GRB240912A

This page lists all entries on GRB240912A in GRBweb

Summary Fermi GBM IPN Swift GCN 37465 GCN 37466 GCN 37469 GCN 37470 GCN 37471 GCN 37476 GCN 37477 GCN 37478 GCN 37479 GCN 37480 GCN 37484 GCN 37487 GCN 37978

Summary table
Variable Value Source
GRB_name_Fermi GRB240912074
T0 1:46:39 UTC GCN_circulars,Swift Det
ra 124.6350° Swift
decl 33.9990° Swift
pos_error 5.57e-05° Swift
T90 88.577 s Fermi_GBM
T90_error 0.923 s Fermi_GBM
T90_start 1:46:59.283 UTC Fermi_GBM
fluence 7.70e-05 erg/cm² Fermi_GBM
fluence_error 4.97e-08 erg/cm² Fermi_GBM
redshift 1.2340
T100 108.86 s
GBM_located False
mjd 60565.0740625 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB240912074
trigger_name bn240912074
ra 124.6350°
decl 33.9989°
pos_error 3.80e+00°
datum 2024-09-12
t_trigger 1:46:40.595 UTC
T90 88.577 s
T90_error 0.923 s
T90_start 1:46:59.283 UTC
fluence 7.70e-05 erg/cm²
fluence_error 4.97e-08 erg/cm²
flux_1024 2.64e+01 erg/cm²/s
flux_1024_error 4.00e-01 erg/cm²/s
flux_1024_time 6.02e+01 erg/cm²/s
flux_64 3.04e+01 erg/cm²/s
flux_64_error 1.79e+00 erg/cm²/s
IPN table
GRB_name GRB240912A
ra 124.6333°
decl 34.0000°
pos_error 5.00e-02°
redshift 1.2340
Swift table
GRB_name GRB240912A
t_trigger 1:46:39 UTC
ra 124.6350°
decl 33.9990°
pos_error 5.57e-05°
redshift 1.2340
GCN 37465 table
GRB_name GRB240912A
GCN_number 37465
Detection_method Fermi GBM final loc
t_trigger 1:46:40 UTC
ra 153.1000°
decl 23.8000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37465 SUBJECT: GRB 240912A: Fermi GBM Final Real-time Localization DATE: 24/09/12 01:57:11 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 01:46:40 UT on 12 Sep 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240912A (trigger 747798405.59471 / 240912074). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 153.1, Dec = 23.8 (J2000 degrees, equivalent to J2000 10h 12m, 23d 48'), with a statistical uncertainty of 4.2 degrees. The angle from the Fermi LAT boresight is 81.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240912074/quicklook/glg_skymap_all_bn240912074.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240912074/quicklook/glg_healpix_all_bn240912074.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240912074/quicklook/glg_lc_medres34_bn240912074.gif
GCN 37466 table
GRB_name GRB240912A
GCN_number 37466
Detection_method Swift Det
t_trigger 1:46:39 UTC
ra 124.6330°
decl 33.9950°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37466 SUBJECT: GRB 240912A: Swift detection of a burst with an optical counterpart DATE: 24/09/12 02:13:06 GMT FROM: K.L. Page at U Leicester P. A. Evans (U Leicester), R. Gupta (NASA GSFC), J. A. Kennea (PSU), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 01:46:39 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240912A (trigger=1253910). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 124.633, +33.995 which is RA(J2000) = 08h 18m 32s Dec(J2000) = +33d 59' 42" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of at least 150 sec, extending into the observation times of the XRT and UVOT. The peak count rate was ~17000 counts/sec (15-350 keV), at ~69 sec after the trigger. The XRT began observing the field at 01:48:25.2 UT, 106.0 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 124.63711, 33.99865 which is equivalent to: RA(J2000) = 08h 18m 32.91s Dec(J2000) = +33d 59' 55.1" with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 17 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (5.53 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 4.2 (+2.90/-2.49) x 10^21 cm^-2 (90% confidence). The initial flux in the 0.1 s image was 8.64e-08 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 115 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 08:18:32.40 = 124.63502 DEC(J2000) = +33:59:56.3 = 33.99896 with a 90%-confidence error radius of about 0.75 arc sec. This position is 8.0 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.40 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.054. Burst Advocate for this burst is P. A. Evans (pae9 AT leicester.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN 37469 table
GRB_name GRB240912A
GCN_number 37469
Detection_method Fermi GBM Other
redshift 1.2340
Circular_text TITLE: GCN CIRCULAR NUMBER: 37469 SUBJECT: GRB 240912A: Redshift from OSIRIS+/GTC DATE: 24/09/12 06:32:02 GMT FROM: Antonio de Ugarte Postigo at LAM/OCA, CNRS A. de Ugarte Postigo (LAM/OCA, CNRS), J. F. Agui Fernandez (CAHA), C. C. Thoene (ASU-CAS), N. A. Rakotondrainibe (LAM), N. R. Tanvir (U. Leicester), L. Izzo (INAF-OACn & DARK/NBI), S. Geier (GTC), G. Lombardi (GTC), J. P. U. Fynbo (DAWN/NBI), A. Martin-Carrillo (UCD), A. Garcia Rodriguez (GTC), A. Perez Romero (GTC) report, We observed the afterglow of GRB 240912A (Fermi GBM team GCN 37465; Evans et al. GCN 37466) using OSIRIS+ on the 10.4 m GTC telescope, at the Roque de los Muchachos Observatory (La Palma, Spain). The observation consisted in 2 acquisition images in r-band, followed by a single 600 s spectra obtained just before the twilight became too bright to continue with observations. The spectrum was obtained with grism R1000B, covering the spectral range between 3650 and 7800 AA at a resolving power of 600. The acquisition image, obtained at 2024-09-12T05:34:23 UT, 3.798 hrs after the burst, shows the afterglow at r(AB) = 19.15 +/- 0.08 mag, as compared to SDSS field stars. The spectrum has a strong continuum throughout the complete range with absorption features due to AlII, AlIII, FeII, MnII, MgII and MgI at a common redshift of 1.234, which we propose as the redshift of GRB 240912A.
GCN 37470 table
GRB_name GRB240912A
GCN_number 37470
Detection_method Swift-XRT Det
ra 124.6347°
decl 33.9990°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37470 SUBJECT: GRB 240912A: Enhanced Swift-XRT position DATE: 24/09/12 07:11:06 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 328 s of XRT Photon Counting mode data and 1 UVOT images for GRB 240912A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 124.63469, +33.99901 which is equivalent to: RA (J2000): 08h 18m 32.32s Dec (J2000): +33d 59' 56.4" with an uncertainty of 2.5 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 37471 table
GRB_name GRB240912A
GCN_number 37471
Detection_method Optical
redshift 1.2300
Circular_text TITLE: GCN CIRCULAR NUMBER: 37471 SUBJECT: GRB 240912A: NOT optical spectroscopy DATE: 24/09/12 09:45:30 GMT FROM: Dong Xu at NAOC/CAS J. An (NAOC), J.P.U. Fynbo (DAWN/NBI), S.Y. Fu, Z.P. Zhu, S.Q. Jiang, X. Liu, D. Xu (NAOC), Niilo Koivisto (NOT) report on behalf of a large collaboration: We carried out the spectroscopy of the optical afterglow of GRB 240912A detected by Fermi/GBM (Fermi GBM team, GCN 37465) and Swift/BAT (Evans et al., GCN 37466), using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera, at a mean time of 2024-09-12T05:20:43, i.e., ~ 3.57 hrs after the Swift/BAT trigger, covering the wavelength range between ~ 3600 AA and ~ 8000 AA. A total of 970 s spectral exposure was obtained. A continuum is throughout the whole spectral wavelength range, superimposed with three relatively strong absorption features, which can be interpreted as due to Fe II, Mg II and Mg I at a common redshift of z = 1.23, in agreement with the GTC measurement (de Ugarte Postigo et al., GCN 37469).
GCN 37476 table
GRB_name GRB240912A
GCN_number 37476
Detection_method Optical
ra 124.6350°
decl 33.9989°
redshift 1.2340
Circular_text TITLE: GCN CIRCULAR NUMBER: 37476 SUBJECT: GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy DATE: 24/09/12 17:23:35 GMT FROM: Ismael Perez-Fournon at Instituto de Astrofisica de Canarias I. Pérez-Fournon and F. Poidevin (IAC and ULL) Report on LCOGT follow-up observations of the optical afterglow of GRB 240912A, detected by the Fermi Gamma-ray Burst Monitor (GBM) (Fermi GBM team, GCN 37465); Swift BAT, XRT, and UVOT (Evans et al., GCN 37466; an enhanced Swift XRT position is given by Goad et al., GCN 37470); and with INTEGRAL ACS SPI (Pawar, GCN 37473). Spectroscopy of the optical afterglow reported by de Ugarte Postigo et al. (GCN 37469) and An et al. (GCN 37471) provides a redshift of z = 1.234, measured from absorption features. We observed the field of GRB 240912A with one of the 1-meter telescopes at the Las Cumbres Observatory node located at McDonald Observatory (Texas), with a single 500-sec exposure in the SDSS-r' band starting at 2024-09-12T11:13:18 (UTC), ~ 9.44 hours after the Fermi GBM trigger. We detect a point-like source at RA = 08:18:32.39, Dec = +33:59:56.1 (J2000) with an uncertainty of ~ 0.4", after astrometric calibration with Gaia DR3 stars, at a magnitude r' = 19.88 +/- 0.05, calibrated with PanSTARRS and not corrected for Galactic extinction. We report also the identification of the likely GRB host galaxy in archival Legacy Surveys DR10 imaging at RA = 08:18:32.38, Dec = +33:59:55.3 (J2000) and magnitudes g = 23.08, r = 22.88; and z = 22.01. The position of the optical afterglow on our LCOGT image is at about 0.2" from the Swift UVOT afterglow position and 0.8" from the DESI galaxy position. This work makes use of observations from the Las Cumbres Observatory global telescope network (program IAC2024B-004).
GCN 37477 table
GRB_name GRB240912A
GCN_number 37477
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37477 SUBJECT: Swift GRB 240912A: Global MASTER-Net observations report DATE: 24/09/12 18:14:29 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich (Blagoveschensk Educational State University) MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the Swift GRB 240912A ( P. A. Evans et al., GCN 37466) errorbox 58397 sec after notice time and 58417 sec after trigger time at 2024-09-12 18:00:16 UT, with upper limit up to 18.1 mag. The observations began at zenith distance = 80 deg. The sun altitude is -33.7 deg. The galactic latitude b = 33 deg., longitude l = 188 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2598499 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 58507 | MASTER-Tunka | C | 180 | 13.3 | 58898 | MASTER-Tunka | C | 180 | 18.1 | 59089 | MASTER-Tunka | C | 180 | 17.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 37478 table
GRB_name GRB240912A
GCN_number 37478
Detection_method Fermi GBM Det
t_trigger 1:46:40.590 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 37478 SUBJECT: GRB 240912A: Fermi GBM Observation DATE: 24/09/12 18:37:53 GMT FROM: Jacob Smith at Fermi-GBM Team J. Smith (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 01:46:40.59 UT on 12 September 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240912A (trigger 747798405/240912074). which was also detected by Swift BAT and XRT (P. A. Evans et al. 2024, GCN 37466), INTEGRAL SPI ACS (D. Pawar 2024, GCN 37473), OSIRIS+/GTC (A. de Ugarte Postigo et al. 2024, GCN 37469), and NOT (J. An et al. 2024, GCN 37471). The Fermi GBM on-ground location is consistent with the Swift BAT/XRT position. The angle from the Fermi LAT boresight is 71 degrees. The GBM light curve single emission episode with a duration (T90) of about 88.6 s (50-300 keV). The time-averaged spectrum from T0+0 to T0+124.930 s is best fit by a Band function with Epeak = 147 +/- 7 keV, alpha = -1.31 +/- 0.02, and beta = -2.21 +/- 0.05. The event fluence (10-1000 keV) in this time interval is (8.953 +/- 0.089)E-05 erg/cm^2. The 1.024-s peak photon flux measured starting from T0+60.2 s in the 10-1000 keV band is 26.43 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN 37479 table
GRB_name GRB240912A
GCN_number 37479
Detection_method Swift-XRT Other
redshift 1.2340
Circular_text TITLE: GCN CIRCULAR NUMBER: 37479 SUBJECT: GRB 240912A: Swift-XRT refined Analysis DATE: 24/09/12 18:50:53 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), M. A. Williams (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.9 ks of XRT data for GRB 240912A, from 99 s to 45.7 ks after the BAT trigger. The data comprise 939 s in Windowed Timing (WT) mode (the first 5 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The late-time light curve (from T0+4.8 ks) can be modelled with a power-law decay with a decay index of alpha=0.82 (+/-0.07). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.925 (+/-0.020). The best-fitting absorption column is 2.61 (+/-0.29) x 10^21 cm^-2, at a redshift of 1.234, in addition to the Galactic value of 5.6 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.86 (+/-0.09) and a best-fitting absorption column of 9 (+11, -9) x 10^20 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Galactic foreground: 5.6 x 10^20 cm^-2 Intrinsic column: 9 (+11, -9) x 10^20 cm^-2 at z=1.234 Photon index: 1.86 (+/-0.09) If the light curve continues to decay with a power-law decay index of 0.82, the count rate at T+24 hours will be 0.12 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.3 x 10^-12 (4.9 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01253910. This circular is an official product of the Swift-XRT team.
GCN 37480 table
GRB_name GRB240912A
GCN_number 37480
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37480 SUBJECT: GRB 240912A: J-band observations with WINTER DATE: 24/09/12 22:02:51 GMT FROM: Geoffrey Mo at MIT Geoffrey Mo (MIT), Tomas Ahumada (Caltech), Benjamin Schneider (MIT), Viraj Karambelkar (Caltech), Danielle Frostig (CfA), Robert Stein (Caltech), Nathan Lourie (MIT), Robert Simcoe (MIT), and Mansi Kasliwal (Caltech) report: We observed the field of GRB 240912A (Fermi GBM Team, GCN 37465; Evans et al., GCN 37466; Pawar et al., GCN 37473; Smith et al., GCN 37478) in the near-infrared J-band with the Palomar 1-m telescope, equipped with the 1 square degree WINTER camera (Lourie et al. 2020). Observations began at 2024-09-12T10:58:40 UTC (~9.2 hours after the GRB) and consisted of 15 x 120 s exposures. The images were processed using the WINTER data reduction pipeline (https://github.com/winter-telescope/mirar, https://doi.org/10.5281/zenodo.13352565). We do not detect a source at the optical and refined Swift/XRT counterpart location (Evans et al., GCN 37466; de Ugarte Postigo et al., GCN 37469; Goad et al., GCN 37470; An et al., GCN 37471; Pérez-Fournon et al., GCN 37476; Lipunov et al., GCN 37477; Burrows et al., GCN 37479). We obtain the following 5-sigma upper limit: J ~ 18.7 mag (AB). WINTER (Wide-field INfrared Transient ExploreR) is a partnership between MIT and Caltech, housed at Palomar Observatory, and funded by NSF MRI, NSF AAG, the David and Lucille Packard Foundation, and the MIT Kavli Institute for Astrophysics and Space Research.
GCN 37484 table
GRB_name GRB240912A
GCN_number 37484
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 37484 SUBJECT: GRB 240912A: SVOM/GRM observation DATE: 24/09/13 08:38:52 GMT FROM: Chenwei Wang at IHEP SVOM/GRM team: Chao Zheng, Wen-Jun Tan, Chen-Wei Wang, Wen-Long Zhang, Yong-Wei Dong, Jiang-Tao Liu, Shi-Jie Zheng, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Shao-Lin Xiong, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Ting Zhang, Yan-Qiu Zhang, Shu-Min Zhao, Xiao-Yun Zhao (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), JeanLuc Attéia (IRAP), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Bing Zhang (UNLV) report on behalf of the SVOM team: During the commissioning phase, the SVOM/GRM was triggered in-flight by a long GRB 240912A (SVOM trigger reference: sb24091203) at 2024-09-12T01:47:37.000 UT (T0), which also triggered Fermi/GBM (Fermi GBM team, GCN 37465), Swift/BAT (Evans et al., GCN 37466) and INTEGRAL SPI ACS (Pawar, GCN 37473). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a duration of about 79 s. The GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb240912A.png The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM point of contact for this burst is: Chao Zheng (IHEP)(zhengchao97@ihep.ac.cn)
GCN 37487 table
GRB_name GRB240912A
GCN_number 37487
Detection_method Swift-UVOT Det
ra 124.6350°
decl 33.9990°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37487 SUBJECT: GRB 240912A: Swift/UVOT Detection DATE: 24/09/13 13:30:34 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and P. A. Evans (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 240912A 115 s after the BAT trigger (Evans et al., GCN Circ. 37466). A fading source consistent with the XRT position (Goad et al., GCN Circ. 37470) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:18:32.40 = 124.63499 (deg.) Dec (J2000) = +33:59:56.3 = 33.99897 (deg.) with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence). 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 (fc) 117 265 144 17.44+/-0.05 white 608 1031 186 17.87+/-0.06 white 1185 1379 38 18.06+/-0.16 v 657 1430 97 17.78+/-0.28 b 583 5154 205 19.08+/-0.25 u (fc) 328 577 245 16.68+/-0.05 u 731 5018 274 18.14+/-0.13 uvw1 707 1479 77 17.76+/-0.25 uvm2 1086 1106 19 >17.18 uvw2 633 1406 97 18.47+/-0.30 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.054 in the direction of the burst (Schlegel et al. 1998).
GCN 37978 table
GRB_name GRB240912A
GCN_number 37978
Detection_method Konus-Wind Det
ra 124.6350°
decl 33.9989°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37978 SUBJECT: GRB 240912A: radio detection with the VLA DATE: 24/10/30 17:05:06 GMT FROM: Stefano Giarratana at INAF-OAB S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.), N. Omodei (Stanford Univ.), O. S. Salafia (INAF-OAB) At 16:50:36 UT on 2024 Oct 8 (T_mid = 26.7 days post-burst) the Karl G. Jansky VLA observed the field of GRB 240912A (Fermi GBM team, GCN 37465; Evans et al., GCN 37466; Pawar et al., GCN 37473; SVOM team, GCN 37484; Konus-Wind team, GCN 37624) in three bands, with central frequencies of 6, 10 and 15 GHz. The standard 3C286 was used as bandpass and flux density calibrator, while J0815+3635 was used as phase calibrator. From a preliminary analysis, an unresolved radio source is clearly detected at a position: RA: 08:18:32.389 +- 0.001 Dec: 33:59:56.13 +- 0.02 consistent with the optical (Evans et al., GCN 37466) and X-ray (Goad et al., GCN 37470) transient. The preliminary analysis yields the following results: +-----------+-----------------------+--------------+-----------+-----------+ | Frequency | Peak surf. brightness | r.m.s. noise | Beam size | Beam P.A. | | (GHz) | (uJy/beam) | (uJy/beam) | arcsec^2 | deg | +-----------+-----------------------+--------------+-----------+-----------+ | 6 | 171 | 8 | 1.34x0.28 | 60 | | 10 | 138 | 7 | 0.93x0.17 | 57 | | 15 | 128 | 7 | 0.54x0.12 | 62 | +-----------+-----------------------+--------------+-----------+-----------+ No source is detected with a >3sigma confidence at the aforementioned position in previous radio surveys (FIRST, VLASS, RACS), all of which have r.m.s. noise levels above 100 uJy/b. We would like to thank the staff of the VLA for approving, executing, and processing the observations. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. These observations were carried out as part of project SF171028, approved in the framework of the Fermi - NRAO joint program agreement.