035; TESS Mission, GCNC 38050; Wang et al. GCNC 38055; Pankov et al. GCNC 38105) is clearly detected. From preliminary analysis, we estimated a magnitude of r=19.29+-0.12 mag (AB; calibrated against r band of SDSS catalog). Further observation is under analysis.

We thank the staff at Padova Astronomical Observatory for their excellent support.

GCN Circular 38134

Subject
GRB 241030A: TESS observations
Date
2024-11-08T19:09:39Z (7 months ago)
From
Rahul Jayaraman at MIT <rjayaram@mit.edu>
Via
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R. Jayaraman (MIT), M.M. Fausnaugh (TTU), R. Vanderspek (MIT), G.R. Ricker (MIT) report:

The Transiting Exoplanet Survey Satellite (TESS; Ricker et al. JATIS 1 2015) observed GRB 241030A (Klingler et al., GCN 37956; Fermi GBM Team, GCN 37955) during its scheduled sky survey. Further information on the TESS observation times and public data postings were given in Petitpas et al., GCN 38050.

We performed forced difference-imaging photometry at the location of the confirmed X-ray afterglow (Beardmore et al., GCN 37962) using the full-frame images from the publicly available TICA data archived at MAST (https://archive.stsci.edu/hlsp/tica). Our analysis routine is described in Fausnaugh et al. 2023 (ApJ 956(2):108). 

The trigger occurred 90 seconds before the end of a concurrent TESS 200-second exposure. The light curve shows a rapid rise that peaks ~600 seconds after the burst, reaching an apparent magnitude of ~12 in the TESS band (600 nm–1000 nm). The light curve has an initial decay slope of -2.07 ± 0.04, with a subsequent shallower slope. It decays to the detection limit of 17.5 (3-sigma, 200s exposure) 0.6 d after the trigger time. These results are consistent with measurements of the afterglow rise and peak from Swift-UVOT (Breeveld et al., GCN 37974). The light curve fades at a rate consistent with other optical observations in red bands (Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; An et al., GCN 37960; Higuchi et al, GCN 37963; and Qiu et al., GCN 37965).

This circular includes data collected with the TESS mission, obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the TESS mission is provided by the NASA Explorer Program. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.


GCN Circular 38220

Subject
GRB 241030A: LCO optical observation
Date
2024-11-14T16:40:32Z (7 months ago)
From
ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994@gmail.com>
Via
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Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Alexander Moskvitin, Yulia Sotnikova (SAO RAS) on behalf of a larger collaboration.

We observed the field of the GRB 241030A (Klingler et al., GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al., GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988;  Wu et al., GCN 37997) using B, R filters of the 1-meter Sinistro telescope and V filter of the 0.4-m SCICAM QHY600 at the Las Cumbres Observatory Global Telescope (LCOGT) node located at Teide Observatory, Tenerife, SPAIN. The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel) and the 0.4 m SCICAM QHY600 is equipped with 9576 x 6388 pixel CCD (FOV: 1.9 x 1.2 degrees, scale: 0.74 arcsec/pixel).

Observations began on October 30 2024, starting from 14.21 to 14.41 hours after the GRB trigger. We clearly detect the optical transient (OT) reported by GCNs (Klingler et al., GCN 37956; Watson et al., GCN 37957; Fernández-Rodríguez et al., GCN 37958; Zheng et al., GCN 37959; An et al., GCN 37960; Higuchi et al., GCN 37963; Qiu et al., GCN 37965; Lin et al., GCN 37966; Wu et al., GCN 37970; Breeveld & Klingler, GCN 37974; Méndez-Lapido et al., GCN 37993, Moskvitin & Goranskij, GCN 38016; Busmann et al., GCN 38019; Schneider et al., GCN 38021; Li et al., GCN 38027; Masi, GCN 38031, Yan et al., GCN 38035, Pankov et al., GCN 38105, Reguitti et al., GCN 38105) in our stacked images. Our detection is well consistent with the observation reported at the similar epoch by Moskvitin & Goranskij, GCN 38016.

Date		UTstart-end	t-T0 (hours)	Exp (sec)	Filter		Magnitude       
2024-10-30 19:55:20--20:05:50   14.21           2 x 300 	B		B = 19.52 +/- 0.14
2024-10-30 19:48:10--20:08:18   14.17           2 x 600 	V		V = 19.51 +/- 0.14
2024-10-30 20:07:31--20:17:59   14.41	        2 x 300 	R		R = 19.10 +/- 0.04


The field was calibrated against nearby SDSS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction.


GCN Circular 38275

Subject
GRB 241030A: J-band observations
Date
2024-11-19T05:08:59Z (6 months ago)
From
dongzhn@mail2.sysu.edu.cn
Via
Web form
Zhong-Nan Dong, Yan Yu , Jia-Qi Lin, Si-Yuan Zhu, Wei-Sen Huang, Jin-Ji Li, Pu Lin, Hao-Nan Yang, Hao-Ran Zhang, Hui-Ying Deng, Pak-Hin Thomas Tam, Bin Ma (Sun Yat-sen University) report:

The Sun Yat-sen University 80cm infrared telescope observed the field of GRB 241030A (Klingler et al., GCN 37956; Beardmore et al., GCN 37962; Wang et al., GCN 37972; Pillera et al., GCN 37979; Ridnaia et al., GCN 37982; Ambrosi et al., GCN 37988; Wu et al., GCN 37997; Adami et al., GCN 38041; Moskvitin & Goranskij, GCN 38016; Busmann et al., GCN 38019; Schneider et al., GCN 38021; Li et al., GCN 38027; Masi, GCN 38031; Moskvitin et al., GCN 38032, Yan et al., GCN 38035; Wang et al., GCN 38055;  Pal et al., GCN 38074; Jayaraman et al., GCN 38134; Ankur et al., GCN 38220).

Our observations began at 2024-10-30 13:50:49 UTC, 8.13 hours after the GRB trigger. We took 100 frames with 20s exposures in J band. The calculated position is RA = 343.1402°, Dec = +88.4499°, which corresponds to RA(J2000) = 22h 52m 33.7s, Dec(J2000) = +80° 26' 59.7". In our stacked images, we clearly detect the near-infrared transient. We observed a peak magnitude of 16.8 ± 0.1 Vega mag, followed by a decline of 1 mag over the next seven hours. We also observed the source on October 31, November 1, 3, 4, 5, and 9. However, in the stacked frames from these subsequent observations, we did not detect the source down to a 5-sigma depth of J ~ 18 Vega mag.

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