GRB240809A

This page lists all entries on GRB240809A in GRBweb

Summary IPN Swift GCN 37110 GCN 37113 GCN 37114 GCN 37115 GCN 37116 GCN 37117 GCN 37121 GCN 37122 GCN 37123 GCN 37125 GCN 37127 GCN 37131 GCN 37132 GCN 37134 GCN 37139 GCN 37154 GCN 37157 GCN 37158 GCN 37159 GCN 37162 GCN 37167 GCN 37194 GCN 37244

Summary table
Variable Value Source
T0 8:30:29 UTC GCN_circulars,Swift Det
ra 237.5438° Swift
decl -2.3176° Swift
pos_error 7.90e-05° Swift
redshift 1.4950 GCN_circulars,Other
GBM_located False
mjd 60531.35450231482 GCN_circulars,Swift Det
IPN table
GRB_name GRB240809A
ra 237.5500°
decl -2.3167°
pos_error 5.00e-02°
redshift 1.4950
Swift table
GRB_name GRB240809A
t_trigger 8:30:29 UTC
ra 237.5438°
decl -2.3176°
pos_error 7.90e-05°
GCN 37110 table
GRB_name GRB240809A
GCN_number 37110
Detection_method Swift Det
t_trigger 8:30:29 UTC
ra 237.5510°
decl -2.3210°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37110 SUBJECT: GRB 240809A: Swift detection of a burst with a bright optical counterpart DATE: 24/08/09 08:44:45 GMT FROM: P.A. Evans at U. Leicester P. A. Evans (U Leicester), R. A. J. Eyles-Ferris (U Leicester), K. L. Page (U Leicester) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 08:30:29 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240809A (trigger=1247745). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 237.551, -2.321 which is RA(J2000) = 15h 50m 12s Dec(J2000) = -02d 19' 15" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 30 sec. The peak count rate was ~22500 counts/sec (15-350 keV), at ~2 sec after the trigger. The XRT began observing the field at 08:31:57.9 UT, 88.3 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 237.5464, -2.3178 which is equivalent to: RA(J2000) = 15h 50m 11.14s Dec(J2000) = -02d 19' 04.1" with an uncertainty of 12 arcseconds (radius, 90% containment). This location is 20 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy. UVOT took a finding chart exposure of 150 seconds with the White filter starting 98 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 15:50:10.51 = 237.54381 DEC(J2000) = -02:19:03.2 = -2.31756 with a 90%-confidence error radius of about 0.61 arc sec. This position is 9.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 14.47 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.249. 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 37113 table
GRB_name GRB240809A
GCN_number 37113
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 37113 SUBJECT: GRB 240809A: SVOM/GRM observation DATE: 24/08/09 12:04:42 GMT FROM: Chenwei Wang at IHEP SVOM/GRM team: Chen-Wei Wang, Yue Huang, Yong-Wei Dong, Jiang-Tao Liu, Shi-Jie Zheng, Jian-Chao Sun, Wen-Jun Tan, 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, Wen-Long Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao, Chao Zheng (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 240809A at 2024-08-09T08:30:28 UT (T0), which also triggered Swift/BAT (GCN 37110). The real-time alert data and light curves of SVOM/GRM were downlinked to the ground through the VHF system with low latency. The light curves show that this burst consists of a single pulse with a T90 of 13.0+1.1 s. The GRM light curve can be found here: https://www.bursthub.cn/admin/static/svgrb240809A.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: Chen-Wei Wang (IHEP)(cwwang@ihep.ac.cn)
GCN 37114 table
GRB_name GRB240809A
GCN_number 37114
Detection_method Swift-UVOT Det
ra 237.5436°
decl -2.3175°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37114 SUBJECT: GRB 240809A: Skynet & Photon Ranch Optical Afterglow Observations DATE: 24/08/09 12:38:21 GMT FROM: maedubay@unc.edu Megan Dubay, Dylan Dutton, Donovan Schlekat, Daniel Reichart, Joshua Haislip, Vladimir Kouprianov, Ruide Fu, Arie Verveer, Daryl Janzen, John Kennewall, Colin Armstrong, Ken Stranger (Skynet Robotic Telescope Network at the University of North Carolina at Chapel Hill); Michael Fitzgerald, Wayne Rosing, Andrew Yen (Photon Ranch/Las Cumbres Observatory). We observed the field of GRB 240809A with one of the Photon Ranch’s 0.4m telescopes at Eltham College Observatory (ECO1) beginning at ~540s post-trigger by the Swift-BAT instrument. Continuing observations on both the ECO1 telescope and Skynet’s PROMPT telescopes at both Meckering Observatory and Perth Observatory are underway. Our first detection occurred at 09:42 UTC on August 9, 2024, approximately 40 minutes after the optical counterpart discovery by Swift (Evans et al., GCN 37110). We detect the optical afterglow at coordinates consistent with the reported coordinates from the Swift-UVOT observation. The coordinates are: R.A. (J2000): 15:50:10.47 Dec. (J2000): -02:19:02.89 We report the most recent photometry below. Additional measurements are underway. ExpLen | Telescope | Filter | Mag | Mag Error | MJD —————————————————————————————————————————————————————————————————— 155 | PROMPT-MO-1 | I | 17.798 | 0.101 | 60531.4581 186 | PROMPT-MO-1 | R | 18.125 | 0.069 | 60531.4561 254 | R-COP | R | 18.634 | 0.253 | 60531.4669 Our images have been calibrated using stars from the APASS catalog.
GCN 37115 table
GRB_name GRB240809A
GCN_number 37115
Detection_method Swift-XRT Det
ra 237.5440°
decl -2.3179°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37115 SUBJECT: GRB 240809A: Enhanced Swift-XRT position DATE: 24/08/09 14:00:39 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 1278 s of XRT Photon Counting mode data and 3 UVOT images for GRB 240809A, 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 = 237.54399, -2.31789 which is equivalent to: RA (J2000): 15h 50m 10.56s Dec (J2000): -02d 19' 04.4" with an uncertainty of 2.0 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 37116 table
GRB_name GRB240809A
GCN_number 37116
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37116 SUBJECT: GRB 240809A: JinShan optical observations DATE: 24/08/09 17:17:02 GMT FROM: Dong Xu at NAOC/CAS S.Q. Jiang, Z.P. Zhu, S.Y. Fu, X. Liu, J. An, D. Xu (NAOC), J.Z. Liu (XAO) report on behalf of a large collaboration: We observed the field of GRB 240809A detected by Swift (Evans et al. GCN 37110) using the 100C telescope of the JinShan project located at Altay, Xinjiang, China. A series of 200 s and 300 s frames were obtained in the Sloan g-, r-, i- and z- bands, starting at 15:08:20.24 UT on 2024-08-09, i.e., 6.63 hr after the Swift/BAT trigger. The optical afterglow (Evans et al. GCN 37110; Dubay et al. GCN 37114) of the burst is clearly detected in our stacked images. Preliminary photometric results are as follows: ----------------------------------------------------------------- Tmid-T0(hr) Exp(s) Filter Mag+/-MagErr ----------------------------------------------------------------- 7.404 3x200 g 20.05 +/- 0.05 7.578 3x200 r 19.86 +/- 0.09 6.758 3x300 i 19.49 +/- 0.04 7.100 5x300 z 19.47 +/- 0.08 ----------------------------------------------------------------- calibrated with nearby PanSTARRS stars and not corrected for Galactic extinction. We acknowledge the excellent support from S.W Luo, M.M. Yang, Z. K. Feng, Q. C. Zhao and L.F. Huo for enabling these observations.
GCN 37117 table
GRB_name GRB240809A
GCN_number 37117
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37117 SUBJECT: Swift GRB 240809A: Global MASTER-Net observations report DATE: 24/08/09 17:46:34 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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 240809A ( P. A. Evans et al., GCN 37110) errorbox 32075 sec after notice time and 32089 sec after trigger time at 2024-08-09 17:25:19 UT, with upper limit up to 16.4 mag. Observations started at twilight. The observations began at zenith distance = 30 deg. The sun altitude is -16.8 deg. The galactic latitude b = 37 deg., longitude l = 6 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2556110 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 32180 | MASTER-SAAO | C | 180 | 16.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 37121 table
GRB_name GRB240809A
GCN_number 37121
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37121 SUBJECT: GRB 240809A: Swift-XRT refined Analysis DATE: 24/08/09 22:48:09 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.8 ks of XRT data for GRB 240809A, from 77 s to 45.8 ks after the BAT trigger. The data comprise 1.3 ks in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=1.02 (+0.06, -0.05). At T+257 s the decay flattens to an alpha of 0.825 (+/-0.028) before breaking again at T+2884 s to a final decay with index alpha=1.57 (+/-0.06). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.706 (+/-0.030). The best-fitting absorption column is 1.94 (+0.13, -0.12) x 10^21 cm^-2, in excess of the Galactic value of 1.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.66 (+/-0.10) and a best-fitting absorption column of 1.9 (+/-0.4) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.4 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.9 (+/-0.4) x 10^21 cm^-2 Galactic foreground: 1.5 x 10^21 cm^-2 Excess significance: 1.8 sigma Photon index: 1.66 (+/-0.10) If the light curve continues to decay with a power-law decay index of 1.57, the count rate at T+24 hours will be 0.050 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x 10^-12 (2.6 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/01247745. This circular is an official product of the Swift-XRT team.
GCN 37122 table
GRB_name GRB240809A
GCN_number 37122
Detection_method Other
redshift 1.4950
Circular_text TITLE: GCN CIRCULAR NUMBER: 37122 SUBJECT: GRB 240809A: Tentative redshift from NOT DATE: 24/08/09 23:39:17 GMT FROM: Antonio de Ugarte Postigo at OCA Rashmi Gottumukkala (DAWN/NBI), Chandana Chandrasherkhar Hegde (DAWN/DTU), Jens Reersted Larsen (IFA), Ulrika Woulhoj Jakobsen (DTU), Rasmus Damgaard Nielsen (DAWN/NBI), Nikolaj Bjerregaard Sillassen (DAWN/DTU), Albert Bjerregard Sneppen (DAWN/NBI), Johan P. U. Fynbo (DAWN/NBI), Antonio de Ugarte Postigo (CNRS), Daniele B. Malesani (DAWN/NBI and Radboud Univ.) and Nial R. Tanvir (U. Leicester) report: We observed the afterglow of GRB 240809A (Evans et al. GCN 37110; Want et al. GCN37113; Dubai et al. GCN37114; Jiang et al. GCN 37116) with ALFOSC on the 2.5 m Nordic Optical Telescope (La Palma, Spain). The observation consisted of 300 s imaging in r-band followed by 4x1200 s spectroscopy covering the range between 3500 and 9500 AA. The observation started at 2024 Aug 9.87846 UT, 12.575 hr after the burst. The afterglow is well detected in imaging at r ~ 20.3 mag. The spectrum shows continuum emission over the complete spectral range. We identify marginal spectral features which seem to match Mg II, Mg I and Fe II at a common redshift of 1.495, which we propose as the most likely redshift of this GRB. Further observations to confirm this measurement are encouraged.
GCN 37123 table
GRB_name GRB240809A
GCN_number 37123
Detection_method Swift-UVOT Det
ra 237.5438°
decl -2.3175°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37123 SUBJECT: GRB 240809A: Swift/UVOT Detection DATE: 24/08/10 01:58:51 GMT FROM: Sam Shilling at Lancaster University S.P.R. Shilling (Lancaster U.) 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 240809A 98 s after the BAT trigger (Evans et al., GCN Circ. 37110). A source consistent with the enhanced XRT position (Osborne et al., GCN Circ. 37115) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 15:50:10.52 = 237.54385 (deg.) Dec (J2000) = -02:19:03.0 = -2.31751 (deg.) with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence). Preliminary detections 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 98 248 147 14.42 +/- 0.02 v 640 660 19 16.11 +/- 0.14 b 565 585 19 16.28 +/- 0.09 u 310 560 246 15.13 +/- 0.03 w1 689 709 19 16.19 +/- 0.17 m2 665 1263 78 17.31 +/- 0.18 w2 616 1387 97 18.33 +/- 0.24 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.249 in the direction of the burst (Schlegel et al. 1998).
GCN 37125 table
GRB_name GRB240809A
GCN_number 37125
Detection_method Swift-UVOT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 37125 SUBJECT: GRB 240809A: GIT afterglow observations DATE: 24/08/10 04:21:01 GMT FROM: Varun Bhalerao at IIT Bombay T. Mohan, A. Mehla, R. Kumar, V. Swain, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team: We observed the field of GRB 240809A detected by Swift (Evans et al., GCN 37110; optical follow-up Dubay et al GCN 37114; Jiang et al GCN 37116; Lipunov et al GCN 37117; Gottumukkala et al GCN 37122) with 0.7m GROWTH-India Telescope (GIT). We started the observation at 2024-08-09 17:15:14 UT, i.e., 8.75 hours after the Swift trigger. We obtained one exposure of 300 seconds in the r' filter. In our image, we clearly detected the afterglow at the coordinates reported by Swift/UVOT Detection (Evans et al., GCN 37110). The photometry results follow as: -------------------------------------------------------------------------------------------------- | JD (mid) | t-t0 (hours) | Filter | Total Exposure (s) | Magnitude (AB) | Limiting mag | | ----------------- | ------------ |------- | ------------------ | -------------- | ------------ | | 2460532.218912037 | 8.75 | r' | 300 | 19.8 +/- 0.2 | 20.26 | -------------------------------------------------------------------------------------------------- Our observations are consistent with those reported by Dubay et al. in GCN 37114 and Jiang et al. in GCN 37116. The magnitude is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and 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 37127 table
GRB_name GRB240809A
GCN_number 37127
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37127 SUBJECT: GRB 240809A: KAIT optical observations DATE: 24/08/10 06:19:23 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to GRB 240809A detected by Swift (Evans et al., GCN 37110) starting about 0.86 days after the bust. Observations were performed in the clear (roughly R) filter, and the exposure time was 60s per image. A total of 30 images were obtained. We detected the optical afterglow (Evans et al., GCN 37110; Dubay et al., GCN 37114; Jiang et al., GCN 37116; Gottumukkala et al., GCN 37122; Mohan et al., GCN 37125) in our coadd image in clear band. We measured its brightness of 21.0 +/- 0.2 mag at a mid time of ~0.86 days after the burst, calibrated to the Pan-STARRS1 catalog.
GCN 37131 table
GRB_name GRB240809A
GCN_number 37131
Detection_method Optical
ra 15.0000°
decl -2.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37131 SUBJECT: GRB 240809A: Bassano Bresciano Observatory optical observations DATE: 24/08/10 12:21:02 GMT FROM: Ulisse Quadri at Bassano Bresciano Observatory U.Quadri, L.Strabla and P.Madurini (Bassano Bresciano Astronomical Observatory), Members of: AAVSO - American Association of Variable Star Observers. UAI/SSV - Unione Astrofili Italiani/SSV-GRB section. GAC - Gruppo Astrofili Cremonesi. 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 imaged the field of GRB 240809A detected by SWIFT(trigger 1247745) with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy. The observations started 11.38 hours after the GRB trigger, At the end of twilight with our Newton telescope D=450 mm F/D=4.5. We co-added 150 exposures of 20 sec each (total 50 min). Start T0+ End T0+ CR lim 11.38 hour 12.29 hour 20.6 We detected a (fading) afterglow in the error box of the XRTcandidate (Evans et al., GCN 37110; Wang et al., GCN 37113; Dubay et al., GCN 37114; Jiang et al., GCN 37116; V. Lipunov et al., GCN 37117; Gottumukkala et al., GCN 37122; Shilling & Evans, GCN 37123; Mohan et al., GCN 37125; Zheng & Filippenko, GCN 37127; B. Schneider et al., GCN 37129) at the following position (+/- 3 arcsec): RA (J2000) = 15 50 10.46 DEC(J2000) = -02 19 04.6 The results of our photometry are: --------------------------------------------- Date UT Exp Afterglow Middle (Min) CR-mag --------------------------------------------- 2024 08 09.84773 50 19.7 +/- 0.2 --------------------------------------------- CR magnitude is unfiltered with R zero point. Comparison stars used: ------------------------------ Pan-STARRS obj ID R-Mag ------------------------------ 105212375756448208 16.639 105202375684658035 17.916 105202375288851708 17.912 105192375172794156 17.312 105182375066235940 17.998 ------------------------------ Magnitudes were estimated with the pan-STARRS cat and are derived using Lupton (2005) equations and are not corrected for galactic dust extinction. Reference: http://www.osservatoriobassano.org/grb.asp The message may be cited.
GCN 37132 table
GRB_name GRB240809A
GCN_number 37132
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37132 SUBJECT: GRB 240809A: REM detection of the optical afterglow DATE: 24/08/10 19:17:29 GMT FROM: Riccardo Brivio R. Brivio, Y.-D. Hu, S. Covino, P. D’Avanzo, D. Fugazza (INAF-OAB) report on behalf of the REM team: We observed the field of GRB 240809A (Evans et al., GCN 37110; Want et al., GCN 37113; Dubai et al., GCN 37114; Jiang et al., GCN 37116) 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 August 09 at 23:07:36 UT (i.e. 14.6 hours after the burst), and lasting for about 1 hour. From preliminary photometry, we detect the optical afterglow at a position consistent with the UVOT detection (Schilling&Evans, GCN 37123), at the following AB magnitude in the r band: r = 20.75 +- 0.20 (calibrated against PanSTARRS catalogue) at a mid-time of t-t0 ~ 15.1 hours after the GRB trigger.
GCN 37134 table
GRB_name GRB240809A
GCN_number 37134
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37134 SUBJECT: GRB240809A: Liverpool Telescope optical follow-up observations DATE: 24/08/10 21:29:26 GMT FROM: A. Bochenek at Liverpool John Moores University A. Bochenek and D. A. Perley (LJMU) report: We observed the Gamma-Ray Burst GRB240809A (Evans et al. GCN 37110 ; Want et al. GCN37113) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 5x120s exposures with the SDSS-R and SDSS-I filters starting at 2024-08-09 21:48:46 UT, approximately 13.3 hours after the trigger. The afterglow is detected in every exposure at a position consistent with previous detections reported by Dubay et al. (GCN 37114) and Jiang et al. (GCN 37116). The obtained results are given below: MJD (mid) T_mid - T_0 Filter Mag. (AB) 60531.91279 13.40 h r 20.54 ± 0.05 60531.18419 13.60 h i 20.43 ± 0.05 The photometry was obtained using nearby PanSTARRS secondary standards and was not corrected for extinction.
GCN 37139 table
GRB_name GRB240809A
GCN_number 37139
Detection_method Konus-Wind Det
t_trigger 8:30:29.035 UTC
redshift 1.4940
Circular_text TITLE: GCN CIRCULAR NUMBER: 37139 SUBJECT: Konus-Wind detection of GRB 240809A DATE: 24/08/11 17:39:32 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 240809A (Swift-BAT detection: Evans et al., GCN 37110; SVOM-GRM detection: Wang et al., GCN 37113) triggered Konus-Wind at T0=30629.035 s UT (08:30:29.035). The burst light curve shows a multipeaked structure which starts at ~T0-4.7 s and has a total duration of ~36.9 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/GRB240809_T30629/ As observed by Konus-Wind, the burst had a fluence of 1.30(-0.09,+0.09)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+5.488 s, of 3.14(-0.45,+0.44)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+32.768 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.84(-0.07,+0.07), the high energy photon index beta = -2.54(-0.62,+0.28), the peak energy Ep = 1097(-146,+164) keV (chi2 = 118/97 dof). The spectrum near the maximum count rate (measured from T0+0.256 to T0+6.144 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.59(-0.07,+0.08), the high energy photon index beta = -2.50(-0.32,+0.21), the peak energy Ep = 1240(-146,+160) keV (chi2 = 111/82 dof). Assuming the redshift z=1.494 (Schneider et al., GCN 37129) and a standard cosmology model with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso is 7.8(-0.5,+0.5)x10^53 erg, the peak luminosity L_iso is 4.7(-0.7,+0.7)x10^53 erg/s, the rest-frame peak energy of the time-integrated spectrum Ep,i,z is 2736(-364,+409) keV, and the rest-frame peak energy at the peak of the emission Ep,p,z is 3093(-364,+399) keV. With the obtained estimates, GRB 240809A is inside 90% prediction bands 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/GRB240809_T30629/GRB240809A_rest_frame.pdf All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 37154 table
GRB_name GRB240809A
GCN_number 37154
Detection_method Swift-BAT Det
ra 237.5450°
decl -2.3310°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37154 SUBJECT: GRB 240809A: Swift-BAT refined analysis DATE: 24/08/12 18:06:35 GMT FROM: Tyler Parsotan at NASA GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240809A (trigger #1247745) (Evans, et al., GCN Circ. 37110). The BAT ground-calculated position is RA, Dec = 237.545, -2.331 deg which is RA(J2000) = 15h 50m 10.8s Dec(J2000) = -02d 19' 51.1" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 72%. The mask-weighted light curve shows a single peaked fast rise exponential decay structure with a tail that lasts until ~100 seconds after the trigger time. T90 (15-350 keV) is 72.86 +- 19.39 sec (estimated error including systematics). The time-averaged spectrum from -10.876 to 180.52 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.17 +- 0.05. The fluence in the 15-150 keV band is 9.7 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+2.68 sec in the 15-150 keV band is 12.8 +- 0.4 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1247745
GCN 37157 table
GRB_name GRB240809A
GCN_number 37157
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37157 SUBJECT: GRB 240809A: ALMA detection DATE: 24/08/12 21:44:40 GMT FROM: Tanmoy Laskar at U of Bath T. Laskar (University of Utah), C. Christy (University of Arizona), K. D. Alexander (University of Arizona), G. Schroeder (Northwestern University), C. Peña (University of Utah), E. Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong (Northwestern University), R. Margutti (UC Berkeley), and P. Schady (University of Bath) report on behalf of a larger collaboration: "We observed GRB 240809A (Evans et al., GCN 37110) with the Atacama Large Millimeter/Submillimeter Array (ALMA) at 97.5 GHz over two epochs, beginning on 2024 August 09 19:30 UT and 2024 August 10 23:28 UT, at 11 h and 39 h after the burst, respectively. Preliminary analysis reveals a fading mm source, with flux density of ~ 0.1 mJy in the first epoch, which we identify as the radio counterpart of GRB 240809A. Further observations are planned. We thank the JAO staff, AoD, P2G, and the entire ALMA team for their help with these observations."
GCN 37158 table
GRB_name GRB240809A
GCN_number 37158
Detection_method VLA Det
ra 237.5437°
decl -2.3181°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37158 SUBJECT: GRB 240809A: VLA detection DATE: 24/08/12 21:45:54 GMT FROM: Tanmoy Laskar at U of Bath C. Christy (University of Arizona), T. Laskar (University of Utah), K. D. Alexander (University of Arizona), G. Schroeder (Northwestern University), C. Peña (University of Utah), E. Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong (Northwestern University), R. Margutti (UC Berkeley), and P. Schady (University of Bath) report on behalf of a larger collaboration: "We observed GRB 240809A (Evans et al., GCN 37110) with the Karl G. Jansky Very Large Array (VLA) beginning on 2024 August 10 02:25 UTC (17.9 h after the burst) at multiple frequencies. In preliminary analysis, we detect the radio counterpart (Laskar et al., GCN 37157) with a flux density of ~ 0.2 mJy at 15 GHz, and position: RA (J2000) = 15h 50m 10.5s Dec (J2000) = -02d 19' 5.1" with a (statistical) uncertainty of 0.2" in each coordinate. This position is consistent with the X-ray and optical position (Evans et al., GCN 37110). Further observations are planned. We thank the VLA staff for scheduling and executing these observations"
GCN 37159 table
GRB_name GRB240809A
GCN_number 37159
Detection_method Other
ra 87.5440°
decl -2.3176°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37159 SUBJECT: GRB 240809A : RAPAS follow-up observations DATE: 24/08/12 21:51:25 GMT FROM: Thierry Midavaine at GRANDMA Thierry Midavaine on behalf of the RAPAS network reports (#1) : P. Martinez and C. Latgé [1], M. Serrau [2] and A. Leroy [3] observed the Gamma-Ray Burst GRB240809A (Evans et al. GCN 37110 ; Want et al. GCN 37113) using [1] ADAGIO N 820mm telescope at Belesta Observatory (IAU A05) equiped with a Moravian CMOS camera, [2] SC 300mm telescope at Vidauban [A77] equiped with a QHYCCD CMOS camera and [3] SC 350mm telescope at Madagascar equiped with a ZWO ASI CMOS camera. [1] and [2] are equiped with the set of 3 RAPAS filters meeting the Gaia G, Gbp and Grp photometric bands. The FITS files are reduced with the Gaia photometric catalog in respective spectral bands. The afterglow is detected RA(J2000) = 5h 50m 10.55s ; Dec(J2000) = -02d 19' 03.3" [1] MJD (mid) Gaia filter band mag.(Gaia) RAPAS station 60531.66128 G 19.75 ± 0.14 [3] 60531.86667 Grp 20.48 ± 0.60 [1] 60531.86736 G 20.52 ± 0.47 [2] 60531.87778 Gbp 20.10 ± 0.32 [1] 60531.89444 G 20.58 ± 0.19 [1] RAPAS ( https://proam-gemini.fr/rapas/ ) is a new ProAm collaboration funded by Paris Observatory, delivering to a network of french amateur observatories a set of 3 filters meeting the Gaia spectral bands. This network is dedicated to deliver data in the Gaia photometric system on selected astrophysical alerts by Astro-COLIBRI ( https://astro-colibri.com/ ) or from Gaia alerts.
GCN 37162 table
GRB_name GRB240809A
GCN_number 37162
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37162 SUBJECT: GRB 240809A: ATA radio non-detection DATE: 24/08/12 23:39:16 GMT FROM: Tanmoy Laskar at U of Bath C. Christy (University of Arizona), W. Farah (SETI Institute), T. Laskar (University of Utah), K. D. Alexander (University of Arizona), G. Schroeder (Northwestern University), C. Peña (University of Utah), A. Pollak (SETI Institute), A. Siemion (SETI Institute), E. Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong (Northwestern University), R. Margutti (UC Berkeley), and P. Schady (University of Bath) report on behalf of a larger collaboration: "We observed GRB 240809A (Evans et al., GCN 37110) with the Allen Telescope Array (ATA) beginning on 2024 August 09 23:25 UTC (14.9 h after the burst) at 5GHz and 8GHz. In our preliminary analysis, we do not detect any radio emission at or near the X-ray and optical position (Evans et al., GCN 37110) or radio position (Christy et al., GCN 37158) to a 3-sigma limit of ~0.9mJy at 5GHz and ~2.0mJy at 8GHz. We thank the ATA staff for quickly scheduling these observations"
GCN 37167 table
GRB_name GRB240809A
GCN_number 37167
Detection_method Other
ra 237.5437°
decl -2.3176°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37167 SUBJECT: GRB 240809A: Correction to the VLA source position in GCN 37158 DATE: 24/08/13 02:57:53 GMT FROM: Tanmoy Laskar at U of Utah C. Christy (University of Arizona), T. Laskar (University of Utah), K. D. Alexander (University of Arizona), G. Schroeder (Northwestern University), C. Peña (University of Utah), E. Berger (Harvard University), R. Chornock (UC Berkeley), W. Fong (Northwestern University), R. Margutti (UC Berkeley), and P. Schady (University of Bath) report on behalf of a larger collaboration: "The declination of the VLA radio counterpart of GRB 240809A given in GCN 37158 is incorrect. The correct source position is: RA (J2000) = 15h 50m 10.5s Dec (J2000) = -02d 19' 3.4" with a (statistical) uncertainty of 0.2" in each coordinate. We apologize for any confusion caused."
GCN 37194 table
GRB_name GRB240809A
GCN_number 37194
Detection_method Optical
ra 237.5500°
decl -2.3208°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37194 SUBJECT: GRB GRB 240809A: Osservatorio Astronomico "Nastro Verde" optical observations: detection of an optical counterpart DATE: 24/08/16 19:54:06 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: Following the Swift trigger no. 1247745 (GCN 37110 P. A. Evans (U Leicester), R. A. J. Eyles-Ferris (U Leicester),K. L. Page (U Leicester) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team) from the Swift Burst Alert Telescope (BAT), we pointed at the coordinates RA(J2000)=15h 50m 12s: Dec(J2000)=-02d 19' 15" and started our observations 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. The observations started at 19:25 UT of 2023/08/09, after about 11 hours after the GRB trigger, with clear sky, with principal telescope SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME I took 48 unfiltered images of 60 sec . Start End Rlim 19:25:37 UT 20:35:28 UT 20.5 All images, calibrated with masterdark and masterflat have been measured with Thycho Tracker software We have detected a faint source at the enhanced position reported by Swift-XRT teamat following position RA (J2000) 15 50 10.54 Dec (J2000) -02 19 05.3 with the following photometry and astrometry: GRB 240809A 15 50 10.54 -02 19 05.3 20.0 C82 Magnitudes were estimated with the GAIA DR2 cat. and are not corrected for galactic dust extinction. The message may be cited.
GCN 37244 table
GRB_name GRB240809A
GCN_number 37244
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 37244 SUBJECT: GRB 240809A: Mondy and AbAO Optical Observations DATE: 24/08/23 11:19:52 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (HSE, IKI), N. Pankov (HSE, IKI), E. Klunko (ISTP), R. Ya. Inasaridze (AbAO), A. Pozanenko (IKI) report on behalf of GRB-IKI-FuN: We observed the field of GRB 240809A, detected by Swift (Evans et al., GCN 37110) and SVOM (Wang et al., GCN 37113), using the AZT-33IK 1.5-meter telescope at the Sayan Observatory (Mondy) and the AS-32 0.7-meter telescope at the Abastumani Observatory (AbAO). The observations began on 2024-08-09 at 13:54:52 (UT) and 17:27:38 (UT), respectively, i.e., about 0.2 and 7 hours after the Swift trigger. The preliminary photometry of the optical counterpart (Evans et al., GCN 37110; Dubay et al., GCN 37114; Jiang et al., GCN 37116; Gottumukkala et al., GCN 37122; Shilling et al., GCN 37123; Mohan et al., GCN 37125; Zheng & Filippenko, GCN 37127; Schneider et al., GCN 37129; Quadri et al., GCN 37131; Brivio et al., GCN 37132; Midavaine et al., GCN 37159; Ruocco et al., GCN 37194) is provided below: Date UT Start t-T0 Exp. Filter OT Err. UL Telescope (mid, days) (s) (3sigma) 2024-08-09 13:54:52 0.24228 49*60 R 19.45 0.05 22.3 AZT-33IK 2024-08-09 17:27:38 0.37302 44*60 R n/d n/d 20.0 AS-32 The magnitudes were calibrated using nearby comparison stars from the USNO-B1.0 catalog (R2 magnitudes). No correction was made for the Galactic extinction toward the GRB, corresponding to E(B-V) = 0.213 (S&F 2011). The optical light curve is well fitted by a power-law model with an index of -1.3, which is typical for GRBs.