GRB200829A

This page lists all entries on GRB200829A in GRBweb

Summary Fermi GBM IPN Swift GCN 28307 GCN 28308 GCN 28309 GCN 28311 GCN 28313 GCN 28314 GCN 28315 GCN 28316 GCN 28317 GCN 28318 GCN 28322 GCN 28323 GCN 28324 GCN 28325 GCN 28326 GCN 28328 GCN 28329 GCN 28330 GCN 28331 GCN 28333 GCN 28338 GCN 28359 GCN 28404

Summary table
Variable Value Source
GRB_name_Fermi GRB200829582
T0 13:58:14.660 UTC Fermi_GBM
ra 251.2047° Swift
decl 72.3293° Swift
pos_error 4.53e-05° Swift
T90 6.912 s Fermi_GBM
T90_error 0.362 s Fermi_GBM
T90_start 13:58:31.556 UTC Fermi_GBM
fluence 2.14e-04 erg/cm² Fermi_GBM
fluence_error 1.05e-07 erg/cm² Fermi_GBM
redshift 1.2500 Swift
T100 92.38 s
GBM_located False
mjd 59090.58211412037 Fermi_GBM
Fermi GBM table
GRB_name_Fermi GRB200829582
trigger_name bn200829582
ra 251.2100°
decl 72.3272°
datum 2020-08-29
t_trigger 13:58:14.660 UTC
T90 6.912 s
T90_error 0.362 s
T90_start 13:58:31.556 UTC
fluence 2.14e-04 erg/cm²
fluence_error 1.05e-07 erg/cm²
flux_1024 2.14e+02 erg/cm²/s
flux_1024_error 1.72e+00 erg/cm²/s
flux_1024_time 1.97e+01 erg/cm²/s
flux_64 2.35e+02 erg/cm²/s
flux_64_error 7.11e+00 erg/cm²/s
IPN table
GRB_name GRB200829A
ra 251.2125°
decl 72.3333°
pos_error 5.00e-02°
Swift table
GRB_name GRB200829A
t_trigger 13:59:34 UTC
ra 251.2047°
decl 72.3293°
pos_error 4.53e-05°
T90 13.04 s
fluence 5.10e-05 erg/cm²
redshift 1.2500
GCN 28307 table
GRB_name GRB200829A
GCN_number 28307
Detection_method Swift Det
t_trigger 13:59:34 UTC
ra 251.2120°
decl 72.3350°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28307 SUBJECT: GRB 200829A: Swift detection of a burst with an optical afterglow DATE: 20/08/29 14:18:33 GMT FROM: Boris Sbarufatti at PSU M. H. Siegel (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), S. Laha (GSFC/UMBC/CRESST) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 13:59:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200829A (trigger=993768). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 251.212, +72.335 which is RA(J2000) = 16h 44m 51s Dec(J2000) = +72d 20' 07" 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 30 sec. The peak count rate was ~1335 counts/sec (15-350 keV), at ~6 sec after the trigger. The XRT began observing the field at 14:01:43.1 UT, 128.7 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 251.2096, 72.3273 which is equivalent to: RA(J2000) = 16h 44m 50.30s Dec(J2000) = +72d 19' 38.3" with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 27 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. The initial flux in the 2.5 s image was 9.30e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 138 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 16:44:49.05 = 251.20439 DEC(J2000) = +72:19:45.3 = 72.32924 with a 90%-confidence error radius of about 0.61 arc sec. This position is 9.0 arc sec. from the center of the XRT error circle. The estimated magnitude is 14.28 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.04. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 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 28308 table
GRB_name GRB200829A
GCN_number 28308
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28308 SUBJECT: GRB 200829A: TSHAO optical observations DATE: 20/08/29 17:02:07 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), I. Reva (FAPHI), A. Serebryanskiy (FAPHI), S. Belkin (IKI), M. Krugov (FAPHI), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of IKI-GRB-FuN: We are observing the afterglow of GRB 200829A (Siegel et al. GCN 28307) with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on Aug. 29 (UT) 14:49:05. The afterglow is clearly visible in single images of 60 s exposure. Preliminary photometry of the afterglow is R=16.8 +/- 0.1 at mid time (UT) 15:00:41. Observations is continuing.
GCN 28309 table
GRB_name GRB200829A
GCN_number 28309
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28309 SUBJECT: Swift GRB 200829A: Global MASTER-Net observations report DATE: 20/08/29 17:36:30 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (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. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (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 200829A ( M. H. Siegel et al., GCN 28307) errorbox 12423 sec after notice time and 12502 sec after trigger time at 2020-08-29 17:27:56 UT, with upper limit up to 18.5 mag. Observations started at twilight. The observations began at zenith distance = 30 deg. The sun altitude is -11.7 deg. The galactic latitude b = 35 deg., longitude l = 104 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1429750 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 12592 | MASTER-Tavrida | C | 180 | 18.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 28311 table
GRB_name GRB200829A
GCN_number 28311
Detection_method Swift-UVOT Det
ra 251.2047°
decl 72.3293°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28311 SUBJECT: GRB 200829A: Swift/UVOT Detection DATE: 20/08/29 19:10:29 GMT FROM: Paul Kuin at MSSL N.P.M. Kuin (MSSL-UCL) and M. H. Siegel (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 200829A 138 s after the BAT trigger (Siegel et al., GCN Circ. 28307). The UV-optical source position is RA=251.204709, Dec=72.329356 deg (J2000) which is in sexagesimal: RA(J2000) = 16h 44m 49.14s Dec(J2000) = 72d 19' 45.63" with a positional uncertainty of 0.35" radius (90% confidence). Preliminary detections and 3-sigma upper limits 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 138 288 147 14.29 +/- 0.02 white 576 596 19 15.43 +/- 0.04 white 1527 1547 19 16.38 +/- 0.06 v 626 646 19 15.50 +/- 0.10 b 552 572 19 15.68 +/- 0.07 u 296 546 246 14.54 +/- 0.03 u 700 720 19 15.12 +/- 0.07 w1 675 696 19 15.19 +/- 0.12 m2 1080 1100 19 16.25 +/- 0.25 w2 1032 1398 39 17.64 +/- 0.30 Note that the times are since the BAT trigger time. The main burst took place around 60s earlier during a Swift Slew. The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
GCN 28313 table
GRB_name GRB200829A
GCN_number 28313
Detection_method Swift-XRT Det
ra 251.2061°
decl 72.3292°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28313 SUBJECT: GRB 200829A: Enhanced Swift-XRT position DATE: 20/08/29 19:22:47 GMT FROM: Phil Evans at U of Leicester M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team. Using 1810 s of XRT Photon Counting mode data and 4 UVOT images for GRB 200829A, 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 = 251.20605, +72.32921 which is equivalent to: RA (J2000): 16h 44m 49.45s Dec (J2000): +72d 19' 45.2" with an uncertainty of 1.7 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 28314 table
GRB_name GRB200829A
GCN_number 28314
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 28314 SUBJECT: GRB 200829A: AGILE/MCAL detection DATE: 20/08/29 19:23:40 GMT FROM: Alessandro Ursi at INAF/IAPS A. Ursi (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli, F. Verrecchia (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team: The AGILE Mini-CALorimeter (MCAL) detected GRB 200829A at T0 = 2020-08-29 13:58:30.90 +/- 0.01 s (UTC), reported by Swift-BAT (Siegel et al., GCN #28307) and Swift-UVOT (Kuin et al., GCN #28311). The event lasted about 5.6 s and it released a total number of ~15550 counts in the detector (in the 0.4-100 MeV energy range), above an average background rate of 570 Hz. The time-integrated spectrum of the burst can be fitted in the energy range 0.4-20 MeV with a single power-law with ph.ind. = 2.26 -0.03/+0.03, resulting in a reduced chi-squared of 1.67 (62 d.o.f.) and a fluence of 6.2e-05 ergs/cm^2 (90% confidence level), in the same energy range. The MCAL light curve can be found at http://www.agilescienceapp.it/notices/GRB_069336_525794310.907011.png . The event is also clearly visible in the scientific ratemeters (RMs) of the SuperAGILE (18-60 keV), MCAL (0.4-100 MeV), and Anti-Coincidence (50-200 keV) detectors. Their light curves can be found at http://www.agilescienceapp.it/notices/GRB200829A_AGILE_RMs.png . The AGILE/MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN 28315 table
GRB_name GRB200829A
GCN_number 28315
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28315 SUBJECT: GRB 200829A: Global MASTER-Net OT detection DATE: 20/08/29 19:50:58 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (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. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (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 200829A ( M. H. Siegel et al., GCN 28307) errorbox 12423 sec after notice time and 12502 sec after trigger time at 2020-08-29 17:27:56 UT, with upper limit up to 18.5 mag. We see OT at Swift/UVOT position (Kuin et al GCN 28311). Datetime: 2020-08-29 17:36:40 Coord: 16h 44m 48.88s , +72d 19m 45s.8 Mag: 18.1 Observations started at twilight. The observations began at zenith distance = 30 deg. The sun altitude is -11.7 deg.
GCN 28316 table
GRB_name GRB200829A
GCN_number 28316
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28316 SUBJECT: GRB200829A: optical afterglow detection DATE: 20/08/29 21:05:19 GMT FROM: Jozsef Vinko at Konkoly Observatory GRB200829A: optical afterglow detection from Konkoly Observatory J. Vinko, K. Vida, A. Pal, L. Kriskovics, R. Szakats, A. Ordasi and K. Sarneczky (Konkoly Observatory, Hungary) report: The optical afterglow of GRB 200829A (Siegel et al. GCN 28307) is detected with the 0.8m RC80 robotic telescope at Piszkesteto Station of Konkoly Observatory starting on Aug 29 19:22:00 UT, 19346 s after the Swift/BAT trigger. The afterglow is measured on stacked Sloan r'- and i'-band frames of 3x300 s exposure. Photometry, tied to nearby comparison stars with PS1 magnitudes, gives. r' = 18.45 +/- 0.09 and i' = 18.49 +/- 0.11 mag, in accord with previous optical detections (Pozanenko et al. GCN 28308; Kuin et al. GCN 28311; Ursi et al. GCN 28314; Lipunov et al. GCN 28315)..
GCN 28317 table
GRB_name GRB200829A
GCN_number 28317
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28317 SUBJECT: GRB 200829A: Swift-XRT refined Analysis DATE: 20/08/30 02:47:18 GMT FROM: Phil Evans at U of Leicester J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), A. Tohuvavohu (U. Toronto) and M.H. Siegel report on behalf of the Swift-XRT team: We have analysed 6.8 ks of XRT data for GRB 200829A (Siegel et al. GCN Circ. 28307), from 135 s to 24.2 ks after the BAT trigger. The data comprise 1.7 ks in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 28313). The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=0.62 (+0.09, -0.10). At T+279 s the decay steepens to an alpha of 8.0 (+0.0, -6.9). The light curve breaks again at T+283 s to a decay with alpha=0.885 (+0.016, -0.017), before a final break at T+1174 s s after which the decay index is 1.19 (+/-0.04). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.700 (+/-0.014). The best-fitting absorption column is 9.9 (+/-0.4) x 10^20 cm^-2, in excess of the Galactic value of 4.7 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.89 (+/-0.09) and a best-fitting absorption column of 1.36 (+0.28, -0.26) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.7 x 10^-11 (4.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.36 (+0.28, -0.26) x 10^21 cm^-2 Galactic foreground: 4.7 x 10^20 cm^-2 Excess significance: 5.6 sigma Photon index: 1.89 (+/-0.09) If the light curve continues to decay with a power-law decay index of 1.19, the count rate at T+24 hours will be 0.23 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.4 x 10^-12 (1.0 x 10^-11) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00993768. This circular is an official product of the Swift-XRT team.
GCN 28318 table
GRB_name GRB200829A
GCN_number 28318
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28318 SUBJECT: GRB 200829A: THO optical observatios DATE: 20/08/30 06:36:53 GMT FROM: Veli-Pekka Hentunen at Taurus Hill Obs,A95 Veli-Pekka Hentunen and Markku Nissinen (Taurus Hill Observatory, Varkaus, Finland) report: We have detected GRB 200829A optical afterglow at Taurus Hill Observatory (A95) using C-14SC 0.35-m f/7.3 telescope, SBIG STT-8300M CCD and RGB filters. The observations were started at 2020-08-29 18:48:29 (UT). The afterglow was detected at the position RA 16 44 49.16 and DEC +72 19 45.9. The following magnitudes were obtained from the observations using NOMAD1 1623-0124683 (R=17.05, V=17.32, B=17.55) as a comparison star: Tmid(h:min:sec)+T0 Filter Exp.time(sec) Mag MagErr 4:53:37 R 3x180 17.98 0.28 5:02:49 R 3x180 18.11 0.34 5:12:36 R 3x180 18.22 0.27 5:25:05 R 5x180 18.26 0.17 6:00:06 R 5x180 18.27 0.14 6:25:44 B 3x180 18.66 0.21 6:35:32 G 3x180 18.69 0.26 URL link for the RGB image: www.kassiopeia.net/wp-content/uploads/2020/08/GRB200829A_RGB_web.png
GCN 28322 table
GRB_name GRB200829A
GCN_number 28322
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28322 SUBJECT: GRB 200829A: SAO RAS optical observations DATE: 20/08/30 13:45:46 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin, V. N. Aitov (SAO RAS) on behalf of GRB follow-up team report. We observed the field of the GRB 200829A (Siegel et al., GCN 28307) with Zeiss-1000 (1-m telescope of SAO RAS) equipped with Multi-Mode Photometer-Polarimeter (MMPP). We obtained 4 x 300 sec. frames in Rc band and similar sequence in Ic band. The OT (Siegel et al., GCN 28307; Pozanenko et al., GCN 28308; Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al., 28316; Hentunen and Nissinen, GCN 28318) is clearly detected with the brightness R = 17.84 +/- 0.09 (T_mid - T0 = 4.587 h), I = 17.65 +/- 0.09 (T_mid - T0 = 4.204 h). Preliminary photometry is based on R2 and I magnitudes of nearby USNO-B1 stars.
GCN 28323 table
GRB_name GRB200829A
GCN_number 28323
Detection_method Konus-Wind Det
t_trigger 13:58:29.990 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 28323 SUBJECT: Konus-Wind detection of GRB 200829A (a clone of GRB 200826B?) DATE: 20/08/30 14:52:11 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration, very bright GRB 200829A (Swift detection: Siegel et al., GCN 28307; Goad et al., GCN 28313; Gropp et al., GCN 28317; AGILE/MCAL detection: Ursi et al., GCN 28314) triggered Konus-Wind at T0=50309.99 s UT (13:58:29.990). The burst light curve shows a bright, multi-peaked pulse which started at ~T0-24 s and had a total duration of ~39 s. A weak post-burst emission is visible in the 18-70 keV band up to the end of the KW trigger record at ~T0+250 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/GRB200829_T50309/ As observed by Konus-Wind, the burst had a fluence of 3.02(-0.07,+0.07)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+3.456 s, of 1.08(-0.07,+0.07)x10^-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+16.384 s) can be described, in the 20 keV - 15 MeV range, by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.49(-0.03,+0.03), the high energy photon index beta = -2.34(-0.05,+0.04), the peak energy Ep = 336(-11,+11) keV (chi2 = 163/98 dof). The spectrum near the maximum count rate (measured from T0+3.072 to T0+3.840 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.23(-0.07,+0.08), the high energy photon index beta = -2.17(-0.06,+0.06), the peak energy Ep = 372(-26,+27) keV (chi2 = 78/71 dof). We note, that this burst is very similar to GRB 200826B, which, as detected by KW (Ridnaia et al., GCN 28304), had the time-integrated spectrum with alpha = -0.54, beta = -2.38, Ep = 337 keV; a factor of ~1.5 smaller energy fluence (~2.0x10^-4 erg/cm^2), and a factor of ~2 smaller peak energy flux ~5x10^-5 erg/cm^2/s. Interestingly, light curves of both bursts are also very similar if we scale the time axis by a factor of ~1.5 (http://www.ioffe.ru/LEA/GRBs/GRB200829_T50309/gWind64_29A_26B.pdf). Given the angular distance between the directions to GRB 200829A (Swift-XRT GCN 28307) and GRB 200826B (IPN GCN 28303) of ~38.6 arcdeg, and the ~3 day difference in the burst arrival times, an idea of a lensed GRB cannot be excluded. All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 28324 table
GRB_name GRB200829A
GCN_number 28324
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28324 SUBJECT: GRB 200829A: Nanshan/NEXT optical observations DATE: 20/08/30 15:27:43 GMT FROM: Dong Xu at NAOC/CAS Z.P. Zhu, S.Y Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), X. Zhang, J.Z. Liu (XAO) report: We observed the field of GRB 200829A (Siegel et al., GCN 28307) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained a series of frames in the Sloan g-/r-/i- bands, starting at 19:55:23 UT on 2020-08-29, i.e., 5.93 hr after the BAT trigger. The GRB optical afterglow (e.g., Pozanenko et al., GCN 28308; Kuin et al., GCN 28311; Ursi et al., GCN 28314; Lipunov et al., GCN 28315; Vinko et al., GCN 28316; Hentunen & Nissinen, GCN 28318; Moskvitin et al., GCN 28322) is clearly detected in our images. Preliminary photometric measurements are as follows: Filter T-mid(hr) Mag Mag_err SDSS-g 6.72 18.89 0.04 SDSS-r 5.98 18.77 0.04 SDSS-i 6.40 18.50 0.05 calibrated with nearby Pan-STARRS stars.
GCN 28325 table
GRB_name GRB200829A
GCN_number 28325
Detection_method Swift-BAT Det
ra 251.1360°
decl 72.3630°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28325 SUBJECT: GRB 200829A: Swift-BAT refined analysis DATE: 20/08/30 17:01:36 GMT FROM: Sibasish Laha at GSFC D. M. Palmer (LANL), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), T. Sakamoto (AGU), M. H. Siegel (PSU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (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 200829A (trigger #993768) (Siegel, et al., GCN Circ. 28307). The BAT ground-calculated position is RA, Dec = 251.136, 72.363 deg which is RA(J2000) = 16h 44m 32.7s Dec(J2000) = +72d 21' 45.6" with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 88%. The mask weighted light curve shows a peak at ~ T-60 s followed by an extended emission. The duration of the initial bright peak is ~15 sec. We note that Swift was slewing from T-150 s to T s. The overall structure starts at ~T-75 s and lasts till ~T+200 s. T90 (15-350 keV) is 13.04 +- 2.91 sec (estimated error including systematics). The time-averaged spectrum from T-74 to T+204 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.83 +- 0.03. The fluence in the 15-150 keV band is 5.1 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T-60.07 sec in the 15-150 keV band is 98.7 +- 1.6 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/993768/BA/
GCN 28326 table
GRB_name GRB200829A
GCN_number 28326
Detection_method Fermi GBM Det
t_trigger 13:58:14.660 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 28326 SUBJECT: GRB 200829A: Fermi GBM detection DATE: 20/08/30 17:12:33 GMT FROM: Stephen Lesage at Fermi-GBM Team S. Lesage (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 13:58:14.66 UT on 29 August 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200829A (trigger 620402299 / 200829582) which was also detected by the Swift Burst Alert Telescope (BAT) (M. H. Siegel et al. 2020, GCN 28307). GBM initially triggered on a weak spike ~15-20 s before the very bright emission. The GBM on-ground location is consistent with the Swift BAT position. The angle from the Fermi LAT boresight at the GBM trigger time is ~148 degrees. The GBM light curve shows an exceptionally bright long GRB with a duration (T90) of about 6.9 s (50-300 keV). The time-averaged spectrum from T0+16.64 s to T0+25.856 s is best fit by a Band function with Epeak = 336.8 +/- 4.3 keV, alpha = -0.43 +/- 0.01, and beta = -2.4 +/- 0.02 The event fluence (10-1000 keV) in this time interval is (2.069 +/- 0.009)E-04 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+19.7 s in the 10-1000 keV band is 213.9 +/- 1.7 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 28328 table
GRB_name GRB200829A
GCN_number 28328
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28328 SUBJECT: GRB 200829A: further SAO RAS optical observations DATE: 20/08/30 20:17:46 GMT FROM: Moskvitin Alexander at SAO RAS A. S. Moskvitin, V. N. Aitov (SAO RAS) on behalf of GRB follow-up team report. We observed the field of the GRB 200829A (Siegel et al., GCN 28307) with Zeiss-1000 (1-m telescope of SAO RAS) equipped with Multi-Mode Photometer-Polarimeter (MMPP) on August 30. We obtained 5 x 300 sec. frames in Rc band and similar sequence in Ic band. The OT (Siegel et al., GCN 28307; Pozanenko et al., GCN 28308; Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al., 28316; Hentunen and Nissinen, GCN 28318; Zhu et al., GCN 28324) is clearly detected in individual images as well as stacked frames with the brightness of R = 20.37 +/- 0.13 (T_mid - T0 = 1.1492 days), I = 20.14 +/- 0.10 (T_mid - T0 = 1.1662 days). Preliminary photometry is based on R2 and I magnitudes of the same nearby USNO-B1 stars (Moskvitin and Aitov, GCN 28322).
GCN 28329 table
GRB_name GRB200829A
GCN_number 28329
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28329 SUBJECT: GRB 200829A: Kitab optical upper limit DATE: 20/08/30 21:20:06 GMT FROM: Alexei Pozanenko at IKI, Moscow N. Pankov (HSE), A. Novichonok (Petrozavodsk State University, KIAM), A. Zhornichenko (KIAM), A. Pozanenko (IKI), S. Belkin (IKI), E. Mazaeva (IKI), A. Volnova (IKI), Sh. Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN: We observed the field of a GRB 200829A (Siegel et al., GCN 28307; see also Ursi et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage et al., GCN 28326) with Kitab-ISON RC-36 telescope in R-filter. We do not detect optical afterglow (Siegel et al., GCN 28307; Pozanenko et al., GCN 28308; Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al., 28316; Hentunen et al., GCN 28318; Zhu et al., GCN 28324; Moskvitin et al., GCNs 28322, 28328). Preliminary photometry of the filed is following Date, UT start, t-T0, Exp., Filter, OT, Err., UL (mid, days) 2020-08-30 15:57:25 1.08184 3600 R n/d n/d 18.8 The photometry is based on nearby USNO-B1.0 star, R2 magnitude USNO_B10_id R2 1626-0124132 14.76
GCN 28330 table
GRB_name GRB200829A
GCN_number 28330
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28330 SUBJECT: GRB 200829A: Continued Nanshan/NEXT optical observations DATE: 20/08/31 07:52:40 GMT FROM: Dong Xu at NAOC/CAS Z.P. Zhu, S.Y Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), X. Zhang, J.Z. Liu (XAO) report: We continued to observe the optical afterglow (e.g., Siegel et al., GCN 28307; Pozanenko et al., GCN 28308; Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al., 28316; Hentunen et al., GCN 28318; Zhu et al., GCN 28324; Moskvitin et al., GCNs 28322, 28328; Pankov et al., GCN 28329) of GRB 200829A (Siegel et al., GCN 28307; Ursi et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage et al., GCN 28326), using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 28 frames in the Sloan r band, starting at 15:24:17 UT on 2020-08-30, i.e., about 1.058 d after the BAT trigger. Preliminary photometric measurements are as follows: Filter T_exp/s T_mid/d Mag Mag_err SDSS-r 8x120 1.062 >20.6 SDSS-r 20x120 1.307 21.20 0.16 calibrated with nearby Pan-STARRS stars.
GCN 28331 table
GRB_name GRB200829A
GCN_number 28331
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28331 SUBJECT: GRB 200829A: Liverpool Telescope observations DATE: 20/08/31 11:52:24 GMT FROM: Luca Izzo at DARK/NBI L. Izzo (DARK/NBI) reports: We observed the field of GRB 200829A (Siegel et al., GCN #28307; Ursi et al., GCN #28314; Ridnaia et al., GCN #28323; Lesage & Meegan, GCN #28326) with the IO:O camera mounted on the 2-m Liverpool Telescope located in La Palma, Spain. Observations started on August 29 at 20:31:39 UT (0.272 days after the GRB trigger) and a second epoch was obtained on August 30 at 22:38:42 UT (1.362 days). In both epochs, we obtained a series of 5x60s images in the griz filters. The optical afterglow (Siegel et al., GCN #28307, Pozanenko et al., GCN #28308; Kuin & Siegel, GCN #28311; Lipunov et al., GCN #28315; Vinko et al., GCN #28316; Hentunen et al., GCN #28318; Moskvitin et al., GCN #28322, GCN #28328, Zhu et al., GCN #28324, GCN #28330; Pankov et al., GCN #28329) is visible in the stacked images in both epochs. We measure the following preliminary AB magnitudes, calibrated against Pan-STARRS catalog stars: Filter mag err MJD SDSS-g 18.91 0.05 (59090.855) SDSS-g 21.17 0.09 (59091.944) SDSS-r 18.76 0.04 (59090.860) SDSS-r 21.34 0.10 (59091.948) SDSS-i 18.65 0.04 (59090.865) SDSS-i 21.25 0.09 (59091.953) SDSS-z 18.57 0.04 (59090.870) SDSS-z 20.50 0.08 (59091.958)
GCN 28333 table
GRB_name GRB200829A
GCN_number 28333
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28333 SUBJECT: GRB 200829A: Koshka Zeiss-1000 optical observations DATE: 20/08/31 19:52:13 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), S. Naroenkov (INASAN), A. Pozanenko (IKI), N. Pankov (HSE), S. Belkin (IKI), E. Mazaeva (IKI) report on behalf of larger GRB IKI FuN collaboration: We observed the the field of GRB 200829A (Siegel et al., GCN 28307; Ursi et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage & Meegan, GCN 28326) with Zeiss-1000 1-m telescope of Koshka Observatory on August, 30 starting (UT) 19:18:21 in I- and R-filters. The optical afterglow (Siegel et al., GCN 28307, Pozanenko et al., GCN 28308; Kuin & Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al., GCN 28316; Hentunen et al., GCN 28318; Moskvitin et al., GCNs 28322, 28328, Zhu et al., GCN 28324, GCN 28330; Pankov et al., GCN 28329; Izzo, GCN 28331) is detected in stacked images of both filters. Preliminary photometry of the afterglow is following. Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2020-08-30 19:18:21 1.29067 I 47*120 20.14 0.20 20.8 2020-08-30 19:20:31 1.29217 R 47*120 21.0 0.25 21.4 The photometry is based on nearby USNO-B1.0 stars.
GCN 28338 table
GRB_name GRB200829A
GCN_number 28338
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28338 SUBJECT: GRB 200829A: Swift/UVOT-XRT photometric redshift DATE: 20/09/01 11:55:48 GMT FROM: Samantha Oates at MSSL S. R. Oates (U.Birmingham), N.P.M. Kuin (MSSL-UCL), M. De Pasquale (Istanbul U.), S. Campana (INAF-OAB), A. Tohuvavohu (U Toronto) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: We have performed a joint spectral analysis of Swift UVOT and XRT observations of GRB 200829A (Siegel et al., GCN Circ. 28307; Kuin et al. GCN Circ. 28311, Goad et al., GCN Circ. 28313), based on the methodology of Schady et al. (2010, MNRAS, 401, 2773). Using this method, we created an SED at 900s after the BAT trigger consisting of 6 UVOT filters and WT mode XRT data. The model with the best fit, broken power-law with a Milky Way extinction curve for the host extinction, gives a photometric redshift for GRB 200829A of 1.25 +\- 0.02 (1 sigma uncertainty; chi^2/dof = 586/538). This circular is an official product of the Swift team.
GCN 28359 table
GRB_name GRB200829A
GCN_number 28359
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28359 SUBJECT: GRB 200829A: optical observations, a light curve in R-filter DATE: 20/09/03 15:15:47 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), N. Pankov (HSE), S. Belkin (IKI), A. Volnova (IKI), I. Reva (FAPHI), A. Zhornichenko (KIAM), A. Novichonok (Petrozavodsk State University, KIAM), S. Naroenkov (INASAN), K. Antoniuk (CrAO), R.Ya. Inasaridze (AbAO), E. Mazaeva (IKI), Sh. Ehgamberdiev (UBAI) report on behalf of larger GRB IKI FuN collaboration: We observed the the field of GRB 200829A (Siegel et al., GCN 28307; Ursi et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage & Meegan, GCN 28326) with Zeiss-1000 telescope of TShAO observatory, RC-36 telescope of Kitab observatory, Zeiss-1000 telescope of Koshka Observatory, AZT-11 telescope of CrAO observatory, and AS-23 telescope of AbAO observatory. The optical afterglow (Siegel et al., GCN 28307, Pozanenko et al., GCN 28308; Kuin & Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al., GCN 28316; Hentunen et al., GCN 28318; Moskvitin et al., GCNs 28322, 28328, Zhu et al., GCNs 28324, 28330; Pankov et al., GCN 28329; Izzo, GCN 28331; Volnova et al., GCN 28333) is detected on first two days after GRB trigger. Preliminary light curve of the afterglow in R-filter can be found at http://grb.rssi.ru/GRB200829A/GRB200829A_LC1_R.png One can tentatively assume a jet break in the light curve at ~0.33 days. (The photometry is based on nearby USNO-B1.0 stars identical for all observations.)
GCN 28404 table
GRB_name GRB200829A
GCN_number 28404
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28404 SUBJECT: GRB 200829A: T100 observations DATE: 20/09/09 08:28:19 GMT FROM: Massimiliano De Pasquale at Istanbul U/FOGTWA De Pasquale, M. (Istanbul Univ.) Sonbas, E. (Adiyaman Univ.), Ozdonmez, A., Er, H. (Ataturk Univ.), Ivantsov, A., (Akdeniz Univ.), Eryilmaz, S. (TUG) on behalf of a larger collaboration: We observed the field of GRB 200829A (Siegel et al., GCN #28307) with the 1.0 meter T100 telescope (TUBITAK National Observatory, Antalya - Turkey), starting on 2020-09-01, at 20:36:18 UT (~78 hours after the trigger). We obtained 12 x 300 s exposures with R filter under good weather conditions. The Moon was present in the sky during observations. We do not detect an optical afterglow within the reported XRT error circle down to a 3 sigma limiting magnitude of 21 in the combined R band image. We are grateful to the TUBITAK National Observatory staff for promptly scheduling the observations and their technical support.