GRB 241030A
GCN Circular 38275
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.
GCN Circular 38220
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 38134
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 38107
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 38105
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 38074
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 38055
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, Breeveld et al. GCN 37974).
Similar to Jin+2023 and Zhou+2023, 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.
GCN Circular 38050
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 38042
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 38041
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 38035
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 38032
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 38031
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 38027
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 & 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 38021
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 38019
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 38016
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 38015
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 38010
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 38000
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 37993
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 37988
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 37982
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