GRB240824A

This page lists all entries on GRB240824A in GRBweb

Summary IPN Swift GCN 37254 GCN 37255 GCN 37256 GCN 37258 GCN 37259 GCN 37263 GCN 37271 GCN 37272 GCN 37312

Summary table
Variable Value Source
T0 1:03:25 UTC GCN_circulars,Swift Det
ra 213.1760° Swift
decl 63.7350° Swift
pos_error 1.09e-02° Swift
T90 39.47 s Swift
T90_start 1:03:25 UTC Swift
fluence 1.30e-06 erg/cm² Swift
T100 39.47 s
GBM_located False
mjd 60546.04403935185 GCN_circulars,Swift Det
IPN table
GRB_name GRB240824A
ra 213.2042°
decl 63.7333°
pos_error 5.00e-02°
Swift table
GRB_name GRB240824A
t_trigger 1:03:25 UTC
ra 213.1760°
decl 63.7350°
pos_error 1.09e-02°
T90 39.47 s
fluence 1.30e-06 erg/cm²
GCN 37254 table
GRB_name GRB240824A
GCN_number 37254
Detection_method Swift Det
t_trigger 1:03:25 UTC
ra 213.2030°
decl 63.7370°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37254 SUBJECT: GRB 240824A: Swift detection of a burst DATE: 24/08/24 01:27:23 GMT FROM: David Palmer at LANL S. B. Cenko (GSFC), S. Dichiara (PSU), M. Ferro (INAF-OAB), A. Y. Lien (U Tampa), D. M. Palmer (LANL), C. Salvaggio (INAF-OAB) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 01:03:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240824A (trigger=1250282). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 213.203, +63.737 which is RA(J2000) = 14h 12m 49s Dec(J2000) = +63d 44' 13" 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 40 sec. The peak count rate was ~1200 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 01:05:39.6 UT, 134.2 seconds after the BAT trigger. No source was detected in 734 s of promptly downlinked data. We are waiting for the full dataset to detect and localise the XRT counterpart. UVOT took a finding chart exposure of 150 seconds with the White filter starting 139 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.014. Although we do not see an X-ray or optical counterpart, the high significance of the source detection in BAT (>9 sigma, confirmed by re-imaging on the ground) gives us confidence that this is an astrophysical source. Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). 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 37255 table
GRB_name GRB240824A
GCN_number 37255
Detection_method Swift-BAT Det
ra 213.1829°
decl 63.7297°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37255 SUBJECT: GRB 240824A: Skynet Optical Afterglow Discovery DATE: 24/08/24 02:59:28 GMT FROM: Dylan Dutton at UNC Chapel Hill Dylan Dutton, Megan Dubay, Donovan Schlekat, Ruide Fu, Daniel Reichart, Joshua Haislip, Vladimir Kouprianov, James Davidson, Edward Murphy, and Carlos Salgado report on behalf of the Skynet Robotic Telescope Network at the University of North Carolina at Chapel Hill. We observed the field of GRB 240824A with the RRRT telescope located in Virginia. The observation began at 01:49:13 UT on August 24 2024, roughly 46 minutes post-trigger by the Swift-BAT instrument. We detected a bright object within the uncertainty radius of the Swift localization, at: R.A. (J2000): 14:12:43.899 Dec. (J2000): 63:43:46.805 We report the discovery photometry below. The time of the exposure is the middle time. Time Since GRB | Telescope | Filter | Exposure Duration | Mag | Mag Error 2780s | RRRT | V | 70s | 15.227 | 0.024 Our images have been calibrated using stars from the APASS catalog. Additional Skynet observations are ongoing.
GCN 37256 table
GRB_name GRB240824A
GCN_number 37256
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37256 SUBJECT: GRB 240824A: KAIT optical upper limit DATE: 24/08/24 04:23:39 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 the Swift GRB 240824A (Cenko et al., GCN 37254) starting at 03:43:04 UT, ~2.67 hours after the burst. Observations were performed in the clear (roughly R) filter in twilight condition. A total of 5 x 60s images were obtained. We did not detect the optical afterglow reported by Dutton et al. (GCN 37255) in our coadd image, which we estimate the limiting magnitude be ~18.5 mag, indicating the afterglow reported by Dutton et al. (GCN 37255) has likely faded.
GCN 37258 table
GRB_name GRB240824A
GCN_number 37258
Detection_method Optical
ra 213.2030°
decl 63.7370°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37258 SUBJECT: GRB240824A: GRANDMA/TAROT-TCA Upper Limit DATE: 24/08/24 09:54:07 GMT FROM: Dalya Akl at American Uni. SHJ D. Akl (AUS), S. Antier (OCA), M. Coughlin (UMN), P-A Duverne (APC), P. Hello (IJCLAB), C. Andrade (UMN), I. Tosta e Melo (UniCT-DFA), S. Karpov (FZU), D. Turpin (CEA-Saclay/Irfu), N. Guessoum (AUS), T. Pradier (Unistra/IPHC), A. Klotz (CNRS-OMP-IRAP), M. Boer, S. Gervasoni, C. Limonta (OCA) on behalf of the GRANDMA collaboration: We imaged the field of GRB 240824A, detected by SWIFT (GCN 37254), with the TAROT-TCA telescope at the Calern observatory. The observations started ~1 min after the GRB trigger (without filter) and finished 150 min later. We did not detect any optical counterpart within the SWIFT localization error box (3 arcmin radius centered on RA, Dec = 213.203, 63.737 (deg)). We estimate an upper limit of 17.0 mag in Gaia G (5-sigma) up to 5 min post-T0, and an upper limit of 17.3 mag in Gaia G for each 30-minute epoch from 15 - 150 min post-T0. The data has been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). We also performed force photometry at the location of the Skynet optical afterglow candidate (GCN 37255), at RA, Dec (deg)=213.183, 63.730, and did not detect any optical counterpart, utilizing various exposures, and estimated an upper limit of 17.3 mag in Gaia G (Vega mag, 5-sigma) from 1 min post-T0 to 150 min, consistent with Zheng et al. (GCN 37256). We can not conclude that the candidate found in Dutton et al. (GCN 37255) is a real source. We use the SkyPortal application (skyportal.io) to monitor our observational campaign. GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 49, 5518).
GCN 37259 table
GRB_name GRB240824A
GCN_number 37259
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37259 SUBJECT: GRB 240824A: Retraction of GCN 37255 DATE: 24/08/24 12:36:31 GMT FROM: Dylan Dutton at UNC Chapel Hill On August 24 2024 at 02:59:28 UT the Skynet team issued a circular (GCN 37255) reporting the detection of an optical afterglow associated with GRB 240824A. Upon closer examination of the photometry, it is clear that the source we reported is actually RBI and not astrophysical in origin. This is consistent with the non-detections for the trigger (GCN 37258, 37257, 37256, and 37253). We apologize for any confusion this error may have caused.
GCN 37263 table
GRB_name GRB240824A
GCN_number 37263
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 37263 SUBJECT: GRB 240824A: Swift/UVOT Upper Limits DATE: 24/08/24 17:11:31 GMT FROM: Paul Kuin at MSSL GRB 240824A: Swift/UVOT Upper Limits N. P. M. Kuin (UCL-MSSL) and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 240824A 139 s after the BAT trigger (Cenko et al., GCN Circ. 37254). No optical afterglow consistent with the BAT position is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 139 289 147 >19.8 u_FC 297 547 246 >19.2 white 139 1717 411 >20.6 v 628 1767 136 >18.7 b 553 1866 136 >19.5 u 297 1841 362 >19.5 w1 677 1817 136 >19.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.014 in the direction of the burst (Schlegel et al. 1998).
GCN 37271 table
GRB_name GRB240824A
GCN_number 37271
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37271 SUBJECT: GRB 240824A: SVOM/C-GFT optical upper limit DATE: 24/08/25 14:38:45 GMT FROM: Chao Wu at NAOC SVOM/C-GFT team: Chao WU (NAOC), Zhe Kang (CHO)，Liping Xin(NAOC),Xuhui Han(NAOC),Pinpin Zhang (NAOC)，Xiaomeng Lu (NAOC), Zhenwei Li (CHO)，You Lv (CHO)，Ruosong Zhang (NAOC)，Yujie Xiao(NAOC) SVOM JSWG: Jian-Yan Wei (NAOC, China), Bertrand Cordier (CEA, F), Shuang-Nan Zhang (IHEP, CN), Stephane Basa (LAM, F), Jean-Luc Attéia (IRAP, F), Arnaud Claret (CEA, F), Zi-Gao Dai (USTC, CN), Frederic Daigne (IAP, F), Jin-Song Deng (NAOC, CN), Andrea Goldwurm (APC, F), Diego Götz (CEA, F), Xu-Hui Han (NAOC, CN), Cyril Lachaud (APC, F), En-Wei Liang (GXU, CN), Yu-Lei Qiu (NAOC, CN), Susanna Vergani (Obs. Paris, F), Jing Wang (NAOC, CN), Chao Wu(NAOC, CN), Li-Ping Xin (NAOC, CN), Bing Zhang (UNLV, CN) We observed the field of the Swift GRB 240824A (Cenko et al., GCN 37254) starting at 11:02:55UT, August 24, 2024, ~10 hr after the burst with C-GFT (Chinese Ground Follow-up Telescope in SVOM mission) in System Test Mode (STM). C-GFT is located at Jilin (long.=126.33 deg, lat.= 43.8243778 deg), Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg X 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope. A series of g ,r,and i band images were obtained. We obtained stacked images of r: 245 x 10s,g: 255 x 10s and i:234 x 10s. No optical afterglow was detected for the candidate reported by Evans (GCN 37269) down to the limit magnitude of mag_g=20.6 , mag_r=20.5, and mag_i=20.0. The photometry was calibrated with UCAC4 catalogs. We thank the observation assistant Bowen Li at Jilin observatory for their excellent support.
GCN 37272 table
GRB_name GRB240824A
GCN_number 37272
Detection_method Swift-BAT Det
ra 213.1760°
decl 63.7350°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37272 SUBJECT: GRB 240824A: Swift-BAT refined analysis DATE: 24/08/25 14:48:57 GMT FROM: Amy C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), 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 240824A (trigger #1250282) (Cenko et al., GCN Circ. 37254). The BAT ground-calculated position is RA, Dec = 213.176, 63.735 deg which is RA(J2000) = 14h 12m 42.3s Dec(J2000) = +63d 44' 06.7" with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 72%. The mask-weighted light curve shows a complex structure that starts at ~T-1 s and ends at ~T+43 s. The main peak occurs at ~T+1 s. T90 (15-350 keV) is 39.47 +- 3.44 sec (estimated error including systematics). The time-averaged spectrum from T-0.66 to T+43.40 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.30 +- 0.14. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.02 sec in the 15-150 keV band is 0.7 +- 0.2 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/1250282
GCN 37312 table
GRB_name GRB240824A
GCN_number 37312
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 37312 SUBJECT: GRB 240824A: GIT optical upper limit DATE: 24/08/27 16:58:54 GMT FROM: vishwajeet.s@iitb.ac.in T. Mohan, 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 the Swift GRB 240824A (Cenko et al., GCN 37254) with the 0.7m GROWTH-India Telescope (GIT). The observations started at 2024-08-24 16:57:29 UT, about 16 hours after the Swift BAT trigger. We obtained 6 images of 300s exposure time in r' filter. We did not detect any new source in our stacked image around the coordinates reported by Swift-XRT (Tohuvavohu et al., GCN 37269). The obtained upper limit follows as: ------------------------------------------------------------------------------------------- | JD (mid) | t-t0 (days) | Filter | Exposure (s) | Limiting Magnitude (AB) | | ----------------- | ----------- |------- | ------------------ | ----------------------- | | 2460547.2170023 | 0.67 | r' | 6x300 | 21.4 | ------------------------------------------------------------------------------------------- Our result is consistent with the upper limits reported by (SVOM/C-GFT team, GCN 37271; Swift/UVOT team, GCN 37263; Akl et al., GCN 37258; KAIT GRB team, GCN 37256). The magnitude are 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/.