GRB240730A

This page lists all entries on GRB240730A in GRBweb

Summary IPN Swift GCN 36976 GCN 36978 GCN 36980 GCN 36982 GCN 36983 GCN 36987 GCN 37005

Summary table
Variable Value Source
T0 7:52:06 UTC GCN_circulars,Swift Det
ra 37.8382° Swift
decl 59.0288° Swift
pos_error 3.37e-04° Swift
GBM_located False
mjd 60521.32784722222 GCN_circulars,Swift Det
IPN table
GRB_name GRB240730A
ra 37.8292°
decl 59.4667°
pos_error 5.00e-02°
Swift table
GRB_name GRB240730A
t_trigger 7:52:06 UTC
ra 37.8382°
decl 59.0288°
pos_error 3.37e-04°
GCN 36976 table
GRB_name GRB240730A
GCN_number 36976
Detection_method Swift Det
t_trigger 7:52:06 UTC
ra 37.8290°
decl 59.0740°
Circular_text TITLE: GCN CIRCULAR NUMBER: 36976 SUBJECT: GRB 240730A: Swift detection of a burst DATE: 24/07/30 08:11:21 GMT FROM: David Palmer at LANL S. B. Cenko (GSFC), P. A. Evans (U Leicester), R. A. J. Eyles-Ferris (U Leicester), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 07:52:06 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240730A (trigger=1245636). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 37.829, +59.074 which is RA(J2000) = 02h 31m 19s Dec(J2000) = +59d 04' 27" 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 80 sec. The peak count rate was ~300 counts/sec (15-350 keV), at ~30 sec after the trigger. The XRT began observing the field at 07:54:14.8 UT, 128.7 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source with an enhanced position: RA, Dec 37.83844, 59.02878 which is equivalent to: RA(J2000) = 02h 31m 21.22s Dec(J2000) = +59d 01' 43.6" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 163 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 consistent with the Galactic value of 7.80 x 10^21 cm^-2 (Willingale et al. 2013). UVOT took a finding chart exposure of 150 seconds with the White filter starting 133 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 none of the XRT error circle. The coverage of the XRT error circle by the 8'x8' region for the list of sources generated on-board is uncertain because the large number of sources filled the available telemetry. The list of sources is typically complete to about 18 mag. No correction has been made for the large, but uncertain, extinction expected. Although this appears to be a long GRB, its long duration and its position near the Galactic plane (lat=-1.35) raise the possibility that this is a Galactic transient instead. If that is the case then we give it the name Swift J0231.3+5902 . 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 36978 table
GRB_name GRB240730A
GCN_number 36978
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 36978 SUBJECT: GRB 240730A: Swift/UVOT Upper Limits DATE: 24/07/30 12:36:41 GMT FROM: Paul Kuin at MSSL Paul Kuin (MSSL/UCL), R. Caputo and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 240730A 133 s after the BAT trigger (Cenko et al., GCN Circ. 36976). No optical afterglow consistent with the XRT position in Evans et al., GCN Circ. 36977, 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 133 283 147 >19.1 u_FC 291 541 246 >19.2 white 133 1026 295 >19.1 u 291 541 246 >19.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.146 in the direction of the burst (Schlegel et al. 1998).
GCN 36980 table
GRB_name GRB240730A
GCN_number 36980
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 36980 SUBJECT: GRB 240730A: KAIT Optical Upper Limit DATE: 24/07/30 15:59:11 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 Swift GRB 240730A (Cenko et al., GCN 36976) starting at 10:24UT, ~2.53 hours after the burst. A total of 50x60s images were obtained in the clear (roughly R) filters. We do not detect any optical afterglow candidate within the enhanced XRT position error circle (Evans et al., GCN 36977), neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 19.5 mag calibrated to the PS1 catalog.
GCN 36982 table
GRB_name GRB240730A
GCN_number 36982
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 36982 SUBJECT: GRB 240730A: Swift-XRT refined Analysis DATE: 24/07/30 16:44:42 GMT FROM: Phil Evans at U of Leicester S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), M. Ferro (INAF-OAB), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 7.2 ks of XRT data for GRB 240730A, from 113 s to 23.5 ks after the BAT trigger. The data comprise 14 s 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 power-law decay with a decay index of alpha=2.04 (+/-0.24). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.6 (+/-0.4). The best-fitting absorption column is 1.4 (+0.6, -0.5) x 10^22 cm^-2, in excess of the Galactic value of 7.8 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 6.8 x 10^-11 (1.0 x 10^-10) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.4 (+0.6, -0.5) x 10^22 cm^-2 Galactic foreground: 7.8 x 10^21 cm^-2 Excess significance: 2.1 sigma Photon index: 1.6 (+/-0.4) If the light curve continues to decay with a power-law decay index of 2.04, the count rate at T+24 hours will be 5.4 x 10^-6 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.6 x 10^-16 (5.7 x 10^-16) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01245636. This circular is an official product of the Swift-XRT team.
GCN 36983 table
GRB_name GRB240730A
GCN_number 36983
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 36983 SUBJECT: Swift GRB 240730A: Global MASTER-Net observations report DATE: 24/07/30 18:56:28 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 240730A ( S. B. Cenko et al., GCN 36976) errorbox 37782 sec after notice time and 37859 sec after trigger time at 2024-07-30 18:23:05 UT, with upper limit up to 16.8 mag. Observations started at twilight. The observations began at zenith distance = 71 deg. The sun altitude is -11.9 deg. The galactic latitude b = -1 deg., longitude l = 136 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2545484 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 32544 | MASTER- | C | 30 | 18.9 | 32585 | MASTER- | C | 30 | 18.8 | 32627 | MASTER- | C | 30 | 18.8 | 32671 | MASTER- | C | 30 | 18.8 | 32719 | MASTER- | C | 30 | 18.6 | 32762 | MASTER- | C | 30 | 19.0 | 33359 | MASTER- | C | 30 | 18.8 | 33403 | MASTER- | C | 30 | 18.9 | 34542 | MASTER- | C | 180 | 19.4 | 34735 | MASTER- | C | 180 | 19.5 | 34928 | MASTER- | C | 180 | 19.4 | 35120 | MASTER- | C | 180 | 19.3 | 35313 | MASTER- | C | 180 | 19.4 | 35509 | MASTER- | C | 180 | 19.1 | 35703 | MASTER- | C | 180 | 19.3 | 35821 | MASTER- | C | 30 | 19.1 | 35868 | MASTER- | C | 30 | 19.1 | 35915 | MASTER- | C | 30 | 19.1 | 35957 | MASTER- | C | 30 | 19.1 | 36000 | MASTER- | C | 30 | 19.1 | 36042 | MASTER- | C | 30 | 19.1 | 36085 | MASTER- | C | 30 | 18.9 | 36121 | MASTER- | C | 30 | 19.1 | 36163 | MASTER- | C | 30 | 19.1 | 36206 | MASTER- | C | 30 | 19.1 | 36248 | MASTER- | C | 30 | 19.1 | 36291 | MASTER- | C | 30 | 18.8 | 36970 | MASTER- | C | 180 | 18.9 | 37949 | MASTER-Tavrida | C | 180 | 16.8 | 38248 | MASTER- | C | 180 | 19.3 | 39462 | MASTER- | C | 180 | 19.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 36987 table
GRB_name GRB240730A
GCN_number 36987
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 36987 SUBJECT: GRB240730A: BOOTES-5/JGT early optical upper limit DATE: 24/07/31 04:48:14 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia S. Guziy, E. Fernandez-Garcia, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S.-Y. Wu and A. J. Castro-Tirado (IAA-CSIC, Granada), Y.-D. Hu (INAF-OAB), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar (UMA), I. M. Carrasco-Garcia (SMA) and I. H. Park (SKKU), on behalf of a larger collaboration, report: Following the detection of GRB 240730A by Swift (Cenko et al. GCNC 36976), the BOOTES-5/JGT 0.6m robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically observed the GRB location starting on Jul. 30, 07:53:50 UT (~ 104 s after trigger). No new optical source is detected on the co-added images (57 x 1 s, clear-filter) within the enhanced Swift/XRT error box (Evans et al. GCNC 36977) down to 18.7 mag. which is consistent with reports from UVOT (Kuin et al., GCNC 36978), KAIT (Zheng et al., GCNC 36980) and MASTER (Lipunov et al. GCNC 36983). We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support.
GCN 37005 table
GRB_name GRB240730A
GCN_number 37005
Detection_method Swift-BAT Det
ra 37.8410°
decl 59.0450°
Circular_text TITLE: GCN CIRCULAR NUMBER: 37005 SUBJECT: GRB 240730A: Swift-BAT refined analysis DATE: 24/08/01 19:55:22 GMT FROM: Michael Moss at NASA GSFC D. Sadaula (GSFC/UMBC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), T. Sakamoto (AGU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240730A (trigger #1245636) (Cenko, et al., GCN Circ. 36976). The BAT ground-calculated position is RA, Dec = 37.841, 59.045 deg which is RA(J2000) = 02h 31m 21.9s Dec(J2000) = +59d 02' 43.5" with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 98%. The BAT mask-weighted light curve displays two spectrally soft peaks. The T90 (15-350 keV) is 50.13 +- 7.60 sec (estimated error including systematics). The time-averaged spectrum from T-6.06 to T+53.43 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.50 +- 0.19. The fluence in the 15-150 keV band is 6.8 +- 0.9 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+5.80 sec in the 15-150 keV band is 0.4 +- 0.1 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/1245636 The long duration and proximity to the Galactic plane raised the initial possibility that this was a Galactic transient. However, its subsequent behavior, including a lack of later BAT detections, is consistent with a GRB, making the Galactic transient interpretation less likely.