Gamma-ray Burst 240128A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #35646
  K. Yamaoka (Nagoya U.), H. Negoro (Nihon U.), M. Serino (AGU), W. Iwakiri (Chiba U.), M. Nakajima, K. Kobayashi, M. Tanaka, Y. Soejima, Y. Kudo (Nihon U.), T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, H. Hiramatsu, H. Nishikawa, A. Yoshida (AGU), Y. Tsuboi, S. Urabe, S. Nawa, N. Nemoto, E.Goto (Chuo U.), M. Shidatsu, Y. Niida (Ehime U.), I. Takahashi, M. Niwano, S. Sato, N. Higuchi, Y. Yatsu (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, T. Kurihara (JAXA), Y. Ueda, K. Setoguchi, T. Yoshitake, Y. Nakatani, Y. Okada (Kyoto U.), M. Yamauchi, Y. Hagiwara, Y. Umeki, Y. Otsuki (Miyazaki U.), Y. Kawakubo (LSU), and M. Sugizaki (NAOC)
  The MAXI/GSC nova alert system triggered on an uncatalogued X-ray transient source at 15:14:03 UT on January 28, 2024. Because our localization program did not run, we can not provide a precise error region. The source position determined with the nova alert system (Negoro et al. 2016) is
  (R.A., Dec) = (139.846 deg, -5.053 deg) = (09 19 23.04, -05 03 10.8) (J2000)
  with an uncertainty of more than 30 arc-min. The burst duration is about 30 sec, and the averaged X-ray flux in the 2-10 keV range was about 600 mCrab. This event was also detected by INTEGRAL SPI-ACS. There was no significant excess flux in the previous transit at 13:37 UT with an upper limit of 20 mCrab.
• GCN Circular #35647
  A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration:
  The long GRB 240128A (MAXI/GSC detection, Yamaoka et al., GCN Circ. 35646) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 15:13:34.34 UTC on 28 January 2024 (http://cgbm.calet.jp/cgbm_trigger/flight/1390489809/). The burst signal was seen by all CGBM detectors.
  The burst light curve shows a multi-peaked structure that starts at T+1.4 sec, peaks at T+10.8 sec, and ends at T+15.2 sec. The T90 and T50 durations measured by the SGM data are 12.5 +/- 0.6 sec and 7.2 +/- 0.6 sec (40-1000 keV), respectively.
  The ground-processed light curve is available at
  http://cgbm.calet.jp/cgbm_trigger/ground/1390489809/index.html
  The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.
• GCN Circular #35648
  P. A. Evans (U. Leicester) reports on behalf of the Swift team:
  Swift has initiated a series of observations, tiled on the sky, of the MAXI GRB 240128A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00120
  Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the MAXI event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
  Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
  This circular is an official product of the Swift-XRT team.
• GCN Circular #35649
  M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner= (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (= Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Sza= kszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Po= valac (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. Lipovs= ky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.)= , Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. B= ozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eot= vos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hi= sadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Ki= ss (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 240128A (MAXI/GSC detection: GCN 35646; CALET/CGBM de= tection: GCN 35647; INTEGRAL/SPI-ACS trigger no. 10493) was observed by the= GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048).
  The detection was confirmed at the peak time 2024-01-28 15:13:46 UTC. The T= 90 duration measured by GRBAlpha is 13 s and the overall significance durin= g T90 reaches 8 sigma.
  The light curve obtained by GRBAlpha is available here: https://grbalpha.ko= nkoly.hu/static/share/GRB240128A_GCN.pdf
  All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/he= a/GRBAlpha/=20 GRBAlpha, launched on 2021 March 22, is a demonstration mission for a futur= e CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GR= BAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM ar= ray, covering the energy range from ~50 keV to ~1000 keV. To increase the d= uty cycle and the downlink rate, the upgrade of the on-board data acquisiti= on software stack is in progress. The ground segment is also supported by t= he radio amateur community and it takes advantage of the SatNOGS network fo= r increased data downlink volume.
• GCN Circular #35650
  M. Perri (SSDC & INAF-OAR), S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
  Swift-XRT has performed follow-up observations of the MAXI-detected burst GRB 240128A in a series of observations tiled on the sky. The total exposure time is 1.4 ks, distributed over 6 tiles; the maximum exposure at a single sky location was 460 s. The data were collected between T0+46.4 ks and T0+52.4 ks, and are entirely in Photon Counting (PC) mode.
  One uncatalogued X-ray source has been detected, it is below the RASS limit and shows no definitive signs of fading. Therefore, at the present time we cannot confirm this as the afterglow. Details of this source are given below:
  Source 1:

    RA (J2000.0):  140.1536  =  09:20:36.87
    Dec (J2000.0): -5.2004  =  -05:12:01.5
    Error: 8.8 arcsec (radius, 90% conf.)
    Count-rate: 0.0149 [+0.0080, -0.0059] ct s^-1   
    Distance: 1224 arcsec from MAXI position.
    Flux: (2.9 [+1.6, -1.2])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
  

  A catalogued source was also detected.
  The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00120.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #35651
  C.C. Cheung, M. Kerr, J.E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A.= Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report: =20 The Glowbug gamma-ray telescope [1,2], operating on the International Space= Station, reports the detection of GRB 240128A, which was also detected by = MAXI/GSC (GCN 35646), CALET/CGBM (GCN 35647), GRBAlpha (GCN 35649), and INT= EGRAL/SPI-ACS (Trigger 10493). =20 Using an adaptive window with a resolution of 32-ms, the burst onset is det= ermined to be 2024-01-28 15:13:35.064 with a duration of 18.4 s and a total= significance of about 44.8 sigma. The light curve comprises a multi-peake= d structure similar to that observed by CALET/CGBM (GCN 35647). =20 Using a standard power-law function with an exponential high-energy cutoff = [3] to model the emission over this duration results in a photon index dN/d= E~E^x of x=3D1.9 and a cutoff energy ("Epeak") of 176 keV. The modeled 10-= 10000 keV fluence is 2.0e-06 erg/cm^2. =20 The analysis results presented here are preliminary and use a response func= tion that lacks a detailed characterization of the surrounding passive stru= cture of the ISS. =20 Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost ga= mma-ray transient telescopes developed, built, and operated by the U.S. Nav= al Research Laboratory (NRL) with support from the University of Alabama in= Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard = the Department of Defense Space Test Program=E2=80=99s STP-H9 to the ISS. = The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering= the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length= ) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2= /3 sky) over a wide energy band of 50 keV to >2 MeV.

  [1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
  [2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
  [3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
  

  Distribution Statement A: Approved for public release. Distribution is unlimited.
• GCN Circular #35723
  P. D'Avanzo (INAF-OAB), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
  Swift-XRT has performed further follow-up observations of the MAXI-detected burst GRB 240128A (Yamaoka et al., GCN Circ. 35646; Yoshida et al., GCN Circ. 35647; Dafcikova et al., GCN Circ. 35649; Cheung et al., GCN Circ. 35651). The data were collected between T0+553.6 ks and T0+1237.1 ks, and are entirely in Photon Counting (PC) mode for a total exposure time of 8.0 ks.
  The uncatalogued X-ray source reported by Perri et al. ("Source 1"; GCN Circ. 35650), is still detected at an average count rate of ~ 4e-2 ct/s and shows no definitive signs of fading. Therefore, we conclude that it is likely a field source unrelated with the GRB.
  The results of the XRT-team automatic analysis of the XRT observations for this GRB, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00120 .
  This circular is an official product of the Swift-XRT team.