GRB231215A

This page lists all entries on GRB231215A in GRBweb

Summary Fermi GBM IPN Swift GCN 35343 GCN 35345 GCN 35349 GCN 35351 GCN 35352 GCN 35353 GCN 35354 GCN 35357 GCN 35361 GCN 35362 GCN 35363 GCN 35364 GCN 35366 GCN 35367 GCN 35368 GCN 35369 GCN 35370 GCN 35373 GCN 35375 GCN 35376 GCN 35377 GCN 35380 GCN 35386 GCN 35392 GCN 35397 GCN 35413 GCN 35507 GCN 35900

Summary table
Variable Value Source
GRB_name_Fermi GRB231215408
T0 9:47:17.810 UTC GCN_circulars,Fermi GBM Det
ra 9.7397° Swift
decl 57.6474° Swift
pos_error 5.82e-05° Swift
T90 16.128 s Fermi_GBM
T90_error 0.572 s Fermi_GBM
T90_start 9:47:19.091 UTC Fermi_GBM
fluence 5.93e-05 erg/cm² Fermi_GBM
fluence_error 7.90e-08 erg/cm² Fermi_GBM
redshift 2.3050 GCN_circulars,Other
T100 27.94 s
GBM_located False
mjd 60293.40784502315 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB231215408
trigger_name bn231215408
ra 9.7417°
decl 57.6464°
pos_error 2.52e+00°
datum 2023-12-15
t_trigger 9:47:17.811 UTC
T90 16.128 s
T90_error 0.572 s
T90_start 9:47:19.091 UTC
fluence 5.93e-05 erg/cm²
fluence_error 7.90e-08 erg/cm²
flux_1024 2.03e+01 erg/cm²/s
flux_1024_error 4.38e-01 erg/cm²/s
flux_1024_time 7.49e+00 erg/cm²/s
flux_64 2.57e+01 erg/cm²/s
flux_64_error 1.98e+00 erg/cm²/s
IPN table
GRB_name GRB231215A
ra 9.7500°
decl 57.6500°
pos_error 5.00e-02°
Swift table
GRB_name GRB231215A
t_trigger 9:47:25 UTC
ra 9.7397°
decl 57.6474°
pos_error 5.82e-05°
T90 20.75 s
fluence 1.00e-05 erg/cm²
redshift 2.3050
GCN 35343 table
GRB_name GRB231215A
GCN_number 35343
Detection_method Swift Det
t_trigger 9:47:25 UTC
ra 9.7500°
decl 57.6420°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35343 SUBJECT: GRB 231215A: Swift detection of a burst DATE: 23/12/15 09:55:59 GMT FROM: David Palmer at LANL P. D'Avanzo (INAF-OAB), R. Brivio (INAF-OAB), M. Ferro (INAF-OAB), J.D. Gropp (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), C. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB), B. Sbarufatti (INAF-OAB) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 09:47:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 231215A (trigger=1202522). Swift could not immediately slew due to an Earth limb observing constraint. The BAT on-board calculated location is RA, Dec 9.750, +57.642 which is RA(J2000) = 00h 39m 00s Dec(J2000) = +57d 38' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 30 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~1 sec after the trigger. Due to an observing constraint, Swift will not slew until T0+42.6 minutes. There will be no XRT or UVOT data until this time. Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo AT inaf.it). 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 35345 table
GRB_name GRB231215A
GCN_number 35345
Detection_method Swift-XRT Other
ra 9.7417°
decl 57.6465°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35345 SUBJECT: GRB 231215A: Swift-XRT observations DATE: 23/12/15 11:15:35 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB) and G. Cusumano (INAF-IASF PA) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 231215A at 10:32:51.0 UT, 2725.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 9.74175, 57.64645 which is equivalent to: RA(J2000) = 00h 38m 58.02s Dec(J2000) = +57d 38' 47.2" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 22 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 (4.25 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 4.7 (+2.34/-2.12) x 10^21 cm^-2 (90% confidence).
GCN 35349 table
GRB_name GRB231215A
GCN_number 35349
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35349 SUBJECT: GRB 231215A: Mondy optical bright afterglow detection DATE: 23/12/15 12:55:34 GMT FROM: Alexei Pozanenko at IKI, Moscow N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN: We observed the field of Swift GRB 231215A (D'Avanzo et al., GCN 35343; Evans et al., GCN 35345) with AZT-33IK telescope of Mondy observatory in R-filter starting on 2023-12-15 (UT) 11:17:39. Preliminary photometry of the fist immaes reveals a new bright source within XRT error circle (Evans et al., GCN 35345) Date UT start t-T0 Exp. Filter OT Err. (mid, days) (s) 2023-12-15 11:17:39 0.063363 1x120 R 17.42 0.07 The photometry is based on nearby USNO-B1.0 R2 stars. We also may suggest that GCN 35347 (Lipunov et al.) refer to the afterglow of GRB 231215A.
GCN 35351 table
GRB_name GRB231215A
GCN_number 35351
Detection_method MITSuME
ra 9.7393°
decl 57.6472°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35351 SUBJECT: GRB 231215A : MITSuME Akeno optical afterglow candidate detection DATE: 23/12/15 13:31:43 GMT FROM: Mahito Sasada at Tokyo Institute of Technology M. Sasada, N. Higuchi, I. Takahashi, M. Niwano, S. Sato, S. Hayatsu, H. Takei, H. Seki, Y. Yatsu and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration: We observed the field of GRB 231215A (D'Avanzo et al., GCN 35343) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The observation with a series of 10 sec exposures started at 2023-12-15 09:50:27 UT (182 seconds after the Swift/BAT trigger). We stacked the first six images. An optical candidate of the afterglow can be found at the location of (RA, Dec) = (9.7393, 57.6472) near the Swift/XRT error position (Evans et al., GCN 35345). Here we report magnitudes by the aperture photometry at the position. T0+[sec] | MID-UT | T-EXP[sec] | magnitudes of aperture photometry ---------------------------------------------------------------------------------------------------------------- 238 | 2023-12-15 09:51:23 | 60 | g’=17.54+/-0.06, Rc=17.86+/-0.05, Ic=17.40+/-0.05 ---------------------------------------------------------------------------------------------------------------- T0+ : Elapsed time after the trigger T-EXP: Total Exposure time The magnitudes are consistent with Lipunov et al., GCN 35347 and Pankov et al., GCN 35349. We are continuing to observe the candidate. We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g'-, Rc- and Ic-band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).
GCN 35352 table
GRB_name GRB231215A
GCN_number 35352
Detection_method AstroSat CZTI
Circular_text TITLE: GCN CIRCULAR NUMBER: 35352 SUBJECT: GRB 231215A: AstroSat CZTI detection DATE: 23/12/15 14:11:50 GMT FROM: Gaurav Waratkar at IIT Bombay P. K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a bright long-duration GRB 231215A which was also detected by Swift-BAT (D'Avanzo et al., GCN Circ. 35343), and Fermi-GBM (Fermi GBM Team, GCN Circ. 35344). The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed two peaks of emission with the strongest peak at 2023-12-15 09:47:26.50 UTC. The measured peak count rate associated with the burst is 775 (+59, -30) counts/s above the background in the combined data of three quadrants (out of four), with a total of 8196 (+334, -292) counts. The local mean background count rate was 267 (+3, -3) counts/s. Using cumulative rates, we measure a T90 of 15 (+1, -1) s. In the preliminary analysis, we find 1372 Compton events associated with this event. The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed two peaks of emission with the strongest peak at 2023-12-15 09:47:25.92 UTC. The measured peak count rate associated with the burst is 2162 (+110, -46) counts/s above the background in the combined data of all quadrants, with a total of 22784 (+686, -737) counts. The local mean background count rate was 1465 (+6, -7) counts/s. We measure a T90 of 14 (+1, -2) s from the cumulative Veto light curve. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project. CZTI GRB detections are reported regularly on the payload site at: http://astrosat.iucaa.in/czti/?q=grb
GCN 35353 table
GRB_name GRB231215A
GCN_number 35353
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35353 SUBJECT: GRB 231215A : Nanshan/HMT optical observations DATE: 23/12/15 14:32:20 GMT FROM: Dong Xu at NAOC/CAS J. An, X. Liu, S.Q. Jiang, S.Y. Fu, T.H. Lu, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 231215A detected by Swift (D'Avanzo et al., GCN 35343) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 11:51:08 UT on 2023-12-15, i.e., 2.06 hr after the BAT trigger. A series of 90, 120, 200 s frames without any filter have been obtained and observations are ongoing. Preliminary analysis of the initial frames shows that the previously reported optical afterglow (e.g., Pankov et al., GCN 35349; Sasada et al., GCN 35351) has decayed to m(r) = 18.3 +/- 0.1 mag at 2.19 hr post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter and the magnitude is not corrected for Galactic extinction.
GCN 35354 table
GRB_name GRB231215A
GCN_number 35354
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35354 SUBJECT: GRB 231215A: GROWTH-India optical follow-up DATE: 23/12/15 15:35:12 GMT FROM: Vishwajeet Swain at IIT Bombay Y. Wagh, R. Kumar, V. Swain, A. Salgundi, V. Bhalerao (IIT Bombay), G. C. Anupama, S. Barway (IIA), K. Angail (IAO) We observed the field of GRB 231215A detected by Swift (D'Avanzo et al., GCN Circ. 35343) with 0.7m GROWTH-India Telescope (GIT). We started the observation at 2023-12-15 13:48:10.312 UT, i.e., 4.01 hours after the Swift trigger. We obtained multiple images in the r' and g' filters. We clearly detected the afterglow near the uncertainty radius of Swift-XRT position reported by P.A. Evans et al., GCN Circ. 35345 and are consistent with the coordinate reported by M. Sasada at al., GCN Circ. 35351. The photometry results follow as: ------------------------------------------------------------------------ | JD (mid) | t-t0 (hours) | Filter | Exposure (s) | Magnitude (AB) | ------------------------------------------------------------------------ | 2460294.07510789 | 4.008 | r' | 380 | 19.65 +/- 0.08 | | 2460294.08452486 | 4.248 | g' | 380 | 20.44 +/- 0.11 | ------------------------------------------------------------------------ The results are consistent to the values reported by V.Lipunov et al., GCN Circ. 35347; N. Pankov et al., GCN Circ. 35349; M. Sasada et al., GCN Circ. 35351; J. An et al., GCN Circ. 35353. The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and are not corrected for Galactic extinction. The GROWTH India Telescope (GIT; Kumar et al. 2022) 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 35357 table
GRB_name GRB231215A
GCN_number 35357
Detection_method Swift-XRT Det
ra 9.7396°
decl 57.6479°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35357 SUBJECT: GRB 231215A: Enhanced Swift-XRT position DATE: 23/12/15 16:29:06 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 1725 s of XRT Photon Counting mode data and 4 UVOT images for GRB 231215A, 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 = 9.73958, +57.64793 which is equivalent to: RA (J2000): 00h 38m 57.50s Dec (J2000): +57d 38' 52.6" with an uncertainty of 2.2 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 35361 table
GRB_name GRB231215A
GCN_number 35361
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 35361 SUBJECT: GRB 231215A: AGILE detection DATE: 23/12/15 20:12:46 GMT FROM: Francesco Verrecchia at SSDC,INAF-OAR F. Verrecchia (SSDC, and INAF/OAR), C. Casentini (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS), L. Baroncelli, A. Bulgarelli, A. Ciabattoni, A. Di Piano, V. Fioretti (INAF/OAS-Bologna), G. Panebianco (Univ. Bologna - INAF/OAS Bologna), N. Parmiggiani (INAF/OAS-Bologna), F. Lucarelli (SSDC, and INAF/OAR), P.W. Cattaneo (INFN Pavia), F. Longo (Univ. Trieste, and INFN Trieste), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), A. Ursi (ASI and INAF/IAPS), I. Donnarumma, E. Menegoni (ASI), A. Giuliani (INAF/IASF-Mi), F. Cutrona (Univ. Milano Bicocca) and P. Tempesta (TeleSpazio) report on behalf of the AGILE Team: The AGILE satellite detected the GRB 231215A at T0 = 2023-12-15 09:47:17.8 s (UTC), reported by Swift (GCNs #35343, #35345, #35357), Mondy (GCN #35349), MITSuME (GCN #35351), Astrosat (GCN #35352), HMT (GCN #35353), GROWTH (GCN #35354). The event lasted about 12 s and it released a total number of 10990 counts in the MCAL detector RM (above a background rate of 548 Hz) and 49280 counts in the AC-Top detector RM (above a background rate of 2741 Hz). The AGILE ratemeters light curves can be found at http://www.agilescienceapp.it/notices/GRB231215A_AGILE_RM_ND.png . The event also triggered a high time resolution MCAL data acquisition, from T0-22 s s to T0+10 s (UTC), and released 8436 counts in the detector, above a background rate of 510 Hz. The MCAL light curve can be found at http://www.agilescienceapp.it/notices/GRB231215A_086695_629718437.810000.png . At the T0, the event was 148 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 35362 table
GRB_name GRB231215A
GCN_number 35362
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 35362 SUBJECT: GRB 231215A: AKO Optical Upper Limit DATE: 23/12/15 21:33:00 GMT FROM: Mohammad Odeh at Al Khatim Observatory M44 Mohammad Odeh (Al-Khatim Observatory, AKO, operated by the International Astronomical Center in Abu Dhabi, UAE), and Dalya Akl (American University of Sharjah, UAE), report: We used our 0.36m f/7.7 robotic telescope to observe the field of GRB 231215A, which was detected by Swift (D'Avanzo et al., GCN 35343), and its optical counterpart was detected by (Pankov et al., GCN 35349; Sasada et al., GCN 35351; An et al., GCN 35353; Wagh et al., GCN 35354). The observation was done on 15 December starting at 20:07:36 UT, which corresponds to 10.34 hours after the GRB trigger time, using an (Ic) filter. We obtained 17x180s images, and we didn't detect a credible source within the uncertainty radius of the Swift-XRT position (Goad et al., GCN. 35357). The following 5-sigma upper limit is calculated using the ATLAS catalog as a reference: Ic = 18.8 The magnitude is not corrected for Galactic extinction.
GCN 35363 table
GRB_name GRB231215A
GCN_number 35363
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35363 SUBJECT: GRB 231215A: BOOTES-4/MET optical detection DATE: 23/12/15 21:36:53 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, E. Fernandez-Garcia, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy, S.-Y. Wu and A. J. Castro-Tirado (IAA-CSIC, Granada), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga) and D. R. Xiong, Y. F. Fan, J. M. Bai, C. J. Wang, Y. X. Xin, X. H. Zhao (Yunnan Observatories of CAS) on behalf of a larger collaboration, report: Following the detection of GRB 231215A by Swift (D'Avanzo et al. GCNC 35343) and AGILE (Verrecchia et al. GCNC 35361), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) automatically responded to this burst starting on Dec. 15 at 14:11 UT (~4.4 hrs after trigger). A series of images in clear filter were gathered and the optical afterglow was detected within the enhanced Swift/XRT position (Goad et al. GCNC 35357) for which we measure a magnitude of 19.91 +- 0.14 on the co-added 60 s x 15 image, which is consistent with the detections of MASTER (Lipunov et al. GCNC 35347), Mondy (Pankov et al. GCNC 34349), MITSuME (Sasada et al. GCNC 35351), Nanshan/HMT (An et al. GCNC 35353) and GROWTH-India (Wagh et al. GCNC 35354). Further imaging is ongoing. We thank the staff at Lijiang observatory for their excellent support.
GCN 35364 table
GRB_name GRB231215A
GCN_number 35364
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 35364 SUBJECT: GRB 231215A: Swift-XRT refined Analysis DATE: 23/12/15 22:14:28 GMT FROM: Phil Evans at U of Leicester K.L. Page (U. Leicester), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU), A.P. Beardmore (U. Leicester) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.7 ks of XRT data for GRB 231215A, from 2.7 ks to 33.0 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The light curve can be modelled with a power-law decay with a decay index of alpha=1.95 (+0.10, -0.09). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.89 (+0.20, -0.13). The best-fitting absorption column is 4.40 (+1.19, -0.15) x 10^21 cm^-2, consistent with the Galactic value of 4.2 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 4.2 x 10^-11 (6.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.40 (+1.19, -0.15) x 10^21 cm^-2 Galactic foreground: 4.2 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.89 (+0.20, -0.13) If the light curve continues to decay with a power-law decay index of 1.95, the count rate at T+24 hours will be 1.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.1 x 10^-14 (1.2 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01202522. This circular is an official product of the Swift-XRT team.
GCN 35366 table
GRB_name GRB231215A
GCN_number 35366
Detection_method Swift-UVOT Det
ra 9.7397°
decl 57.6474°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35366 SUBJECT: GRB 231215A: Swift/UVOT Detection DATE: 23/12/15 22:38:34 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (UCL-MSSL) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 231215A 2733 s after the BAT trigger (D'Avanzo et al., GCN Circ. 35343). A source consistent with the XRT position (Goad et al., GCN Circ. 35357) is detected in the initial UVOT exposures. The burst was also detected by Fermi GBM (GCN Circ. 35344),Astrosat CZTI (Navaneeth et al., GCN Circ. 35352), and in the optical by Master (Lipunov et al., 35347), MONDY (Pankov et al. GCN Circ. 35349), MITSume Akeno (Sasada et al., GCN Circ. 35351), GROWTH-India (Wagh et al., GCN Circ 35354), BOOTES-4/MET (Hu et al., GCN Circ 35363), HMT-Nanshang (An et al. GCN Circ. 35353) and an upper limit from AKO (Odeh, GCN Circ. 36362). The preliminary UVOT position is: RA (J2000) = 00:38:57.52 = 9.73967 (deg.) Dec (J2000) = +57:38:50.5 = 57.64735 (deg.) with an estimated uncertainty of 0.45 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 2733 2883 147 18.10 +/- 0.05 v 3713 3912 197 17.48 +/- 0.08 b 3096 3296 197 18.63 +/- 0.09 u 2891 3091 197 18.17 +/- 0.10 w1 4124 4323 197 19.57 +/- 0.31 m2 3918 4117 197 >19.4 w2 3507 3707 197 >19.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.506 in the direction of the burst (Schlegel et al. 1998).
GCN 35367 table
GRB_name GRB231215A
GCN_number 35367
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35367 SUBJECT: GRB 231215A : OHP/T193 optical afterglow detection DATE: 23/12/15 22:40:38 GMT FROM: Damien Turpin at CEA-Saclay D. Turpin (CEA Paris-Saclay), C. Adami (LAM), E. Le Floc'h, D. Götz, F. Schüssler (CEA Paris-Saclay), B. Schneider (MIT), S. Basa (Pytheas/OHP/LAM), A. Saccardi, S. D. Vergani (GEPI, Obs. de Paris), report on behalf of a larger collaboration: We observed the field of the long GRB 231215A (D'Avanzo et al., GCN 35343) and its afterglow candidate (Evans et al. GCN 35345) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL instrument. A total of 5 images were taken in r-band (total exposure = 3000s) and 3 others in the g-band (total exposure = 2100s) starting at 17:13:33.32 UT on 2023-12-15, ~7.43h after the trigger. In the combined frames, we clearly detect the optical afterglow reported by Lipunov et al. GCN 35347, Pankov et al. GCN 35349, Sasada et al. GCN 35351, An et al. GCN 35353, Wagh et al. GCN 35354, Hu et al. GCN 35363. The preliminary magnitude derived are the following: ----------------------------------------------- T-T0 (in days, midtime) | mag | filter ----------------------------------------------- 0.3302 | 21.32 ± 0.10 mag (AB) | r' 0.3795 | 21.76 ± 0.07 mag (AB) | g' ----------------------------------------------- The photometric calibration was performed using nearby stars from the PanSTARRS catalog and magnitudes are not corrected for Galactic extinction. Our results are compatibe with the fading behavior observed in previous GCN (Lipunov et al. GCN 35347, Pankov et al. GCN 35349, Sasada et al. GCN 35351, An et al. GCN 35353, Wagh et al. GCN 35354, Ferro et al. GCN 35355, Hu et al. GCN 35363). We note that the afterglow flux decay is steep with a temporal index alpha ~ 1.9. We encourage further follow-up observation with large telescopes to better characterize the flux and spectral evolution of this afterglow. We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Balcaen for the MISTRAL observations and the SOPHIE observer Clément Ranc.
GCN 35368 table
GRB_name GRB231215A
GCN_number 35368
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 35368 SUBJECT: GRB 231215A: CALET Gamma-Ray Burst Monitor detection DATE: 23/12/16 03:33:37 GMT FROM: Yuta Kawakubo at Louisiana State University N. Cannady (GSFC/UMBC), A. Yoshida, T. Sakamoto, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), T. Tamura, Y. Shimizu (Kanagawa U), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 231215A (Swift detection of a burst: D'Avanzo et al., GCN Circ. 35343; AstroSat CZTI detection: Navaneeth et al., GCN Circ. 35352; AGILE detection: Verrecchia et al., GCN Circ. 35361) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 09:47:15.26 UTC on 15 December 2023 (http://cgbm.calet.jp/cgbm_trigger/flight/1386668712/). The burst signal was seen by all CGBM detectors. The burst light curve shows a multi-peaked structure that starts at T+1.5 sec, peaks at T+10.4 sec, and ends at T+20.4 sec. The T90 and T50 durations measured by the SGM data are 15.2 +/- 1.3 sec and 5.6 +/- 0.2 sec (40-1000 keV), respectively. The ground-processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1386668712/index.html The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.
GCN 35369 table
GRB_name GRB231215A
GCN_number 35369
Detection_method Fermi GBM Det
t_trigger 9:47:17.810 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 35369 SUBJECT: GRB 231215A: Fermi GBM observation DATE: 23/12/16 07:57:56 GMT FROM: Elisabetta Bissaldi at Politecnico and INFN Bari E. Bissaldi (Politecnico and INFN Bari), P. Veres (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 09:47:17.81 UT on 15 December 2023, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 231215A (trigger 724326442 / 231215408), which was also detected by the Swift/BAT (D'Avanzo et al. 2023, GCN 35343). The GBM on-ground location is consistent with the Swift position. We note that the burst was automatically named incorrectly (GRB 231215B, GCN 35344), likely because the GBM trigger differs from the BAT trigger by 8 s. The angle from the Fermi LAT boresight at the GBM trigger time is 111 degrees. The GBM light curve consists of a single bright pulse with a duration (T90) of about 16 s (50-300 keV). The time-averaged spectrum from T0-1.8 s to T0+32 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is 0.73 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 761 +/- 22 keV. The event fluence (10-1000 keV) in this time interval is (7.15 +/- 0.05)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+7.5 s in the 10-1000 keV band is 20.3 +/- 0.4 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 759 +/- 23 keV, alpha = -0.73 +/- 0.02 and beta = 4.7 +/- 1.4. 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 35370 table
GRB_name GRB231215A
GCN_number 35370
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35370 SUBJECT: GRB 231215A: GAD Observatory, La Spezia, Italy upper limit; DATE: 23/12/16 11:12:34 GMT FROM: Claudio Lopresti Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy) in collaboration with: M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno), Unione Astrofili Italiani (UAI) report: We imaged the field of GRB 231215A (trigger=1202522) with the telescope LX200 12” of GAD Observatory, La Spezia, Italy Member of: UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section. GAD - Gruppo Astronomia Digitale. The observations started 551 min after the GRB trigger, with a Shmidt-Cassegrain telescope D=304 mm with reducer F/D=4.75. Weather conditions were medium. The observation with a series of 60 sec exposures started at 2023-12-15 18:58:47 UT We co-added 230 exposures of 60 sec each. Start T0+ End T0+ R lim 551 min 815 min 17,99 We did not found any optical counterpart in 00:38:58.02 +57:38:47.2 position and in the error box of the XRT candidate. ref.: P. D'Avanzo et al. GCN 35343, P.A. Evans et al. GCN 35345 Magnitudes were estimated with the Gaia EDR3 cat. and are not corrected for galactic dust extinction. Reference: https://www.parcodellestelle.com/ The message may be cited.
GCN 35373 table
GRB_name GRB231215A
GCN_number 35373
Detection_method Other
redshift 2.3050
Circular_text TITLE: GCN CIRCULAR NUMBER: 35373 SUBJECT: GRB 231215A: Redshift from OSIRIS+ / GTC DATE: 23/12/16 12:43:06 GMT FROM: Christina Thöne at ASU-CAS C. C. Thoene (ASU-CAS), A. de Ugarte Postigo (CNRS/OCA and LAM), J. F. Agui Fernandez (CAHA), L. Izzo (INAF/Capodimonte), J. P. U. Fynbo (DAWN/NBI), N. R. Tanvir (U. Leicester), M. Blazek (CAHA), S. Geier, A. Cabrera-Lavers, Fabricio Perez Toledo and Miguel Rivero (all GTC) report: We obtained spectroscopy of the afterglow of GRB 231215A (D’Avanzo et al. GCN 35343, Evans et al. GCN 35345, Pankov et al. GCN 35349) with OSIRIS+ at the 10.4m GTC at a mean epoch of 0.4958 days after the GRB. The observation consisted of 3x900s exposures with grism R1000B, covering the range between 3700 and 7780 AA at a resolving power of about 600. The spectrum shows a strong but reddened continuum with multiple absorption features. The highest redshift features include Lyman alpha, SII 1250,53,59, SiII1260, 1304, OI1302, CII 1334, SiIV1393, 1402, CIV 1548, 1550, AlII1670, FeII 1608, 1611 at a common redshift of z=2.305. We also identify fine structure lines of SiII* 1264 and 1309 at the same redshift, which we hence assume as the redshift of the GRB. Additionally, we detect two intervening systems, at z=2.076 showing CIV and SiIV absorption and at z=0.574 showing the MgII 2796, 2803 doublet. We thank the GTC staff for excellent support. This GRB reached Earth on the name's day of the first author.
GCN 35375 table
GRB_name GRB231215A
GCN_number 35375
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35375 SUBJECT: GRB 231215A: NOT optical observations DATE: 23/12/16 16:50:36 GMT FROM: Zipei Zhu at NAOC Z. Zhu, J. An, D. Xu (NAOC), D. B. Malesani (DAWN/NBI), L. Izzo (INAF/Capodimonte), A. de Ugarte Postigo (CNRS/OCA and LAM), Z. Gray (NOT) report on behalf a large collaboration: We observed the optical afterglow of GRB 231215A detected by Swift/BAT (D’Avanzo et al., GCN 35343, Evans et al., GCN 35345, Pankov et al., GCN 35349), using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started at 20:23:33 UT on 2023-12-15, i.e., 10.6 hr after the BAT trigger. We obtained 2x120 s in the Sloan r-band and then 2x1800 s spectroscopy. The previously reported optical counterpart (e.g., Lipunov et al., GCN 35347, Pankov et al., GCN 35349, Sasada et al., GCN 35351, An et al., GCN 35353, Wagh et al., GCN 35354, Hu et al., GCN 35363, Turpin et al., GCN 35367) was clearly detected in our stacked image with m(r) = 21.21 +/- 0.03 at 10.64 hr post-burst, calibrated with nearby Pan-STARRS stars. However, the S/N of the spectrum is quite low. The spectrum shows a rather flat and featureless continuum. No unambiguous absorption feature can be identified at the reported GTC redshift (Thoene et al., GCN 35373).
GCN 35376 table
GRB_name GRB231215A
GCN_number 35376
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35376 SUBJECT: GRB 231215A: optical afterglow detection from the INAF Asiago Observatory DATE: 23/12/16 18:18:47 GMT FROM: Paolo D'Avanzo at INAF-OAB A. Reguitti (INAF-OAB / INAF-OAPd), P. D'Avanzo (INAF-OAB), L. Tomasella (INAF -OAPd), E. Cappellaro (INAF -OAPd), report on behalf of the CIBO and of the GRAWITA collaborations: We carried out follow-up optical observations of GRB 231215A (D'Avanzo et al., GCN Circ. 35343; Navaneeth et al. GCN Circ. 35352; Verrecchia et al. GCN Circ. 35361; Cannady et al., GCN Circ. 35368; Bissaldi et al., GCN Circ. 35369) from the INAF - Padova Astronomical Observatory located in Asiago (Italy) with the 67/92 Schmidt telescope starting on 2023-12-15 at 16:45:00 UT (~ 7.0 hours after the burst) with the clear filter. In our stacked image the optical afterglow (Lipunov et al., GCN Circ. 35347, Pankov et al., GCN Circ. 35349, Sasada et al., GCN Circ. 35351, An et al., GCN Circ. 35353, Wagh et al., GCN Circ. 35354, Hu et al., GCN Circ. 35363; Kuin et al., GCN Circ. 35366; Turpin et al., GCN Circ. 35367; Zhu et al., GCN Circ. 35375) is detected. From preliminary analysis we estimate a magnitude of 21.2 +/- 0.2 (AB; calibrated against r band of the PanSTARRS catalog).
GCN 35377 table
GRB_name GRB231215A
GCN_number 35377
Detection_method Konus-Wind Det
t_trigger 9:47:19.795 UTC
redshift 2.3050
Circular_text TITLE: GCN CIRCULAR NUMBER: 35377 SUBJECT: Konus-Wind detection of GRB 231215A DATE: 23/12/16 18:27:11 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 long, bright GRB 231215A (Swift detection: D'Avanzo et al., GCN 35343; AstroSat CZTI detection: Navaneeth et al., GCN 35352; CALET Gamma-Ray Burst Monitor detection: Cannady et al., GCN 35368; AGILE detection: Verrecchia et al., GCN 35361; Fermi GBM detection: Lesage et al., GCN 35369) triggered Konus-Wind (KW) at T0=35239.795 s UT (09:47:19.795). The burst light curve shows a single multi-peaked pulse, which starts at ~T0-1 s, peaks at ~T0+9.5 s, and has a total duration of ~25 s. The emission is seen up to ~10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB231215_T35239/ As observed by Konus-Wind, the burst had a fluence of (1.02 ± 0.09)x10^-4 erg/cm^2 and a 64-ms peak energy flux, measured from T0 + 28.352 s, of (1.14 ± 0.12)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+24.320 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 = -0.67 (-0.07,+0.08), the high energy photon index beta = -2.49 (-0.43,+0.22), the peak energy Ep = 612 (-63,+74) keV, chi2 = 80/97 dof. The spectrum near the peak count rate (measured from T0+6.400s to T0+9.984s) 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 = -0.49 (-0.09,+0.09), the high energy photon index beta = -3.07 (-2.04,+0.44), the peak energy Ep = 582 (-54,+58) keV, chi2 = 69/80 dof. Assuming the redshift z=2.305 (Thoene et al., GCN 35373) 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 (1.35 ± 0.12)x10^54 erg, the isotropic peak luminosity L_iso to (4.93 ± 0.49)x10^53 erg/s, the rest-frame peak energy of the time-integrated spectrum Ep,i,z to ~2023 keV, and the rest-frame peak energy at the peak of the emission Ep,p,z to ~1924 keV. With the obtained estimates, GRB 230818A is inside 68% prediction band for both 'Amati' and 'Yonetoku' relations derived for the sample of >300 long KW GRBs with known redshifts (Tsvetkova et al., 2017; Tsvetkova et al., 2021), see http://www.ioffe.ru/LEA/GRBs/GRB231215_T35239/GRB231215A_rest_frame.pdf All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary.
GCN 35380 table
GRB_name GRB231215A
GCN_number 35380
Detection_method Fermi GBM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 35380 SUBJECT: GRB 231215A: GRBAlpha detection DATE: 23/12/16 19:56:14 GMT FROM: Marianna Dafčíková at Masaryk University <500025@mail.muni.cz> M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration. The long-duration GRB 231215A (Swift/BAT detection: GCN 35343; Fermi/GBM detection: GCN 35344; AstroSat detection: GCN 35352; AGILE detection: GCN 35361; CALET/CGBM detection: GCN 35368; Konus/Wind detection: GCN 35377; INTEGRAL/SPI-ACS peak detection at 2023-12-15 ~09:47:26 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048). The detection was confirmed at the peak time 2023-12-15 09:47:27 UTC. The T90 duration measured by GRBAlpha is 16 s and the overall significance during T90 reaches 42 sigma. The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB231215A_GCN.pdf All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
GCN 35386 table
GRB_name GRB231215A
GCN_number 35386
Detection_method Swift-BAT Det
ra 9.7300°
decl 57.6340°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35386 SUBJECT: GRB 231215A: Swift-BAT refined analysis DATE: 23/12/17 04:59:08 GMT FROM: Takanori Sakamoto at AGU S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. Moss (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-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 231215A (trigger #1202522) (D'Avanzo, et al., GCN Circ. 35343). The BAT ground-calculated position is RA, Dec = 9.730, 57.634 deg which is RA(J2000) = 00h 38m 55.1s Dec(J2000) = +57d 38' 00.8" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 6%. The mask-weighted light curve shows a structure of several overlapping pulses. The emission starts from T-10 s, peaks at T0 and ends at T+20 s. T90 (15-350 keV) is 20.75 +- 3.69 sec (estimated error including systematics). The time-averaged spectrum from T-7.04 to T+19.79 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.01 +- 0.09. The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+0.18 sec in the 15-150 keV band is 9.6 +- 1.4 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/1202522/BA/
GCN 35392 table
GRB_name GRB231215A
GCN_number 35392
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 35392 SUBJECT: GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit DATE: 23/12/17 19:52:34 GMT FROM: Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy in a large collaboration with: M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy), B. De Simone (Universita' degli Studi Di Salerno) report: We image the field of GRB 231215A detected by Swift Burst Alert Telescope (BAT)(trigger 1202522) with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. Member of: AAVSO - American Association of Variable Star Observers. UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili. AstroCampania Associazione The observations started at 16:28 UT of 2023/12/15, after 6,40 hours after the GRB trigger, at the end of twilight with principal telescope SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME I took 20 image of 60 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software We have not detected any clearly visible sources, up to 20th magnitude with clear skies. Start T0+ End T0+ Rlim 16:28:50 UT 17:08:29 UT 20 We did not found any optical counterpart in the error box of the XRTcandidate. P. D'Avanzo et al. GCN 35343 Magnitudes were estimated with the Gaia DR2 cat. and are not corrected for galactic dust extinction. The message may be cited.
GCN 35397 table
GRB_name GRB231215A
GCN_number 35397
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 35397 SUBJECT: GRB 231215A: AMI-LA radio detection DATE: 23/12/18 15:27:07 GMT FROM: Lauren Rhodes at Oxford Lauren Rhodes, Rob Fender (Oxford), Dave Green, Dave Titterington (Cambridge) report: We observed the field of the afterglow candidate GRB 231215A (GCN 35343) with the Arcminute Microkelvin Imager Large-Array (AMI-LA) at 15.5 GHz beginning at UT 19:57:45 on 17-Dec-2023 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 J0102+5824 was used as an interleaved complex gain calibrator. We detect an unresolved radio source at the position of the afterglow candidate as reported in GCN 35345 with a flux density of ~220uJy/beam. 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 35413 table
GRB_name GRB231215A
GCN_number 35413
Detection_method Konus-Wind Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 35413 SUBJECT: GRID detection of GRB 231215A DATE: 23/12/22 09:12:33 GMT FROM: GRID Student Team at Tsinghua University Chenyu Wang, Zirui Yang and Longhao Li report on behalf of the GRID Collaboration: GRID-04 reports the detection of the long-duration GRB 231215A, which was also detected by Swift/BAT, AstroSat CZTI, AGILE, Fermi/GBM, Konus-Wind and GRBAlpha(GCN Circular 35343, 35352, 35361, 35369, 35377 and 35380). The event was triggered with GRID on 2023-12-15 at 09:47:18.5 UTC. The measured burst duration (T90) in the 30-2000 keV range is approximately 17.0 ± 1.5 seconds. The time-averaged spectrum of GRID-04 realtime data from T+0 to T+18 sec is best fit by a cutoff power-law model. The index of the time-averaged spectrum is -0.576(-0.108,+0.114) with a fluence in the 10-1000 keV band is about 5.2488E-05 erg/cm2. All the quoted errors are at the 1-sigma confidence level. The GRID light curve of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB231215A/GRID_231215A_ltcv.pdf. The GRID spectrum of this event can be found at https://mirrors.tuna.tsinghua.edu.cn/GRID/data/GRID-GCN/GRB231215A/GRID_231215A_spec_pl.pdf. GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.
GCN 35507 table
GRB_name GRB231215A
GCN_number 35507
Detection_method Other
ra 9.7397°
decl 57.6474°
Circular_text TITLE: GCN CIRCULAR NUMBER: 35507 SUBJECT: GRB 231215A: radio detection with the VLA DATE: 24/01/09 13:31:45 GMT FROM: Stefano Giarratana at University of Bologna S. Giarratana (University of Bologna, INAF-IRA), M. Giroletti (INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.), N. Omodei (Stanford Univ.) At 03:57:39 UT on 2023 December 20 (T_mid = 4.8 days post-burst) the Karl G. Jansky VLA started observing the field of GRB 231215A (D'Avanzo et al., GCN 35343) at a central frequency of 6 and 10 GHz. The standard J0542+4951 was used as bandpass and flux density calibrator, while J0102+5824 was used as complex gain calibrator. From a preliminary analysis, an unresolved radio source (Rhodes et al., GCN 35397) is clearly detected at both frequencies at a position: RA: 00:38:57.53 +- 0.05 Dec: +57:38:50.7 +- 0.6 The surface brightness peak is 61 uJy/beam and 128 uJy/beam at 6 and 10 GHz, respectively. The r.m.s. noise level of the images is 7 uJy/beam at both 6 and 10 GHz. The synthesized beams are 13.1 x 9.9 arcsec (PA: -66deg) at 6 GHz and 7.7 x 6.0 arcsec (PA: -59deg) at 10 GHz. 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 SF161095, approved in the framework of the Fermi - NRAO joint program agreement.
GCN 35900 table
GRB_name GRB231215A
GCN_number 35900
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 35900 SUBJECT: GRB 231215A: further radio observations with the VLA DATE: 24/03/08 07:53:00 GMT FROM: Stefano Giarratana at University of Bologna S. Giarratana (University of Bologna, INAF-IRA), M. Giroletti (INAF-IRA), G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.), N. Omodei (Stanford Univ.) At 02:46:36 UT on 2023 December 28 (T_mid = 12.7 days post-burst) and at 01:39:51 UT on 2024 January 17 (T_mid = 32.7 days post-burst) the Karl G. Jansky VLA observed the field of GRB 231215A (D'Avanzo et al., GCN 35343) at a central frequency of 6 and 10 GHz. The standard J0542+4951 was used as bandpass and flux density calibrator, while J0102+5824 was used as phase calibrator. From a preliminary analysis, the radio source coincident with GRB 231215A (Rhodes et al., GCN 35397; Giarratana et al., GCN 35507) is still detected. We derive the following surface brightness peak estimates. ================================================================ T_mid Freq Peak r.m.s. Beam PA [days] [GHz] [uJy/b] [uJy/b] [arcsec] [deg] ================================================================ 12.7 6 110 8 11.69x9.50 -44 12.7 10 127 7 7.06x5.79 -33 32.7 6 48 7 7.34x4.23 -31 32.7 10 62 6 5.27x3.13 -24 ================================================================ 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 SF161095, approved in the framework of the Fermi - NRAO joint program agreement.