December 2024 - vsnet-grb-info - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-grb-info 36558] GRB 241212A: Swift ToO observations
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38559 SUBJECT: GRB 241212A: Swift ToO observations DATE: 24/12/13 15:26:28 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the SVOM/ECLAIRs GRB 241212A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021740 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the SVOM/ECLAIRs event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. View this GCN Circular online at https://gcn.nasa.gov/circulars/38559. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36557] GRB 241213A: LCOGT Optical Upper Limits
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38558 SUBJECT: GRB 241213A: LCOGT Optical Upper Limits DATE: 24/12/13 14:28:54 GMT FROM: Robert Strausbaugh at Eastern Illinois University <rstrausbaugh(a)eiu.edu> R. Strausbaugh (Eastern Illinois University), A. Cucchiara (NASA) report on behalf of a larger collaboration: We observed the Swift GRB 241213A field (Gupta et al., GCN 38547) with the LCOGT 1-meter Sinistro instrument at the McDonald Observatory USA site, on December 13, from 06:49 to 07:19 UT (corresponding to 4.50 to 5.00 hours after the GRB trigger time) with the sdss r and i filters. We performed a series of 3x300s exposures in i-band and 2x300s in r-band. We do not detect a source within the Swift XRT enhanced error region (Osborne et al., GCN 38552) in either band, consistent with other optical upper limits (Lipunov et al., GCN 38548; Spiridonova et al., GCN 38550; Brivio et al., GCN 38553). The following 5-sigma upper limits are calculated using the PanSTARRS catalog as reference: r > 21.2 i > 21.5 These magnitudes are not corrected for galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/38558. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36556] EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38557 SUBJECT: EP 241208A : Detection of a long soft transient by SVOM/ECLAIRs DATE: 24/12/13 14:10:43 GMT FROM: SVOM_group <svomgroup(a)bao.ac.cn> SVOM/ECLAIRs Commissioning Team: Jean-Luc Atteia, Laurent Bouchet, Marius Brunet, Sebastien Guillot, Juliette Alaux, Hui Yang (IRAP), Stéphane Schanne, Damien Turpin, Nicolas Dagoneau, Frédéric Chateau, Hervé Le Provost (CEA), Wenjin Xie, Donghua Zhao (NAOC), Floriane Cangemi (APC), Tais Maiolino (LUPM), Karine Mercier, Marie-Claire Charmeau, Stefano Crepaldi (CNES) SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Olivier Godet (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/ECLAIRs telescope detected and localized the long soft transient EP241208A, also detected by Einstein Probe (GCN circular [https://gcn.nasa.gov/circulars/38477](38477)) at 2024-12-08T16:35:50.016 UTC (Tb) through an offline search with the event-by-event data downloaded through the X-band ground station. The burst was detected by several methods and within several energy ranges and timescales. The best detection is obtained by the image trigger with a signal-to-noise ratio of 6.1 within 4-8 keV over a time window of 10.24 seconds starting at Tb. The lightcurve shows a single peak of duration of about 10s. No emission has been detected above 20 keV. The localization of the best Alert is RA, Dec = 127.785, 48.861 (J2000) which is consistent with EP one.The statistical uncertainty on this position is 13 arcminutes, to which we recommend adding 2 arcminutes of systematic uncertainty in quadrature. Spectral analysis is ongoing and will be published in a future circular. ECLAIRs did not detect this burst onboard because its significance was below the onboard trigger Alert threshold. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES, and IRAP. The SVOM point of contact for this burst is: Marius Brunet (IRAP) marius.brunet(a)irap.omp.eu View this GCN Circular online at https://gcn.nasa.gov/circulars/38557. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36555] EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38556 SUBJECT: EP241213a/GRB241213a: Likely joint detection and INTEGRAL/SPI-ACS counterpart DATE: 24/12/13 13:46:38 GMT FROM: Aishwarya L Thakur at INAF-IAPS, Rome <aishth(a)outlook.com> Patrizia Barria(a,b), Giulia Gianfagna(a), James Craig Rodi(a), Aishwarya Linesh Thakur(a), Luigi Piro(a), Lorenzo Natalucci(a,b) report: The fast X-ray transient, EP241213a, was discovered by the Einstein Probe/WXT (GCN 38554). This transient appears to be spatially coincident with GRB 241213A (BAT: GCN 38547, XRT: GCN 38552), as the XRT coordinates are consistent with the 2.8 arcmin WXT error circle. There is a temporal delay of ~ 100 s between the BAT and WXT detections. We searched for any corresponding emission in the INTEGRAL/SPI-ACS data. In a light curve above 80 keV, we find a pulse temporally coincident with the BAT detection (thus occurring ~ 100 s after the EP/WXT detection, assuming they are the same event), with an approximate duration of 10 sec. The approximate peak count rate is 80000 cts/s over a median background rate of 62500 cts/s. This work is based on observations with INTEGRAL, an ESA project with instruments and a science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, and Spain), and with the participation of Russia and the USA. The SPI-ACS detector system has been provided by MPE Garching/Germany. ----- (a) INAF/IAPS-Rome (b) ICSC National Research Centre for High-Performance Computing View this GCN Circular online at https://gcn.nasa.gov/circulars/38556. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36554] GRB 241213B: MAXI/GSC detection
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38555 SUBJECT: GRB 241213B: MAXI/GSC detection DATE: 24/12/13 13:30:39 GMT FROM: Hitoshi Negoro at Nihon University/MAXI team <negoro.hitoshi(a)nihon-u.ac.jp> H. Negoro (Nihon U.), M. Serino, Y. Kawakubo (AGU), W. Iwakiri (Chiba U.), M. Nakajima, Y. Kudo, H. Shibui, K. Takagi, H. Takahashi, K. Tatano, H. Nishio (Nihon U.), T. Mihara, T. Kawamuro, S. Yamada, S. Wang, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, H. Hiramatsu, H. Nishikawa, Y. Kondo, S. Sasao, A. Yoshida (AGU), Y. Tsuboi, H. Sugai, N. Nagashima (Chuo U.), M. Shidatsu, Y. Niida (Ehime U.), I. Takahashi, M. Niwano, N. Higuchi, Y. Yatsu (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA), Y. Ueda, Y. Okada, K. Fujiwara (Kyoto U.), M. Yamauchi, Y. Otsuki, T. Hasegawa, M. Nishio (Miyazaki U.), K. Yamaoka (Nagoya U.), and M. Sugizaki (Kanazawa U.) The MAXI/GSC nova alert system triggered on a bright uncatalogued X-ray transient source at 12:56:30 UT on 2024 December 13. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (331.450 deg, 4.282 deg) = (22 05 48, +04 16 55) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.16 deg and 0.15 deg, respectively. The roll angle of the long axis from the north direction is 141.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 465 +- 58 mCrab (4.0-10.0keV, 1 sigma error). Without assumptions on the source constancy, we obtain a rectangular error box for the transient source with the following corners: (R.A., Dec) = (331.162, 4.788) deg = (22 04 38, +04 47 16) (J2000) (R.A., Dec) = (330.936, 4.585) deg = (22 03 44, +04 35 05) (J2000) (R.A., Dec) = (331.900, 3.518) deg = (22 07 35, +03 31 04) (J2000) (R.A., Dec) = (332.126, 3.721) deg = (22 08 30, +03 43 15) (J2000) There was no significant excess flux in the previous transit at 11:23 UT with an upper limit of 20 mCrab. View this GCN Circular online at https://gcn.nasa.gov/circulars/38555. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36553] EP241213a: EP detection of An X-ray Transient
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38554 SUBJECT: EP241213a: EP detection of An X-ray Transient DATE: 24/12/13 12:12:13 GMT FROM: EP Team at NAOC/CAS <ep_ta(a)bao.ac.cn> X.-Y. Zhou (PRIC), R.-Z. Li (YNAO, CAS), D.-F. Hu (PMO, CAS), S.-X. Wen, H.-W. Pan (NAO, CAS) report on behalf of the Einstein Probe team: We report on the detection of an X-ray transient by the Einstein Probe (EP), designated as EP241213a. The source was first detected by the Wide-field X-ray Telescope (WXT) on board EP in a single pointing observation (with an exposure time of 1.6 ks) at 2024-12-13T02:17:15 (UTC). The position of the transient is R.A. = 116.182 deg, Dec. = 35.271 deg, with an uncertainty of 2.8 arcmin. No previously known bright X-ray sources are found within the error circle around the transient position. The WXT spectrum of the observation can be fitted by an absorbed power law with a photon index of 2.2+/-1.4, with the NH of (5.9+/-4.8) e21 cm^-2. The derived absorbed flux in 0.5-4 keV is ~5.2e-11 ergs/s/cm^2. A Swift-XRT ToO proposal was submitted to observe the transient. Multi-wavelength follow-up observaitons are encouraged. Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES. View this GCN Circular online at https://gcn.nasa.gov/circulars/38554. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36552] GRB 241213A: REM optical/NIR upper limits
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38553 SUBJECT: GRB 241213A: REM optical/NIR upper limits DATE: 24/12/13 12:02:01 GMT FROM: Riccardo Brivio at INAF-OAB <riccardo.brivio(a)inaf.it> R.Brivio, M. Ferro, P. D’Avanzo, S. Covino, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB 241213A detected by Swift/BAT (Gupta et al., GCN 38547) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, J, H, K bands, starting on 2024 December 13 at 03:50:29 UT (i.e. 1.5 hours after the Swift trigger), and lasting for about 1 hour. From preliminary photometry we do not detect any counterpart in the optical and NIR images at the enhanced Swift-XRT position (Osborne et al., GCN 38552) down to the following 3sigma magnitude upper limits: r > 19.5 (AB; calibrated against the PanSTARRS catalogue) at a mid-time of t - t0 = 2.1 hr after the trigger, J > 17.8 (Vega; calibrated against the 2MASS catalogue) at a mid-time of t - t0 = 2.2 hr after the trigger. View this GCN Circular online at https://gcn.nasa.gov/circulars/38553. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36551] GRB 241213A: Enhanced Swift-XRT position
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38552 SUBJECT: GRB 241213A: Enhanced Swift-XRT position DATE: 24/12/13 11:28:36 GMT FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk> J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 433 s of XRT Photon Counting mode data and 1 UVOT images for GRB 241213A, 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 = 116.16998, +35.27882 which is equivalent to: RA (J2000): 07h 44m 40.80s Dec (J2000): +35d 16' 43.8" with an uncertainty of 3.4 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/38552. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36550] GRB241212A: OHP/T193 optical observations
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38551 SUBJECT: GRB241212A: OHP/T193 optical observations DATE: 24/12/13 10:32:53 GMT FROM: Christophe Adami at LAM <christophe.adami(a)lam.fr> C. Adami (LAM/Pytheas/AMU), J. Schmitt (OHP/Pytheas/AMU), S. Basa (LAM/OHP/Pytheas/AMU) report on behalf of a larger collaboration: We observed the field of GRB241212A (Fermi GBM team, GCN 38540; Zhang Li et al., GCN 38541; Joshi et al., GCN 38544; Qiu et al., GCN 38545; Zhe Kang et al., GCN 38546) using the T193cm telescope at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. Six exposures were obtained in the Y-band (6x300s) with the MISTRAL red mode during technical time from 2024 12 December 18:43 UT to 2024 12 December 19:15 UT (~+9.5h after detection). The moon was at an illumination of ~92% and at a distance of 13deg from target. We do not detect the SVOM VT GRB counterpart provided by Qiu et al. (GCN 38545). The combined frame has a detection upper limit of Y~19.25+/-0.6 (5sigma limit). The photometric calibration was performed using objects from the PanSTARRS catalog. The magnitude is not corrected for Galactic extinction. We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Pierre Troncin and the SOPHIE observers Guillaume Hebrard and Florian Destriez. View this GCN Circular online at https://gcn.nasa.gov/circulars/38551. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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[vsnet-grb-info 36549] GRB 241213A: SAO RAS optical upper limit
by GCN Circulars 13 Dec '24

13 Dec '24

TITLE: GCN CIRCULAR NUMBER: 38550 SUBJECT: GRB 241213A: SAO RAS optical upper limit DATE: 24/12/13 09:16:58 GMT FROM: Moskvitin Alexander at SAO RAS <mosk(a)sao.ru> O. I. Spiridonova and A. S. Moskvitin (SAO RAS), report on behalf of the GRB follow-up team. We observed the field of GRB 241213A (Gupta et al. GCN Circ. 38547) with the 1-m telescope of SAO RAS, Zeiss-1000 + CCD-photometer on December 12, 02:30:40--02:52:17 UT (t_mid - T0 = 1349 sec.), observations started 700 seconds after the trigger. We obtained 4 x 300 sec images in Rc band under poor seeing and weather conditions. Inside the XRT error circle we did not detect any significant object (as well as Lipunov et al., GCN Circ. 38548) down to the limiting magnitude of R_lim = 21.0, calibrated against nearby PS1 stars (magnitudes were converted with the Lupton 2005 equations and not corrected for the MW extinction). View this GCN Circular online at https://gcn.nasa.gov/circulars/38550. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0L…

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