GRB221009A

This page lists all entries on GRB221009A in GRBweb

Summary Fermi GBM IPN Swift GCN 32635 GCN 32636 GCN 32637 GCN 32638 GCN 32641 GCN 32642 GCN 32644 GCN 32645 GCN 32646 GCN 32647 GCN 32648 GCN 32650 GCN 32651 GCN 32652 GCN 32653 GCN 32654 GCN 32655 GCN 32656 GCN 32657 GCN 32658 GCN 32659 GCN 32661 GCN 32662 GCN 32663 GCN 32664 GCN 32665 GCN 32667 GCN 32668 GCN 32669 GCN 32671 GCN 32676 GCN 32677 GCN 32678 GCN 32679 GCN 32680 GCN 32683 GCN 32684 GCN 32685 GCN 32686 GCN 32688 GCN 32690 GCN 32691 GCN 32692 GCN 32693 GCN 32694 GCN 32695 GCN 32700 GCN 32705 GCN 32707 GCN 32709 GCN 32727 GCN 32729 GCN 32730 GCN 32738 GCN 32739 GCN 32740 GCN 32741 GCN 32743 GCN 32744 GCN 32745 GCN 32746 GCN 32748 GCN 32749 GCN 32750 GCN 32751 GCN 32752 GCN 32753 GCN 32754 GCN 32755 GCN 32757 GCN 32758 GCN 32759 GCN 32760 GCN 32761 GCN 32762 GCN 32763 GCN 32765 GCN 32766 GCN 32767 GCN 32769 GCN 32771 GCN 32780 GCN 32788 GCN 32791 GCN 32793 GCN 32795 GCN 32799 GCN 32800 GCN 32802 GCN 32803 GCN 32804 GCN 32805 GCN 32808 GCN 32809 GCN 32811 GCN 32818 GCN 32819 GCN 32821 GCN 32828 GCN 32850 GCN 32852 GCN 32860 GCN 32877 GCN 32907 GCN 32912 GCN 32916 GCN 32921 GCN 32934 GCN 32944 GCN 32949 GCN 32973 GCN 32995 GCN 33038 GCN 33243 GCN 33305 GCN 33676

Summary table
Variable Value Source
GRB_name_Fermi GRB221009553
T0 13:16:59 UTC GCN_circulars,Fermi GBM Det
ra 288.2645° Swift
decl 19.7735° Swift
pos_error 7.90e-05° Swift
T90 325.831 s Fermi_GBM
T90_error 6.785 s Fermi_GBM
T90_start 13:20:41.113 UTC Fermi_GBM
fluence 3.88e-02 erg/cm² Fermi_GBM
fluence_error 5.50e-05 erg/cm² Fermi_GBM
redshift 0.1510
T100 4266.4 s
GBM_located False
mjd 59861.553460648145 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB221009553
trigger_name bn221009553
ra 288.2642°
decl 19.7731°
pos_error 2.56e+00°
datum 2022-10-09
t_trigger 13:16:59.988 UTC
T90 325.831 s
T90_error 6.785 s
T90_start 13:20:41.113 UTC
fluence 3.88e-02 erg/cm²
fluence_error 5.50e-05 erg/cm²
flux_1024 2.38e+03 erg/cm²/s
flux_1024_error 3.33e+00 erg/cm²/s
flux_1024_time 2.39e+02 erg/cm²/s
flux_64 2.50e+03 erg/cm²/s
flux_64_error 1.30e+01 erg/cm²/s
IPN table
GRB_name GRB221009A
ra 288.2625°
decl 19.8000°
pos_error 5.00e-02°
redshift 0.1510
Swift table
GRB_name GRB221009A
t_trigger 14:10:17 UTC
ra 288.2645°
decl 19.7735°
pos_error 7.90e-05°
T90 1068.4 s
fluence 7.40e-05 erg/cm²
redshift 0.1510
GCN 32635 table
GRB_name GRB221009A
GCN_number 32635
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32635 SUBJECT: GRB 221009A: Swift detected transient may be GRB DATE: 22/10/09 20:44:25 GMT FROM: Jamie Kennea at Penn State U J. A. Kennea and M. Williams (PSU) report on behalf of the Swift Team: We provide an update on the BAT trigger 1126853, AKA Swift J1913.1+1946 (GCN #32632). Examination of XRT data from this trigger shows strong fading. We also note that Fermi/LAT has triggered on the same location. There is also a possible association with a Fermi/GBM trigger @ 13:16:59UT. Given this, we believe that this source is now likely a Gamma-Ray Burst and not a Galactic Transient. If the GBM trigger is the same source, this would suggest a highly energetic outburst, and therefore we strongly encourage follow-up of this usual event.
GCN 32636 table
GRB_name GRB221009A
GCN_number 32636
Detection_method Fermi GBM Det
t_trigger 13:16:59 UTC
ra 290.4000°
decl 22.3000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32636 SUBJECT: GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB DATE: 22/10/09 20:54:36 GMT FROM: Peter Veres at UAH P. Veres (UAH), E. Burns (LSU), E. Bissaldi (Politecnico and INFN Bari), S. Lesage (UAH), O. Roberts (USRA) report on behalf of the Fermi GBM Team: "At 2022-10-09 13:16:59.000 UT on 9 October 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 221009A (trigger 687014224 / 221009553). This event, if it is a GRB, it is the brightest among the GBM detected GRBs. If it is not a GRB then it is a rare transient event. Follow-up across all wavelengths is encouraged. The on-ground calculated location, using the GBM trigger data, is RA = 290.4, DEC = 22.3 (J2000 degrees, equivalent to 19 h 22 m, 22 d 15 '), with a statistical uncertainty of 1 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). This location is consistent with the Swift J1913.1+1946 localization (Dichiara et al. GCN 32632) though it precedes the Swift trigger by an hour. The angle from the Fermi LAT boresight at the GBM trigger time is 76 degrees. The GBM light curve consists of an initial ~10 s long pulse, followed by an extraordinarily bright episode at ~180 s after the trigger time, lasting at least 100 seconds. The 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 32637 table
GRB_name GRB221009A
GCN_number 32637
Detection_method Fermi LAT Det
t_trigger 14:17:05.990 UTC
ra 288.2100°
decl 19.7300°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32637 SUBJECT: GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection DATE: 22/10/09 21:45:05 GMT FROM: Elisabetta Bissaldi at INFN,Bari E Bissaldi (Politecnico and INFN Bari), N. Omodei (Stanford Univ.), M. Kerr (NRL), report on behalf of the Fermi-LAT team: At 14:17:05.99 on October, 09, 2022 Fermi-LAT detected high-energy emission from Swift J1913.1+1946 or GRB 221009A, which was reported by Swift (Dichiara et al. GCN #32632) and by GBM (Veres et al. GCN #32636). The best LAT on-ground location is found to be RA, Dec = 288.21, 19.73 (J2000) with an error radius of 0.09 deg (90 % containment, statistical error only). This was 94 deg from the LAT boresight at the time of the trigger. The data from the Fermi-LAT show a significant increase in the event rate that is spatially and temporally correlated with the trigger with high significance. The 100 MeV - 1 GeV photon flux in the time interval 500-3500 s after the Swift trigger is (1.27 +/- 0.16)E-05 ph/cm2/s. The estimated photon index above 100 MeV is -2.12 +/- 0.11. The highest-energy photon is a 7.8 GeV which is observed 766 seconds after the Swift trigger. The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@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 32638 table
GRB_name GRB221009A
GCN_number 32638
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32638 SUBJECT: Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy DATE: 22/10/09 21:53:41 GMT FROM: Daniel Perley at Liverpool JMU D. A. Perley (LJMU) reports: Imaging and spectroscopy were acquired of the optical counterpart of Swift J1913.1+1946 (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634), potentially the optical afterglow of GRB 221009A (Kennea & Williams, GCN 32635; Veres et al., GCN 32636). The spectrum, taken with SPRAT between 20:49 and 21:06 UT on 2022-10-09, covers a wavelength range of 4000-8000 Angstroms and reveals a red continuum with no strong features. Due to the low resolution of the spectrograph, we cannot rule out potential narrow absorption lines. The shape is consistent with a heavily dust-reddened afterglow. Galactic extinction towards this direction is about 3.52 mag in r-band (from the NED extinction calculator). Imaging was acquired using IO:O in the SDSS g, r, i, and z filters between 21:18 and 21:23 UT on the same night. We measure the following magnitudes, calibrating relative to local PS1 secondary standards: MJD filter mag emag 59861.88806 g 18.53 0.06 59861.88896 r 17.00 0.03 59861.88982 i 15.98 0.03 59861.89069 z 15.32 0.03 Analysis is ongoing, and additional observations are planned. DisclaimerNone
GCN 32641 table
GRB_name GRB221009A
GCN_number 32641
Detection_method IPN Triangulation
t_trigger 13:17:00 UTC
ra 1.4440°
decl 3.5900°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32641 SUBJECT: IPN triangulation of extremely bright GRB 221009A DATE: 22/10/10 01:10:40 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The extremely bright, long-duration GRB 221009A (Swift-BAT detection of Swift J1913.1+1946: Dichiara et al., GCN Circ. 32632; Kennea and Williams, GCN Circ. 32635; Fermi-GBM detection: Veres et al., GCN Circ. 32636; Fermi-LAT detection: Bissaldi et al., GCN Circ. 32636) has been detected by Fermi (GBM trigger 687014224), INTEGRAL (SPI-ACS), and Konus-Wind, so far, at about 47820 s UT (13:17:00). We have triangulated it to a Konus-GBN annulus centered at RA(2000)=1.444 deg (00h 05m 47s) Dec(2000)=+3.590 deg (+3d 35' 25") whose radius is 73.473 +/- 4.089 deg (3 sigma). This localization may be improved. The IPN localization is consistent with, but reduces the area of, the Fermi-GBM one (glg_healpix_all_bn221009553_v01). The IPN localization is consistent with Swift-BAT (GCN 32632) and Fermi-LAT (GCN 32636) position of Swift J1913.1+1946, supporting that Swift J1913.1+1946 is the afterglow of GRB 221009A. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB221009_T47819/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.
GCN 32642 table
GRB_name GRB221009A
GCN_number 32642
Detection_method Fermi GBM Det
t_trigger 13:16:59.990 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 32642 SUBJECT: GRB 221009A: Fermi GBM observation DATE: 22/10/10 04:04:41 GMT FROM: Stephen Lesage at Fermi-GBM Team S. Lesage (UAH), P. Veres (UAH), O.J. Roberts (USRA), E. Burns (LSU), and E. Bissaldi (Politecnico and INFN Bari) report on behalf of the Fermi GBM Team: "At 13:16:59.99 UT on 09 October 2022, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 221009A (trigger 687014224/221009553) which was also detected by Swift-BAT (S. Dichiara, et al. 2022, GCN 32632; J. A. Kennea, et al. 2022, GCN 32635), Fermi-LAT (E. Bissaldi et al. 2022, GCN 32637), INTEGRAL (SPI-ACS), Konus-Wind, and triangulated by IPN (D. Svinkin et al. 2022, GCN 32641). The GBM on-ground location (GCN 32636) is consistent with the Swift-BAT and Fermi-LAT locations and the IPN localization. The angle from the Fermi LAT boresight is 73 degrees. The GBM light curve consists of two emission episodes, a single isolated peak followed by a longer, extremely bright, multi-pulsed emission episode with a duration (T90) of about 327 s (10-1000 keV). The time-averaged spectrum for the first emission episode from T0-0.0 to T0+43.4 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.70 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 375 +/- 87 keV. The event fluence (10-1000 keV) in this time interval is (2.12 +/- 0.05)E-05 erg/cm^2. Due to the brightness of the second emission episode, the likelihood of pulse pile-up and other systematic effects are very high and no single spectral model provides an adequate fit in this preliminary analysis. The event fluence (10-1000 keV) from T0+175 to T0+1458 s is on the order of (2.912 +/- 0.001)E-02 erg/cm^2. The 1.024 sec peak photon flux measured starting from T0+238.8 s in the 10-1000 keV band is on the order of 2385 +/- 3 ph/s/cm^2, making this the most intense and fluent GRB detected by Fermi GBM. Further analysis is being performed. 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 32644 table
GRB_name GRB221009A
GCN_number 32644
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32644 SUBJECT: GRB 221009A BOOTES-2/TELMA and OSN optical detections DATE: 22/10/10 07:40:13 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, V. Casanova, E. Fernandez-Garcia, M. A. Castro Tirado, M.D. Caballero-Garcia, I. Olivares, I. Perez-Garcia and R. Sanchez-Ramirez and A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar and A. Castellon (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC) and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report: The 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) responded to the extraordinarily bright GRB 221009A detected by Swift, Fermi, MAXI/GSC, INTEGRAL (SPI-ACS), Konus-Wind, and the IPN (Dichiara et al. GCNC 32632, Veres et al. GCNC 32636, Bissaldi et al. GCNC 32637, Svinkin et al. GCNC 32641, Negoro et al. ATEL 15651). A number of images (60s exposures in clear filter) were taken starting at 18:23 UT on 9 Oct (~ 4.2 hours after trigger). Due to passing clouds, the optical afterglow was only detected in frames around 18:44 UT with 16.21+/-0.11 mag. Later on, we triggered the 0.9m telescope of the Observatiorio Sierra Nevada (OSN) near Granada, Spain. Observations started on 9 Oct 18:45 UT (~ 4.6 hours after trigger) in BVRI-bands (90 s exposures each). The optical afterglow is clearly detected with R=16.57+-0.02 mag on the first R-band image (gathered at 18:49 UT). These detections are consistent with the ones reported by Lipunov et al. (GCNC 32634), Perley et al. (GCNC 32638) and Broens et al. (GCNC 32640). Further observations are ongoing. We thank both the staff at La Mayora and OSN for their excellent support.
GCN 32645 table
GRB_name GRB221009A
GCN_number 32645
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32645 SUBJECT: GRB 221009A (Swift J1913.1+1946): Mondy optical observations DATE: 22/10/10 08:10:47 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI, HSE), A. Pozanenko (IKI), E. Klunko (ISTP), N. Pankov (HSE) report on behalf of GRB IKI FuN: We observed GRB 221009A (Swift J1913.1+1946) (Swift-BAT detection of Swift J1913.1+1946: Dichiara et al., GCN 32632; Kennea and Williams, GCN 32635; Fermi-GBM detection: Veres et al., GCN 32636; Fermi-LAT detection: Bissaldi et al., GCN 32636, IPN localization: Svinkin et al., GCN 32641) with AZT-33IK telescope of Sayan observatory (Mondy) starting on 2022-10-09 (UT) 14:26:54 and continuing to 15:34:05. We clearly detect the optical afterglow (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634; Perley GCN 32638; Hu et al., GCN 32644). Preliminary photometry of the afterglow at the first image is following Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2022-10-09 14:26:54 0.01223 R 120 14.84 0.09 20.8 We observe a monotonic decay in brightness, which can be approximated by a power law with an index of -0.52. The photometry is based on the nearby USNO-B1.0 stars (R2)
GCN 32646 table
GRB_name GRB221009A
GCN_number 32646
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32646 SUBJECT: GRB 221009A (Swift J1913.1+1946): MeerLICHT observations DATE: 22/10/10 09:14:47 GMT FROM: Simon de Wet at UCT S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO) report on behalf of the MeerLICHT consortium: Following the detection by Swift of a bright hard new X-ray and optical transient (Dichiara et al., GCN 32632), the 0.6m wide-field MeerLICHT telescope, located at Sutherland, South Africa, started automatic observations of the BAT error box beginning at 17:49:44 UT on 2022 October 9. Observations consisted of 60s exposures in the q,u,g,r,i,z bands following the sequence quqgqrqiqz and continued for approximately 1 hour. Some of our observations were affected by cirrus clouds. We detect a source at the Swift/UVOT position (Dichiara et al., GCN 32632) consistent with other optical detections (Lipunov et al., GCN 32634; Perley et al., GCN 32638; Broens, GCN 32640), and report the following 3-sigma u-band upper limit and detections in the AB magnitude system: u > 17.91 at 18:06:27 UT g = 18.22 +/- 0.33 at 18:21:07 UT q = 17.19 +/- 0.07 at 18:05:00 UT r = 17.76 +/- 0.08 at 18:23:59 UT i = 15.58 +/- 0.03 at 18:26:56 UT z = 14.89 +/- 0.03 at 18:29:55 UT MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.
GCN 32647 table
GRB_name GRB221009A
GCN_number 32647
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32647 SUBJECT: GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy DATE: 22/10/10 09:19:26 GMT FROM: Dong Xu at NAOC/CAS D. Xu, S.Q. Jiang, S.Y. Fu, X. Liu (NAOC), Z.P. Zhu (NAOC, HUST), T.H. Lu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of the optical counterpart of Swift J1913.1+1946 or GRB 221009A detected by Swift (Dichiara, GCN 32632), using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. Observations started at 14:25:55 UT on 2022-10-09, i.e., 762 s after the Swift/BAT trigger. A series of frames in the Sloan r- and z- filters were obtained. The optical counterpart is clearly detected in each of our images, which decays from r ~ 14.93 to r ~ 16.50 within ~ four hours, with a decay index of \alpha ~ 0.5 (F_t ~ t^-\alpha), calibrated the nearby PS1 stars. The decaying behavior is consistent with that for conventional GRBs. Spectroscopy of the optical counterpart was performed at the 2.16m telescope equipped with the BFOSC camera at Xinglong, Hebei, China. The spectrum covers the wavelength range 3800-9000 AA. The observation mid time is 2022 Oct 10.63 UT, i.e., 0.95 hr after the BAT trigger. The spectrum is dominated by a red continuum due to very high Galactic extinction, and no prominent absorption feature can be identified. Given the detections by Swift/UVOT as well as spectral continuum, the event could be real GRB 221009A at a rather low redshift. We thank the great support of the Xinglong-2.16m staff, in particular Junjun Jia, Min He, Aiying Zhou, and Jie Zheng.
GCN 32648 table
GRB_name GRB221009A
GCN_number 32648
Detection_method Swift-BAT Det
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32648 SUBJECT: GRB 221009A: Redshift from X-shooter/VLT DATE: 22/10/10 09:39:41 GMT FROM: Antonio de Ugarte Postigo at OCA A. de Ugarte Postigo (OCA), L. Izzo (DARK/NBI), G. Pugliese (Amsterdam Univ. and Leiden Observatory), D. Xu (NAOC), B. Schneider (CEA Paris-Saclay), J.P.U. Fynbo (DAWN/NBI), N.R. Tanvir (Univ. Leicester), D.B. Malesani (Radboud Univ. and DAWN/NBI), A. Saccardi (GEPI, Observatoire de Paris), D. A. Kann (Goethe Univ.), K. Wiersema (Lancaster Univ.), B. P. Gompertz (Birmingham), C. C. Thoene (ASU-CAS) and A. J. Levan (Radboud Univ.) report on behalf of the Stargate collaboration: We observed the afterglow of the extremely bright GRB221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., GCN 32637; Veres et al., GCN 32636; Lesage et al., GCN 32642) with X-shooter at ESO's UT3 of the Very Large Telescope (Paranal, Chile). The observations started at 00:49:58.9 UT (11.55 hr after the GBM trigger and 10.66 hr after the BAT trigger). The observation consisted of 4x600s with a spectral coverage between 3000 and 21000 AA. We detect a very red continuum with absorption features that correspond to CaII, CaI and NaID at a redshift of z = 0.151. We also detect multiple features due to the Milky Way’s interstellar medium, due to the large Galactic column density of material along this line of sight. At this redshift the event has an isotropic equivalent energy of Eiso=2x10^54 erg (using the GBM fluence reported in GCN 32642), barring saturation effects in the Fermi/GBM fluence. This is within the upper end of GRB energetics. Further follow-up is strongly encouraged. We acknowledge the excellent support provided by the Paranal staff, in particular A. Escorza and Zahed Wahhaj.
GCN 32650 table
GRB_name GRB221009A
GCN_number 32650
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32650 SUBJECT: GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection DATE: 22/10/10 10:50:44 GMT FROM: Alessandro Ursi at INAF/IAPS A. Ursi (INAF/IAPS), G. Panebianco (INAF/OAS-Bologna), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), F. Longo (Univ. Trieste and INFN Trieste), N. Parmiggiani (INAF/OAS-Bologna), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano, E. Menegoni, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Addis, L. Baroncelli, A. Bulgarelli, A. Di Piano, V. Fioretti, F. Fuschino (INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), and P. Tempesta (TeleSpazio), report on behalf of the AGILE Team: The AGILE satellite detected the bright emission classified as GRB 221009A or Swift J1913.1+1946, reported by Swift BAT (GCN #32635) at T0 = 2022-10-09 13:16:59 (UTC), by Fermi GBM (GCNs # 32636, #31782), Fermi LAT (GCN #32637), and IPN (GCN #32641). The burst is clearly visible in the AGILE scientific ratemeters of the MiniCALorimeter detector (MCAL; 0.4-100 MeV) and in all the five panels of the AntiCoincidence system (AC Top, 50-200 keV; AC Lat, 80-200 keV). The event consisted of several episodes, exhibiting an entire duration of about 600 s. The first episode lasted about 10 s and it released a total number of 13870 counts in the MCAL detector (above a background rate of 1130 Hz), and 31880 counts in the AC Top detector (above a background rate of 2980 Hz). The central episodes released a very large fluence, which produced saturation effects in both MCAL and AC count rates, preventing a reliable evaluation of the integrated counts. The last episode lasted 73 s and released a total number of 517170 counts in the AC Top detector (above a background rate of 2755 Hz). The AGILE ratemeter light curves can be found at http://www.agilescienceapp.it/notices/GRB221009A_AGILE_RM.png . The event also triggered two partial high time resolution MCAL data acquisitions, covering the onset of the central episodes. The time-integrated spectrum of the first trigger, from T0+181.00 s to T0+194.03 s, can be fitted in the energy range 0.5-5 MeV with a power-law with ph.ind. = -2.07 (-0.04,+0.04), resulting in a reduced chi-squared of 1.98 (32 d.o.f.) and a fluence of 5.88e-04 erg/cm^2 (90% confidence level), in the same energy range. Due to the extremely high fluence, the second trigger is affected by pile-up and count rate saturation, preventing a reliable evaluation of the corresponding energy spectrum. The MCAL light curve can be found at http://www.agilescienceapp.it/notices/GRB221009A_080412_592406219.000000.png . At the T0, the event was 100 deg off-axis. Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN 32651 table
GRB_name GRB221009A
GCN_number 32651
Detection_method Swift-XRT Other
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32651 SUBJECT: GRB 221009A: Swift-XRT refined Analysis DATE: 22/10/10 11:19:36 GMT FROM: Phil Evans at U of Leicester J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU) and E Bissaldi report on behalf of the Swift-XRT team: We have analysed 12 ks of XRT data for GRB 221009A (E Bissaldi et al. GCN Circ. 32637), from 159 s to 58.4 ks after the BAT trigger. The data are entirely in Windowed Timing (WT) mode (the first 10 s were taken while Swift was slewing). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.836 (+0.012, -0.011). The best-fitting absorption column is 6.76 (+/-0.16) x 10^21 cm^-2, at a redshift of 0.151, in addition to the Galactic value of 5.4 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.7 x 10^-11 (1.0 x 10^-10) erg cm^-2 count^-1. A summary of the WT-mode spectrum is thus: Galactic foreground: 5.4 x 10^21 cm^-2 Intrinsic column: 6.76 (+/-0.16) x 10^21 cm^-2 at z=0.151 Photon index: 1.836 (+0.012, -0.011) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01126853. This circular is an official product of the Swift-XRT team.
GCN 32652 table
GRB_name GRB221009A
GCN_number 32652
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32652 SUBJECT: GRB 221009A: REM optical and NIR detection of the afterglow DATE: 22/10/10 11:22:17 GMT FROM: Paolo D'Avanzo at INAF-OAB R. Brivio, M. Ferro, P. D'Avanzo, D. Fugazza (INAF-OAB), A. Melandri (INAF-OAR), S. Covino (INAF-OAB) on behalf of the REM team, report: We observed the field of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) with the REM 60cm robotic telescope located at the ESO premise of La Silla (Chile). The observations were carried in the g, r, i, z, J, H and K bands, starting on 2022 Oct 09 at 23:43:02 UT (i.e. about 10.43 hours after the GBM trigger) and lasted for about 1 hour. The optical and NIR afterglow is detected in all bands. From preliminary photometry, we derive the following magnitudes: r = 17.36 +/- 0.12 (AB; calibrated against the the Pan-STARRS catalogue) H = 12.21 +/- 0.04 (Vega; calibrated against the 2MASS catalogue) at a mid time of t-t0 ~ 10.47 hours after the GBM trigger.
GCN 32653 table
GRB_name GRB221009A
GCN_number 32653
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32653 SUBJECT: GRB 221009A/Swift J1913.1+1946: AMI-LA observations DATE: 22/10/10 12:10:49 GMT FROM: Lauren Rhodes at Oxford Joe Bright, Lauren Rhodes, Rob Fender (University of Oxford), Wael Farah, Alex Pollak, Andrew Siemion (SETI Institute) report: We observed the field of the candidate gamma-ray burst GRB 221009A (Swift J1913.1+1946; ATel #15650, ATel #15651) with the Arcminute Microkelvin Imager Large-Array (AMI-LA) at 15.5 GHz beginning at UT 16:25:25.5 on 09-Oct-2022 (approximately 2 hours 15 minutes after the initial BAT trigger reported in ATel #15650) for a total of 4 hours. The flux standard 3c286 was used to calibrate the bandpass response and flux scale of the AMI-LA and J1925+2106 was used as an interleaved complex gain calibrator. We detect a bright unresolved source at a position consistent with the one reported in ATel #15651 at a (preliminary) flux density of 39 +/- 2 mJy (including both a statistical uncertainty and a 5% absolute flux scale uncertainty). There is no significant emission at this position in either the VLA Sky Survey (VLASS; Lacy+2020) or the NRAO VLA Sky Survey (NVSS; Condon+1998), and so we identify this new source as the radio counterpart to GRB221009A/Swift J1913.1+1946. Further observations are planned. We thank the staff at the Mullard Radio Astronomy Observatory for carrying out these observations and operating the AMI-LA.
GCN 32654 table
GRB_name GRB221009A
GCN_number 32654
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32654 SUBJECT: GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection DATE: 22/10/10 12:15:59 GMT FROM: Igor Andreoni at JSI J. M. Durbak (UMD), A. S. Kutyrev (NASA/GSFC), I. Andreoni (JSI), K. De (MIT), E. Troja (U Tor Vergata/ASU), S. B. Cenko (NASA/GSFC), R. Hamada (Osaka U), Y. Hirao (Osaka U), R. Kirikawa (Osaka U), I. Kondo (Osaka U), S. Miyazaki (ISAS/JAXA), G. Mosby (NASA/GSFC), T. Sumi (Osaka U), D. Suzuki (Osaka U), H. Yama (Osaka U) We observed the field of the transient Swift J1913.1+1946 or GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) with the PRIME near-infrared camera mounted on the 1.8m Telescope at SAAO. Observations were carried out on 2022-10-09 around 18:50 UT, i.e. about 4.7 hours from the Swift/BAT detection (Dichiara et al., GCN 32632), 5.5 hours after the Fermi/GBM detection (Veres et al., GCN 32636), and 1 day after the PRIME instrument first light. We detected a near-infrared source spatially consistent with the bright optical transient previously reported, with preliminary photometry H~12.2 mag, calibrated against nearby 2MASS sources. Our result is consistent with the REM detection (Brivio et al. GCN 32652) and suggests no significant fading between 5.5 hr and 10.5 hr after the GBM trigger. Archival deep near-infrared images of the field taken with WFCAM during the UKIRT Galactic plane survey (Lawrence et al., 2007) do not show any persistent source in J and H bands at the transient location. These results are based on data obtained from PRIME at the South African Astronomical Observatory (SAAO), Sutherland, South Africa.
GCN 32655 table
GRB_name GRB221009A
GCN_number 32655
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32655 SUBJECT: GRB221009A/Swift J1913.1+1946: ATA follow-up observations DATE: 22/10/10 12:32:57 GMT FROM: Lauren Rhodes at Oxford Wael Farah (SETI Institute), Joe Bright (University of Oxford), Alex Pollak, Andrew Siemion (SETI Institute), David DeBoer (UC Berkeley), Rob Fender, Lauren Rhodes, Ian Heywood (University of Oxford) report: After the detection of a bright radio counterpart to GRB221009A at 15.5 GHz was reported in ATel #15653 /GCN #32653, we conducted follow-up observations with the Allen Telescope Array (ATA) at 1.5, 3, 4, 6, 8, and 10 GHz. Observations were carried out simultaneously at 1.5 + 3, 4 + 6 and 8 + 10 GHz, with a 672 MHz bandwidth centered on each frequency, using a newly deployed wideband correlator (Farah et al., in prep.), at spectral and temporal resolution of 0.5MHz and 10s, respectively. The target field was observed for 1 hour per pair of frequencies. The primary flux standard 3c286 was used to calibrate the absolute flux scale and bandpass response of the array, and J1925+2106 was used to calibrate the time dependent complex gains. Data flagging was performed with AOFlagger (Offringa+2012) while calibration and imaging were performed using standard techniques in CASA (McMullin+2007). We clearly detect an unresolved radio source at a position consistent with the one reported in ATel #15650 at 1.5, 3, 6, 8, and 10 GHz. Preliminary flux densities at 3, 6, 8, and 10 GHz are reported below, and include a 10% absolute flux scale uncertainty in addition to the statistical error from the fit. Observations conducted at 4 GHz were severely corrupted by radio frequency interference and were not processed. Our observations indicate that the radio counterpart to GRB221009A/Swift J1913.1+1946 is self-absorbed below around 10 GHz, although there is apparently significant flux density evolution between observing epochs. MJD Frequency (GHz) Flux density (mJy) 59862.0492 3.0 3.6 +/- 0.7 59861.9414 6.0 9.0 +/- 1 59862.1242 8.0 28 +/- 3 59862.1242 10.0 38 +/- 4 The Allen Telescope Array is a 42-element radio interferometer located at the Hat Creek Radio Observatory in Northern California. The facility is fully operated by the SETI Institute.
GCN 32656 table
GRB_name GRB221009A
GCN_number 32656
Detection_method Swift-UVOT Det
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32656 SUBJECT: GRB 221009: Swift/UVOT Detection DATE: 22/10/10 12:41:35 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and S. Dichiara (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 221009 179 s after the BAT trigger (Dichiara et al., GCN Circ. 32632, and 32633). This GRB was initially reported as being a new bright hard X-ray transient and named SwiftJ1913.1+1946. Further analysis shows this is a GRB (Kennea et al, GCN Circ. 32635, and 32651). The preliminary UVOT position was reported in the Dichiara et al. GCN. The GRB was also detected by Fermi (Veres et al. GCN Circ 32636; Bissaldi et al. GCN Circ. 32637; Lesage etal. GCN Circ. 32642), IPN (Svinkin et al., GCN Circ. 32641); Agile (Ursi et al. GCN Circ 32650). A redshift of 0.151 has been reported by de Ugarte Postigo et al. (GCN Circ. 32648), and optical detections were reported also (MASTER: Lipunov et al., GCN Circ. 32634 and 32639; Liverpool Telescope photometry and spectrum: Perley GCN Circ 32638; VVS: Broens, GCN Circ. 32640; BOOTES-2/TELMA: Hu et al., GCN Circ. 32644; Mondy: Belkin et al. GCN Circ. 32645; MeerLICHT: de Wet et al. GCN Circ. 32646; Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy Xu et al. GCN Circ. 32647; Al Khatim Observatory: Odeh, GCN Circ. 32649; REM: Brivio et al. GCN Circ. 32652). Near IR was reported for PRIME by Durbak et al. GCN Circ. 32654 and radio AMI-LA: Bright et al. GCN Circ. 32653 and ATA:Farah et al. GCN Circ. 32655. Pre-discovery limits from ZTF: Karambelkar et al. GCN Circ. 32643. Preliminary detections and 3-sigma upper limits 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 179 329 147 16.68 +/- 0.03 v 668 688 20 15.55 +/- 0.10 b 593 613 20 17.05 +/- 0.11 u 337 587 246 17.68 +/- 0.06 w1 718 1293 58 >18.2 w2 817 1219 39 >19.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.563 in the direction of the burst (Schlegel et al. 1998).
GCN 32657 table
GRB_name GRB221009A
GCN_number 32657
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32657 SUBJECT: GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection DATE: 22/10/10 12:49:03 GMT FROM: Alessandro Ursi at INAF/IAPS G. Piano (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli (INAF/OAS-Bologna), A. Ursi (INAF/IAPS), G. Panebianco (INAF/OAS-Bologna), C. Pittori, (SSDC, and INAF/OAR), F. Longo (Univ. Trieste and INFN Trieste), N. Parmiggiani (INAF/OAS-Bologna), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano, E. Menegoni, (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Addis, L. Baroncelli, A. Di Piano, V. Fioretti, F. Fuschino (INAF/OAS-Bologna), M. Romani (INAF/OA-Brera), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi), and P. Tempesta (TeleSpazio), report on behalf of the AGILE Team: The GRID detector onboard the AGILE satellite detected the bright emission classified as GRB 221009A or Swift J1913.1+1946, reported by Swift BAT (GCN #32635) at T0 = 2022-10-09 13:16:59 (UTC), by Fermi GBM (GCNs # 32636, #31782), Fermi LAT (GCN #32637), IPN (GCN #32641), AGILE/MCAL (GCN #32650), Swift XRT (GCN #32651), and Swift UVOT (GCN #32656). Integrating from 2022-10-09 UT 13:16:59 (T0) to 2022-10-09 UT 14:16:59 (T0 + 1h), a preliminary multi-source likelihood analysis yields a detection with a significance of 42 sigma and a gamma-ray flux F(>100 MeV) = (1.11 +/- 0.08) x 10^-3 photons/cm^2/s, by adopting a power-law model with a (reference) photon index value of -2.1. The angular position of the gamma-ray event, as detected by the AGILE/GRID, is: (l, b) = (52.99, 4.26) +/- 0.17 deg (stat.) +/- 0.10 deg (syst.) These measurements were obtained with AGILE observing a large portion of the sky in spinning mode. Additional analysis of AGILE data is in progress.
GCN 32658 table
GRB_name GRB221009A
GCN_number 32658
Detection_method Fermi LAT Other
ra 288.2820°
decl 19.4950°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32658 SUBJECT: GRB 221009A: Fermi-LAT refined analysis DATE: 22/10/10 13:42:46 GMT FROM: Roberta Pillera at Politecnico and INFN Bari GRB 221009A: Fermi-LAT refined analysis R. Pillera (Politecnico and INFN Bari), E Bissaldi (Politecnico and INFN Bari), N. Omodei (Stanford Univ.), G. La Mura (LIP, Portugal), F. Longo (University and INFN Trieste) report on behalf of the Fermi-LAT team: We report updated observations of GRB 221009A which was detected by Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637), and the IPN (Svinkin et al. GCN #32641). GRB 221009A triggered Fermi-GBM on October 10, 2022, at 13:16:59.99 UT (trigger 687014224/221009553), about 1 hour earlier with respect to the Swift trigger, which was reported as a new bright hard X-ray and optical transient and tentatively classified as Swift J1913.1+1946 (Dichiara et al., GCN 32632). Prompt GCN notices from Fermi-GBM were not distributed due to problems with the real-time downlink from TDRS, therefore no automatic Fermi-LAT GRB pipelines were triggered by the GBM event. Using LAT events with E>100 MeV between T0+200 s and T0+800 s, we find a LAT localization of RA = 288.282, Dec = 19.495, with a 90% containment radius of 0.027 degrees (statistical only). The LAT lightcurve shows a bright structured emission episode which is temporally coincident with the GBM main emission episode starting at T0+200s. The 100 MeV - 1 GeV photon flux in the time interval 200-800 s after the GBM trigger is (6.2 +/- 0.4)E-03 ph/cm2/s. The estimated photon index above 100 MeV is -1.87 +/- 0.04. From a preliminary analysis, the LAT emission is extending for about 25ks post GBM trigger. The highest-energy photon is 99.3 GeV (with a probability of 99.2%) which is observed 240 seconds after the GBM trigger. This represents the highest GRB photon energy ever detected by Fermi-LAT (the previous record holder being a 95 GeV event from GRB 130427A). The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@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 32659 table
GRB_name GRB221009A
GCN_number 32659
Detection_method Optical
ra 288.2650°
decl 19.7740°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32659 SUBJECT: ​GRB 221009A: Multi-color detection of the optical DATE: 22/10/10 14:16:00 GMT FROM: Gregory SungHak Paek at SNU Gregory S.H. Paek (SNU ARC/SNU), Myungshin Im (SNU ARC/SNU), Yuji Urata (NCU), Hyun-Il Sung (KASI) on behalf of a larger collaboration We detected the optical counterpart/NIR afterglow of extremely bright GRB 221009A (Dichiara et al., GCN #32632) with the 1-m class telescopes in Lemonsan Optical Astronomy Observatory (LOAO) facilities of the GW EM-Counterpart Korean Observatory (GECKO). We observed the center of UVOT localization (RA, Dec = 288.265, +19.774) +15 hours after the report in B, V, R, I, z, and Y-bands. We clearly detected the afterglow in all V, R, I, z, and Y-bands except for the B-band. We calibrated flux with the PANSTARRS catalog and used an AB magnitude system. Depth means 5 sigma upper limit for a point source detection. The magnitudes are not corrected for galactic extinction. ------------------- ----------- ----------- ------ ----------- ---------- ----- ------ ----- DATE-OBS[UTC] JD t-t0[days] FILTER Observatory EXPTIME[s] MAG MAGERR DEPTH ------------------- ----------- ----------- ------ ----------- ---------- ----- ------ ----- 2022-10-10T04:18:54 2459862.680 0.626 B LOAO 60s*5 None None 19.66 2022-10-10T04:20:38 2459862.681 0.628 V LOAO 60s*5 18.74 0.13 19.48 2022-10-10T04:22:04 2459862.682 0.629 R LOAO 60s*5 17.55 0.06 19.75 2022-10-10T04:23:31 2459862.683 0.630 I LOAO 60s*5 16.41 0.05 19.56 2022-10-10T04:24:39 2459862.684 0.631 z LOAO 60s*5 TBD TBD TBD 2022-10-10T04:25:58 2459862.685 0.631 Y LOAO 60s*5 TBD TBD TBD We will continue the follow-up observation for this target with the LOAO, and other GECKO facilities in Australia, and Chile. Gravitational-wave EM Counterpart Korean Observatory (GECKO) is a network of 10+ 0.5m to 1m class telescopes worldwide.
GCN 32661 table
GRB_name GRB221009A
GCN_number 32661
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32661 SUBJECT: GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements DATE: 22/10/10 15:23:32 GMT FROM: Hualin Xiao at FHNW Hualin Xiao, Sm Krucker and Ryan Daniel on behalf of the STIX team report: At 2020-10-09T13:16:56 UT (Solar Orbiter onboard time), STIX detected GRB221009A, when STIX was 1.22 AU from the earth. The gamma-ray burst is clearly visible in the STIX quick-look light curves of five energy bands in the range between 4 -150 keV. The initial pulse lasted about 10 seconds, followed by two bright pulses, lasting about 80 seconds. The fourth pulse was detected at ~ 323 s after the initial pulse. STIX recorded 185000 triggers from the burst in total. STIX light curves can be found at: https://datacenter.stix.i4ds.net/pub/GRB/GRB221009A/stix_GRB221009A_light_curves.png and https://datacenter.stix.i4ds.net/view/ql/lightcurves Solar Orbiter location during the GRB: https://datacenter.stix.i4ds.net/pub/GRB/GRB221009A/GRB221009A_solar_orbiter_orbit.png The analysis results presented above are preliminary. The science data will only be down-linked from the instrument in a month or two. Detailed analysis of the event will be started after downloading the science data. The Solar Orbiter (SolO) is a Sun-observing satellite developed by the European Space Agency, it was launched on 10th Feb. 2020. It has a unique elliptical orbit around the sun, with distances varying from 0.3 - 1 AU. The Spectrometer Telescope for Imaging X-rays (STIX) is one of the ten instruments onboard the Solar Orbiter. It measures X-rays emitted during solar flares in the energy range of 4 150 keV and takes X-ray images by using an indirect imaging technique, based on the Moir effect. Its detectors consist of thirty-two pixelated CdTe detectors with a total effective area of 6 cm^2. More information about STIX can be found on the STIX data center website: https://datacenter.stix.i4ds.net/
GCN 32662 table
GRB_name GRB221009A
GCN_number 32662
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32662 SUBJECT: GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow DATE: 22/10/10 15:38:59 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), V. Swain (IITB), G. Waratkar (IITB), K. Angail (IAO), V. Bhalerao (IITB), G. C. Anupama(IIA), S. Barway (IIA) report on behalf of the GIT team: We observed Swift J1913.1+1946/GRB 221009A detected by Swift (S. Dichiara et al., GCN #32632), Fermi (P. Veres et al., GCN #32636), INTEGRAL (SPI-ACS) (Gotz et al., GCN #32660), and Konus-Wind (D. Svinkin et al., GCN #32641), with 0.7m GROWTH-India Telescope (GIT). We obtained 200-sec exposures in the g' and r' filters. We clearly detected the afterglow candidate in our images at the position of Swift J1913.1+1946/GRB 221009A. The photometric results follow as: ------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Filter | Magnitude (AB) | ------------------------------------------------------------------- 2459862.18181 | 2.19 | g' | 17.66 +/- 0.07 | 2459862.18451 | 2.25 | r' | 16.16 +/- 0.07 | ------------------------------------------------------------------- The results are consistent with Lipunov et al., GCN #. 32634 and 32639; Perley GCN #32638; Broens, GCN #32640; Hu et al., GCN #32644; Belkin et al. GCN #32645; de Wet et al. GCN #32646; Xu et al. GCN #32647; Odeh, GCN #32649; Brivio et al. GCN # 32652. The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
GCN 32663 table
GRB_name GRB221009A
GCN_number 32663
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32663 SUBJECT: GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation DATE: 22/10/10 15:51:44 GMT FROM: Sergey Molkov at Space Research Inst., Moscow I. Lapshov, S. Molkov, I. Mereminsky, A. Semena, V. Arefiev, A. Tkachenko, A.Lutovinov (IKI RAS) on behalf of the SRG/ART-XC team: At 13:19:55 UT on 09 October 2022, the Mikhail Pavlinsky ART-XC telescope on board the SRG observatory detected a strong burst lasting few hundred seconds. Further analysis showed that the source of emission was out of the field of view of the instrument and the signal passed through the telescope structure. We associate this event with a gamma-ray burst GRB 221009A which was detected by Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637, Pillera et al. GCN #32658), the IPN (Svinkin et al. GCN #32641), SPI/ACS (Gotz et al. GCN #32660). The ART-XC event corresponds to the second (brightest) burst episode (see e.g. GCN #32642). Since the radiation came out of the FoV, a prompt spectral analysis of the event is impossible, however, due to the strong attenuation of the signal passed through the surrounding matter, we register a light curve shape that is practically not distorted by instrumental effects such as deadtime, pile-up or telemetry problems. The light curve in the full ART-XC energy range has a complex multi-peak structure with two main maxima on 60th and 340th seconds from the start. The event duration is near of 550 seconds.
GCN 32664 table
GRB_name GRB221009A
GCN_number 32664
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32664 SUBJECT: GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations DATE: 22/10/10 16:21:51 GMT FROM: Filipp Dmitrievich Romanov at Amateur astronomer I observed the optical afterglow of the extremely bright GRB 221009A = Swift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using 0.61-m f/6.5 Corrected Dall-Kirkham telescope of Burke-Gaffney Observatory (Lane, 2018, RTSRE, 1, 119) on 2022-10-10. Twelve images with exposures of 300 seconds and Iс filter were obtained, midtime of the first image is 02:06:45 UTC (11h56m after the trigger), midtime of the last image is 03:09:02 UTC (12h58m after the trigger). I clearly detected the afterglow and measured (aperture photometry, without deblending) following magnitudes of the afterglow from comparison to transformed (from Lupton 2005 formula) magnitudes of nearby stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016): Time (UTC)//Ic magnitude//Error 02:06:45 15.54 0.12 02:12:20 15.60 0.10 02:17:55 15.54 0.11 02:23:29 15.60 0.11 02:29:04 15.64 0.12 02:34:38 15.59 0.11 02:41:08 15.67 0.11 02:46:43 15.69 0.10 02:52:18 15.69 0.11 02:57:53 15.64 0.12 03:03:27 15.70 0.13 03:09:02 15.92 0.13 Magnitudes were not corrected for Galactic extinction. FITS files available here: https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20769 and https://observatory.smu.ca/~bgo/sm/id.php?app=0&id=20770 Stacked image: https://observatory.smu.ca/~bgo/research/GRB_221009A.jpg F. D. Romanov (AAVSO member, observer code: RFDA).
GCN 32665 table
GRB_name GRB221009A
GCN_number 32665
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32665 SUBJECT: GRB 221009A: Upper limits from a neutrino search with IceCube DATE: 22/10/10 16:43:52 GMT FROM: Jessie Thwaites at IceCube/U Wisc-Madison The IceCube Collaboration (http://icecube.wisc.edu/) reports: IceCube has performed a search for track-like muon neutrino events arriving from the direction of GRB 221009A (GCN Circular 32632 (Swift); 32636 (Fermi-GBM)) in a time range of -1 hour/+2 hours from the initial trigger reported by Fermi-GBM (T0=2022-10-09 13:16:59.99 UTC) during which IceCube was collecting good quality data. Zero track-like events are found coincident with the position of the GRB. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 3.9 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum have energies in the approximate energy range between 800 GeV and 1 PeV. A subsequent search was performed including 2 days of data centered on the Fermi-GBM trigger (2022-10-08 13:16:59.99 UTC to 2022-10-10 13:16:59.99 UTC). In this case, we report a p-value of 1.0, consistent with background expectation. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 4.1 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu. [1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)
GCN 32667 table
GRB_name GRB221009A
GCN_number 32667
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32667 SUBJECT: GRB 221009A: Lulin SLT-40cm optical observations DATE: 22/10/10 20:05:50 GMT FROM: Ting-Wan Chen at MPE T.-W. Chen (Stockholm), D. B. Malesani (Radboud Univ. and DAWN/NBI), S. Yang (Stockholm), W.-J. Hou, C.-C. Ngeow, Y.-C. Pan, H.-Y. Hsiao, C.-S. Lin, and J.-K. Guo (IANCU) report: We observed the field of GRB 221009A (a.k.a. Swift J1913.1+1946; Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., GCN 32637; Veres et al., GCN 32636; Lesage et al., GCN 32642; Gotz et al., GCN 32660), using the SLT-40cm at Lulin Observatory, Taiwan, to obtain g,r,i,z-band images as part of the Kinder collaboration (Chen et al., AstroNote 2021-92). Observations started at 12:25 UT on 10 of October 2022 (MJD = 59862.518), 1.04 days after the Fermi GBM trigger time. The images were combined from 2 frames with 150 sec exposure time for each band, taken under variable seeing conditions (2".5 average) and at an airmass of 1.3. We used aperture photometry to measure the transient brightness without template subtraction, and derived the following preliminary magnitudes and 3-sigma limits (all in the AB system): g > 18.33 mag, r = 18.67 +/- 0.16 mag, i = 17.38 +/- 0.09 mag, and z = 16.60 +/- 0.09 mag. Given magnitudes are calibrated against Pan-STARRS1 field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 1.40 mag in the direction of the counterpart (Schlafly & Finkbeiner 2011).
GCN 32668 table
GRB_name GRB221009A
GCN_number 32668
Detection_method Konus-Wind Det
t_trigger 13:17:01.648 UTC
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32668 SUBJECT: Konus-Wind detection of GRB 221009A DATE: 22/10/10 20:18:09 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The extraordinary bright GRB 221009A (Fermi-GBM detection: Veres et al. GCN Circ 32636, Lesage et al. GCN Circ 32642; Fermi-LAT detection: Bissaldi et al. GCN Circ 32637; IPN triangulation: Svinkin et al. GCN Circ 32641; AGILE/MCAL detection detection: Ursi et al., GCN Circ 32650) triggered Konus-Wind (KW) at T0=47821.648 s UT (13:17:01.648). The burst light curve starts with a FRED-like initial pulse (IP) that lasts from ~T0-1 s to ~T0+25 s. The IP is followed by an extremely bright multi-peaked emission in the interval from ~T0+170 s to ~T0+600 s, where a preliminary-estimated count rate reaches several hundred counts/s. The emission at this stage is seen up to at least ~15 MeV. The pulsed phase of the burst evolves to a steadily decaying emission tail, which is visible in the KW data for more than 10000 s. The preliminary Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB221009_T47821/ A time-averaged spectrum of the IP (measured from T0 to T0+28.842 s) is best fit in the 20 keV - 15 MeV range by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.62(-0.04,+0.05) and Ep = 975(-332,+712) keV (chi2 = 80/98 dof). The fluence in this time interval is estimated to (2.4 ± 0.3)x10^-05 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 5.760 s, to (6.2 ± 0.7)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). A time-averaged spectrum at the onset of the brightest phase of the event (measured from T0+180.48 to T0+200.064 s) is best fit in the 20 keV - 15 MeV range by a GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.09 (-0.01,+0.01), the high energy photon index beta = -2.60 (-0.06,+0.06), the peak energy Ep = 1060 (-30,+31) keV, chi2 = 161/97 dof. The fluence in this time interval is estimated to (8.8 ± 0.1)x10^-04 erg/cm^2 The brightness of the main burst episode doesn't allow to perform the standard KW spectral analysis of the emission at this stage of the event. However, using the latter spectrum and a count rate light curve in the 80-320 keV range with preliminary dead-time corrections applied, we obtain a rough estimate of the fluence of the event in the interval from T0 to T0+600 s of ~0.052 erg/cm^2, which is the highest value observed for GRBs for almost 28 years of the KW operation. Further analysis of this extraordinary event is ongoing and the results will be reported eslsewhere. Assuming the redshift z=0.151 (de Ugarte Postigo et al., GCN 32648) 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 burst isotropic energy release E_iso to a high, but reasonable value of ~3.0x10^54 erg. The rest-frame peak energy of the spectrum Ep,z is estimated to ~1150 keV. With these preliminary values, GRB 221009A perfectly fits the 'Amati' relation 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/GRB221009_T47821/GRB221009A_rest_frame.pdf All the quoted errors are at the 68% confidence level. All the presented results are preliminary.
GCN 32669 table
GRB_name GRB221009A
GCN_number 32669
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32669 SUBJECT: GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations DATE: 22/10/10 20:34:25 GMT FROM: Weikang Zheng at UC Berkeley Edgar Vidal, WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: We observed the field of GRB 221009A (=Swift J1913.1+1946; Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650; Lesage et al., GCN 32642; Gotz et al., GCN 32660) with the 1-m Nickel telescope located at Lick observatory, California. Observations started about 15.73 hours after the burst. Filtered B,V,R and I band images were taken with each exposure time of 300s. We detect the reported optical afterglow and measure its brightness with the following mag calibrated to the APASS catalog. B = 20.18 +/- 0.2 V = 18.94 +/- 0.1 R = 17.59 +/- 0.1 I = 16.29 +/- 0.1 Additional images were also obtained with the 0.76-m Katzman Automatic Imaging Telescope (KAIT) also located at Lick Observatory. A set of clear (roughly R) band images were taken and the measured magnitude is consistent with the above Nickel R band magnitude.
GCN 32671 table
GRB_name GRB221009A
GCN_number 32671
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32671 SUBJECT: GRB 221009A: Continued Swift/XRT observations DATE: 22/10/10 22:17:35 GMT FROM: Aaron Tohuvavohu at U Toronto A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , B. Sbarufatti (PSU), D.N. Burrows (PSU) and M. Williams (PSU), report on behalf of the Swift-XRT team: Swift XRT has continued to observe GRB 221009A from 159s to 100 ks after the BAT trigger. The WT-mode spectrum for the afterglow was given in GCN 32651. The lightcurve can be best modelled as a four-component power law decay with: Alpha_1 : 2.6 (+0.4, -0.7) Tbreak_1: 177.4 (+2.0, -9.6) Alpha_2 : 0.144 (+0.022, -0.026) Tbreak_2: 610 (+84, -78) Alpha_3 : 0.31 (+0.04, -0.03) Tbreak_3: (4.06 [+0.23, -0.19]) × 10^3 Alpha_4 : 1.357 (+/-0.010) With T0 the BAT trigger time. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01126853. This circular is an official product of the Swift-XRT team.
GCN 32676 table
GRB_name GRB221009A
GCN_number 32676
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32676 SUBJECT: GRB 221009A: NOEMA mm detection DATE: 22/10/11 09:09:27 GMT FROM: Antonio de Ugarte Postigo at OCA A. de Ugarte Postigo (OCA), Michael Bremer (IRAM), C. C. Thoene (ASU-CAS), M. Michalowski (AOI-AMU) K. Misra (ARIES), S. Antier (OCA), D. A. Kann (Goethe Univ.), J. F. Agui Fernandez (IAA-CSIC), L. Resmi (IIST), S. Martin (ALMA), D. A. Perley (LJMU) and S. Schulze (Uni. of Stockholm) report, We observed the afterglow of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., GCN 32637; Veres et al., GCN 32636; Lesage et al., GCN 32642) with NOEMA at 90 and150 GHz starting at 16:32 UT of the 10th of October, (27.35 hr after the Fermi GBM trigger; Veres et al., GCN 32636). The afterglow is strongly detected at 90 GHz with a flux of ~15 mJy. This is significantly below the extrapolation of the data reported at lower frequencies in previous GCNs (Bright et al. GCN 32653; Farah et al., GCN 32655), indicating that our observations are beyond the peak Frequency, and that the earlier observations may have been affected by a reverse shock that has already faded.
GCN 32677 table
GRB_name GRB221009A
GCN_number 32677
Detection_method IPN Triangulation
ra 288.3000°
decl 19.7000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32677 SUBJECT: LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV DATE: 22/10/11 09:21:54 GMT FROM: Judith Racusin at GSFC Yong Huang, Shicong Hu, Songzhan Chen, Min Zha, Cheng Liu, Zhiguo Yao and Zhen Cao report on behalf of the LHAASO experiment We report the observation of GRB 221009A, which was detected by Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637), IPN (Svinkin et al. GCN #32641) and so on. GRB 221009A is detected by LHAASO-WCDA at energy above 500 GeV, centered at RA = 288.3, Dec = 19.7 within 2000 seconds after T0, with the significance above 100 s.d., and is observed as well by LHAASO-KM2A with the significance about 10 s.d., where the energy of the highest photon reaches 18 TeV. This represents the first detection of photons above 10 TeV from GRBs. The LHAASO is a multi-purpose experiment for gamma-ray astronomy (in the energy band between 10^11 and 10^15 eV) and cosmic ray measurements.
GCN 32678 table
GRB_name GRB221009A
GCN_number 32678
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32678 SUBJECT: GRB 221009A: BlackGEM optical observations DATE: 22/10/11 09:47:33 GMT FROM: Paul Groot at Radboud University Nijmegen P.J. Groot (Radboud/UCT/SAAO), P.M. Vreeswijk (Radboud), R. Ter Horst (NOVA), S.D. Bloemen (Radboud), P.G. Jonker (Radboud/SRON), S. de Wet (UCT), D.B. Malesani (Radboud and DAWN/NBI), D. Pieterse (Radboud) report on behalf of the BlackGEM consortium: During commissioning the BlackGEM Unit Telescope 3 (BG3-Opal), located at ESO La Silla, Chile, observed the optical counterpart of GRB221009A (Dichiara et al., GCN 32632, Lesage et al. GCN 32642, Lipunov et al., 32634) on 2022-10-11 in a series of 60s exposures in the q,u,z,g,i,r,q bands. No debiasing or flatfielding was performed. The optical counterpart is detected in q,z,i: 2022-10-11 00:47UT q = 18.98 +/- 0.09 +/- 0.05 (T0+35h30m) 2022-10-11 00:50UT z = 16.92 +/- 0.05 +/- 0.03 (T0+35h33m) 2022-10-11 00:54UT i = 17.92 +/- 0.06 +/- 0.02 (T0+35h37m), where the first uncertainty is the statistical uncertainty and the second is the uncertainty on the zeropoint photometric calibration. T0 is taken as the Fermi/GBM trigger time 2022-10-09 13:17UT (Lesage et al., GCN 32642). All magnitudes are in the AB system. BlackGEM is an array of wide-field telescopes designed, built and operated by a consortium consisting of Radboud University, the Netherlands Research School for Astronomy NOVA, KU Leuven, the University of Manchester, Tel Aviv University, the Weizmann Institute, the Hebrew University of Jerusalem, the University of Potsdam, Texas Tech University, the University of California at Davis, the Danish Technical University and the Armagh Observatory and Planetarium.
GCN 32679 table
GRB_name GRB221009A
GCN_number 32679
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32679 SUBJECT: GRB 221009A (Swift J1913.1+1946): iTelescope optical observation DATE: 22/10/11 10:03:35 GMT FROM: Filipp Dmitrievich Romanov at Amateur astronomer I observed the optical afterglow of the extremely bright GRB 221009A = Swift J1913.1+1946 (Dichiara et al., GCN Circ. 32632) remotely using telescope T24 (0.61-m f/6.5 reflector + CCD) of iTelescope.Net in Sierra Remote Observatory (Auberry, California, USA) on 2022-10-11. Two images (exposures 300 seconds, BINx1) were obtained with Ic filter, midtime of the stacked image is 06:12:42 UT (1d16h02m after the trigger). I clearly detected the afterglow and measured (aperture photometry, without deblending) following magnitude: 17.1 Ic +/- 0.2 from comparison to transformed (from Lupton 2005) magnitudes of nearby stars from the Pan-STARRS DR1 catalogue (Chambers et al., 2016). Magnitude was not corrected for the Galactic extinction. Stacked image available here: https://www.flickr.com/photos/filipp-romanov/52419866941 F. D. Romanov (AAVSO member, observer code: RFDA).
GCN 32680 table
GRB_name GRB221009A
GCN_number 32680
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32680 SUBJECT: Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A DATE: 22/10/11 10:37:56 GMT FROM: Sandro Mereghetti at IASF-Milano/INAF Andrea Tiengo (IUSS Pavia), Fabio Pintore (INAF IASF Palermo), Sandro Mereghetti, Ruben Salvaterra (INAF IASF Milano) on behalf of a larger collaboration report: Swift/XRT observed GRB221009A (GCN #32632, #32635, GCN #32636, #32637) in PC mode three times (Obs.ID: 01126853004, 01126853005, 01126853006) between 2022-10-10 14:08:49 UT and 2022-10-11 01:22:52 UT, for a net exposure time of 7464.5 s. The stacked Swift/XRT image in the 0.3-10 keV energy band shows the presence of a complex system of at least 9 bright expanding rings with radii from about 2.5 to 7.5 arcmin. We adopted the method described in Tiengo & Mereghetti (2006, A&A 449, 203) to derive the following distances of the dust clouds: 179.3 +/- 0.7 pc, 290 +/- 5 pc, 406.2 +/- 0.9 pc, 467.6 +/- 1.5 pc, 554 +/- 2 pc, 714 +/- 1 pc, 1094 +/- 24 pc, 2092 +/- 22 pc and 3635 +/- 36 pc.
GCN 32683 table
GRB_name GRB221009A
GCN_number 32683
Detection_method IPN Triangulation
ra 288.2820°
decl 19.4950°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32683 SUBJECT: GRB 221009A: Upper limits from HAWC 8 hours after trigger DATE: 22/10/11 12:04:14 GMT FROM: Hugo Ayala at Pennsylvania State University Hugo Ayala (PSU) reports on behalf of the HAWC collaboration (http://www.hawc-observatory.org/collaboration) reports observations of GRB 221009A which was detected by Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637), and the IPN (Svinkin et al. GCN #32641). We use the position measured by Fermi LAT (GCN #32658), located at: RA = 288.282, Dec = 19.495 (0.027 deg 90% containment radius) This position started transiting over HAWC at 21:19:57 UTC on 2022/10/09 (~8 hours after the trigger time) and ended at 03:42:07 UTC on 2022/10/10. Assuming a power law spectra with index of -2.0 we found no significant detection in the region. We proceeded to calculate the 95% upper limit on the flux at 1 TeV: 4.16e-12 (TeV cm2 s)^-1 HAWC is a very-high-energy gamma-ray observatory operating in Central Mexico at latitude 19 deg. north. Operating day and night with over 95% duty cycle, HAWC has an instantaneous field of view of 3.14 sr and surveys <5/6 of the sky every day. It is sensitive to gamma rays from 300 GeV to 100 TeV.
GCN 32684 table
GRB_name GRB221009A
GCN_number 32684
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32684 SUBJECT: GRB 221009A: Sintez-Newton/CrAO optical observations DATE: 22/10/11 13:01:20 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI, HSE), S. Nazarov (CrAO), A. Pozanenko (IKI), N. Pankov (HSE) report on behalf of IKI GRB FuN: We observed GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632; Kennea and Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32636; Svinkin et al., GCN 32641; Piano et al., GCN 32657; Pillera et al., GCN 32658; Gotz et al., GCN 32660; Frederiks et al., GCN 32668) with Sintez-Newton 350mm f/5 telescope equipped with QHY600M camera and g'r'i'z' filters. Observation started on 2022-10-10 (UT) 17:24:54. The series consists of images with an exposure of 120 s in r'-filter. In the stacked image we clearly detect the optical afterglow (e.g. Dichiara et al., GCN 32632; Lipunov et al., GCN 32634; Perley GCN 32638; Hu et al., GCN 32644; Belkin et al., GCN 32645; Kuin et al., GCN 32656; Kim et al., GCN 32670). Preliminary photometry of the afterglow is following Preliminary photometry of the stacked images is following Date UT start t-T0 Filter Exp. OT err UL(3) (mid, days) (s) 2022-10-10 17:24:54 1.16293 r' 40*120 18.43 0.10 20.9 The photometry is based on nearby PS1 stars
GCN 32685 table
GRB_name GRB221009A
GCN_number 32685
Detection_method Fermi GBM Det
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32685 SUBJECT: GRB 221009A: Detection by GRBAlpha DATE: 22/10/11 13:24:38 GMT FROM: Jakub Ripa at Masaryk University <245487@mail.muni.cz> J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), M. Dafcikova, F. Munz, N. Husarikova, J.-P. Breuer, M. Topinka, 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 extraordinarily bright long-duration GRB 221009A (Swift/BAT detection: Kennea et al., GCN 32635; Fermi-GBM detection: Veres et al., GCN 32636; Fermi-LAT detection: Pillera et al., GCN 32658; INTEGRAL SPI/ACS detection: Gotz et al., GCN 32660; Konus-Wind detection: Frederiks et al., GCN 32668; IPN triangulation: Svinkin et al., GCN 32641; LHAASO detection: Huang et al., GCN 32677) at a redshift of z = 0.151 (de Ugarte Postigo et al., GCN 32648) was detected by the GRBAlpha 1U CubeSat (Pal et al. Proc. SPIE 2020). The GRB did not saturate our detector and the peak count rate reached ~22 000 count/s in the ~70-890 keV energy band (for a 50 cm^2 detector) at 2022-10-09 13:20:52 UTC. The duration of the GRB was >250s. GRBAlpha was flying above the northern polar region with elevated background levels. The end part of the GRB was recorded while passing the outer Van Allen radiation belt. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB221009A_GCN_GRBAlpha.pdf GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Its detector consists of a 75 x 75 x 5 mm^3 CsI(Tl) 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, we are continuously upgrading the on-board data acquisition software stack. 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 32686 table
GRB_name GRB221009A
GCN_number 32686
Detection_method CALET
redshift 0.1505
Circular_text TITLE: GCN CIRCULAR NUMBER: 32686 SUBJECT: GRB 221009A: 10.4m GTC spectroscopic redshift confirmation DATE: 22/10/11 13:37:44 GMT FROM: Alberto J. Castro-Tirado at IAA-CSIC A. J. Castro-Tirado, R. Sanchez-Ramirez, Y.-D. Hu, M.D. Caballero-Garcia, M. A. Castro Tirado, E. Fernandez-Garcia, I. Perez-Garcia (IAA-CSIC), G. Lombardi (GTC, IAC), S. B. Pandey (ARIES), J. Yang (NJU) and B.-B. Zhang (NJU) on behalf of a larger collaboration, report: Following the detection of the extraordinarily bright GRB 221009A detected by Swift, Fermi, MAXI/GSC, INTEGRAL (SPI-ACS), Konus-Wind, the IPN, AGILE/MCAL, SolO/STIX, SRG/ART-XC, CALET and GRBAlpha (Dichiara et al. GCNC 32632, Veres et al. GCNC 32636, Bissaldi et al. GCNC 32637, Svinkin et al. GCNC 32641, Negoro et al. ATEL 15651, Ursi et al. GCNC 32650, Xiao et al GCNC 32661, Lapshov et al. GCNC 32663, Cannady et al. GCNC 32674, Ripa et al. GCNC 32685), we triggered the 10.4m Gran Telescopio de Canarias (GTC) equipped with Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) in La Palma (Spain), starting on Oct 9, 22:19 UT (~9 hrs after the GBM trigger). Spectroscopy was obtained with both the R1000B (2x900s) and R1000R (2x300s) grisms, covering the 363-1000 nm spectral range. A red continuum is noticeable, in agreement with earlier reports by Perley (GCNC 32638) and Xu et al. (GCNC 32647). The GTC spectrum clearly shows the Ca II H & K absorption doublet implying a redshift of z=0.1505, consistent the value derived from X-shooter/VLT (de Ugarte Postigo et al. GCNC 32648). With this redshift of z= 0.1505, a time-averaged peak energy of 2.52 MeV and a total fluence of 2.6e-2 erg cm^-2, we found that the main emission episode (between 174 and 700 s post trigger) of GRB 221009A is consistent with the Type II (collapsar origin; Zhang et al, 2007, 2009) bursts in the Ep-Eiso diagram (Amati et al. 2002). We thank the staff at GTC for their excellent support.
GCN 32688 table
GRB_name GRB221009A
GCN_number 32688
Detection_method Swift-BAT Det
ra 288.2540°
decl 19.8090°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32688 SUBJECT: GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis DATE: 22/10/11 14:12:57 GMT FROM: Amy Lien at GSFC H. A. Krimm (NSF), S. D. Barthelmy (GSFC), S. Dichiara (PSU), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+1371 sec from the recent telemetry downlink, we report further analysis of BAT GRB 221009A (trigger #1126853 and #1126854) (Dichiara et al., GCN Circ. 32632). The BAT ground-calculated position is RA, Dec = 288.254, 19.809 deg which is RA(J2000) = 19h 13m 00.9s Dec(J2000) = +19d 48' 34.1" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 9%. The mask-weighted light curve shows a flat and long-lasting emission that may have started before the burst came into the BAT FOV at T-26 s. The burst emission seems to end at ~T+1320 s, however, we cannot rule out the possibility that the emission extends beyond the available event data that end at T+1371 s. The lower limit of T90 (15-350 keV) is 1068.40 +- 13.34 sec (estimated error including systematics). The time-averaged spectrum from T+103.3 s to T+1338.7 s sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.08 +- 0.03. The fluence in the 15-150 keV band is 7.4 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+776.47 sec in the 15-150 keV band is 1.9 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1126853/BA/
GCN 32690 table
GRB_name GRB221009A
GCN_number 32690
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32690 SUBJECT: GRB 221009A: planned observation with the Imaging X-ray Polarimetry Explorer (IXPE) DATE: 22/10/11 15:56:24 GMT FROM: Michela Negro at CREST/NASA-GSFC/UMBC Michela Negro, Alberto Manfreda and Nicola Omodei on behalf of the IXPE Collaboration report that: IXPE will begin observing GRB 221009A on 2022-10-11 at 23:34:28.40 UTC and will observe for 100k s. The detailed weekly timeline for IXPE observations (which currently includes the slew to GRB 221009A) can be found here: https://ixpe.msfc.nasa.gov/for_scientists/weekly.html The Imaging X-ray Polarimetry Explorer, commonly known as IXPE is a space observatory with three identical telescopes designed to measure the polarization of cosmic X-rays. The observatory, which was launched on 9 December 2021, is an international collaboration between NASA and the Italian Space Agency (ASI).
GCN 32691 table
GRB_name GRB221009A
GCN_number 32691
Detection_method INTEGRAL
Circular_text TITLE: GCN CIRCULAR NUMBER: 32691 SUBJECT: GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger DATE: 22/10/11 16:05:23 GMT FROM: Volodymyr Savchenko at ISDC,U of Geneve Volodymyr Savchenko (UNIGE, EPFL), Carlo Ferrigno, Enrico Bozzo (UNIGE), D. Gotz (CEA Paris Saclay), S. Mereghetti (INAF/IASF Milano), Antonio Martin Carrillo, Lorraine Hanlon (UCD), Elisabeth Jourdain, Jean-Pierre Roques (IRAP), Thomas Siegert (University of Würzburg), Erik Kuulkers, Celia Sanchez (ESA) Following the detection of the record-breaking GRB221009A by Swift/BAT (GCN #32632,#32635), Fermi/GBM (GCN #32636), INTEGRAL/SPI-ACS (GCN #32660), we have performed INTEGRAL pointed observations of the GRB221009A location. INTEGRAL pointed observation lasted from 2022-10-10T14:31:40 (T0 + 25.2 hours, where T0 is 2022-10-09T13:17:00) to 2022-10-11T03:18:20 (T0 + 38.0 hours) with a total exposure time of 30.2 ks (for ISGRI). In the complete observation, the source is clearly detected in JEM-X1, JEM-X2 (3-30 keV), and ISGRI (28 - 80 keV), with S/N of 27.8, 27.3, 15.0 respectively. The joint JEM-X and ISGRI spectra can be satisfactorily modeled between 3 and 80 keV with a single powerlaw of slope 2.15 +/- -0.07 (90% confidence) with a flux of 4.4e-10 +/- -2.1e-11 erg/cm2/s (3 - 80 keV). This might indicate a single spectral component spanning from from hard X-ray to Fermi/LAT (GCN #32658). Combination of bright Hard X-ray afterglow with gamma-ray emission was also found in GRB120711A (Martin-Carrillo et al. 2014 A&A 567, 84) and GRB130427A (Kouveliotou et al. 2013 ApJ 779L, 1K) - in fact GRB221009A appears rather similar to GRB120711A, but at 10 times smaller distance. Within the relatively short JEM-X not ISGRI lightcurves, we do not observe any evidence for flux decrease. Further INTEGRAL observations are scheduled between 2022-10-11 13:52:21 and 2022-10-13 00:58:26. These observations will overlap with the planned observation of IXPE (GCN #32690). We are grateful to the INTEGRAL Ground Segment team for quickly scheduling the observations. Images and reduced data related to this publication can be found here: https://zenodo.org/record/7186289
GCN 32692 table
GRB_name GRB221009A
GCN_number 32692
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32692 SUBJECT: GRB 221009A: COATLI Detection of the Afterglow DATE: 22/10/11 16:41:09 GMT FROM: Alan M Watson at UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Simone Dichiara (PSU), Rosa L. Becerra (UNAM), Tzveti Dimitrova (ASU), Océlotl López (UNAM), Diego González (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra (UNAM), Eleonora Troja (UTV/ASU) and report: We observed the field of the bright GRB 220930A (Dichiara et al., GCN Circ. 32632, Veres et al., GCN Circ. 32636) with the COATLI 50-cm telescope and HUITZI f/8 imager at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir (http://coatli.astroscu.unam.mx) from 2022-10-11 06:05 UTC to 06:39 UTC (40.2 hours after the trigger), obtaining a total of 405 seconds of exposure in each of the g, r, i, and z filters. At the position of the UVOT afterglow (Dichiara et al., GCN Circ. 32632), we detect a source with the following magnitudes and 3-sigma upper limit: g > 20.27 r = 19.48 +/- 0.13 i = 18.49 +/- 0.07 z = 17.92 +/- 0.08 Our photometry is calibrated against the Pan-STARRS1 catalog, is on an approximate AB system, and is not corrected for Galactic extinction in the direction of the GRB. We thank the COATLI/HUITZI technical team and the staff of the Observatorio Astronómico Nacional.
GCN 32693 table
GRB_name GRB221009A
GCN_number 32693
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32693 SUBJECT: GRB 221009A: LCOGT Optical Afterglow Detection DATE: 22/10/11 17:04:03 GMT FROM: Robert Strausbaugh at University of Minnesota R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632) field with the LCOGT 1-meter Sinistro instrument at the Teide Observatory, on Tenerife, on October 10, from 19:33 to 19:50 (corresponding to 29.38 to 29.66 hours from the GRB trigger time) with the SDSS g, r and i filters. We performed a series of 3x100s exposures in each band. We clearly detect the optical transient at the UVOT coordinates (Dichiara et al., GCN 32632), in r and i bands, and marginally in g-band (2-sigma detection), consistent with other optical detections. The following magnitudes are calculated using the Pan-STARRS catalog as reference: g = 20.87 +/- 0.36 r = 18.80 +/- 0.21 i = 17.77 +/- 0.20 These magnitudes are not corrected for galactic extinction. Further observations are planned.
GCN 32694 table
GRB_name GRB221009A
GCN_number 32694
Detection_method Other
redshift 0.1507
Circular_text TITLE: GCN CIRCULAR NUMBER: 32694 SUBJECT: GRB 221009A: NICER follow-up observations DATE: 22/10/11 18:41:54 GMT FROM: George A. Younes at George Washington U W. Iwakiri (Chuo U.), G. K. Jaisawal (DTU Space), G. Younes (NASA/GSFC/GWU), Z. Wadiasingh (UMCP, NASA/GSFC), S. Guillot (IRAP/CNRS), K. C. Gendreau (NASA/GSFC), Z. Arzoumanian (NASA/GSFC), E. C. Ferrara (UMCP, NASA/GSFC), T. Mihara (RIKEN), D. Pasham (MIT), J. M. Miller (Univ. of Michigan), A. Sanna (Univ. of Cagliari), C. Malacaria (ISSI), C. B. Markwardt (NASA/GSFC) We report on initial NICER observations of the exceptionally bright GRB 221009A, at a redshift of 0.1505 (GCN #32648, #32686) and observed from radio to TeV energies (GCNs #32632, #32635, #32636, #32641, #32658, #32661, #32668, #32677, and ATels #15653, #15655, #15656, #15660, #15661). NICER observed GRB 221009A intermittently from 2022 Oct 9 17:11 to Oct 11 00:12 UT, or 14.7 ksec to 126 ksec after the Fermi/GBM trigger time (GCN #32636). During this period, NICER made 12 observations with exposure times ranging from 40 to 400 sec each. The initial count rate registered with NICER is 1400 counts/s which declined to about 38 counts/s at the time of the last observation reported here. From a preliminary analysis, we find that the decline follows a power law with an index of -1.6. The 1-10 keV spectrum of each observation is well reproduced by an absorbed power-law model with a spectral index of about 2.0. We used the tbabs model with wilms abundance in XSPEC (Wilms, Allen & McCray 2000) for an assumed Galactic absorption of 5.4 x 10^21 cm^-2 (Willingale et al. 2013; GCN #32651). The average column density of these observations with the ztbabs model is 1.1 x 10^22 cm^-2 at a redshift of 0.151 (GCN #32648). The absorbed (unabsorbed) flux in the 0.3 - 10 keV band declined from 6.1 x 10^-9 (1.3 x 10^-8) to 1.8 x 10^-10 (3.3 x 10^-10) erg/sec/cm^2. NICER initially received notification of the GRB through OHMAN (On-orbit Hookup of MAXI and NICER) at 14:10:57 UT on Oct 9, but poor visibility delayed a prompt follow-up. OHMAN is software on an International Space Station laptop computer that provides a new automated triggering capability, monitoring live MAXI data and communicating new transient alerts to NICER for follow-up within minutes, visibility permitting. NICER is continuing to monitor GRB 221009A. Detailed temporal and spectral analysis is ongoing. The NICER schedule can be found at https://heasarc.gsfc.nasa.gov/docs/nicer/schedule/nicer_sts_current.html. NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA.
GCN 32695 table
GRB_name GRB221009A
GCN_number 32695
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32695 SUBJECT: GRB 221009A: NuSTAR Detection DATE: 22/10/11 19:38:52 GMT FROM: Ryan Chornock at UC Berkeley Daniel Brethauer (UC Berkeley), Brian Grefenstette (Caltech), Judith Racusin (NASA/GSFC), Raffaella Margutti (UC Berkeley), Kate D. Alexander (Arizona), Tom Barclay (NASA/GSFC), Edo Berger (Harvard), Eric Burns (LSU), Brad Cenko (NASA/GSFC), Yvette Cendes (Harvard), Ryan Chornock (UC Berkeley), Tarraneh Eftekhari (Northwestern), Jamie Kennea (PSU), and Tanmoy Laskar (Utah) report: NuSTAR began a Target of Opportunity observation of GRB 221009A (GCN #32632) on October 11, 2022 at 03:10:07 UTC, approximately 38 hours after the GBM Trigger (GCN #32642), with an exposure of 23.4 ks (PIs Racusin and Margutti). The 3-79 keV spectrum is well fit by a power law with a photon index of Gamma= 1.81 +/- 0.01, which is consistent with the value inferred from Swift-XRT observations acquired during the same time window. The corresponding unabsorbed flux is (3.37 +/- 0.02) e-10 erg/cm2/s (3-79 keV). Over the NuSTAR observation, the source X-ray flux declines by about 30%. However, preliminary analysis does not indicate a significant evolution of the 10-20 keV / 3-6 keV hardness ratio. These findings are consistent with the hard X-ray afterglow observed by INTEGRAL JEM-X and ISGRI (GCN #32691) and support an absorbed simple power-law spectrum extending from soft X-ray to hard X-ray energies. Three additional NuSTAR monitoring observations are planned and are anticipated to occur on October 15th, 20th, and November 2nd. We thank the NuSTAR SOC for promptly implementing these observations.
GCN 32700 table
GRB_name GRB221009A
GCN_number 32700
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32700 SUBJECT: GRB 221009A/Swift J1913.1+1946: eMERLIN observations DATE: 22/10/12 12:47:01 GMT FROM: Lauren Rhodes at Oxford L. Rhodes, J. Bright, R. Fender (Oxford), and D.R.A. Williams (JBCA) report: We observed the position of GRB 221009A (Swift J1913.1+1946; ATel #15650, ATel #15651) with the eMERLIN at 1.51GHz beginning at 17:55UT on 11th October for a total of 6 hours. OQ208 was used as the flux and bandpass calibrator while J1905+1943 was used as the complex gain calibrator. We detect an unresolved source at a position consistent with the one reported in ATel #15651 with a (preliminary) flux density of ~4mJy. We are in the process of obtaining further radio observations. We thank the e-MERLIN staff for the time allocation and their assistance with the observations.
GCN 32705 table
GRB_name GRB221009A
GCN_number 32705
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32705 SUBJECT: GRB 221009A: COATLI Continued Monitoring of the Afterglow DATE: 22/10/12 15:23:25 GMT FROM: Alan M Watson at UNAM Nat Butler (ASU), Alan M. Watson (UNAM), Simone Dichiara (PSU), Rosa L. Becerra (UNAM), Tzveti Dimitrova (ASU), Océlotl López (UNAM), Diego González (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Margarita Pereyra (UNAM), Eleonora Troja (UTV/ASU) and report: We observed the field of the bright GRB 221009A (Dichiara et al., GCN Circ. 32632, Veres et al., GCN Circ. 32636) with the COATLI 50-cm telescope and HUITZI f/8 imager at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir (http://coatli.astroscu.unam.mx) from 2022-10-12 04:00 UTC to 06:34 UTC (63.1 hours after the trigger), obtaining a total of 7560 seconds of exposure in the i filter. At the position of the UVOT afterglow (Dichiara et al., GCN Circ. 32632), we detect a source with the following magnitude: i = 19.10 +/- 0.02 Our photometry is calibrated against the Pan-STARRS1 catalog, is on an approximate AB system, and is not corrected for Galactic extinction in the direction of the GRB. Compared to our observations on the previous night (Watson et al., GCN Circ. 32692), the decay has a power-law index of 1.24 +/- 0.13. Further observations are planned. We thank the COATLI/HUITZI technical team and the staff of the Observatorio Astronómico Nacional.
GCN 32707 table
GRB_name GRB221009A
GCN_number 32707
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32707 SUBJECT: GRB 221009A/Swift J1913.1+1946: SMA observations DATE: 22/10/12 18:54:52 GMT FROM: Lauren Rhodes at Oxford Lauren Rhodes (University of Oxford), Kuiyun Huang (CYCU/PCCU) and Yvette Cendes (Harvard) report on behalf of a larger collaboration: We observed the field of the candidate gamma-ray burst GRB 221009A (Swift J1913.1+1946; ATel#15650, ATel#15651) with the Submillimeter Array (SMA) at 230.7GHz beginning at 03:27UT on 12 October 2022 for a total of 3.3 hours. Uranus was used as the flux calibrator, while 3c84 was used to calibrate the bandpass response. 1925+211 and mwc349a were used as interleaved complex gain calibrators. We detect an unresolved source at a position consistent with the UVOT position reported in ATel #15650 at a (preliminary) flux density of 9.30 +/- 0.75mJy. Further observations are planned. We thank the staff at the SMA for carrying out these observations.
GCN 32709 table
GRB_name GRB221009A
GCN_number 32709
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32709 SUBJECT: GRB221009A: optical afterglow measurements from Konkoly Observatory DATE: 22/10/12 22:29:55 GMT FROM: Jozsef Vinko at Konkoly Observator J. Vinko, A. Bodi, A. Pal, L. Kriskovics, R. Szakats, K. Vida (Konkoly Observatory, Hungary) report: We observed the field of the bright GRB221009A (Dichiara et al., GCN #32632, Veres et al., GCN #32636) with the RC80 robotic telescope at Piszkesteto Station of Konkoly Observatory on 2022 Oct 10.81 UT and Oct 12.85 UT, during inferior sky conditions. A series of 300 sec frames were collected through Sloan r'- and i' bands. The bright optical afterglow (Lipunov et al. GCN #32634; Perley et al. GCN #32638; Broens GCN #32640; Hu et al. GCN #32644; Belkin et al. GCN #32645; Wet et al. GCN #32646; Xu et al. GCN #32647; de Ugarte Postigo et al. GCN #32648; Odeh GCN #32649; Brivio et al. GCN #32652; Kuin et al. GCN #32656; Paek et al. GCN #32659; Kumar et al. GCN #32662; Romanov GCN #32664; Odeh GCN #32666; Chen et al. GCN #32667; Vidal et al. GCN #32669; Kim et al. GCN #32670; Groot et al. GCN #32678; Romanov GCN #32679; Castro-Tirado et al. GCN #32686; Watson et al. GCN #32692; Strausbaugh et al. GCN #32693; Butler et al. GCN #32705) was clearly detected on the stacked frames with the following magnitudes, calibrated via nearby PS1 stars: Date UT-middle t-T0(hr) Exp(s) r'(AB-mag) i'(AB-mag) 2022-10-10 19:26:51 30.16 600 18.74 (0.12) 17.50 (0.08) 2022-10-12 20:18:24 79.02 300 20.58 (0.70) 18.74 (0.18) These magnitudes are not corrected for galactic extinction.
GCN 32727 table
GRB_name GRB221009A
GCN_number 32727
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32727 SUBJECT: GRB 221009A: GMG observation DATE: 22/10/13 03:01:54 GMT FROM: Jirong Mao at Yunnan Obs J. Mao, K.-X. Lu, X.-H. Zhao, and J.-M. Bai (YNAO) report: We observed the field of GRB 221009A (Dichiara et al. GCN 32632) with the 2.4-meter optical telescope at Gao-Mei-Gu (GMG) station of Yunnan Observatories. The observation began at UT 14:34:40, 12, Oct. 2022, about 3 days after the trigger. We marginally detected the afterglow. The preliminary magnitude was measured to be z~18.9. We caution that the magnitude has a relatively large uncertainty due to the very poor seeing.
GCN 32729 table
GRB_name GRB221009A
GCN_number 32729
Detection_method Konus-Wind Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32729 SUBJECT: GRB 221009A: Sayan observatory 1.6-m telescope observations DATE: 22/10/13 07:08:22 GMT FROM: Rodion Burenin at IKI, Moscow I. Zaznobin, R. Burenin (IKI), M. Eselevich (ISTP SB RAS) report: The field of an extraordinarily bright GRB 221009A, detected by Swift (Kennea et al., GCN 32635), Fermi GBM (Veres et al., GCN 32636), SRG/ART-XC (Lapshov, et al., GCN 32663), Konus-Wind (Frederiks et al., GCN 32668), and others, was observed with the Sayan observatory (Mondy) 1.6-m telescope AZT-33IK, using a CCD photometer, starting at 2022/10/10 13:38 UT, i.e. approximately 24.4 hours after the burst. The optical transient found earlier (Dichiara et al., GCN 32632, Lipunov et al., GCN 32634, Perley et al., GCN 32638, Belkin et al., GCN 32645, and others), was observed in griz filters with the following magnitudes: g = 20.57 +- 0.08 r = 18.84 +- 0.02 i = 17.80 +- 0.02 z = 16.99 +- 0.02 The decay in OT brigtness in all filters is observed during approximately 2 hours of our observations. Spectra of the OT in 3700--10000A wavelength range were also obtained using ADAM low and medium resolution spectrograph. The analysis of these data is underway.
GCN 32730 table
GRB_name GRB221009A
GCN_number 32730
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 32730 SUBJECT: GRB 221009A: MITSuME Okayama optical observation DATE: 22/10/13 07:58:56 GMT FROM: Yuri Imai at Tokyo Inst of Tech M. Sasada, Y. Imai, K. L. Murata, R. Hosokawa, M. Niwano, I.Takahashi, M. Tateda, N. Ito, S. Sato, N. Higuchi, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 221009A (Dichiara et al. #32632, Kennea et al. #32635, Veres et al. #32636, Bissaldi et al. #32637, Perley et al. #32638, Broens et al. #32640, Svinkin et al. #32641, Lesage et al. #32642, Karambelkar et al. #32643, Hu et al. #32644, Belkin et al. #32645, Wet et al. #32646, Xu et al. #32647, Postigo et al. #32648, Ursi et al. #32650, Kennea et al. #32651, Brivio et al. #32652, Bright et al. #32653, Durbak et al. #32654, Farah et al. #32655, Piano et al. #32657, Pillera et al. #32658, Paek et al. #32659, Gotz et al. #32660, Xiao et al.#32661, Kumar et al. #32662, Lapshov et al. #32663, Romanov et al. #32664, The IceCube Collaboration et al. #32665, Odeh et al. #32666, Chen et al. #32667, Frederiks et al. #32668, Vidal et al. #32669, Kim et al. #32670, Tohuvavohu et al. #32671, Postigo et al. #32676, Huang et al. #32677, Groot et al. #32678, Romanov et al. #32679, Tiengo et al. #32680, Ayala et al. #32683, Belkin et al. #32684, Ripa et al. #32685, Castro-Tirado et al. #32686, Krimm et al. #32688, Negro et al. #32690, Savchenko et al. #32691, Watson et al.#32692, Strausbaugh et al. #32693, Iwakiri et al. #32694, Brethauer et al. #32695, Rhodes et al. #32700, Butler et al. #32705, Rhodes et al. #32707, Vinko et al. #32709, Mao et al. #32727, Zaznobin et al. #32729) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Okayama. The observation with a series of 60 sec exposures started at 2022-10-09 9:51:38 UT (0.857 day after the Swift detection). We stacked the images with good conditions. Here we report a Ic-band magnitude by the forced-photometry at the Swift/UVOT position (Dichiara et al. GCN Circular #32632), and the 5-sigma limits of the stacked images in the g' and Rc bands. T0+[day] |MID-UT | T-EXP[sec] | magnitudes of forced-photometry ------------------------------------------------------------------------------------------------ 0.9320 | 2022-10-10 11:39:09| 8340 | g'>18.3, Rc>17.0, Ic=17.1+/-0.2 ------------------------------------------------------------------------------------------------ T0+ : Elapsed time after the burst T-EXP: Total Exposure time We used PS1 catalog for flux calibration. 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, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN 32738 table
GRB_name GRB221009A
GCN_number 32738
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32738 SUBJECT: GRB221009A: LCOGT Continued Observations - Optical Upper Limits DATE: 22/10/13 16:00:24 GMT FROM: Robert Strausbaugh at University of Minnesota R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the GRB 221009A/Swift J1913.1+1946 (Dichiara et al., GCN 32632) field with the LCOGT 1-meter Sinistro instrument at the McDonald Observatory, Texas, USA site, on October 13, from 03:34 to 04:18 (corresponding to 84.60 to 85.50 hours from the GRB trigger time) with the SDSS g, r, and i filters. We performed a series of 3x300s exposures in each band. We do not detect the optical transient at the UVOT coordinates (Dichiara et al., GCN 32632), in any bands. The following upper limits are calculated using the Pan-STARRS catalog as reference: g > 22.3 r > 21.4 i > 20.5 These magnitudes are not corrected for galactic extinction.
GCN 32739 table
GRB_name GRB221009A
GCN_number 32739
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32739 SUBJECT: GRB 221009A: Lowell Discovery Telescope Afterglow Detection DATE: 22/10/13 17:07:17 GMT FROM: Brendan O'Connor at UMD B. O'Connor (UMD/GWU), S. B. Cenko (NASA/GSFC), E. Troja (UTV/ASU), S. Dichiara (PSU), A. Kutyrev (NASA/GSFC), S. Veilleux (UMD), J. Durbak (UMD), on behalf of a larger collaboration: We performed target of opportunity observations of GRB 221009A (Dichiara et al., GCN 32632, Veres et al., GCN 32636) with the 4.3m Lowell Discovery Telescope in Happy Jack, AZ. Observations began on October 13, 2022 at 03:09:27 UT corresponding to ~3.6 d after the GRB. We obtained images in the griz filters at an airmass ~1.2 with seeing ~1.2". The afterglow is clearly detected in all filters. We obtain the following magnitudes calibrated against the PS1 catalog: r = 20.44 +/- 0.02 AB mag i = 19.37 +/- 0.01 AB mag Compared to observations at 63 hr (Watson et al., GCN 32705) the temporal decay has a power-law index of about -0.9, shallower than observed in X-rays. These magnitudes are not corrected for Galactic extinction. We thank the staff of the Lowell Observatory for assistance with these observations.
GCN 32740 table
GRB_name GRB221009A
GCN_number 32740
Detection_method Optical
ra 288.2645°
decl 19.7736°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32740 SUBJECT: GRB 221009A: MeerKAT detection DATE: 22/10/13 17:34:58 GMT FROM: Tanmoy Laskar at U of Bath T. Laskar (University of Utah), K. D. Alexander (Arizona), E. Ayache (Stockholm), E. Berger (Harvard), S. Bhandari (ASTRON/JIVE), J. Bright (Oxford), R. Chornock (UC Berkeley), D. Coppejans (Warwick), H. van Eerten (Bath), W. Fong (Northwestern), P. Groot (Radboud), R. Margutti (UC Berkeley), C.G. Mundell (Bath), P. Schady (Bath), G. Schroeder (Northwestern), and S. de Wet (Cape Town) report: "We observed GRB 221009A (Dichiara et al. GCN 32632) with the MeerKAT radio telescope array beginning on 2022 October 10 19:10 UTC (1.3 d after the burst). Preliminary analysis reveals a radio counterpart with 1.284 GHz flux density of ~ 2.1 mJy at position: RA (J2000) = 19:13:03.47 +/- 0.04" Dec (J2000) = 19:46:25.08 +/- 0.06" This position is consistent with the optical position (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634). Further observations are planned. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation."
GCN 32741 table
GRB_name GRB221009A
GCN_number 32741
Detection_method Fermi GBM Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32741 SUBJECT: GRB 221009A: search for neutrinos with KM3NeT DATE: 22/10/13 18:57:37 GMT FROM: Damien Dornic at CPPM,France The KM3NeT Collaboration (https://www.km3net.org/) reports:

Using the data from the online fast processing chain, the KM3NeT Collaboration has performed a dedicated search for track-like muon neutrino events arriving from the direction of GRB 221009A (Dichiara et al. GCN 32632 (Swift); Veres et al. GCN 32636 (Fermi-GBM)). The search covers the time range of [T0-50s, T0+5000s], with T0 being the trigger time reported by Fermi-GBM (T0=2022-10-09 13:16:59.00 UTC), during which both KM3NeT detectors were collecting good quality data. However, the GRB location was above the KM3NeT horizon (mean elevation of about ~40deg) during the search time window, significantly reducing the point-like source sensitivity. In both detectors, zero events were observed in the search window, while o(0.1) were expected from the background. The online fast processing uses preliminary calibrations and detector alignment, which will be superseded in a future elaborated analysis.

A parallel search has been performed in the MeV range (Eur.Phys.J.C 82 (2022) 4, 317) without any significant neutrino coincidence.

KM3NeT is a large undersea (Mediterranean Sea) infrastructure hosting two neutrino detectors, sensitive to burst of supernova neutrinos in the MeV range and to astrophysical neutrinos in the GeV-PeV energy range: ARCA at high energy and ORCA at low energy. A total of 21 and 11 detection lines are currently in operation in ARCA and ORCA, respectively.
GCN 32743 table
GRB_name GRB221009A
GCN_number 32743
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32743 SUBJECT: GRB221009A: RTT-150 optical observations DATE: 22/10/13 20:12:07 GMT FROM: Rodion Burenin at IKI, Moscow Ilfan Bikmaev (KFU, AST, Kazan), Irek Khamitov (TUG, Antalya, KFU, Kazan), Eldar Irtuganov (KFU, AST, Kazan), Mark Gorbachev (KFU, AST, Kazan), Nail Sakhibullin (KFU, AST, Kazan), Rodion Burenin (IKI, Moscow) report: We have performed optical observations of the OT GRB221009A (Dichiara et al., GCN 32632, GCNs 32635, 32636,32636, 32641, 32657, 32658, 32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679, 32680, 32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695, 32700, 32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739) by using 1.5-meter joint Russian-Turkish telescope (RTT-150, TUBTAK National Observatory, Antalya, Turkey) in October 10-12, 2022. We used TFOSC instrument for photometry in griz filters and low resolution spectroscopy in the 3800 - 8870 A range. During 3 consecutive nights starting 27.6 hours since the trigger we make series of images in griz with 600 sec exposures each. We clearly see the OT in all frames. Photometric data were calibrated using nearby PS1 star. Results of our photometry are given in the Table. JD T-T0 Filter mag merr (hours) 2459863.2056537 27.653 g 20.13 0.08 2459863.2131298 27.832 r 18.65 0.02 2459863.2205018 28.009 i 17.52 0.01 2459863.2278493 28.185 z 16.81 0.01 2459863.3452805 31.004 g 20.44 0.25 2459863.3681597 31.553 r 18.81 0.05 2459863.3760363 31.742 i 17.69 0.02 2459863.3840870 31.935 z 16.99 0.01 2459864.1923863 51.334 r 19.53 0.04 2459864.2002009 51.522 i 18.40 0.02 2459864.2076914 51.702 z 17.69 0.02 2459864.2153146 51.884 g 21.15 0.21 2459864.3645166 55.465 r 19.67 0.11 2459864.3728065 55.664 i 18.49 0.04 2459864.3804310 55.847 z 17.72 0.03 2459865.2047148 75.630 i 18.82 0.03 2459865.2122502 75.811 r 20.03 0.06 2459865.2198393 75.993 z 18.20 0.04 2459865.2273203 76.173 i 19.02 0.07 2459865.2347618 76.351 r 19.97 0.08 2459865.2422699 76.531 z 18.19 0.05 2459865.2497386 76.711 i 19.09 0.10 2459865.2571590 76.889 r 20.07 0.19 2459865.2646685 77.069 z 18.40 0.08 2459865.2720521 77.246 i 18.95 0.07 2459865.2795044 77.425 r 20.32 0.17 2459865.2869724 77.604 z 18.26 0.03 2459865.2943683 77.782 i 18.93 0.04 2459865.3092743 78.140 z 18.23 0.03 2459865.3167266 78.318 i 18.93 0.04 2459865.3241129 78.496 r 20.17 0.12 2459865.3315775 78.675 z 18.23 0.04 2459865.3389639 78.852 i 18.92 0.04 2459865.3507442 79.135 r 20.26 0.16 2459865.3583217 79.317 z 18.30 0.04 2459865.3733491 79.677 r 20.24 0.19 2459865.3809028 79.859 z 18.18 0.04 Two series of low resolution (12 A) spectra were obtained in October 10, UT = 17:43 - 19:54 and in October 11, UT = 17:24 - 20:32. Their analysis is underway.
GCN 32744 table
GRB_name GRB221009A
GCN_number 32744
Detection_method Swift-BAT Det
ra 288.2540°
decl 19.8090°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32744 SUBJECT: GRB221009A: Detection as sudden ionospheric disturbances (SID) DATE: 22/10/13 21:42:27 GMT FROM: Doug Welch at McMaster University P.W. Schnoor (Kiel Longwave Monitor, Germany), P. Nicholson (Todmorden, UK), D.L. Welch (McMaster University, Canada) A sudden disturbance of the Earth's ionosphere (SID) was observed by the Kiel Longwave Monitor (Germany) and a VLF-Monitor at Todmorden (near Manchester, UK) coincident with the detection of GRB221009A (SWIFT, #32635). This SID was seen as a sudden increase or decrease in the signal strengths from radio transmitters below 100 kHz (19.6 to 63.9 kHz; VLF/LF) received at Kiel and Todmorden. These naval transmitting stations are located at France, Germany, Iceland, Israel, Italy, Japan (Okinawa), United Kingdom and United States. Note: This is not a radio detection of GRB221009A; this disturbance was caused by the prompt X-rays and/or gamma-rays from GRB221009A ionizing the upper atmosphere and modifying the radio propagation properties of the waveguide between ground and ionosphere. According to the SWIFT-BAT refined analysis (RA, Dec = 288.254, 19.809 deg, GCN #32688) GRB221009A was above local horizon at both receiving sites (2022-10-09, 13:16:59 UT). Kiel: az = 101.8, el = 32.9 deg Todmorden: az = 94.6, el = 28.3 deg Plots of the SID detection are available at the following URLs: Kiel https://www.qsl.net/df3lp/grb221009/KLM_grb221009a_magnitudes.png Todmorden http://abelian.org/vlf/grb221009a-DHO.png http://abelian.org/vlf/grb221009a-NAA.png http://abelian.org/vlf/grb221009a-NSY.png The Kiel Longwave Monitor consists of a set of very low frequency radio receivers attached to a crossed pair of loop antennas (16m^2 each), monitoring the radio spectrum from 1.0 to 96.0 kHz at 50Hz-steps. The VLF-monitor at Todmorden consists of a set of very low frequency radio receivers attached to a crossed pair of loop antennas (20m^2 each) and a vertical antenna, monitoring the radio spectrum below 100 kHz.
GCN 32745 table
GRB_name GRB221009A
GCN_number 32745
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32745 SUBJECT: GRB221009A: Ionospheric disturbance observed in India DATE: 22/10/13 21:48:26 GMT FROM: Doug Welch at McMaster University Authors: A. Guha (Centre for Lightning and Thunderstorm Studies (CeLTS), Department of Physics, Tripura University, India.), P. Nicholson (Todmorden, UK) We report the observation of a sudden disturbance of radio propagation in the very low frequency (VLF) band between 18kHz and 23kHz coincident with GRB221009A. Affected were phase and amplitude of MSK ("Minimum Shift Keying") signals from naval transmitters monitored by the Indian Lightning Detection Network. The GRB221009A exceeded 70 degrees elevation at all receiver sites. https://ildn.in/gallery/ILDN-GRB221009A-VTX3.png https://ildn.in/gallery/ILDN-GRB221009A-NWC.png https://ildn.in/gallery/ILDN-GRB221009A-NDT.png The Indian Lightning Detection Network (ILDN) is an experimental network of 10 VLF receivers operated by collaborating institutions for lightning location and observation of other VLF phenomena on the Indian subcontinent.
GCN 32746 table
GRB_name GRB221009A
GCN_number 32746
Detection_method Swift-BAT Det
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32746 SUBJECT: GRB 221009A: Gamma-ray Detection by SIRI-2 DATE: 22/10/14 00:18:42 GMT FROM: Lee Mitchell at Naval Research Laboratory L. J. Mitchell, B. F. Phlips, (Naval Research Laboratory), W.N. Johnson (Technology Service Corporation) The SIRI-2 gamma-ray spectrometer (Mitchell et al. 2019, Proc. SPIE 11118) detected the bright long-duration GRB 221009A detected by Swift/BAT (Dichiara et al., GCN 32632, Kennea et al., GCN 32635), Fermi-GBM (Lesage et al., GCN 32642, Veres et al., GCN 32636), Fermi-LAT (Bissaldi et al. GCN 32637, Pillera et al., GCN 32658), AGILE-MCAL (Ursi et al., GCN 32650), AGILE-GRID (Piano et al. GCN 32657), INTEGRAL SPI/ACS (Gotz et al., GCN 32660), Konus-Wind (Frederiks et al., GCN 32668), at a redshift of z = 0.151 (de Ugarte Postigo et al., GCN 32648; Castro-Tirado et al., GCN 32686). The GRB was 19.9 degrees off-axis from the un-collimated instrument. With 10-second binning, the background-subtracted peak count rates in the 300-7000 keV energy range were ~65e3 count/s and ~24e3 count/s from 2022-10-09 13:20:51-13:21:11 and 13:21:11-13:21:41 UTC, respectively, coinciding with the previously-reported brightest two gamma-ray peaks. De-convolving the instrument response for the incident angle, the photon spectra for both peaks are consistent with a power law slope of -1.7 +/- 0.1. SIRI-2 (Mitchell et al. 2019, Proc. SPIE 11118) was launched on 2021 DATE aboard the DoD Space Test Program's STPSat-6. It consists of seven hexagonal europium-doped strontium iodide (SrI2:Eu) scintillation detectors (each 3.81 cm by 3.81 cm), with a frontal area of 66 cm2, and read out by a SiPM array, covering the energy range of ~300 keV to ~7000 keV.
GCN 32748 table
GRB_name GRB221009A
GCN_number 32748
Detection_method Fermi LAT Other
ra 288.2820°
decl 19.4950°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32748 SUBJECT: GRB 221009A: a 397.7 GeV photon observed by Fermi-LAT at 0.4 day after the GBM trigger DATE: 22/10/14 01:09:54 GMT FROM: Zi-Qing Xia at Purple Mountain Observatory Zi-Qing Xia, Yun Wang, Qiang Yuan and Yi-Zhong Fan (Purple Mountain Observatory) report: We have analyzed the long-term (MET: 687014224, 687139205) Fermi-LAT gamma-ray observations above 100 MeV of GRB 221009A, a burst characterized by its huge power, a low redshift as well as the highest energy photons (Kennea et al. GCN #32635, Veres et al. GCN #32636, Lesage et al. GCN #32642, Bissaldi et al. GCN #32637, Svinkin et al. GCN #32641, Huang et al. GCN #32677). We find a 397.7 GeV photon at 0.27 degree from the LAT localization of GRB 221009A (RA = 288.282, Dec = 19.495, from Pillera et al. GCN #32658), arriving at 33554 seconds after the Fermi-GBM trigger. The location of this event is RA = 288.252, Dec = 19.763, which is close to the LHAASO localization of GRB 221009A (RA = 288.3, Dec = 19.7, from Huang et al. GCN #32677). From a preliminary analysis, the 397.7 GeV event is found to be associated with GRB 221009A at a significance level of >3 sigma, which would be the most energetic GRB photon detected by Fermi-LAT so far (The previous records are a 99.3 GeV photon from GRB 221009A at an early time and a 95 GeV photon from GRB 130427A). Pre-GRB 221009A, just two photon events around 100 GeV had been observed by Fermi-LAT within 0.5 degree of GRB 221009A, suggesting a rather low chance coincidence probability of being a background. Furthermore, the GeV emission of GRB 221009A lasted more than one day. The detection of such a high energy photon at t~0.4 day after the GRB trigger seems to favor the inverse compton origin rather than the synchrotron radiation (Fan et al. 2013 ApJ, 776, 95; https://arxiv.org/abs/1305.1261), which can reach very-high-energy domain in particular for the nearby luminous GRBs (Xue et al. 2009 ApJ, 703, 60; https://arxiv.org/abs/0907.4014).
GCN 32749 table
GRB_name GRB221009A
GCN_number 32749
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32749 SUBJECT: GRB221009A: Gemini-South Optical Afterglow Detection DATE: 22/10/14 01:58:41 GMT FROM: Jillian Rastinejad at Northwestern Univ. J. Rastinejad and W. Fong (Northwestern) report on behalf of a larger collaboration: We observed the location of GRB 221009A (Dichiara et al. GCN 32632) with the Gemini Multi-Object Spectrograph (GMOS) mounted on Gemini-South under Program GS-2022B-DD-103 (PI: Rastinejad). We obtained 7x60-sec imaging in i-band at a mid-time of 2022 October 14 00:40:12 UT (4.437 days post-burst), at a median airmass of 1.9. We clearly detect the optical afterglow. Calibrated to Panstarrs, we measure a brightness of i ~ 19.8 AB mag at seeing < 0.8'', not corrected for Galactic extinction. This is consistent with recently reported measurements (e.g. Bikmaev et al. GCN 32743) and indicates significant fading from the i-band measurement of 15.58 +/- 0.03 AB mag reported by de Wet et al. (GCN 32646) at 0.178 days. Further observations are planned to monitor the variability of the source. We thank Jennifer Andrews, Janice Lee, and additional Gemini staff for the rapid DDT approval, as well as the planning and execution of these observations.
GCN 32750 table
GRB_name GRB221009A
GCN_number 32750
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32750 SUBJECT: GRB 221009A: Gemini-South Infrared Afterglow Detection DATE: 22/10/14 03:46:29 GMT FROM: Brendan O'Connor at UMD B. O'Connor (UMD/GWU), E. Troja (UTV/ASU), S. Dichiara (PSU), J. Gillanders (UTV), S. B. Cenko (NASA/GSFC): We performed target of opportunity observations of GRB 221009A (Dichiara et al., GCN 32632, Veres et al., GCN 32636) with the FLAMINGOS-2 spectrograph mounted on the Gemini-South telescope. Observations began on October 13, 2022 at 23:58:42 UT corresponding to ~4.4 d after the GRB. We obtained images in the JHK filters with a total exposure of 60 s in each. The target was at airmass 1.75 under seeing of ~0.7". The afterglow is clearly detected in the JHK filters. We obtain the following magnitudes calibrated against the 2MASS catalog: J = 17.93 +/- 0.03 AB mag H = 17.23 +/- 0.05 AB mag K = 16.69 +/- 0.02 AB mag Compared to previous nIR photometry (Brivio et al., GCN 32652, Durbak et al. GCN 32654), our observation yields a power-law decay with index ~ -1.4. This is steeper than reported in the optical (O'Connor et al., GCN 32739) and consistent with that observed in X-rays. These magnitudes are not corrected for Galactic extinction. Further infrared observations are planned. We thank the staff (Janice Lee, Jennifer Andrews, and Jeong-Eun Heo) of the Gemini Observatory for rapidly approving and scheduling these observations.
GCN 32751 table
GRB_name GRB221009A
GCN_number 32751
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32751 SUBJECT: GRB 221009A: HEBS detection DATE: 22/10/14 10:09:17 GMT FROM: Dong Xu at NAOC/CAS J. C. Liu, Y. Q. Zhang, S. L. Xiong, C. Zheng, C. W. Wang, W. C. Xue, R. Qiao, W. J. Tan, D. L. Zhang, X. Q. Li, X. Y. Wen, W. X. Peng, L. M. Song, S. J. Zheng, D. Y. Guo, X. B. Li, X. Ma, Y. Huang, X. Y. Zhao, P. Wang, J. Wang, Z. Zhang, Y. Q. Du, J. Liang, Y. Q. Lu, H. Wu, W. H. Yu, S. Xiao, C. Cai, P. Zhang, B. Li, Z. H. An, M. Gao, K. Gong, X. J. Liu, Y. Q. Liu, X. L. Sun, Y. B. Xu, S. Yang, P. Y. Feng, J. Z. Wang, F. Zhang, G. Chen, F. J. Lu, S. N. Zhang (IHEP) report on behalf of GECAM and HEBS teams: During the commissioning phase, HEBS detected the prompt emission of the extraordinarily bright burst GRB 221009A, which was also observed by Fermi/GBM (Lesage et al., GCN 32642, Veres et al., GCN 32636), Swift/BAT (Dichiara et al., GCN 32632, Kennea et al., GCN 32635) Insight-HXMT/HE (Tan et al., Atel 15660), Fermi/LAT (Bissaldi et al. GCN 32637, Pillera et al., GCN 32658), AGILE/MCAL (Ursi et al., GCN 32650), AGILE/GRID (Piano et al. GCN 32657), INTEGRAL SPI/ACS (Gotz et al., GCN 32660), Konus-Wind (Frederiks et al., GCN 32668), SIRI-2 (Mitchell et al., GCN 32746), and LHAASO (Huang et al., GCN 32677). At the beginning of the burst (2022-10-09T13:17:00.050 UTC, denoted as T0), HEBS was in the high latitude region where the in-flight triggering of HEBS was disabled to eliminate false triggers caused by particle background. However, one gamma-ray detector (i.e. GRD01) and one charged particle detector (i.e. CPD02) are set to collect data normally during this region. The full burst of GRB 221009A prompt emission was well monitored by HEBS. The incident angle to GRD01 is about 70 deg during the prompt emission. Despite of the extreme brightness, the GRB 221009A main burst (T0+180s to T0+270s) was clearly observed by HEBS without data saturation. The dead-time is reasonable and the pulse pileup effect is negligible for the low gain readout channel of GRD01. The dead-time corrected light curves of HEBS could be found at: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/HEBS-GRB221009A.png From the 50 ms light curve, we note that there are complicated spiky structures during the main peaks. All results above are preliminary. Refined analysis is ongoing and will be reported later. HEBS is an all-sky monitor for gamma-ray transients in 10 keV to 5 MeV aboard the Space advanced technology demonstration satellite (SATech-01) satellite, which is funded and built by Chinese academic of sciences, and was launched on July 27, 2022. Both the payload and the science operation of HEBS are inherited from GECAM mission (made of two mini-satellites, GECAM-A and GECAM-B), and thereafter HEBS is also called GECAM-C.
GCN 32752 table
GRB_name GRB221009A
GCN_number 32752
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32752 SUBJECT: GRB221009A: RTT-150 optical observations DATE: 22/10/14 11:03:17 GMT FROM: Rodion Burenin at IKI, Moscow Ilfan Bikmaev (KFU, AST, Kazan), Irek Khamitov (TUG, Antalya, KFU, Kazan), Eldar Irtuganov (KFU, AST, Kazan), Mark Gorbachev (KFU, AST, Kazan), Nail Sakhibullin (KFU, AST, Kazan), Rodion Burenin (IKI, Moscow) report: We have performed additional optical observations of the OT GRB221009A (Dichiara et al., GCN 32632, GCNs 32635, 32636,32636, 32641, 32657, 32658, 32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679, 32680, 32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695, 32700, 32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739, 32740, 32743, 32746, 32749, 32750) by using 1.5-meter joint Russian-Turkish telescope (RTT-150, TUBITAK National Observatory, Antalya, Turkey) and TFOSC instrument in October 13, 2022. We made series of images in riz filters with 600 sec exposures each. We clearly see the OT in all frames. Photometric data were calibrated using nearby PS1 star. Results of our photometry are given in the Table: JD T-T0 Filter mag merr (hours) 2459866.2034967 99.601 r 20.53 0.09 2459866.2115203 99.793 i 19.51 0.06 2459866.2189183 99.971 z 18.63 0.05 2459866.2263488 100.149 r 20.63 0.09 2459866.2339414 100.332 i 19.41 0.05 2459866.2413937 100.510 z 18.76 0.05 2459866.2488331 100.689 r 20.71 0.15 2459866.2562889 100.868 i 19.52 0.05 2459866.2636921 101.046 z 18.69 0.04 2459866.2711805 101.225 r 20.54 0.10 2459866.2786139 101.404 i 19.44 0.04 2459866.2862528 101.587 z 18.75 0.04 2459866.2937201 101.766 r 20.55 0.12 2459866.3010995 101.943 i 19.45 0.05 2459866.3088004 102.128 z 18.74 0.05 2459866.3162909 102.308 r 20.74 0.16 2459866.3238331 102.489 i 19.43 0.05 2459866.3314625 102.672 z 18.83 0.05 2459866.3389523 102.852 r 20.90 0.23 2459866.3464004 103.031 i 19.48 0.06 2459866.3558217 103.257 z 18.74 0.05 2459866.3633150 103.437 r 20.86 0.27 2459866.3707428 103.615 i 19.50 0.07 2459866.3798291 103.833 z 18.71 0.06 RTT-150 light curves for 4 nights observations are shown in the Figure: https://www.srg.cosmos.ru/static/images/grb/lc_grb221009A_RTT150.jpg Power law decay indexes based on RTT-150 griz observations, taking in account our data obtained earlier (Bikmaev et al., GCN 32743) are as follows: g: -1.42 +- 0.20 r: -1.47 +- 0.07 i: -1.40 +- 0.04 z: -1.38 +- 0.04 Our measurements of the OT power law decay agree well with that measured in infrared bands (O'Connor et al., GCN 32750, Brivio et al., GCN 32652, Durbak et al. GCN 32654), obtained during nearly the same periods of OT observations. The mean value of (r - z) color indicates no any significant changes in the optical spectrum slope during four nights of our observations.
GCN 32753 table
GRB_name GRB221009A
GCN_number 32753
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32753 SUBJECT: GRB 221009A: OHP optical observations DATE: 22/10/14 12:40:52 GMT FROM: Benjamin Schneider at CEA B. Schneider (CEA Paris-Saclay), C. Adami (LAM), E. Le Floc'h, D. Turpin, D. Götz (CEA Paris-Saclay) S. D. Vergani, A. Saccardi (GEPI, Observatoire de Paris), S. Basa, A. Le Van Suu (LAM) report on behalf of a larger collaboration: We observed the field of GRB 221009A (Dichiara et al., GCN 32632; Veres et al., GCN 32636) using the T120cm telescope at Observatoire de Haute-Provence (France). Four exposures were obtained in the r band (2x300s + 2x600s), three exposures in the i band (3x600s) and the z band (1x300s + 2x900s) from 2022 12 Oct 19:11:05 UT to 2022 12 Oct 20:41:23 UT (mid time ~78h after trigger). In the combined frame, we clearly detect the source in the three filters and obtain the following magnitudes: r = 20.23 ± 0.09 mag (AB) i = 18.91 ± 0.11 mag (AB) z = 18.35 ± 0.13 mag (AB) The photometric calibration was performed using nearby stars from the PanSTARRS catalog and magnitudes are not corrected for Galactic extinction. These values are consistent with observations obtained at a similar time by Bikmaev et al. (GCN 32743). Further observations using the MISTRAL instrument mounted on the T193-OHP are planned for the coming nights. We acknowledge the excellent support from Observatoire de Haute Provence, in particular François Huppert and Jérome Schmitt.
GCN 32754 table
GRB_name GRB221009A
GCN_number 32754
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32754 SUBJECT: GRB 221009A: IXPE preliminary upper limits of X-ray polarization DATE: 22/10/14 12:58:40 GMT FROM: Michela Negro at CRESST/NASA-GSFC/UMBC Michela Negro, Alberto Manfreda, Nicola Omodei and Fabio Muleri report on behalf of the IXPE Collaboration IXPE performed the first observation of X-ray polarization of a GRB afterglow in the 2 — 8 keV energy range. IXPE observed GRB 221009A from 2022-10-11T23:34:28UTC to 2022-10-14T00:45:31UTC for an effective exposure of 100 ks. From a quick-look analysis of the *image-, time- and energy- averaged low-level instrument data (prior to pipeline processing at the IXPE SOC), we report: Polarization degree (PD) < 11.1% upper limits are derived with 99% C.L. These results are preliminary. The IXPE Collaboration will report the final results in a forthcoming publication. The Imaging X-ray Polarimetry Explorer, commonly known as IXPE is a space observatory with three identical telescopes designed to measure the polarization of cosmic X-rays. X-ray polarimetry enabled by IXPE can be performed in energy-, time-, and angle-resolved fashions. The observatory, which was launched on 9 December 2021, is an international collaboration between NASA and the Italian Space Agency (ASI). [Editor's note: Reformatted at the request of the submitter.]
GCN 32755 table
GRB_name GRB221009A
GCN_number 32755
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32755 SUBJECT: GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve DATE: 22/10/14 14:29:16 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D’Avanzo, M. Ferro, R. Brivio, M. G. Bernardini, D. Fugazza, S. Campana, S. Covino (INAF-OAB), V. D’Elia (ASI/SSDC), M. De Pasquale (Messina Univ.), D. B. Malesani (Radboud Univ. and DAWN/NBI), A. Melandri (INAF-OAR), E. Palazzi (INAF-OAS), S. Piranomonte (INAF-OAR), A. Rossi (INAF-OAS), B. Sbarufatti, G. Tagliaferri (INAF-OAB) on behalf of the REM team and of the CIBO collaboration, report: We continued to observe the field of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) with the REM 60cm robotic telescope located at the ESO premises of La Silla (Chile). The observations were carried in the optical and NIR bands, from about 0.4 to 3.5 days after the GBM trigger, with a nightly cadence. A refined analysis of the first REM epoch reveals that the H-band photometry reported in Brivio et al. (GCN Circ. 32652) is affected from contamination from a field star located at an angular separation of about 5" from the NIR afterglow. We report here an updated value of H = 12.62 +/- 0.02 mag (Vega, calibrated against the 2MASS catalogue) at 0.4 days after the GBM trigger. Inspection of the H- and z-band afterglow light curves obtained with REM reveals evidence for a steepening in the decay after about 1 day. We carried out a fit of the 0.3 - 10 keV Swift/XRT afterglow light curve (https://www.swift.ac.uk/xrt_curves/01126853/ ), rescaling the t-t0 with respect to the time of the GBM trigger, and find statistical evidence that a broken power-law decay provides a better fit with respect to a single power-law decay, with a break time at about 1 day. By performing a joint fit to the H, z and X-ray bands, with a broken power-law model we find the the overall dataset is best fit with a broken power-law with decay indices alpha1_X ~ 1.5, alpha2_X ~ 1.9, alpha1_NIR = alpha1_opt ~ 0.8, alpha2_NIR = alpha2_opt ~ 1.6 with a break time (forced to be equal in all light curves) t_b ~ 0.98 days. Under the assumption that such an achromatic break is the GRB jet-break, starting from the computed GRB Eiso (Frederiks et al., GCN Circ. 32668) we obtain a jet half-opening angle theta_jet ~ 3.5 deg and a beaming-corrected energy for the GRB of ~ 6e51 erg (using efficiency 0.2 and density n = 1 cm^(-3); Sari et al., 1999, ApJ, 519, L17; Rhoads, 1999, ApJ, 525, 737 ).
GCN 32757 table
GRB_name GRB221009A
GCN_number 32757
Detection_method VLA Det
ra 288.2646°
decl 19.7734°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32757 SUBJECT: GRB 221009A: VLA detection DATE: 22/10/14 20:44:52 GMT FROM: Tanmoy Laskar at U of Bath T. Laskar (Utah), K. D. Alexander (Arizona), E. Ayache (Stockholm), E. Berger (Harvard), R. Chornock (Berkeley), H. van Eerten (Bath), W. Fong (Northwestern), R. Margutti (Berkeley), C.G. Mundell (Bath), and P. Schady (Bath) report: "We observed GRB 221009A (Dichiara et al. GCN 32632) with the Karl G. Jansky Very Large Array (VLA) beginning on 2022 October 12 23:08 UTC at multiple frequencies (3.5 d after the burst). In preliminary analysis, we detect the radio counterpart (Trushkin et al., ATEL 15671; Bright et al., GCN 32653; Farah et al., GCN 32655; Rhodes et al., GCN 32700; Leung et al., GCN 32836; Laskar et al., GCN 32740) with a flux density of ~ 9.2 mJy at 11 GHz, and position: RA (J2000) = 19:13:03.50 Dec (J2000) = 19:46:24.23 with a (statistical) uncertainty of 0.01" in each coordinate. This position is consistent with the optical position (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634) and the radio position (Laskar et al., GCN 32740). Further observations are planned. We thank the VLA staff for scheduling and executing these observations"
GCN 32758 table
GRB_name GRB221009A
GCN_number 32758
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32758 SUBJECT: GRB 221009A: Pan-STARRS optical photometry DATE: 22/10/14 21:35:08 GMT FROM: Ken Smith at Queen's University Belfast M. Huber, A. Schultz, K. C. Chambers (IfA, Hawaii), K. W. Smith, M. Fulton, S. J. Smartt (QUB), T.-W. Chen (Stockholm), M. Nicholl (Birmingham), D. R. Young, L. J. Shingles, S. Srivastav, S. Sim (QUB), T. de Boer, J. Bulger, J. Fairlamb, C.-C. Lin, T. Lowe, E. Magnier, R. J. Wainscoat, H. Gao (IfA), C. Stubbs (Harvard), A. Rest (STScI) Daily imaging has been acquired (weather permitting) of the optical counterpart of Swift J1913.1+1946 (Dichiara et al., GCN 32632; Lipunov et al.,GCN 32634), the optical afterglow of GRB 221009A (Kennea & Williams, GCN 32635; Veres et al., GCN 32636) with Pan-STARRS2 since MJD 59863 (2022-10-11). The following table shows the most recent observations. MJD filter mag dmag 59866.22756 r 20.92 0.05 59866.22504 i 19.88 0.02 59866.22371 z 19.21 0.02 59866.22239 y 18.77 0.03 We observed an initial fade of approximately 0.9 mags per day in i, z and y, slowing to about 0.4 mags per day in these filters over the last 2 days.
GCN 32759 table
GRB_name GRB221009A
GCN_number 32759
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32759 SUBJECT: GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection DATE: 22/10/15 00:09:35 GMT FROM: Manisha Shrestha at University of Arizona GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection M. Shrestha (Univ. of Arizona), D. Sand (Univ. of Arizona), K. D. Alexander (Univ. of Arizona), J. Andrews (Gemini), J. Pearson (Univ. of Arizona), N. Smith (Univ. of Arizona), K. Bostroem (Univ. of Arizona) report on behalf of a wider collaboration: We observed the field of Swift GRB 221009A (Dichiara et al. GCN 32632 ) with the Large Binocular Telescope Observatory, located in Mount Graham, Arizona, on 2022 October 12 starting at 02:40:10.027 UT (~2.5 days after the trigger) using the MODS instrument in imaging mode in the g, i and z bands. Data were calibrated with respect to nearby PanSTARRS catalog stars. We clearly detect the optical counterpart in the i and z bands and obtain an upper limit on the g band. The magnitudes are as follows: g > 23 i = 19.00 +- 0.02 mag z = 18.26 +- 0.01 mag These values are not corrected for galactic extinction and are consistent with (Butler et al. GCN 32705, Bikmaev et al. GCN 32743) which were obtained in similar time. We would like to thank A Cardwell and LBTO staff for obtaining the observations.
GCN 32760 table
GRB_name GRB221009A
GCN_number 32760
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32760 SUBJECT: GRB 221009A: Fermi LAT data rate effects due to extremely high flux DATE: 22/10/15 07:21:01 GMT FROM: Elisabetta Bissaldi at INFN,Bari N. Omodei (Stanford Univ.), P. Bruel (CNRS/IN2P3), J. Bregeon (CNRS/IN2P3), M. Pesce-Rollins (INFN Pisa), D. Horan (CNRS/IN2P3), E. Bissaldi (Politecnico and INFN Bari), and R. Pillera (Politecnico and INFN Bari) report on behalf of the Fermi-LAT team: We report updated observations of GRB 221009A which was detected by Swift (Kennea et al. GCN #32635), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637, Pillera et al. #32658), and the IPN (Svinkin et al. GCN #32641). GRB 221009A triggered Fermi-GBM on October 9, 2022, at 13:16:59.99 UT (T0, trigger 687014224/221009553). During some time periods of the main emission episode of GRB 221009A as seen in GBM, the LAT gamma-ray flux was so high that more than one photon was recorded at the same time, which strongly affected event reconstruction. We are currently investigating the consequences of such a pile-up but, until further notice, we discourage the use of LAT data in the time intervals T0+225 to T0+236 seconds and T0+257 to T0+265 seconds with respect to the GBM trigger time. The photon with 99 GeV observed 240 seconds after the GBM trigger is not affected by thesedata rate effects. The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@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 32761 table
GRB_name GRB221009A
GCN_number 32761
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32761 SUBJECT: GRB 221009A: ALMA and ACA detections DATE: 22/10/15 10:52:14 GMT FROM: Kuiyun Huang at CYCU Y. Urata, K.Y. Huang, S. Covino, K. Wiersema, K. Asada, H. Nagai,S. Takahashi, K. Yamaoka, M. Tashiro, K.Toma, J. Shimoda, A. Kuwata and J. Shimoda We observed the field of GRB 221009A (Dichiara GCN 32632) with ALMAand ACA at 97.5, 145, and 203 GHz. The afterglow is significantly detected at all bands, and the flux at 97.5 GHz was ~7 mJy at 4.3 days after the burst. Together with the SMA measurements at the similar epoch (Rhodes et al. GCN 32707), the spectrum seems to be flat around the mm/submm band. We thank ALMA staff for rapidly scheduling and supporting these observations.
GCN 32762 table
GRB_name GRB221009A
GCN_number 32762
Detection_method Konus-Wind Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32762 SUBJECT: GRB 221009A: Armchair Energetics DATE: 22/10/15 13:52:06 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (Goethe Univ.) and J. F. Agui Fernandez (IAA) report: The ultra-bright, nearby (de Ugarte Postigo et al., GCN #32648) GRB 221009A (Swift (afterglow) discovery: Dichiara et al., GCN #32632) was so intense, it saturated multiple sensitive satellite detectors that registered the prompt emission (Fermi GBM: Veres et al., GCN #32636, Lesage et al., GCN #32642; Konus-Wind: Frederiks et al., GCN #32668; Fermi LAT: Omodei et al. GCN #32760; Agile/MCAL: Ursi et al. GCN #32650; INTEGRAL SPI/ACS, Gotz et al., GCN #32660; Insight-HXMT, Tan et al., ATel #15660). Some missions detected GRB 221009A without saturation effects, because they are either smaller and less sensitive (GRBAlpha: Ripa et al., GCN #32685; SIRI-2: Mitchell et al., GCN #32746) or the burst was off-axis and passed through the spacecraft body (SRG ART-XC, Lapshov et al., GCN #32663). An especially interesting detection was made by HEBS (Liu et al., GCN #32751), which was also not saturated owing to its orbital position and environment. Konus-Wind determined the energetics and spectrum of the first ("onset") pulse of the main emission episode (unsaturated, preceding the two brightest pulses), from T_0+180 - 200 s, finding a fluence of 8.8E-04 erg cm^-2 (even this episode alone would be one of the brightest GRBs ever detected) and a peak energy of ~1 MeV. Using this spectrum and the raw, preliminarily corrected count rates of the other episodes, they determined a total fluence of 5.2E-02 erg cm^-2 (Frederiks et al., GCN #32668). We take the count-rate light curve linked in the Konus-Wind GCN and determine the counts of the "onset" pulse, thereby determining a "fluence per count" conversion. With this value, and assuming the third episode of the GRB (from 380 to 610 s) is unsaturated (or corrected successfully) and has the same spectrum, we find a fluence of 1.28E-02 erg cm^-2 for this episode. This is probably an overestimate, as the final episode of the GRB is likely softer (see the similar GRB 160625B, e.g., B.-B. Zhang et al. 2018, Nature Astronomy, 2, 69). For the HEBS data, we derive a significantly lower fluence of ~3E-03 erg cm^-2. A potential explanation is that the high background during the time of the GRB led to the softer bands being discarded, losing a lot of counts for the softer episode. For the main episode (200 - 300 s), we derive a fluence of 7.65E-02 erg cm^-2 from the HEBS light curve, a value somewhat higher than the one derived for the entire burst from Konus-Wind. Again, this is dependent on the spectrum being the same as during the "onset" pulse. If it is even harder, the fluence would increase correspondingly. Summing all together (the precursor is negligible), we derive, in a broad bolometric band from 0.1 keV to 100 MeV (see Agui Fernandez et al., 2021, MNRAS, submitted, arXiv:2109.13838), an isotropic energy release of log E_iso = 54.77, a value in perfect agreement with GRB 160625B in the same band. This places GRB 221009A within the very highest isotropic energy releases measured so far. On the one hand, this implies the GRB is extreme but not an outlier, whereas, on the other hand, combined with the very low distance, it makes it an even rarer event.
GCN 32763 table
GRB_name GRB221009A
GCN_number 32763
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32763 SUBJECT: GRB 221009A: ATCA detection DATE: 22/10/15 15:37:33 GMT FROM: Tanmoy Laskar at U of Bath S. Bhandari (ASTRON/JIVE), T. Laskar (Utah), K. D. Alexander (Arizona), E. Berger (Harvard), R. Chornock (Berkeley), D. Coppejans (Warwick), M. Drout (Toronto), H. van Eerten (Bath), W. Fong (Northwestern), C. Guidorzi (Ferrara), R. Margutti (Berkeley), C.G. Mundell (Bath), P. Schady (Bath) and G. Schroeder (Northwestern) report: "ATCA observed GRB 221009A (Dichiara et al. GCN 32632) beginning on 2022 October 15 05:00 UTC (5.7 d after the burst) at multiple frequencies. In a preliminary analysis, we detect the radio counterpart (Trushkin et al., ATEL 15671; Bright et al., GCN 32653; Farah et al., GCN 32655; de Ugarte Postigo et al., GCN 32676; Rhodes et al., GCN 32700; Rhodes et al., GCN 32707; Leung et al., GCN 32836; Laskar et al., GCN 32740; Laskar et al., GCN 32757; Urata et al., GCN 32761) with a flux density of ~ 6.8 mJy at 16.7 GHz at a position consistent with the optical position (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634) and the radio position (Laskar et al., GCN 32740, Laskar et al., GCN 32757). Further observations are planned. We thank the CSIRO staff for approving and carrying out these observations. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO. We acknowledge the Gomeroi people as the traditional owners of the Observatory site."
GCN 32765 table
GRB_name GRB221009A
GCN_number 32765
Detection_method Optical
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32765 SUBJECT: GRB 221009A: VLT spectroscopic detection of the host galaxy DATE: 22/10/15 16:56:06 GMT FROM: Daniele B Malesani at Radboud U L. Izzo (DARK/NBI), A. Saccardi (GEPI, Observatoire de Paris), J. P. U. Fynbo (DAWN/NBI), J. Palmerio (GEPI, Paris obs.), D. B. Malesani (Radboud Univ. and DAWN/NBI), J. F. Agui Fernandez (IAA/CSIC), D. A. Kann (Goethe Univ.), A. Melandri (INAF/OAR), S. D. Vergani (GEPI, Paris obs.), K. Wiersema (Lancaster univ.), report on behalf of the Stargate consortium: We observed the optical counterpart of GRB 221009A (Dichiara et al., GCN 32632; Veres et al., GCN 32636; and very many other GRB satellites) using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph. A 40-min spectrum was secured covering the wavelength range 3000-25000 AA, with a mean time 2022 October 14.02 UT (4.46 days after the Fermi/GBM trigger). From the acquisition image, we measure for the optical counterpart a magnitude i = 19.89 +- 0.05 (AB; calibrated against Pan-STARRS), 4.45 days after the Fermi/GBM trigger. The continuum is still dominated by the afterglow. However, narrow emission lines can be seen from the host galaxy. We identify H alpha in the optical and Pa alpha in the near-infrared, at redshift z = 0.151, consistent with the one measured from the afterglow absorption features (de Ugarte Postigo et al., GCN 32648). The H alpha FWHM is about 110 km s^-1. From the H alpha flux, corrected for Galactic extinction (A_V = 4.2 mag), we infer a SFR > 0.25 M_Sun yr^-1 (this value is a lower limit due to unaccounted host extinction and slit losses). We acknowledge expert support from the ESO observing staff in Paranal, in particular Zahed Wahhaj and Matias Jones.
GCN 32766 table
GRB_name GRB221009A
GCN_number 32766
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32766 SUBJECT: GRB 221009A: ATCA radio spectrum DATE: 22/10/15 23:15:43 GMT FROM: James Leung at U of Sydney/VAST James Leung (University of Sydney/CSIRO), Tara Murphy (University of Sydney), Emil Lenc (CSIRO), Gemma Anderson (Curtin) We report the radio spectrum for the Australia Compact Telescope Array (ATCA) observations (Bhandari et al., GCN 32763) taken on 2022 October 15 from 05:00 to 11:30 UTC (5.6 to 5.9d after the Swift/BAT trigger). ATCA observed at 16.7, 21.2, 33, 35, 45 and 47 GHz. In our preliminary analysis, we detect the radio counterpart at each frequency (Trushkin et al., ATel 15671; Bright et al., GCN 32653; Farah et al., GCN 32655; de Ugarte Postigo et al., GCN 32676; Rhodes et al., GCN 32700; Leung et al., GCN 32836; Laskar et al., GCN 32740; Laskar et al., GCN 32757; Urata et al., GCN 32761; Bhandari et al., GCN 32763) at a position consistent with the Swift/UVOT position (Dichiara et al., GCN 32632). The preliminary flux density measurements are reported below, with uncertainties being purely statistical: 7.1 +/- 0.1 mJy/beam at 16.7 GHz 6.1 +/- 0.1 mJy/beam at 21.2 GHz 4.8 +/- 0.1 mJy/beam at 33 GHz 4.4 +/- 0.1 mJy/beam at 35 GHz 3.6 +/- 0.2 mJy/beam at 45 GHz 3.5 +/- 0.2 mJy/beam at 47 GHz Ongoing observations are planned. We thank CSIRO staff for rapidly scheduling, supporting and executing these observations. The Australia Telescope Compact Array is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO. We acknowledge the Gomeroi people as the traditional owners of the Observatory site.
GCN 32767 table
GRB_name GRB221009A
GCN_number 32767
Detection_method Swift-BAT Det
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32767 SUBJECT: GRB 221009A: LEIA X-ray Afterglow Detection DATE: 22/10/16 02:21:05 GMT FROM: LEIA Team at NAOC/CAS Y. Liu, C. Zhang, Z.X. Ling, H.Q. Cheng, C.Z. Cui, D.W. Fan, H.B. Hu, M.H. Huang, C.C. Jin, D.Y. Li, H.Y. Liu, H. Sun, H.W. Pan, W.X. Wang, Y.F. Xu, M. Zhang, W.D. Zhang, D.H. Zhao, and W. Yuan (NAOC, CAS), report on behalf of the LEIA and Einstein Probe team: LEIA (Lobster Eye Imager for Astronomy) has performed one follow-up observation of GRB 221009A detected by Swift/BAT (Dichiara et al., GCN 32632, Kennea et al., GCN 32635), Fermi-GBM (Lesage et al., GCN 32642, Veres et al., GCN 32636), Fermi-LAT (Bissaldi et al. GCN 32637, Pillera et al., GCN 32658), AGILE-MCAL (Ursi et al., GCN 32650), AGILE-GRID (Piano et al. GCN 32657), INTEGRAL SPI/ACS (Gotz et al., GCN 32660), Konus-Wind (Frederiks et al., GCN 32668), HEBS (Liu et al., GCN 32751), at a redshift of z = 0.151 (de Ugarte Postigo et al., GCN 32648; Castro-Tirado et al., GCN 32686). The pointed observation was conducted from 2022-10-12T05:31:48 to 2022-10-12T05:51:39 with a net exposure of 1012 s. The X-ray afterglow of GRB 221009A is detected at a significance of 4.9 sigma. Assuming an absorbed power-law model with a photon index of 2.0, a Galactic absorption of 5.4 x 10^21 cm^-2 (Willingale et al. 2013; GCN #32651), and an intrinsic absorption of 1.1 x 10^22 cm^-2 at a redshift of 0.151 (GCN #32648), the unabsorbed flux in the 0.5 - 4.0 keV band is (1.8+/-0.4) x 10^-10 ergs/cm^2/s. LEIA (Zhang et al, ApJL submitted) is a soft X-ray monitor (0.5 - 4.0 keV) with a FoV of 340 square degrees aboard the SATech-01 satellite of the CAS, launched on July 27, 2022. The above result is preliminary and the final result will be published elsewhere.
GCN 32769 table
GRB_name GRB221009A
GCN_number 32769
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32769 SUBJECT: GRB 221009A: continued Assy optical afterglow observations, possible SN evidence DATE: 22/10/16 15:33:29 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI, HSE), V. Kim (FAI), A. Pozanenko (IKI), M. Krugov (FAI), Y. Aimuratov (FAI), N. Pankov (HSE) report on behalf of GRB IKI FuN: We continue observations of GRB 221009A (Swift J1913.1+1946) (Dichiara et al., GCN 32632; Kennea and Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32636; Svinkin et al., GCN 32641; Piano et al., GCN 32657; Pillera et al., GCN 32658; Gotz et al., GCN 32660; Frederiks et al., GCN 32668) with AZT-20 telescope of Assy-Turgen observatory. The observations were carried out on 2022-10-11 -- 2022-10-15. The optical afterglow ( GCNs 32632, 32635, 32636, 32641, 32657, 32658, 32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679, 32680, 32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695, 32700, 32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739, 32740, 32743, 32746, 32749, 32750; 32752; 32753; 32755; 32758; 32765). Preliminary photometry of the afterglow on 2022-10-15 is following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2022-10-15 15:29:43 6,10259 30*60 g' 22.60 0.12 23.4 2022-10-15 14:25:00 6,05765 30*60 r' 20.96 0.05 22.9 2022-10-15 14:56:19 6,07939 30*60 i' 20.00 0.04 23.2 2022-10-15 16:01:07 6,11918 15*60 z' 19.31 0.08 21.0 The photometry is based on the nearby PS1 stars. The light curve based in our photometry can be found in http://grb.rssi.ru/GRB221009A/GRB221009A_lc_cc_7_cut.png The power law (PL) fit parameters are also shown in the figure and do not include photometry on 2022-10-15. It can be seen that the color change g-i and photometry g, r on October 15, 2022 deviate significantly from the PL approximation. We hypothesize that this behaviour may indicate a supernova rise.
GCN 32771 table
GRB_name GRB221009A
GCN_number 32771
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32771 SUBJECT: GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up DATE: 22/10/16 21:35:11 GMT FROM: Manisha Shrestha at University of Arizona M. Shrestha (Univ. of Arizona), K. Bostroem (Univ. of Arizona), D. Sand (Univ. of Arizona), K. D. Alexander (Univ. of Arizona), J. Andrews (Gemini), J. Pearson (Univ. of Arizona), G. Hosseinzadeh (Univ. of Arizona), N. Smith (Univ. of Arizona), D. A. Howell (LCO/UCSB), C. McCully (LCO/UCSB), M. Newsome (LCO/UCSB), E Padilla Gonzalez (LCO/UCSB), C. Pellegrino (LCO/UCSB), G. Terreran (LCO/UCSB), J. Farah (LCO/UCSB) report on behalf of a wider Global Supernova Project collaboration: We observed the field of Swift GRB 221009A (Dichiara et al. GCN 32632 ) with Faulkes Telescope North, on 2022 October 15 starting at 6:34:12.198 UT (~5.7 days after the trigger) using the MuSCAT3 imager in the r, i, and z bands. Data were calibrated with respect to nearby PanSTARRS sources for r, i, and z bands . We clearly detect the optical counterpart in the r, i and z bands and obtain an upper limit on the g band. The magnitudes are as follows: r = 21.13 +- 0.06 i = 20.01 +- 0.05 z = 19.39 +- 0.05 These values are not corrected for galactic extinction and are consistent with the magnitudes reported in Belkin et al. GCN 32769 observed in a similar time frame.
GCN 32780 table
GRB_name GRB221009A
GCN_number 32780
Detection_method Optical
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32780 SUBJECT: GRB 221009A: A type I BdHN of exceptional energetics DATE: 22/10/17 11:16:22 GMT FROM: Remo Rufinni at ICRA Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report: GRB221009A detected by Swift (Kennea et al. 2022 GCN32635), Fermi-GBM (Veres et al. 2022, GCN32636, Lesage et al. 2022, GCN32642), Fermi-LAT (Bissaldi et al. 2022, GCN32637), with redshift of z=0.151 and an isotropic equivalent energy of Eiso=2x10^54 erg (de Ugarte Postigo et al. 2022, GCN32648 and GCN32642) is a typical Binary driven Hypernova of type I (BdHNI), originating from the collapse of a carbon-oxygen core (CO-core) in presence of a companion neutron star (NS) with common feature with three BdHNeI: GRB130427A with "pile up" in the prompt phase (Ruffini et al. 2013, GCN14526); GRB190114C (Ruffini et al. 2019, GCN23715); and GRB180720B (Ruffini et al. 2018, GCN23019). As the above three sources, GRB221009A presents: 1) the optical (Lipunov et al. 2022, GCN32634 and GCN32639; Perley. 2022 GCN32638; Broens. 2022, GCN32640; Hu et al. 2022, GCN32644; Mondy: Belkin et al. 2022, GCN32645; de Wet et al.2022, GCN32646; Xu et al. 2022 GCN32647; Odeh 2022, GCN32649; Brivio et al. 2022, GCN32652; Izzo et al. 2022, GCN32765), radio (Bright et al. 2022, GCN32653 and Farah et al. 2022, GCN32655) and X-ray (Kennea et al, 2022, GCN32635, and GCN32651) synchrotron afterglow emissions as well as the TeV emission (Yong Huang et al. 2022, GCN32677), which in BdHNI originate from accreting millisecond spinning newborn NS (Rueda et al. 2022, e-Print: 2204.00579 [astro-ph.HE]); 2) the ultra-relativistic prompt emission (UPE) phase (Moradi et al. 2021, PRD 104, 063043 and Rastegarnia et al. 2022, EPJC 82, 778) and GeV emission (Rueda et al 2022 ApJ 929 56) originated from the black hole formed by hypercritical accretion of the supernova ejecta on the NS companion; and 3) the optical emission of the nickel decay of the supernova (SN), created by the collapse of the CO-core. The first evidence of the supernova rise is reported by S. Belkin et al. 2022, (GCN32769). In this GRB the bolometric optical peak of SN is expected to be observed at 15.57+/-2.0 days after the Fermi-GBM trigger (October 24th 2022, uncertainty from October 22nd 2022 to October 26th 2022, with the bolometric optical luminosity of L=(9.45+/-2.8)x10^42 erg/s; Aimuratov et al. in preparation).
GCN 32788 table
GRB_name GRB221009A
GCN_number 32788
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32788 SUBJECT: GRB 221009A: Second epoch of NuSTAR data DATE: 22/10/18 03:28:57 GMT FROM: Daniel Brethauer at UC Berkeley Daniel Brethauer (UC Berkeley), Raffaella Margutti (UC Berkeley), Judith Racusin (NASA/GSFC), Brian Grefenstette (Caltech), Kate D. Alexander (Arizona), Tom Barclay (NASA/GSFC), Edo Berger (Harvard), Eric Burns (LSU), Brad Cenko (NASA/GSFC), Yvette Cendes (Harvard), Ryan Chornock (UC Berkeley), Tarraneh Eftekhari (Northwestern), Jamie Kennea (PSU), Tanmoy Laskar (Utah) A second epoch of NuSTAR observations of GRB221009A was obtained on October 15, 2022 starting at 05:21:09 UTC (~5.6 days since trigger; Dichiara et al., GCN 32632; Veres et al., GCN 32636) with an exposure time of 25 ks (PIs Racusin and Margutti). The 3-79 keV spectrum is well fit by a power law with a photon index of Gamma = 1.91 +/- 0.02 (1 sigma c.l.), which suggests spectrally softer emission than observed during the first NuSTAR epoch (Brethauer et al., GCN 32695). The inferred NuSTAR power-law index is consistent with the value inferred from contemporaneous Swift-XRT observations, which indicate Gamma= 1.79 +/- 0.11 and a best-fitting intrinsic absorption NHint=(0.46 +/- 0.10)e22 cm-2 at z=0.151 for an assumed Galactic neutral hydrogen column density NH_mw=0.563e22 cm-2 (Willingale et al., 2013). The corresponding unabsorbed flux is ~4.5e-11 ergs/cm^2/s (3-79 keV), indicating a factor ~10 fading with respect to the previous epoch of NuSTAR data (Brethauer et al., GCN 32695). Additional epochs of NuSTAR monitoring are planned on October 20th, and November 2nd. We thank the entire NuSTAR SOC for promptly implementing these observations.
GCN 32791 table
GRB_name GRB221009A
GCN_number 32791
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32791 SUBJECT: GRB 221009A: Medicina Radio Telescope observations DATE: 22/10/18 14:16:50 GMT FROM: Marco Marongiu at Ferrara U M. Marongiu, E. Egron, A. Pellizzoni (INAF/OAC), S. Righini (INAF/IRA), C. Guidorzi (UniFe), and S. Mulas (UniCa), report: We observed GRB 221009A (Dichiara et al. GCN 32632) with the Medicina Radio Telescope (www.radiotelescopes.inaf.it) through single-dish imaging in X-band (central frequency 8.2 GHz, bandwidth 0.3 GHz) in two time intervals: (1) 13:30-19:30 UTC on October 14, 2022 (4.97-5.22 days after the burst), and (2) 11:30-19:30 UTC on October 17, 2022 (7.89-8.22 days after the burst). In our analysis, at 5.1 days (after the burst) we detected a faint radio emission at 8.2 GHz with a flux density of 26 +- 5 mJy at a position consistent with the optical position (Dichiara et al., GCN 32632) and the radio position (Laskar et al., GCN 32740, Laskar et al., GCN 32757). We did not detect any significant signal with a 2-sigma upper limit of 20 mJy at 8.1 days. We acknowledge the scheduler and the staff of the Medicina Radio Telescope for approving and executing these observations.
GCN 32793 table
GRB_name GRB221009A
GCN_number 32793
Detection_method INTEGRAL
redshift 0.1510
Circular_text TITLE: GCN CIRCULAR NUMBER: 32793 SUBJECT: The probability of observing GRB 221009A at z = 0.151 DATE: 22/10/18 14:47:32 GMT FROM: Jean-Luc Atteia at IRAP The prompt emission of the extraordinarily bright GRB 221009A was detected in space by Swift (Dichiara et al. GCNC 32632, Krimm et al. 32688), Fermi (Veres et al. GCNC 32636, Bissaldi et al. GCNC 32637, Lesage et al. GCNC 32642, Pillera et al. GCNC 32658, Omodei et al. GCNC 32760), AGILE (Ursi et al. GCNC 32650, Piano et al. GCNC 32657), INTEGRAL (Gotz et al. GCNC 32660), Solar Orbiter (Xiao et al. GCNC 32661), SRG (Lapshov et al. GCNC 32663), Konus (Frederiks et al. GCNC 32668), GRBAlpha (Ripa et al. GCNC 32685), STPSat-6 (Mitchell et al. GCNC 32746), HEBS (Liu et al. GCNC 32751). Various estimates of its prompt isotropic energy ranks it among the most energetic GRBs (Cenko et al. 2011, Atteia et al. 2017): Gotz et al. GCNC 32660 - Eiso = 8e53 ergs in [75 keV 1 MeV] ; Frederiks et al. GCNC 32668 - Eiso = 3e54 ergs in [20 keV - 10 MeV ?] ; Kann et al. GCNC 32762 - Eiso = 6e54 ergs in [0.1 keV - 100 MeV] ; We discuss here the chance to observe such an energetic GRB at redshift z = 0.151 (de Ugarte Postigo GCNC 32648, Castro-Tirado et al. GCNC 32686), considering the rate of such extremely energetic GRBs observed at higher redshifts. Considering a flat cosmology with H0 = 67.4 km/s/Mpc and Omegam = 0.315 (Planck Collaboration et al. 2020), we extrapolate the rate of ≈4 extremely energetic GRBs per year derived by Atteia et al. (2017) in the redshift range [1,5], to the volume of the nearby universe enclosed within z = 0.151. - Assuming a constant GRB formation rate, we obtain 1 extremely energetic GRB per ~130 yr. - Assuming the GRB formation rate of Palmerio & Daigne (2021), we obtain 1 extremely energetic GRB per ~520 yr. We conclude that there is a ~10% probability to observe an event like GRB 221009A about 50 years after the discovery of the first GRB. Bibliography : - Cenko, S. B., Frail, D. A., Harrison, F. A., et al. 2011, ApJ, 732, 29 - Atteia, J.-L., Heussaff, V., Dezalay, J.-P., et al. 2017, ApJ, 837, 119 - Palmerio, J.T. & Daigne, F. 2021, A&A, 649, 166 - Planck Collaboration, Aghanim, N., Akrami, Y., et al. 2020, A&A, 641, A6
GCN 32795 table
GRB_name GRB221009A
GCN_number 32795
Detection_method Swift Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32795 SUBJECT: GRB 221009A: GRANDMA observations DATE: 22/10/18 15:32:46 GMT FROM: Sarah Antier at OCA Y. Rajabov, T. Sadibekova (UBAI), Y. Tillayev (UBAI, NUUz), C. Rinner, Z. Benkhaldoun (OUCA), X. F. Wang (THU/BJP), J. Zhu (BJP), X. Y. Zeng (CGTU), L. T. Wang, A. Iskandar (XAO), A. M. Fouad, A. Takey A. Shokry, M. Soliman (NRIAG), P. Hello, T. Hussenot (IJCLAB), M. Boer, A. de Ugarte Postigo, S. Antier (OCA/Artemis) D. A. Kann (Goethe Univ.), E. Burns (LSU), A. Simon, A. Baransky (Kyiv Univ), L. Abe, Ph. Bendjoya, J.-P. Rivet (Lagrange-OCA), D. Vernet (Galilee-OCA), S. Brunier (KNC), R. Inasaridze, R. Natsvlishvili, N. Kochiashvili (AbAO), S.Beradze, V. Aivazyan, G. Kapanadze, O.Burkhonov, J. G. Ducoin (IAP), S.Ehgamberdiev (UBAI, NUUz), A. Klotz (OMP/IRAP), I. Tosta e Melo (INFN-LNS) report on behalf of GRANDMA collaboration: The GRANDMA telescope network responded to the alert of the ultra-bright GRB 221009A (Swift detection: Dichiara et al., GCN 32632; Fermi GBM detection: Veres et al., GCN 32636). The first observations started 2.30 h after the Fermi/GBM trigger time with TAROT-TRE without filter. Below, we report select observations. We also report our 5-sigma upper limits. Magnitudes are given in the AB system. T-T0 (day)| MJD | Obser. |Exposure| Filter | Mag +/- err |Upp.Lim. (AB) ___________________________________________________________________________ 1.069 |59862.622720|UBAI-ST| 6x180s |R-Bessel| 18.3 +/- 0.1 | 19.2 1.136 |59862.689664| KAO | 11x100s| sdssr | 18.57 +/- 0.05| 20.5 1.134 |59862.687523| KAO | 2x120s | sdssg | 20.43 +/- 0.2 | 19.8 1.154 |59862.707801| KAO | 9x80s | sdssi | 17.56 +/- 0.05| 20.3 1.166 |59862.719039| KAO | 2x120s | sdssz | 16.93 +/- 0.05| 19.7 1.223 |59862.776151|Lisnyky| 10x30s |R-Bessel| 18.15 +/- 0.1 | 19.6 1.258 |59862.811817| MOSS | 20x60s | clear | 18.5 +/- 0.1 | 20.3 1.301 |59862.854179|C2PU-O | 2x300s | sdssr | 18.96 +/- 0.1 | 20 3.027 |59864.580925| SNOVA | 10x150s| clear | - | 19.7 3.047 |59864.600648|UBAI-ST| 5x240s |R-Bessel| 19.85 +/- 0.1| 19.3 4.191 |59865.743981| KAO | 21x110s| sdssz | 18.8 +/- 0.1| 19.7 These detections and limits are consistent with the detections and limits previously reported in Lipunov et al., GCN 32634; Perley, GCN 32638; Broens, GCN 32640; Hu et al., GCN 32644; Belkin et al., GCN 32645; GCN 32769 ; Wet et al., GCN 32646; Xu et al., GCN 32647; de Ugarte Postigo et al., GCN 32648; Odeh, GCN 32649; GCN 32666; Brivio et al., GCN 32652; Kuin et al., GCN 32656; Paek et al., GCN 32659; Kumar et al., GCN 32662; Romanov, GCN 32664; 32679; Chen et al., GCN 32667; Vidal et al., GCN 32669; Kim et al., GCN 32670; Groot et al., GCN 32678; Castro-Tirado et al., GCN 32686; Watson et al., GCN 32692; Strausbaugh et al. GCN 32693; Butler et al., GCN 32705; Vinko et al., GCN 32709; Mao et al., GCN 32727; Zaznobin et al., GCN 32729; Sasada et al., GCN 32730; Strausbaugh & Cucchiara, GCN 32738; O'Connor et al., GCN 32739; GCN 32750; Bikmaev et al., GCN 32743; GCN 32752; Rastinejad & Fong, GCN 32749; Schneider et al., GCN 32753; D’Avanzo et al., GCN 32755; Huber et al., GCN 32758; Shrestha et al., GCN 32759; 32771; Izzo et al., GCN 32765. The observations were contaminated by the nearly full Moon. Further analysis are ongoing in GRANDMA especially on TAROT, ShAO-T60, AbAO-T70 and C2PU-O. The KAO, UBAI-ST have been calibrated using nearby stars from the Pan-STARRS catalog in sdss r, g, i and z, measured with STDpipe (Karpov 2022). Lisnyky-AZT has been calibrated using field stars from the PanSTARRS-DR1 catalog, measured with the MUPHOTEN pipeline (Duverne et al. 2022). MOSS and SNOVA data have been calibrated with Gaia DR2. We advocate a joint multi-wavelength publication for this event and we are happy to collaborate with teams that have the same spirit, to be able to explore the best astrophysical scenario. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).
GCN 32799 table
GRB_name GRB221009A
GCN_number 32799
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32799 SUBJECT: GRB 221009A: Continued LDT Afterglow Monitoring DATE: 22/10/19 03:59:58 GMT FROM: Brendan O'Connor at UMD B. O'Connor (UMD/GWU), S. B. Cenko (NASA/GSFC), E. Troja (UTV/ASU), S. Dichiara (PSU), A. Kutyrev (NASA/GSFC), S. Veilleux (UMD), J. Durbak (UMD), on behalf of a larger collaboration: We performed target of opportunity observations of GRB 221009A (Dichiara et al., GCN 32632, Veres et al., GCN 32636) with the 4.3m Lowell Discovery Telescope (LDT) in Happy Jack, AZ. Observations began on October 13, 2022 at 02:05:29 UT corresponding to ~9.5 d after the GRB. We obtained images in the riz filters at an airmass ~1.1 with seeing ~1.7". The afterglow is clearly detected in each filter. We obtain the following magnitudes calibrated against the PS1 catalog: r = 21.68 +/- 0.07 AB mag i = 20.72 +/- 0.05 AB mag These magnitudes are not corrected for Galactic extinction. We thank the staff of the Lowell Observatory for assistance with these observations.
GCN 32800 table
GRB_name GRB221009A
GCN_number 32800
Detection_method Swift Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32800 SUBJECT: GRB 221009A: Spectroscopic detection of emerging SN features DATE: 22/10/19 11:23:30 GMT FROM: Antonio de Ugarte Postigo at OCA A. de Ugarte Postigo (OCA), L. Izzo (DARK/NBI), C. C. Thoene (ASU-CAS), J. P. U. Fynbo (DAWN/NBI), D. A. Kann (Goethe Univ.), J. F. Agui Fernandez (IAA-CSIC), N. R. Tanvir (Leicester Univ.) report: We have been spectroscopically monitoring the evolution of the extremely bright GRB 221009A (Swift detection: Dichiara et al., GCN 32632; Fermi GBM detection: Veres et al., GCN 32636) using OSIRIS at the 10.4m GTC telescope. In a spectrum combining data taken on 16 and 17 October (at an average time of ~8 days after the burst), covering the spectral range between 3700 and 10000 AA, the emission is still clearly dominated by the afterglow. However, after subtracting a model of the continuum, the spectrum shows undulations characteristic of a GRB-SN. In particular we identify broad features at similar wavelengths (after correcting for the redshift difference) as those present in SN 1998bw, with somewhat larger velocities. This is indicative of the emergence of the associated supernova. Further follow-up observations are planned.
GCN 32802 table
GRB_name GRB221009A
GCN_number 32802
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32802 SUBJECT: GRB 221009A X-ray light-curve and the indication of TeV light-curve DATE: 22/10/19 15:28:45 GMT FROM: Remo Rufinni at ICRA Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report: LHAASO observed more than 5000 very high energy (VHE) photons in GRB 221009A, with the highest energy reaching 18 TeV (GCN 32677). Previously, high energy TeV emissions were also observed in GRB 180720B (Abdalla et al. 2019), 190114C (MAGIC Collaboration 2019), 190829A (H.E.S.S. Collaboration 2021) and 201216C (Blanch et al. GCN 29075). A common feature of these bursts is that the TeV light-curve follows a power-law decay with a similar index as the X-ray light-curve, and the TeV luminosity is tens of percent of the X-ray luminosity (see attached figure 1 and the references of Abdalla et al. 2019, MAGIC Collaboration 2019 and H.E.S.S. Collaboration 2021, Ruffini et al. 2021, Rueda et al. 2022, Rastegarnia et al. 2022, Wang et al. 2022). Here we present the X-ray light-curve of GRB 221009A observed by Swift-XRT (GCN 32651), and the t0 is taken from the Fermi-GBM trigger time (GCN 32636), see attached figure 2, a power-law of index -1.58 is fitted. The shadow region shows 20%-60% of the X-ray luminosity, which is expected to be the 0.3-1 TeV luminosity (17% less luminous for 0.5-18 TeV assuming a power-law spectrum of photon index -2) of this new burst if it shares the same behavior as the previous ones. We encourage further observations, especially the VHE observations, because this burst probably is more luminous than the previous ones, and it will be precious to have a late time (after days) VHE luminosity which was never achieved before, as well as the optical observations for the supernova appearance (GCN 32670, GCN 32780). Figure 1: http://www.icranet.org/docs/fig1.png Figure 2: http://www.icranet.org/docs/fig2.png http://www.icranet.org http://www.icranet.org
GCN 32803 table
GRB_name GRB221009A
GCN_number 32803
Detection_method Swift Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32803 SUBJECT: GRB 221009A: BOAO NIR detections DATE: 22/10/19 15:52:11 GMT FROM: Myungshin Im at Seoul Nat U Myungshin Im, Gregory S.-H. Paek, Gu Lim, Hyeonho Choi, Sophia Kim (SNU), Hyun-Il Sung (KASI), Yuji Urata (NCU) on behalf of a larger collaboration We observed the field of GRB 221009A (Swift detection: Dichiara et al., GCN 32632; Fermi GBM detection: Veres et al., GCN 32636), in J and K filters with the KASINICS instrument on the 1.8 m telescope of the Bohyunsan Optical Astronomy Observatory (BOAO), Korea. The observation started at 2022-10-18-11:34 (UT) or JD=2459870.98230324, taking a series of images for about 1.25 hrs. We identify the afterglow in the KASINICS images, with a rough photometry of K ~ 18.6 AB mag. Further observations and analysis are being carried out to obtain more data and refine the photometry. We thank the staff of BOAO for carrying out the observation.
GCN 32804 table
GRB_name GRB221009A
GCN_number 32804
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32804 SUBJECT: GRB 221009A: TNG NIR detection DATE: 22/10/19 16:28:04 GMT FROM: Paolo D'Avanzo at INAF-OAB M. Ferro, R. Brivio, P. D’Avanzo (INAF-OAB), S. Piranomonte (INAF-OAR), V. Lorenzi, G. Mainella (INAF-TNG), on behalf of the CIBO collaboration report: We observed the field of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) with the Italian 3.6m TNG telescope equipped with the near-infrared camera NICS. A series of images were obtained with the J, H and K filters on 2022-01-16 at a mid time of about 7.3 days after the GBM trigger time. The NIR afterglow (Brivio et al., GCN Circ. 32652) is clearly detected in all bands. From preliminary photometry we derive the following magnitude: H = 16.45 +/- 0.04 (Vega; calibrated against the 2MASS catalogue). We acknowledge the TNG visiting astronomers B. Lakeland and B. Nicholson for their support.
GCN 32805 table
GRB_name GRB221009A
GCN_number 32805
Detection_method IPN Triangulation
ra 287.7610°
decl 20.6700°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32805 SUBJECT: Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve) DATE: 22/10/19 16:43:28 GMT FROM: Dmitry Svinkin at Ioffe Institute A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin on behalf of the MGNS/BepiColombo team, J. Benkhoff on behalf of the BepiColombo team, D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, A. Goldstein, M. S. Briggs, C. Wilson-Hodge, and E. Burns on behalf of the Fermi GBM team, E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu on behalf of the Swift-BAT team, report: The extremely bright, long-duration GRB 221009A (GCNs 32632, 32635, 32636, 32637, 32641, 32642, 32650, 32657, 32658, 32668, 32685, 32751; ATels 15650, 15656, 15660) was detected by the MGNS/BepiColombo interplanetary gamma-ray detector. The burst light curves in the energy range 280-460 keV exhibit a multi-peaked pulse structure with a total duration of ~6.6 min. The source of GRB 221009A was obscured for MGNS by spacecraft structure that have limited transparency in the specified above energy range. The link below provides a plot of the time profile of the gamma-ray count rate. The GRB221009A.TXT file, also available at this link, contains light curve data in three columns: time in UTC, accumulated count and accumulation time. http://l503.iki.rssi.ru/owncloud/index.php/s/HZtqdQ1b9QW3ojv Using the BepiColombo (MGNS) data we have triangulated GRB 221009A to the 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 287.761 (19h 11m 03s) +20.670 (+20d 40' 11") Corners: 283.599 (18h 54m 24s) +27.415 (+27d 24' 54") 283.634 (18h 54m 32s) +28.133 (+28d 08' 00") 291.780 (19h 27m 07s) +12.770 (+12d 46' 14") 291.767 (19h 27m 04s) +11.822 (+11d 49' 20") --------------------------------------------- The error box area is 6.63 sq. deg, and its maximum dimension is 18 deg (the minimum one is 23 arcmin). The Sun distance was 92 deg. This box may be further improved. The Swift-XRT source (GCN 32632) is inside the box. The distance between the source and the Konus-MGNS annulus center line is 1.7 arcmin. An updated triangulation map and HEALPix FITS file are posted at http://www.ioffe.ru/LEA/GRBs/GRB221009_T47819/IPN/
GCN 32808 table
GRB_name GRB221009A
GCN_number 32808
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32808 SUBJECT: GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow DATE: 22/10/20 14:57:47 GMT FROM: Remo Rufinni at ICRA Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report: GRB 221009A appears to be a rare example (Jean-Luc Atteia et al. 2022, GCN 32793) of a particularly energetic and close GRB (de Ugarte Postigo et al. 2022, GCN 32648 and Lesage et al. 2022, GCN 32642 and N.P.M. Kuin et al. 2022, GCN 32656). Within the BdHN model, we have followed the X-ray, optical, and radio afterglows originating from synchrotron emission powered by fast spinning newborn neutron stars (vNS) with initial periods of fraction of a millisecond, accreting the supernova ejecta, created by the collapse of a carbon-oxygen core (Rueda et al. 2022, arXiv:2204.00579). Figures 1, 2 and 3 show the afterglows of three type I BdHNe, namely GRB 180720B (Ruffini et al. 2018, GCN 23019), GRB 190114C (Ruffini et al. 2019, GCN 23715), and GRB 211023A (Aimuratov et al. 2021, GCN 31056), and the prediction of their associated supernova. We have indicated the expected time of the occurrence of the supernova in GRB 221009A (Aimuratov et al. 2022, GCN 32780). The ongoing observations in optical, radio, and X-ray bands are strongly recommended for allowing the determination of the spin and magnetic field of the vNS. This will probe as well if the optical synchrotron emission, at ~ 10^6 s from the Fermi-GBM trigger, impedes the observations of the optical emission of the supernova originating from nickel decay (Aimuratov et al. in preparation, see also data from Ilfan Bikmaev et al. 2022, GCN 32752, and Jia. Ren et al. 2022, arXiv:2210.10673, reproduced in Fig. 4). Fig1: http://www.icranet.org/docs/Fig1.pdf Fig2: http://www.icranet.org/docs/Fig2.pdf Fig3: http://www.icranet.org/docs/Fig3.pdf Fig4: http://www.icranet.org/docs/Fig4.pdf
GCN 32809 table
GRB_name GRB221009A
GCN_number 32809
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32809 SUBJECT: GRB221009A: LBT optical imaging DATE: 22/10/20 15:24:03 GMT FROM: Andrea Rossi at INAF A. Rossi, E. Maiorano (INAF-OAS), D. B. Malesani (Radboud Univ. and DAWN/NBI)on behalf of the CIBO collaboration, F. Cusano (INAF-OAS), and D. Paris (INAF-OA Roma), report: We observed the field of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN Circ. 32650) simultaneously in the blue and red arms with the g'+r' and g'+i' bands with the MODS instrument mounted on LBT (Mt Graham, AZ, USA). We observed for 22 min per arm at the midtime 03:11 UT on 2022-10-18, 8.58 days after the burst trigger. Observations were performed under modest weather conditions with an average seeing of ~1" but high humidity and passing cirrus. We clearly detect the afterglow and we preliminary measure r=21.63+-0.02 (AB system), calibrated against Pan-STARRS field stars. We acknowledge the excellent support from the LBTO and LBT-INAF staff, particularly A. Becker and D. G. Huerta in obtaining these observations.
GCN 32811 table
GRB_name GRB221009A
GCN_number 32811
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32811 SUBJECT: GRB 221009A: 1.3m DFOT Optical Observations DATE: 22/10/21 07:11:24 GMT FROM: Rahul Gupta at ARIES, India Rahul Gupta, Amit Kumar Ror, S. B. Pandey, A. Aryan, A. Ghosh, Dimple, and K. Misra (ARIES) report as a part of a larger international collaboration: We performed target of opportunity observations of the extremely bright GRB 221009A (Dichiara et al., GCN 32632; Kennea and Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637; Svinkin et al., GCN 32641; Ursi et al., GCN 32650; Piano et al., GCN 32657; Pillera et al., GCN 32658; Gotz et al., GCN 32660; Xiao et al., GCN 32661; Frederiks et al., GCN 32668; Ripa et al., GCN 32685) using the 2Kx2K CCD Imager mounted at the 1.3m Devasthal Fast Optical Telescope (DFOT) located at the Devasthal observatory of Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2022-10-16 at 14:41:41 UT, i.e., ~ 7.06 days after the detection. We have taken multiple frames in the R filter at different epochs. We clearly detected the optical afterglow of GRB 221009A (GCNs 32632, 32635, 32636, 32641, 32657, 32658, 32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679, 32680, 32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695, 32700, 32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739, 32740, 32743, 32746, 32749, 32750; 32752; 32753; 32755; 32758; 32765; 32769; 32771; 32795; 32799; 32800; 32803; 32804; 32809) in our stacked image. The preliminary photometric estimate of the afterglow is the following : Date Start UT T-T0 (mid, days) Filter Exp time (sec) Magnitude ========================================================= 2022-10-16 14:41:41 ~7.09 R 200*25 21.30 +/- 0.04 Further follow-up observations are planned. The magnitude is not corrected for the Galactic extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalog. This circular may be cited.
GCN 32818 table
GRB_name GRB221009A
GCN_number 32818
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32818 SUBJECT: GRB 221009A: optical observations, SN photometric evidence DATE: 22/10/22 22:47:16 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI, HSE), A. Moskvitin (SAO RAS), V. Kim (FAI), A. Pozanenko (IKI), M. Krugov (FAI), R. Uklein (SAO RAS), N. Pankov (HSE) report on behalf of GRB IKI FuN: We continue observations of GRB 221009A (Swift J1913.1+1946) (Dichiara et al., GCN 32632; Kennea and Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32636; Svinkin et al., GCN 32641; Piano et al., GCN 32657; Pillera et al., GCN 32658; Gotz et al., GCN 32660; Xiao et al., GCN 32661; Frederiks et al., GCN 32668; GCN 32668; Ripa et al., GCN 32685; Kozyrev et al., GCN 32805). Observations with AZT-20 telescope of Assy-Turgen observatory obtained on October 20, 21 and TOO photometry with BTA SAO RAS telescope equipped with SCORPIO-2 was obtained on October 16 and 18. The optical afterglow (GCNs 32632, 32635, 32636, 32641, 32657, 32658, 32660, 32666, 32668, 32670, 32671, 32676, 32677, 32678, 32679, 32680, 32683, 32684, 32685, 32686, 32691, 32692, 32693, 32694, 32695, 32700, 32705, 32707, 32709, 32727, 32729, 32730, 32736, 32738, 32739, 32740, 32743, 32746, 32749, 32750; 32752; 32753; 32755; 32758; 32765; 32769; 32771; 32795; 32799; 32803; 32804; 32809; 32811) is detected in combined images of g',r',i' filters. Preliminary photometry of the afterglow on 2022-10-20/21 obtained in Assy observatory with AZT-20 telescope is following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) (AB) 2022-10-20/21 n/d 11.55024 59*60 g' 23.7 0.2 24.5 2022-10-21 14:18:18 12.05299 30*60 r' 21.94 0.07 23.9 2022-10-21 14:49:37 12.08516 30*60 i' 20.72 0.11 23.3 The photometry is based on nearby PS1 stars. The light curve based on our observations can be found in http://grb.rssi.ru/GRB221009A/GRB221009A_lc_cc_15_cut.png We observe a bump in the light curve starting on 6th days since trigger. The light curve is clearly chromatic at the bump. We can assume that the chromatic bump is a supernova over an afterglow of GRB 221009A (Belkin et al., GCN 32769).
GCN 32819 table
GRB_name GRB221009A
GCN_number 32819
Detection_method INTEGRAL
Circular_text TITLE: GCN CIRCULAR NUMBER: 32819 SUBJECT: GRB 221009A: Analysis of the initial episode using data of GBM/Fermi and SPI-ACS/INTEGRAL DATE: 22/10/22 23:05:12 GMT FROM: Alexei Pozanenko at IKI, Moscow P. Minaev (IKI), A. Pozanenko (IKI), I. Chelovekov (IKI) report on behalf of GRB IKI FuN: We analyze the first episode of GRB 221009A (Dichiara et al., GCN 32632; Kennea and Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32636; Svinkin et al., GCN 32641; Piano et al., GCN 32657; Pillera et al., GCN 32658; Gotz et al., GCN 32660; Xiao et al., GCN 32661; Frederiks et al., GCN 32668; GCN 32668; Ripa et al., GCN 32685; Kozyrev et al., GCN 32805) not affected by dead time and pile-up instrumental effects, using publicly available data of GBM/Fermi and SPI-ACS/INTEGRAL. We investigate energy spectrum of the time interval (T0-1, T0+55) s, where T0 = 13:16:59 UTC 2022-10-09 is a time of GBM/Fermi trigger. The spectrum can be fitted by a simple power law model with the spectral index of gamma = -1.68 +/- 0.01. See the spectrum in http://grb.rssi.ru/GRB221009A/GRB221009A_1st_episode.png It is in a contradiction with CPL (power law with exponential cutoff) spectral model for the episode, obtained by Lesage et al., GCN 32642 using GBM/Fermi data (Epeak = 375 +/- 87 keV) and by Frederiks et al., GCN 32668 using Konus/WIND data (Epeak = 975 (-332, +712) keV). The value of spectral index is not typical for indexes before the break (in CPL or Band model), but it is a rather typical for the index after the break in Band model. We hypothesize the actual break to be placed at low energies (Epeak < 20 keV). The hypothesis could be supported by placing Eiso parameter into Amati correlation diagram. The Eiso = (3.2 +/- 0.1)E51 erg is calculated within our power law model with gamma = -1.68 and using redshift value of z = 0.151 (de Ugarte Postigo et al., GCN 32648; Castro-Tirado et al., GCN 32686). The Eiso value corresponds to 2 sigma range of possible Epeak value of (20, 315) keV for type II (long) GRBs (Minaev et al., MNRAS, 492, 2, 1919, 2020). See the correlation diagram in http://grb.rssi.ru/GRB221009A/GRB221009_Amati_1st_episode.png The softness of the spectrum is also confirmed by our analysis of SPI-ACS/INTEGRAL data: assuming high values of Epeak (e.g. Epeak = 975 keV) and using SPI-ACS - GBM cross-calibration method to convert SPI-ACS count fluxes to energy units (Minaev et al., in preparation) we obtain underestimated value of fluence F_ACS = (1.3 +/- 0.3)E-5 erg/cm^2 for Epeak = 975 keV, which is less than reference value of F_GBM = (2.38 +/- 0.04)E-5 erg/cm^2 in (10, 1000) keV range, calculated within our power law model with gamma = -1.68. Using data of GBM/Fermi we perform cross-correlation analysis of the initial episode and find significant spectral lags, typical for type II (long) GRBs (e.g. Minaev et al., Astronomy Letters, 40, 5, 235, 2014). Spectral lag – energy dependence is fitted satisfactory by logarithmic function lag ~ A*log(E) with spectral lag index A = 0.11 +/- 0.03. The spectral lag and its parameter can be found in http://grb.rssi.ru/GRB221009A/GRB221009_GBM_lags_1st_episode.png
GCN 32821 table
GRB_name GRB221009A
GCN_number 32821
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32821 SUBJECT: GRB 221009A: James Webb Space Telescope Observations DATE: 22/10/22 23:17:34 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (Radboud Univ.), T. Barclay (NASA/GSFC), E. Burns (LSU), S. B. Cenko (NASA/GSFC), A. A. Chrimes (Radboud Univ.), P. D’Avanzo (INAF/OABr), V. D’Elia (INAF/OAR and ASI/SSDC), M. Della Valle (INAF/OAC), A. de Ugarte Postigo (Obs. Cote d’Azur), W. Fong (Northwestern), A. S. Fruchter (STScI), B. P. Gompertz (Birmingham), C. L. Hedges (NASA/GSFC), K. E. Heintz (DAWN/NBI), L. Izzo (DARK/NBI), D. A. Kann (Goethe Univ.), J. A. Kennea (PSU), E. Le Floc’h (CEA Paris-Saclay), D. B. Malesani (Radboud Univ. and DAWN/NBI), A. Melandri (INAF/OAR), B. D. Metzger (Columbia and Flatiron/CCA), S. E. Mullally (STScI), S. Piranomonte (INAF/OAR), M. E. Ravasio (Radboud Univ and INAF/OABr), J. L. Racusin (NASA/GSFC), J. C. Rastinejad (Northwestern), R. Salvaterra (INAF/IASF Milan), B. Sbarufatti (INAF/OABr), B. Schneider (CEA Paris-Saclay), R. L. C. Starling (U. Leicester), N. R. Tanvir (U. Leicester), C. C. Thoene (ASU-CAS), R. A. M. J. Wijers (Amsterdam), D. Xu (NAOC) report: We observed the afterglow of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., GCN 32637; Veres et al., GCN 32636) with the James Webb Space Telescope on 22 October 2022, approximately 13 days after the Fermi/GBM trigger. Observations were obtained with the NIRSpec prism, spanning the range 0.6-5.3 microns at low resolution (exposure time 1803 s starting at 13:50 UT), and with MIRI using the Low Resolution Spectroscopy mode, spanning the range 5-12 microns (exposure time 555 s starting at 14:51 UT). The optical/IR counterpart is well detected in both acquisition and spectral series, providing high signal to noise across the window. Based on provisional NIRSpec data the afterglow appears to be reasonably well described by an absorbed power-law (MW absorption, A_V = 4.2 mag), with a relatively blue spectral slope (nu^-0.4), although we caution that the uncertainty in foreground absorption and photometric calibration means strong statements cannot be made at this stage. Further analysis is ongoing. We thank the staff of STScI for the rapid assessment of our DDT proposal (GO 2782, PI Levan) and in particular Alison Vick, Greg Sloan and Patrick Ogle for their work to get the observations rapidly into the schedule.
GCN 32828 table
GRB_name GRB221009A
GCN_number 32828
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32828 SUBJECT: GRB 221009A: Determination of the black holes mass and spin DATE: 22/10/24 15:43:08 GMT FROM: Remo Rufinni at ICRA Y. Aimuratov, L. Becerra, C.L. Bianco, C. Cherubini, S. Filippi, M. Karlica, Liang Li, R. Moradi, F. Rastegar Nia, J.A. Rueda, R. Ruffini, N. Sahakyan, Y. Wang, S.S. Xue, on behalf of the ICRANet team, report: In GRB 221009A, as in GRB 130427A (Ackermann et al. 2014, Science, 343, 42; and Ruffini et al. 2019, ApJ, 886, 82), the Fermi-GBM data in the prompt phase are piled up (Lesage et al. 2022, GCN 32642). In both cases there are missing the ultra-relativistic prompt emission (UPE) phases originating from quantum electrodynamical process around a Kerr BH (Ruffini et al. 2019, ApJ, 886, 82; and Rueda et al. 2022, ApJ, 929, 56), which were well observed in GRB 190114C (Moradi et al. 2021, Phys Rev D 104, 063043) and GRB 180720B (Rastegarnia et al. 2022, EPJC 82, 77). Under these conditions, for GRB 130427A the 0.1-100 GeV data of Fermi-LAT had allowed to determine only the lower limit on the BH mass, M>2.31 solar masses, and the upper limit of its spin parameter, α<0.4 (Ruffini et al. 2019, ApJ, 886, 82). For the BDHNI GRB 190114C (Ruffini et al. 2019, GCN 23715), the values of the BH mass and spin had been determined by taking into account the UPE contribution: M=4.53 solar masses, α=0.54 (Moradi et al. 2021, Phys Rev D 104, 063043). The analysis of GRB 130427A applied to GRB 221009A gives for the BH mass and spin parameters: M>2.36 solar masses and α<0.5. We identify the spike at 500s as the X-ray flare (see e.g. Ruffini et al. 2021 MNRAS 504, 5301–5326 for similar GRBs). We also identify the trigger in the 10 keV-10 MeV data of Fermi-GBM as the dawn of the supernova (SN-rise), associated with the gravitational collapse of the progenitor CO-core. The SN ejecta, accreting on the binary NS companion, give origin to the BH (BH rise, Rueda & Ruffini 2012, ApJL, 758, L7) and accreting on the vNS they originate the afterglow (vNS rise, Ruffini et al. 2018, ApJ, 869.101; Becerra, et al. 2022, Phys Rev D 106, 083002). Additional data analysis from AGILE (GCN 32650), Fermi (GCN 32636, 32637, 32642, 32819), Swift (GCN 32635), LHAASO (GCN 32677), HXMT (Atel 15660) are needed to relate the SN-rise to the first appearance of the vNS (the vNS-rise) by the TeV radiation (GCN 32780, 32820, 32808), and also to relate the appearance of the BH (BH-rise) to the identification of the first GeV emission.
GCN 32850 table
GRB_name GRB221009A
GCN_number 32850
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 32850 SUBJECT: GRB 221009A: spectroscopic confirmation of SN in LBT spectra DATE: 22/10/25 16:50:09 GMT FROM: Andrea Rossi at INAF E. Maiorano, E. Palazzi, A. Rossi (INAF-OAS), V. D'Elia (SSDC & INAF-OAR), and A. Melandri (INAF-OAR) on behalf of the CIBO collaboration, and F. Cusano (INAF-OAS), L. Izzo (DARK/NBI) report: We report the results of the spectroscopic follow-up observations of the afterglow of GRB 221009A (Dichiara et al., GCN 32632; Fermi GBM detection: Veres et al., GCN 32636). The optical spectra were obtained with the Multi-Object Double Spectrographs (MODS) instrument mounted on the 2x8.4-m LBT telescope (Mt. Graham, AZ, USA) at 3 UT on 2022-10-18, 8.56 days after the burst trigger. The spectra cover the wavelength range 3200-10000 AA, and we obtained a total of 6 exposures of 900 s. After correction for the foreground Galactic extinction (E(B-V)=1.324, Schlafly & Finkbeiner 2011), we find that the resulting spectrum is clearly dominated by the afterglow. We subtracted the afterglow contribution assuming a spectral slope -0.7 (using the convention F_nu ~ nu^-beta), anchored to the simultaneous NIR flux. This value has been obtained modeling the NIR light curve of the afterglow (Ferro et al., GCN 32804; D'Avanzo et al., GCN 32755). The remaining low S/N spectrum shows features typical of type Ic-BL supernovae. Therefore, we confirm the emerging contribution of SN 2022xiw (de Ugarte Postigo et al. et al. TNSCR, 2022-3047) as reported by de Ugarte Postigo et al. (GCN 32800). We acknowledge the excellent support from the LBTO and LBT-INAF staff, particularly A. Becker and D. G. Huerta, in obtaining these observations.
GCN 32852 table
GRB_name GRB221009A
GCN_number 32852
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32852 SUBJECT: GRB 221009A: SARA-RM 1m Optical Afterglow Detection DATE: 22/10/26 03:04:37 GMT FROM: Kyle Pellegrin at Clemson University K. Pellegrin, K. Rumstay, and D. Hartmann report: We observed the field of GRB 221009A detected by Swift(Kennea & Williams, GCN 32635; Veres et al., GCN 32636) Swift BAT (Dichiara et al., GCN 32632), Fermi LAT (Bissaldi, GCN 32637), Liverpool Telescope (Perley, GCN 32638), Vereniging Voor Sterrenkunde (Broens, GCN 32640), IPN (Svinkin, GCN 32641), BOOTES-2/TELMA (Hu et al., GCN 32644), Mondy (Belkin, GCN 32645), MeerLICHT (Wet et al., GCN 32646), Nanshan/NEXT (Xu et al., GCN 32647), ESO X-shooter (de Ugarte Postigo, GCN 32648), Al Khatim Observatory M44 (Odeh, GCN 32649 & GCN 32666), AGILE/MCAL (Ursi et al, GCN 32650), REM (Brivio et al., GCN 32652), AMI-LA (Bright et al., GCN 32653), SAAO (Durbak et al., GCN 32654), ATA (Farah et al., GCN 32655), Swift UVOT (Kuin and Dichiara, GCN 32656), AGILE/GRID (Piano et al., GCN 32657), LOAO (Paek et al., GCN 32659), INTEGRAL SPI/ACS (Gotz et al., GCN 32660), GIT (Kumar et al., GCN 32662), Burke-Gaffney Observatory (Romanov, GCN 32664), SLT-40cm (Chen et al., GCN 32667), Lick/Nickel Telescope (Vidal et al., GCN 32669), Assy (Kim et al., GCN 32670 & Belkin et al., GCN 32769), Global MASTER-Net (Lipunov et al. GCN 32672 & GCN 32673), BlackGEM (Groot et al., GCN 32678), iTelescope (Romanov, GCN 32679), Sintez-Newton/ CrAO (Belkin et al., GCN 32684), COATLI (Watson et al. GCN 32692), LCOGT (Strausbaugh et al., GCN 32693 & GCN 32738), COATLI (Butler et al., GCN 32705), Konkoly Observatory (Vinko et al., GCN 32709), GMG (Mao et al., GCN 32727), Sayan Observatory (Zaznobin et al., GCN 32729), MITSuME Okayama (Sasada et al., GCN 32730), Lowell Discovery Telescope (O’Connor et al., GCN 32739 & GCN 32799), RTT-150 (Bikmaev et al., GCN 32743 & GCN 32752), Gemini-South (Rastinejab and Fong, GCN 32749), Gemini-South (O’Connor et al., GCN 32750), OHP (Schneider et al., GCN 32753), REM (D’Avanzo et al., GCN 32755), Pan-STARRS (Huber et al., GCN 32758), Large Binocular Telescope (Shrestha et al., GCN 32759), Faulkes Telescope North (Shrestha et al., GCN 32771), GRANDMA (Rajabov et al., GCN 32795), BOAO (Im et al., GCN 32803), TNG (Ferro et al., GCN 32804), LBT (Rossi et al., GCN 32809), DFOT (Gupta et al., GCN 32811), AZT-20 (Belkin et al., GCN 32818), and James Webb (Levan et al., GCN 32821) using the SARA 1m optical telescope located at the Roque de los Muchachos Observatory on La Palma, Canary Islands, Spain, equipped with the Andor Ikon-L camera. Observations started at 20:50:13 UTC on 2022-10-23 and ended at 22:29:27 UTC on 2022-10-23. We obtained a series of 90 images with an exposure time of 60s each in the Johnson-Cousins R filter. The afterglow is faintly seen after stacking all 90 images together. Photometry on the stacked image found the afterglow to be R=22.19 +/= 0.07 mag at 14.90190 days (midpoint of stacked observations) after the Swift trigger (GCN 32632). Photometry based on the PanSTARRS catalog. The Southeastern Association for Research in Astronomy (SARA) consortium operates three telescopes: the 0.9-m SARA-KP at Kitt Peak in Arizona, the 0.6-m SARA-CT at Cerro Tololo in Chile, and the 1.0-m SARA-RM (formerly the JKT) telescope at Roque de los Muchachos Observatory in the Canary Islands. For more information see: Keel et al. (2016): https://iopscience.iop.org/article/10.1088/1538-3873/129/971/015002
GCN 32860 table
GRB_name GRB221009A
GCN_number 32860
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32860 SUBJECT: GRB 221009A: Further Gemini-South Infrared Observations DATE: 22/10/27 01:33:55 GMT FROM: Brendan O'Connor at UMD B. O'Connor (UMD/GWU), E. Troja (UTV/ASU), S. Dichiara (PSU), J. Gillanders (UTV), S. B. Cenko (NASA/GSFC): We performed target of opportunity observations of GRB 221009A (Dichiara et al., GCN 32632, Veres et al., GCN 32636) with the FLAMINGOS-2 spectrograph mounted on the Gemini-South telescope. Observations began on October 26, 2022 at 23:40:44 UT corresponding to ~17.4 d after the GRB. We obtained images in JHK with a total exposure of 75 s in each filter. The afterglow is clearly detected in each filter. We obtain the following magnitudes calibrated against the 2MASS catalog: J = 20.1 +/- 0.2 AB mag H = 19.43 +/- 0.15 AB mag K = 18.94 +/- 0.08 AB mag These magnitudes are not corrected for Galactic extinction. Further infrared observations are planned. We acknowledge the staff of the Gemini Observatory for assistance with these observations.
GCN 32877 table
GRB_name GRB221009A
GCN_number 32877
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32877 SUBJECT: LIGO-Virgo-KAGRA and GEO600 statement on GRB 221009A DATE: 22/10/28 15:30:08 GMT FROM: Francesco Pannarale at LIGO-Virgo-KAGRA Collaboration None of the LIGO, Virgo, or KAGRA detectors were in observing operation at the time of GRB 221009A. The detectors are currently being prepared for the O4 observing run, which is expected to begin in March 2023. The observing run planning can be viewed here: https://observing.docs.ligo.org/plan/ GEO600 was taking data at the time of GRB 221009A. However, its sensitivity is insufficient to detect any viable GRB progenitor at the estimated z=0.151 (de Ugarte Postigo et al. GCNC 32648), and the data show no evidence of an astrophysical transient at the time of GRB 221009A.
GCN 32907 table
GRB_name GRB221009A
GCN_number 32907
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32907 SUBJECT: High-precision position of the compact radio counterpart to GRB221009A DATE: 22/11/03 15:45:05 GMT FROM: Dr. Pikky Atri at ASTRON P. Atri (ASTRON), T. An (SHAO), M. Giroletti (INAF-IRA), Y.-K. Zhang (SHAO), J. Bright (Oxford), W. Farah (SETI Institute), Rob Fender (Oxford, UCT), J.-J. Geng (PMO), G. Ghirlanda (INAF - OAB), S. Giarratana (University of Bologna, INAF-IRA), Alexander van der Horst (GWU), Y. Li (PMO), Y. Liu (SHAO), B. Marcote (JIVE), J. C. A. Miller-Jones (ICRAR-Curtin), Sara E. Motta (INAF-OAB, Oxford), M. Prez-Torres (IAA-CSIC), L. Rhodes (Oxford), O.S. Salafia (INAF - OAB), A. Wang (SHAO), X.-F. Wu (PMO), Z. Xu (SHAO), J. Yang (OSO) The Very Long Baseline Array (VLBA) observed GRB221009A on 14-15th October 2022 at 2cm (15.2 GHz) to measure the position of the radio counterpart of the GRB with high accuracy (Project code TG015). These were done ~5 days after the GRB was first reported by the Swift Burst Alert Telescope on 9th October 2022 (ATel #15650). A compact radio source was detected with a >10sigma significance (rms of 0.06 mJy/beam). Fitting a Gaussian elliptical model to the target shows that the peak emission is from the position: RA 19h13m03s.500792 (2) Dec 19d46m24s.22891 (7) Note that the uncertainties here are purely from a fit to the image plane. Due to a 2 arcminutes offset between the pointing position of the VLBA and the position of the GRB, there was a ~25% drop in sensitivity at the location of the GRB. The systematic uncertainties could be of the order of ~0.1mas based on the beamsize of the VLBA and the uncertainties due to the target-calibrator throw are smaller than this. Follow-up observations of GRB221009A will be conducted with the VLBA. We would like to thank the VLBA schedulers for conducting these service observations for a quick first-epoch look at the GRB.
GCN 32912 table
GRB_name GRB221009A
GCN_number 32912
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32912 SUBJECT: Correction to GCN 32852 (GRB 221009A: SARA-RM 1m Optical Afterglow Detection) DATE: 22/11/05 19:13:51 GMT FROM: Kyle Pellegrin at Clemson University K. Pellegrin, K. Rumstay, and D. Hartmann report: The midpoint of observations since the swift trigger stated in GCN 32852 was incorrectly stated at 14.90190 days. The midpoint of observations occurred on 2022-10-23 at 21:38:42 UTC which makes it 14.3114 days since the swift trigger on 2022-10-09 at 14:10:17 UTC. We apologize for any inconvenience this may have caused.
GCN 32916 table
GRB_name GRB221009A
GCN_number 32916
Detection_method Fermi LAT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32916 SUBJECT: GRB 221009A: Extended Bad Time Intervals for Fermi LAT data DATE: 22/11/07 17:38:36 GMT FROM: Nicola Omodei at Stanford U. N. Omodei (Stanford Univ.), P. Bruel (CNRS/IN2P3), J. Bregeon (CNRS/IN2P3), M. Pesce-Rollins (INFN Pisa), D. Horan (CNRS/IN2P3), E. Bissaldi (Politecnico and INFN Bari), and R. Pillera (Politecnico and INFN Bari) report on behalf of the Fermi-LAT team: Further investigation of the low-level data has shown that X-ray and soft gamma-ray pile-up, multiple photons being recorded at the same time, impacted a larger time interval than reported in the first GCN (Omodei et al. GCN #32760). This very high level of pile-up means that the LAT data cannot be analyzed with the standard tools. We have thus extended the Bad Time Interval (BTI) to cover the time between T0+203 and T0+294, where T0 is the Fermi-GBM trigger time, October 9, 2022, at 13:16:59.99 UT. We are currently working on analysis methods that would allow us to reduce the duration of these BTIs. The signals in the instrument produced by the 99 GeV photon observed 240 seconds after the GBM trigger were well above the noise due to the GRB induced pile-up. Because the extra energy deposited in the instrument at that time was much less than 99 GeV, we are confident that the photon energy was well reconstructed. The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (elisabetta.bissaldi@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 32921 table
GRB_name GRB221009A
GCN_number 32921
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 32921 SUBJECT: GRB 221009A: Hubble Space Telescope observations DATE: 22/11/08 21:17:06 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (Radboud Univ.), T. Barclay (NASA/GSFC), K. Bhirombhakdi (STScI), E. Burns (LSU), S. B. Cenko (NASA/GSFC), A. A. Chrimes (Radboud Univ.), P. D’Avanzo (INAF/OABr), V. D’Elia (INAF/OAR and ASI/SSDC), M. Della Valle (INAF/OAC), A. de Ugarte Postigo (Obs. Cote d’Azur), W. Fong (Northwestern), A. S. Fruchter (STScI), B. P. Gompertz (Birmingham), D. Hartmann (Clemson University), C. L. Hedges (NASA/GSFC), K. E. Heintz (DAWN/NBI), L. Izzo (DARK/NBI), P. Jakobsson (U. Iceland), P.G. Jonker (Radboud Univ. & SRON), D. A. Kann (Goethe Univ.), J. A. Kennea (PSU), E. Le Floc’h (CEA Paris-Saclay), D. B. Malesani (Radboud Univ. and DAWN/NBI), A. Melandri (INAF/OAR), B. D. Metzger (Columbia and Flatiron/CCA), S. E. Mullally (STScI), E. Pian (INAF, Bologna), S. Piranomonte (INAF/OAR), G. Pugliese (Amsterdam Univ.), J. L. Racusin (NASA/GSFC), J. C. Rastinejad (Northwestern), M. E. Ravasio (Radboud Univ and INAF/OABr), A. Rossi (INAF/OAS), R. Salvaterra (INAF/IASF Milan), B. Sbarufatti (INAF/OABr), B. Schneider (CEA Paris-Saclay), R. L. C. Starling (U. Leicester), N. R. Tanvir (U. Leicester), C. C. Thoene (ASU-CAS), S. D. Vergani (CNRS - Paris Obs.), R. A. M. J. Wijers (Amsterdam), D. Xu (NAOC) report: We observed the afterglow of GRB 221009A (Dichiara et al., GCN 32632; Kennea & Williams, GCN 32635; Bissaldi et al., GCN 32637; Veres et al., GCN 32636) with the Hubble Space Telescope on 8 November 2022, approximately 30 days after the Fermi/GBM trigger. Observations were obtained in five filters spanning the optical and NIR region (F625W, F775W, F098M, F125W and F160W). The optical/IR counterpart is well detected in all images, with provisional AB magnitudes of F625W = 23.61 +/- 0.04, F775W = 22.43 +/- 0.04, F098M = 21.21 +/- 0.01, F125W = 20.63 +/- 0.01, F160W = 20.37 +/- 0.01 mag, based on small apertures around the source location (errors statistical only). After correction for foreground extinction the spectral shape is indicative of a peak around 1 micron, which could be due to the contribution from the associated supernova (de Ugarte Postigo et al. GCN 32800, Belkin et al. GCN 32818, Maiorano et al. GCN 32850). Inspection of the images reveals faint emission to the NE which is only visible in the NIR bands, and which extends for approximately 1" (2.6 kpc at z = 0.151; de Ugarte Postigo et al., GCN 32648; Castro-Tirado et al. GCN 32686). We suggest this extension is the host galaxy of GRB 221009A and is only visible in the NIR due to foreground extinction. Analysis is ongoing, and further observations are planned in late November and early December. We thank the staff of STScI, in particular Claus Leitherer, William Januszewski and Joel David Green for their work in rapidly implementing the related DDT proposal (GO 17264, PI Levan).
GCN 32934 table
GRB_name GRB221009A
GCN_number 32934
Detection_method Swift Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 32934 SUBJECT: GRB 221009A: GRANDMA/Kilonova-Catcher observations DATE: 22/11/11 17:01:38 GMT FROM: Damien Turpin at NAOC (CAS) O. Aguerre, F. Bayard, E. Broens, H-B. Eggenstein, M. Freeberg, R. Kneip (KNC), A. Lekic, B. Delaveau, E. Durand (KNC/IPSA), S. Leonini, D. Marchais, E. Maris, R. Mnard, G. Parent, M. Richmond, F. Romanov, M. Serrau, S. Vanaverbeke (KNC), S. Antier (OCA/Artemis), D. A. Kann (Goethe Univ.), S. Karpov (FZU), A. Klotz (OMP/IRAP), T. Midavaine (SAF), D. Turpin (CEA) report on behalf of GRANDMA and Kilonova-Catcher collaborations: The Kilonova-Catcher telescope network responded to the alert of the ultra-bright GRB 221009A (Swift detection: Dichiara et al., GCN 32632; Fermi GBM detection: Veres et al., GCN 32636). In total, 220 science images sent by the KNC amateur astronomers were analyzed. The KNC observations cover the period from 6.3h to about 17.5 days after the Fermi/GBM trigger time. Below, we report a subset of these observations. Magnitudes are given in the AB system and we also report our 5-sigma upper limits. T-T0 (day)| MJD | Obser. |Exposure| Filter | Mag +/- err |Upp.Lim. (AB) ___________________________________________________________________________ 0.285 | 59861.838073 | T-BRO | 5 x 180s | Ic | 15.65 +/- 0.03 | 18.0 0.578 | 59862.131620 | BGO | 60s | I | 16.58 +/- 0.07 | 17.8 1.241 | 59862.794004 | Astrolab IRIS | 14 x 180s | I | 17.47 +/- 0.07 | 18.5 1.365 | 59862.918754 | Ch-Perdrix | 10 x 180s | Clear | 18.76 +/- 0.14 | 19.2 1.447 | 59863.000000 | Ste-Sophie | 16 x 360s | TR-rgb | 18.89 +/- 0.06 | 20.4 1.531 | 59863.084675 | HVO | 59 x 120s | R | 18.93 +/- 0.09 | 19.8 1.703 | 59863.256925 | SRO Auberry | 300s | I | 17.85 +/- 0.13 | 18.1 2.217 | 59863.770555 | Montarrenti | 2 x 30s | Clear | 18.65 +/- 0.24 | 18.5 2.229 | 59863.782465 | EHEA-WL | 199 x 32s | I | 18.64 +/- 0.21 | 18.7 2.267 | 59863.820289 | CO-K26 | 8884s | Lum | -- | 19.7 2.308 | 59863.861789 | GPO | 5700s | Clear | -- | 19.8 2.522 | 59864.075696 | LCO-MDO | 7 x 180s | sdss-r | 19.56 +/- 0.12 | 20.2 2.555 | 59864.108314 | NMSkies | 11 x 300s | Ic | 18.74 +/- 0.13 | 19.3 3.250 | 59864.803399 | Atlas | 30 x 120s | R | -- | 18.4 5.323 | 59866.876810 | Crous Gats | 180 x 32s | TR-rgb | 20.46 +/- 0.14 | 21.0 These detections and limits are consistent with the detections and limits previously reported in Lipunov et al., GCN 32634; Perley, GCN 32638; Broens, GCN 32640; Hu et al., GCN 32644; Belkin et al., GCN 32645; GCN 32769 ; Wet et al., GCN 32646; Xu et al., GCN 32647; de Ugarte Postigo et al., GCN 32648, 32800; Odeh, GCN 32649; GCN 32666; Brivio et al., GCN 32652; Kuin et al., GCN 32656; Paek et al., GCN 32659; Kumar et al., GCN 32662; Romanov, GCN 32664; 32679; Chen et al., GCN 32667; Vidal et al., GCN 32669; Kim et al., GCN 32670; Groot et al., GCN 32678; Castro-Tirado et al., GCN 32686; Watson et al., GCN 32692; Strausbaugh et al. GCN 32693; Butler et al., GCN 32705; Vinko et al., GCN 32709; Mao et al., GCN 32727; Zaznobin et al., GCN 32729; Sasada et al., GCN 32730; Strausbaugh & Cucchiara, GCN 32738; O'Connor et al., GCN 32739; GCN 32750, GCN 32799, GCN 32860; Bikmaev et al., GCN 32743; GCN 32752; Rastinejad & Fong, GCN 32749; Schneider et al., GCN 32753; DAvanzo et al., GCN 32755; Huber et al., GCN 32758; Shrestha et al., GCN 32759; 32771; Izzo et al., GCN 32765; Levan et al., GCN 32821, GCN 32921; Maiorano et al., GCN 32850; Pellegrin et al., GCN 32852. The GRANDMA/Kilonova-Cacther images have been calibrated using field stars from the PanSTARRS-DR1 catalog using the STDpipe pipeline (Karpov 2022). We advocate a joint multi-wavelength publication for this event and we are happy to collaborate with teams that have the same spirit, to be able to explore the best astrophysical scenario. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).
GCN 32944 table
GRB_name GRB221009A
GCN_number 32944
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32944 SUBJECT: Correction to GCN 32646 (GRB 221009A (Swift J1913.1+1946): MeerLICHT observations) DATE: 22/11/17 11:39:27 GMT FROM: Simon de Wet at UCT S. de Wet (UCT) reports on behalf of the MeerLICHT consortium: The r-band magnitude for the afterglow of GRB 221009A reported in GCN 32646 was incorrectly reported as r = 17.76 +/- 0.08 at 18:23:59 UT. The correct magnitude is r = 16.76 +/- 0.08. We apologize for any inconvenience this may have caused.
GCN 32949 table
GRB_name GRB221009A
GCN_number 32949
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 32949 SUBJECT: GRB 221009A: Japanese VLBI Network observation DATE: 22/11/19 04:37:23 GMT FROM: Kotaro Niinuma at Yamaguchi University ========================================================================= K. Niinuma (Yamaguchi Univ.), Y. Yonekura (Ibaraki Univ.), K. Fujisawa, K. Motogi (Yamaguchi Univ.), and W. Iwakiri (Chiba Univ.) We carried out the very long baseline interferometry (VLBI) observations of GRB221009A/Swift J1913.1+1946 (Dichiara et al. GCN 32632, ATel 15650) at 9:00 - 10:15 UT on October 11, at 8:00 - 9:15 on October 25 and 26, 2022 (1.82 days, 15.78 days, and 16.78 days after the Fermi-GBM trigger (Veres et al. GCN 32632), respectively). The observation was performed in both C-band (center frequency of 6856 MHz with a bandwidth of 512 MHz) and X-band (center frequency of 8448 MHz with a bandwidth of 512 MHz), simultaneously by single baseline interferometry consisting of Yamaguchi-34m radio telescope operated by Yamaguchi University and Hitachi-32m radio telescope operated by Ibaraki University. Both telescopes recorded only left-circular polarization. This array is a part of the Japanese VLBI Network and the baseline length is of 873 km. GRB221009A/Swift J1913.1+1946 was successfully detected on October 11, and its VLBI flux densities were 13+/–3 mJy at 6.86 GHz and of 11+/-3 mJy at 8.45 GHz. On the other hand, it was not detected on October 25 and 26, and the 5-sigma upper limits of VLBI flux density were 3mJy at both 6.86GHz and 8.45GHz. The bright quasar J1905+1943 was also observed to determine the VLBI flux density of GRB221009A/Swift J1913.1+1946. The radio emission from the very compact component detected by our VLBI observation showed slightly steep spectrum in radio band on 1.82 days after the Fermi-GBM trigger. ========================================================================= -- NIINUMA Kotaro Graduate School of Sciences and Technology for Innovation, Yamaguchi Univ., Yoshida 1677-1, Yamaguchi 753-8512, Japan Phone: +81-(0)83-933-5759 E-mail:niinuma@yamaguchi-u.ac.jp 新沼 浩太郎 山口大学大学院 創成科学研究科 〒753-8512 山口県山口市吉田１６７７−１
GCN 32973 table
GRB_name GRB221009A
GCN_number 32973
Detection_method Fermi LAT Other
ra 289.9300°
decl 19.7740°
Circular_text TITLE: GCN CIRCULAR NUMBER: 32973 SUBJECT: GRB 221009A：DAMPE observed a 34.7 GeV p DATE: 22/11/23 01:26:16 GMT FROM: Kai-Kai Duan at Purple Mountain Observatory Kai-Kai Duan (Purple Mountain Observatory), Zun-Lei Xu (PMO), Zhao-Qiang Shen (PMO), Wei Jiang (PMO), Lu-Yao Jiang (PMO), Dong-Ya Guo (Institute of High Energy Physics), Wen-Xi Peng (IHEP), Fabio Gargano (Istituto Nazionale di Fisica Nucleare) and Xiang Li (PMO), report on behalf of the DAMPE collaboration: We report the observation of GRB 221009A with DAMPE, which has been reported by Swift (Kennea et al. GCN #32635, Krimm et al. GCN #32688), Fermi-GBM (Veres et al. GCN #32636, Lesage et al. GCN #32642), Fermi-LAT (Bissaldi et al. GCN #32637, Pillera et al. GCN #32658, Xia et al. GCN #32748), LHAASO (Huang et al. GCN #32677) and so on. Though the GRB is about 90 deg from the boresight of DAMPE at the moment of Fermi-GBM trigger (out of the normal FOV), the Unbiased-Trigger counts of DAMPE increased significantly from 227 to 233 seconds after the Fermi-GBM trigger. We believe that about 21 out of 35 events during the 6-second timespan were from the GRB, and the highest deposit energy is 2.4 GeV for these events. The FOV of DAMPE began to cover the GRB position about one hour later, and it observed a 34.7 GeV (RA = 289.93 deg, DEC = 19.96 deg) photon at 1.58 deg (with the 95% containment of the PSF as ~ 2 deg) from the swift localization of this GRB (RA = 288.265 deg, Dec = 19.774 deg, from Dichiara et al. GCN #32632) 4896 seconds after the Fermi-GBM trigger. The p-value of this photon emitted from background is 0.0003, corresponding to 3.6-sigma significance locally. During the past 6-year observation, DAMPE observed only one photon with energy above 30 GeV within 2 deg around this GRB position. At 9.37 and 16.26 days after the Fermi-GBM trigger, DAMPE observed 8.33 GeV (RA = 287.82 deg, DEC = 20.35 deg) and 10.74 GeV (RA = 287.48 deg, DEC = 19.88 deg) photons around 0.71 deg and 0.75 deg from the LAT localization of GRB 221009A. The local significance of these two photons are 3.10 and 3.22 sigma, respectively. The 95% containment of the PSF above 10 GeV is about 2 deg. The detailed data analysis is still on going. DAMPE is a satellite for dark matter detection indirectly, cosmic-ray physics and gamma-ray astronomy by detection of the high-energy electrons, cosmic rays and gamma rays. Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 P.R.China email: duankk@pmo.ac.cn
GCN 32995 table
GRB_name GRB221009A
GCN_number 32995
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 32995 SUBJECT: Optical polarization observation of GRB 221009A DATE: 22/11/30 22:48:23 GMT FROM: Ioannis Liodakis at Finnish Centre for Astronomy with ESO E. Lindfors (FINCA), K. Nilsson (FINCA), I. Liodakis (FINCA), A. Kasikov (NOT, Aarhus University, Tartu Observatory), I. Negueruela (University of Alicante) We observed gamma-ray burst GRB221009A following the GCN alert #32632 (Dichiara et al., 2022) in optical polarization. The source was observed with the Nordic Optical Telescope (NOT) and the ALFOSC instrument in the R-band using the standard setup for linear polarization observations (lambda/2 retarder followed by a calcite). The observations started 2022-10-12 at 20:15UT, i.e. approximately 3 days and 6 hours after the trigger (2022-10-09 14:10:17 UT). The observations were performed with clear sky with seeing 1.2 arcseconds. As the GRB occurred in crowded galactic field the ordinary beam image of the GRB221009A ended up behind the extraordinary beam of the nearby bright star. Therefore, we had to perform careful modelling of the PSF using the second bright star in the field of view and subtracted the modeled PSF from the image. We repeated this for each image separately. As the PSF subtraction can result in some artifacts to the background, we measured the resulting images with small aperture of 1.5 arcsec radius. Using the standard formulas, we derived a 2 sigma upper limit of 5.1% percent on the polarization degree.
GCN 33038 table
GRB_name GRB221009A
GCN_number 33038
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 33038 SUBJECT: GRB 221009A: MuSCAT3 observations DATE: 22/12/10 03:40:25 GMT FROM: Mariko Kimura at RIKEN M. Kimura (RIKEN), K. Isogai (Tokyo Univ./Kyoto Univ.), M. Arimoto, D. Yonetoku (Kanazawa Univ.), N. Narita, M. Tamura (Tokyo Univ./Astrobiology Center), A. Fukui (Tokyo Univ.), M. Ikoma (NAOJ) We have monitored the afterglow of GRB 221009A since three days after the Swift and Fermi alerts (GCN 32632; GCN 32636) by MuSCAT3 on the 2-meter telescope at Las Cumbres Observatory. MuSCAT3 is multi-channel imagers with the filters of SDSS g', r', i', zs, which is designed for observing transiting exoplanets. https://lco.global/observatory/instruments/muscat3/ The measurements are here: BJD Mag Err Filter 2459864.82404 21.33 0.15 g 2459864.82404 20.01 0.03 r 2459864.82404 19.48 0.03 i 2459864.82404 18.26 0.01 z 2459870.80681 23.55 0.21 g 2459870.80681 21.74 0.05 r 2459870.80681 20.47 0.04 i 2459870.80681 19.90 0.03 z 2459872.82760 23.64 0.26 g 2459872.82760 21.91 0.07 r 2459872.82760 20.82 0.06 i 2459872.82760 20.22 0.05 z 2459876.80690 23.99 0.34 g 2459876.80690 21.96 0.09 r 2459876.80690 21.00 0.08 i 2459876.80690 20.50 0.07 z By plotting these data with the other optical measurements reported to GCN (GCNs 32625, 32640, 32644, 32645, 32646, 32652, 32659, 32662, 32666, 32667, 32670, 32678, 32679, 32692, 32693, 32705, 32709, 32729, 32730, 32743, 32750, 32758, 32769, 32771, 32799, 32809, 32818), we found that the optical afterglow light curve shows a power-law decay, and only i'-band light curve fluctuates along the decline possibly because of systematic errors. We did not find a bump reported by GCN 32818 at least around a week after the Swift and Fermi trigger. If you have any queries, please contact M. Kimura at the following address. mariko.kimura@riken.jp
GCN 33243 table
GRB_name GRB221009A
GCN_number 33243
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 33243 SUBJECT: GRB 221009A: radio afterglow detection with the EVN DATE: 23/02/01 10:41:25 GMT FROM: Stefano Giarratana at University of Bologna S. Giarratana (University of Bologna, INAF-IRA), M. Giroletti (INAF-IRA), T. An (Shanghai A.O.), G. Anderson (Curtin University), P. Atri (ASTRON), J. S. Bright (University of Oxford), R. Fender (University of Oxford), G. Ghirlanda (INAF-OAB), J. K. Leung (University of Sydney, CSIRO), B. Marcote (JIV-ERIC), M. Pérez-Torres (IAA-CSIC), L. Rhodes (University of Oxford), O. S. Salafia (INAF-OAB), J. Yang (OSO) On UT 2022 November 18 and 21 (40 and 43 days post-burst) we observed the radio counterpart of GRB 221009A (Dichiara et al, GCN 32632; Veres et al., GCN 32636) with the European VLBI Network (EVN) at a central frequency of 8.3 and 5 GHz, respectively. From a preliminary analysis, the source is clearly detected at both frequencies with >30 sigma significance. The 8.3 GHz surface brightness peak is ~1.3 mJ/beam. The synthesized beam is 0.9 x 0.5 mas (PA = 7.7 deg). The 5 GHz surface brightness peak is ~1.4 mJy/beam. The synthesized beam is 1.7 x 0.9 mas (PA = 9.25 deg). The source is found at a position within ~1 mas of the one previously reported by Atri et al., GCN 32907 with the VLBA at 15.2 GHz. The offset is most likely accounted for by systematics. All the results presented here are preliminary. Further analysis is in progress. We will report the final results in a forthcoming publication. We would like to thank the directors and staff of all the EVN telescopes for approving, executing, and processing these out-of-session ToO observations. The European VLBI Network is a joint facility of independent European, African, Asian, and North American radio astronomy institutes. Scientific results from data presented in this publication are derived from the following EVN project code: RG013.
GCN 33305 table
GRB_name GRB221009A
GCN_number 33305
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 33305 SUBJECT: GRB 221009A: Continued Swift Observations DATE: 23/02/08 18:41:45 GMT FROM: Maia Williams at Penn State M. Williams (PSU) reports on behalf of the Swift Team: Swift resumed observations of GRB 221009A on February 7 at 00:51 UTC after the end of Sun constraint, ~10 Ms after the Fermi/GBM trigger (Veres et al., GCN Circ. 32636). The X-ray afterglow is still faintly detectable (1.9 x 10^-3 counts s^-1) in a 9.4 ks XRT exposure. Further observations are planned for this weekend.
GCN 33676 table
GRB_name GRB221009A
GCN_number 33676
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 33676 SUBJECT: GRB 221009A: Late-time JWST Observations and Detection of Supernova Emission DATE: 23/04/23 02:40:59 GMT FROM: Peter K. Blanchard at Northwestern University P. K. Blanchard (Northwestern/CIERA), V. A. Villar (PSU), R. Chornock (UC Berkeley), H. Sears (Northwestern/CIERA), N. LeBaron (UC Berkeley), S. K. Yadavalli (PSU), T. Laskar (Utah), K. D. Alexander (Arizona), R. Margutti (UC Berkeley), E. Berger (Harvard/CfA), J. Barnes (UCSB), D. Siegel (U. Guelph/Perimeter), B. Metzger (Columbia and Flatiron/CCA), D. Kasen (UC Berkeley), Y. Cendes (Harvard/CfA), T. Eftekhari (Northwestern/CIERA), and J. Leja (PSU) report: We obtained spectra at the position of the afterglow of GRB 221009A (Dichiara et al., GCN 32632; Lipunov et al., GCN 32634; Kennea & Williams, GCN 32635; Veres et al., GCN 32636; Bissaldi et al., GCN 32637) with JWST/NIRSpec under DDT program 2784 (P.I. Blanchard) starting at 2023 April 20 14:40 UT (193 observer-frame days after the burst). The spectra were taken with the G140M/F100LP and G235M/F170LP grating/filter combinations with an exposure time of 11,015 seconds in each setup. This yields a total wavelength coverage of about 1 - 3 microns. We correct our combined G140M+G235M spectrum for Galactic extinction using the fitted extinction parameters found by Levan et al., ApJL, 946, L28 (2023). The spectrum significantly differs from a power-law continuum observed 13 days after the burst (observer frame; Levan et al., GCN 32821). This suggests that there is now significant contribution from the SN/host galaxy. We detect a broad emission line feature centered at ~1 micron (observer frame) consistent with the Ca II IR triplet from a SN, and prominent narrow, host galaxy emission lines. If confirmed by further analysis, this would represent the first identification of specific SN spectral features associated with GRB 221009A. Further analysis is ongoing. We thank STScI staff members Crystal Mannfolk, Leonardo Ubeda, Armin Rest and the entire JWST team for the successful implementation of this DDT program.