GRB241228A

This page lists all entries on GRB241228A in GRBweb

Summary Fermi GBM IPN Swift GCN 38681 GCN 38683 GCN 38686 GCN 38689 GCN 38693 GCN 38695 GCN 38701 GCN 38709 GCN 38727 GCN 38815 GCN 39684

Summary table
Variable Value Source
GRB_name_Fermi GRB241228165
T0 3:57:10.170 UTC GCN_circulars,Fermi GBM Det
ra 344.8013° Swift
decl 18.6100° Swift
pos_error 2.46e-04° Swift
T90 8.32 s Fermi_GBM
T90_error 0.181 s Fermi_GBM
T90_start 3:57:10.494 UTC Fermi_GBM
fluence 5.12e-06 erg/cm² Fermi_GBM
fluence_error 1.35e-08 erg/cm² Fermi_GBM
T100 12.89 s
GBM_located False
mjd 60672.164701041664 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB241228165
trigger_name bn241228165
ra 344.8242°
decl 18.6039°
datum 2024-12-28
t_trigger 3:57:10.174 UTC
T90 8.32 s
T90_error 0.181 s
T90_start 3:57:10.494 UTC
fluence 5.12e-06 erg/cm²
fluence_error 1.35e-08 erg/cm²
flux_1024 1.99e+01 erg/cm²/s
flux_1024_error 3.89e-01 erg/cm²/s
flux_1024_time 6.98e+00 erg/cm²/s
flux_64 2.46e+01 erg/cm²/s
flux_64_error 1.54e+00 erg/cm²/s
IPN table
GRB_name GRB241228A
ra 344.8250°
decl 18.6000°
pos_error 5.00e-02°
Swift table
GRB_name GRB241228A
t_trigger 3:57:15 UTC
ra 344.8013°
decl 18.6100°
pos_error 2.46e-04°
T90 8.06 s
fluence 3.00e-06 erg/cm²
GCN 38681 table
GRB_name GRB241228A
GCN_number 38681
Detection_method Swift Det
t_trigger 3:57:15 UTC
ra 344.8240°
decl 18.6040°
Circular_text TITLE: GCN CIRCULAR NUMBER: 38681 SUBJECT: GRB 241228A: Swift detection of a burst DATE: 24/12/28 04:14:28 GMT FROM: Simone Dichiara at Pennsylvania State University V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), S. Dichiara (PSU), R. Gupta (NASA GSFC) and N. P. M. Kuin (UCL-MSSL) report on behalf of the Neil Gehrels Swift Observatory Team: At 03:57:15 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 241228A (trigger=1277277). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 344.824, +18.604 which is RA(J2000) = 22h 59m 18s Dec(J2000) = +18d 36' 14" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multipeak structure with a duration of about 20 sec. The peak count rate was ~11085 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 03:58:52.3 UT, 97.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 344.80173, 18.61005 which is equivalent to: RA(J2000) = 22h 59m 12.42s Dec(J2000) = +18d 36' 36.2" with an uncertainty of 1.9 arcseconds (radius, 90% containment). This location is 79 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. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (6.67 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 6.2 (+4.07/-3.30) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 100 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 100% of the XRT 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 XRT 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 0.091. Burst Advocate for this burst is V. D'Elia (valerio.delia AT ssdc.asi.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 38683 table
GRB_name GRB241228A
GCN_number 38683
Detection_method Swift-XRT Det
ra 344.8019°
decl 18.6106°
Circular_text TITLE: GCN CIRCULAR NUMBER: 38683 SUBJECT: GRB 241228A: Enhanced Swift-XRT position DATE: 24/12/28 08:09:14 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 1737 s of XRT Photon Counting mode data and 4 UVOT images for GRB 241228A, 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 = 344.80186, +18.61065 which is equivalent to: RA (J2000): 22h 59m 12.45s Dec (J2000): +18d 36' 38.3" with an uncertainty of 2.3 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 38686 table
GRB_name GRB241228A
GCN_number 38686
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 38686 SUBJECT: GRB 241228A: Swift-XRT refined Analysis DATE: 24/12/28 13:27:42 GMT FROM: Phil Evans at U of Leicester C. Salvaggio (INAF-OAB), J.A. Kennea (PSU), D.N. Burrows (PSU), M. A. Williams (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), M. Ferro (INAF-OAB), R. Brivio (INAF-OAB) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 9.1 ks of XRT data for GRB 241228A, from 82 s to 28.8 ks after the BAT trigger. The data comprise 83 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The late-time light curve (from T0+4.8 ks) can be modelled with a power-law decay with a decay index of alpha=1.54 (+0.13, -0.12). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.00 (+0.18, -0.17). The best-fitting absorption column is 2.2 (+0.7, -0.6) x 10^21 cm^-2, in excess of the Galactic value of 6.7 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.86 (+0.15, -0.14) and a best-fitting absorption column of 3.6 (+0.8, -0.7) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x 10^-11 (6.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 3.6 (+0.8, -0.7) x 10^21 cm^-2 Galactic foreground: 6.7 x 10^20 cm^-2 Excess significance: 6.9 sigma Photon index: 1.86 (+0.15, -0.14) If the light curve continues to decay with a power-law decay index of 1.54, the count rate at T+24 hours will be 4.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x 10^-13 (2.7 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/01277277. This circular is an official product of the Swift-XRT team.
GCN 38689 table
GRB_name GRB241228A
GCN_number 38689
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 38689 SUBJECT: GRB 241228A: GROWTH-India telescope optical upper limit DATE: 24/12/28 16:25:15 GMT FROM: V. Swain at IIT Bombay T. Mohan, V. Swain, A.P. Saikia, 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 GRB 241228A (D'Elia et al., GCN 38681) with the 0.7m GROWTH-India Telescope (GIT). Observation started at 2024-12-28T13:13:58 UT, about 9.27 hours after the trigger. We responded to the enhanced Swift-XRT coordinates (Evans et al., GCN 38683) and obtained multiple images of 360s in r' filter. The obtained upper limit in our stacked image is: | MJD (mid) | Filter | Exposure (s) | Limiting Magnitude (AB) | | ----------- | ------ | ------------ | ----------------------- | | 60672.56537 | r' | 4x360 | 20.8 The upper limit is consistent with Kuin et al., GCN 38685. 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 38693 table
GRB_name GRB241228A
GCN_number 38693
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 38693 SUBJECT: Swift GRB 241228A: Global MASTER-Net observations report DATE: 24/12/28 19:16:36 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko, A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) 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 241228A ( V. D'Elia et al., GCN 38681) errorbox 53242 sec after notice time and 53275 sec after trigger time at 2024-12-28 18:45:10 UT, with upper limit up to 16.7 mag. Observations started at twilight. The observations began at zenith distance = 72 deg. The sun altitude is -11.2 deg. The galactic latitude b = -37 deg., longitude l = 90 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2724378 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 53366 | MASTER-SAAO | C | 180 | 12.2 | 53565 | MASTER-SAAO | C | 180 | 16.4 | 53764 | MASTER-SAAO | C | 180 | 16.5 | 53964 | MASTER-SAAO | C | 180 | 16.6 | 54163 | MASTER-SAAO | C | 180 | 16.7 | 54364 | MASTER-SAAO | C | 180 | 16.5 | 54563 | MASTER-SAAO | C | 180 | 16.6 | 54763 | MASTER-SAAO | C | 180 | 16.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 38695 table
GRB_name GRB241228A
GCN_number 38695
Detection_method Fermi GBM Det
t_trigger 3:57:10.170 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 38695 SUBJECT: GRB 241228A: Fermi GBM Observation DATE: 24/12/28 21:20:27 GMT FROM: Lorenzo Scotton at UAH L. Scotton (UAH) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 03:57:10.17 UT on 28 December 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241228A (trigger 757051035/241228165), which was also detected by Swift BAT (V. D'Elia et al. 2024, GCN 38681). The Fermi GBM on-ground location is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 55 degrees. The GBM light curve consists of a minor triggering episode followed by a two-peak episode, with a duration (T90) of about 8.3 s (50-300 keV). The time-averaged spectrum from T0-0.5 to T0+10.9 s is best fit by a Band function with Epeak = 66 +/- 3 keV, alpha = -0.68 +/- 0.08, and beta = -2.8 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (5.6 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+7.0 s in the 10-1000 keV band is 19.9 +/- 0.4 ph/s/cm^2. 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 38701 table
GRB_name GRB241228A
GCN_number 38701
Detection_method Swift-BAT Det
ra 344.8100°
decl 18.6080°
Circular_text TITLE: GCN CIRCULAR NUMBER: 38701 SUBJECT: GRB 241228A: Swift-BAT refined analysis DATE: 24/12/29 03:23:00 GMT FROM: Amy D. Sadaula (GSFC/UMBC), S. D. Barthelmy (GSFC), D’Elia (SSDC & INAF-OAR), 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-240 to T+1101 sec from the recent telemetry downlink, we report further analysis of BAT GRB 241228A (trigger #1277277) (D'Elia et al., GCN Circ. 38681). The BAT ground-calculated position is RA, Dec = 344.810, 18.608 deg which is RA(J2000) = 22h 59m 14.4s Dec(J2000) = +18d 36' 28.6" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 39%. The mask-weighted light curve shows several overlapping pulses that start at ~T-5 s and end at ~T+5 s. T90 (15-350 keV) is 8.06 +- 0.53 sec (estimated error including systematics). The time-averaged spectrum from T-5.16 to T+4.71 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.90 +- 0.24, and Epeak of 61.0 +- 5.2 keV (chi squared 82.23 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.0 +- 0.1 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+1.94 sec in the 15-150 keV band is 13.1 +- 0.6 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/1277277
GCN 38709 table
GRB_name GRB241228A
GCN_number 38709
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 38709 SUBJECT: GRB 241228A: Mondy optical afterglow observations DATE: 24/12/29 16:43:08 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), N. Pankov (HSE) report on behalf of GRB IKI FuN: We observed the field of GRB 241228B triggered by Fermi (Fermi GBM team, GCN 38682) with AZT-33IK telescope of Mondy observatory in R-filter starting on (UT) 2024-12-28 19:42:31. We clearly detect optical afterglow (Kumar et al., GCN 38684 and GCN 38691; An et al. GCN 38687; Ortega-Casas et al., GCN 38692; Ghosh et al., GCN 38702; An et al., GCN 38704). Preliminary photometry of the afterglow is the following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2024-12-28 19:42:31 0.66628 30x120 R 20.28 0.04 23.0 The photometry is based on nearby SDSS DR16 stars (R mags by Lupton transformation).
GCN 38727 table
GRB_name GRB241228A
GCN_number 38727
Detection_method Konus-Wind Det
t_trigger 3:57:13.924 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 38727 SUBJECT: Konus-Wind detection of GRB 241228A DATE: 24/12/30 11:44:36 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 241228A (Swift-BAT detection: D'Elia et al., GCN 38681; Sadaula et al., GCN 38701; Fermi-GBM detection: Scotton & Meegan, GCN 38695) triggered Konus-Wind at T0=14233.924 s UT (03:57:13.924). The burst light curve shows a two-peak structure which starts at ~T0-0.2 s and has a total duration of ~5.1 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB241228_T14233/ As observed by Konus-Wind, the burst had a fluence of 3.35(-0.17,+0.18)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+1.760 s, of 1.74(-0.01,+0.01)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+8.448 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.88(-0.24,+0.26) and Ep = 75(-5,+5) keV (chi2 = 96/81 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.7 (chi2 = 96/80 dof). All the quoted errors are at the 68% confidence level. All the quoted values are preliminary.
GCN 38815 table
GRB_name GRB241228A
GCN_number 38815
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 38815 SUBJECT: GRB 241228A: 1.3m DFOT upper limit DATE: 25/01/04 05:40:01 GMT FROM: Amit Kumar Ror at ARIES Amit K. Ror, Anshika Gupta, Pranshu, Shashi B. Pandey, Kuntal Mishra (ARIES) report: We observed the field of GRB 241228A detected by Swift (Swift Observatory Team, D'Elia et al. 2024, GCN 38681) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located at the Devasthal Observatory of the Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2024-12-30 at 13:16:07 UT, i.e., ~ 2.38 days after the Swift-BAT trigger. We have taken multiple frames with an exposure time of 300 s in the R filter. We stacked the images after the alignment. We could not detect the optical emission reported by Volnova et al. (2024, GCN 38709) in our stacked image within the error box enhanced Swift-XRT position (GCN 38683). We obtain the following 3-sigma upper limit in the stacked image: Date Start_UT T_start-T0 (days) Filter Exp time (s) Magnitude ========================================================= 2024-12-30 13:16:07 ~ 2.38 R 300s*12 >21.2 The non-detection of the burst is consistent with the upper limits reported by Kuin et al. 2024, GCN 38685; Mohan et al. 2024, GCN 38689; Lipunov et al. 2024, GCN 38693; Zhu et al. 2024, GCN 38703. The magnitude is not corrected for the Galactic extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalogue. This circular may be cited.
GCN 39684 table
GRB_name GRB241228A
GCN_number 39684
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 39684 SUBJECT: GRB 241228A: VIRT Optical Upper Limit DATE: 25/03/12 13:10:18 GMT FROM: Priya Gokuldass at ERAU R. Querrard (UVI), P. Gokuldass (ERAU), N. Orange (OrangeWave Innovative Science, LLC), B. Gendre (UVI), D. Morris (NASA), T. Lombardi (Eckerd College), F. George (ERAU), D. Smith (UVI), K. Smith (UVI), C. Watson (UVI) report: We observed the field of GRB241228A (D'Elia et al., GCN 38681) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 2024-12-28 starting at 03:57:15 UT (T-mid ~ T0 + 43.91 hrs). We performed a series of exposures in an R filter with a total exposure of 2060s. The weather conditions were partly cloudy during the hours of observation with an average airmass of 1.68. We do not detect any source within the enhanced XRT position (Evans et al. GCN 38683). This non-detection is consistent with reported upper limits (Kuin et al., GCN 38685; Mohan et al., GCN 38689; Lipunov et al., GCN 38693; Zhu et al., GCN 38703; Volnova et al., GCN 38709; and Ror et al., GCN 38815). We report the following 3-sigma upper limit: T_mid ||Exposure ||Filter ||Limit T+43.91 h || 2060 s || R || > 20.4 The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. We acknowledge financial support from NASA EPSCoR award 80NNSC22M0063, NSF PAARE award 2319415, and NASA EPSCoR award 80NSSC24M0112. This message can be cited.