GRB200806A

This page lists all entries on GRB200806A in GRBweb

Summary IPN Swift GCN 28211 GCN 28212 GCN 28214 GCN 28215 GCN 28216 GCN 28218 GCN 28221 GCN 28222 GCN 28223 GCN 28224 GCN 28227 GCN 28229 GCN 28234

Summary table
Variable Value Source
T0 15:28:49 UTC GCN_circulars,Swift Det
ra 52.9322° Swift
decl 37.0787° Swift
pos_error 1.81e-04° Swift
T90 38.8 s Swift
T90_start 15:28:49 UTC Swift
fluence 1.00e-06 erg/cm² Swift
T100 38.8 s
GBM_located False
mjd 59067.64501157407 GCN_circulars,Swift Det
IPN table
GRB_name GRB200806A
ra 52.9042°
decl 37.0833°
pos_error 5.00e-02°
Swift table
GRB_name GRB200806A
t_trigger 15:28:49 UTC
ra 52.9322°
decl 37.0787°
pos_error 1.81e-04°
T90 38.8 s
fluence 1.00e-06 erg/cm²
GCN 28211 table
GRB_name GRB200806A
GCN_number 28211
Detection_method Swift Det
t_trigger 15:28:49 UTC
ra 52.9050°
decl 37.0820°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28211 SUBJECT: GRB 200806A: Swift detection of a burst DATE: 20/08/06 15:57:43 GMT FROM: David Palmer at LANL E. Ambrosi (INAF-IASFPA), D. N. Burrows (PSU), V. D'Elia (SSDC), J.D. Gropp (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), M. J. Moss (GWU), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team: At 15:28:49 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200806A (trigger=987016). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 52.905, +37.082 which is RA(J2000) = 03h 31m 37s Dec(J2000) = +37d 04' 55" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a pulse that starts at ~T0 and lasts beyond the currently available data, which ends at ~T+8 s. The peak count rate was ~4800 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 15:30:07.6 UT, 77.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 52.93173, 37.07845 which is equivalent to: RA(J2000) = 03h 31m 43.62s Dec(J2000) = +37d 04' 42.4" with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 77 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 2.56 x 10^21 cm^-2 (Willingale et al. 2013). The initial flux in the 2.5 s image was 2.59e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 86 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 0.42. Burst Advocate for this burst is E. Ambrosi (elena.ambrosi AT inaf.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 28212 table
GRB_name GRB200806A
GCN_number 28212
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28212 SUBJECT: Swift GRB 200806A: Global MASTER-Net observations report DATE: 20/08/06 21:40:17 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), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), 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 200806A ( E. Ambrosi et al., GCN 28211) errorbox 17964 sec after notice time and 17986 sec after trigger time at 2020-08-06 20:28:36 UT, with upper limit up to 17.5 mag. The observations began at zenith distance = 80 deg. The sun altitude is -26.8 deg. The galactic latitude b = -15 deg., longitude l = 156 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1414905 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 18076 | MASTER-Tavrida | C | 180 | 16.8 | 21887 | MASTER-Tavrida | C | 180 | 17.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 28214 table
GRB_name GRB200806A
GCN_number 28214
Detection_method Swift-XRT Det
ra 52.9321°
decl 37.0788°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28214 SUBJECT: GRB 200806A: Enhanced Swift-XRT position DATE: 20/08/07 02:48:55 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 619 s of XRT Photon Counting mode data and 1 UVOT images for GRB 200806A, 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 = 52.93214, +37.07876 which is equivalent to: RA (J2000): 03h 31m 43.71s Dec (J2000): +37d 04' 43.5" 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 28215 table
GRB_name GRB200806A
GCN_number 28215
Detection_method MITSuME
Circular_text TITLE: GCN CIRCULAR NUMBER: 28215 SUBJECT: GRB 200806A: MITSuME Akeno optical upper limits DATE: 20/08/07 05:56:59 GMT FROM: Katsuhiro L. Murata at Nagoya U K. L. Murata, R. Adachi, R. Hosokawa, M. Niwano, F. Ogawa, N. Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration: We observed the field of GRB 200806A (Ambrosi et al., GCN 28211; Beardmore et al., GCN 28214) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation with a series of 60 sec exposures started on 2020-08−06 15:30:34 UT. The first 15 images were heavily affected by the presence of the moon. We stacked the images excluding the 15 images and did not find any new point sources within the enhanced Swift/XRT error circle (Beardmore et al., GCN 28214) of the stacked images. We obtained the 5-sigma limits as follows. T0+[min] MID-UT T-EXP[sec] 5-sigma limits ------------------------------------------------------------------------------------------------ 19 2020-08-06T15:57:10 960 g'>16.7, Rc>16.7, Ic>16.9 ------------------------------------------------------------------------------------------------ T0+: Elapsed time after the burst T-EXP: Total Exposure time We used the PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al., submitted; https://github.com/MNiwano/Eclaire)
GCN 28216 table
GRB_name GRB200806A
GCN_number 28216
Detection_method AstroSat CZTI
Circular_text TITLE: GCN CIRCULAR NUMBER: 28216 SUBJECT: GRB 200806A: AstroSat CZTI detection DATE: 20/08/07 07:50:04 GMT FROM: Soumya Gupta at IUCAA/ASTROSAT S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed the detection of a long GRB 200806A, which was also detected by Swift (Ambrosi E. et al., GCN #28211), Global MASTER-Net (Lipunov V. et al., GCN #28212) and Swift-XRT (Beardmore A. et al., GCN #28214). The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-08-06 15:29:11.500 UT. The measured peak count rate associated with the burst is 665 +/- 33 cts/s above the background in the combined data of four quadrants, with a total of 5023 +/- 36 cts. The local mean background count rate was 402 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 33.93 +/- 0.05 s. In the preliminary analysis, we find that 636 Compton events are associated with this event. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-08-06 15:29:10.000 UT. The measured peak count rate is 987 +/- 50 cts/s above the background in the combined Veto data of four quadrants, with a total of 6708 +/- 67 cts. The local mean background count rate was 1506 +/- 1 cts/s. We measure a T90 of 33.68 +/- 0.13 s from the cumulative Veto light curve. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN 28218 table
GRB_name GRB200806A
GCN_number 28218
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28218 SUBJECT: GRB 200806A: AbAO optical upper limit DATE: 20/08/07 12:55:16 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), R.Ya. Inasaridze (AbAO), N. Pankov (HSE), K. Kamyshnikov (HSE), V.R. Ayvazian (AbAO), G.V. Kapanadze (AbAO), E. Mazaeva (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of GRB IKI FuN: We observed the field of Swift GRB 200806A (Ambrosi et al., GCN 28211) also registered by AstroSat CZTI (Gupta et al., GCN 28216) with AS-32 (0.7m) telescope of Abastumani Observatory starting on 2020-08-06 (UT) 23:42:53. We do not detect any object within the enhanced XRT position error circle (Beardmore et al., GCN 28214). Preliminary photometry of the field is following. Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2020-08-06 23:42:53 0.36498 R 63*60 n/d n/d 21.0 The photometry is based on nearby USNO-B1.0 stars USNO-B1.0_id R2 1270-0058216 15.48 1270-0058260 14.22 1270-0058260 14.98 1271-0065622 15.31
GCN 28221 table
GRB_name GRB200806A
GCN_number 28221
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28221 SUBJECT: GRB 200806A: Swift-XRT refined Analysis DATE: 20/08/07 15:57:06 GMT FROM: Phil Evans at U of Leicester K.L. Page (U. Leicester), M. Capalbi (INAF-IASFPA), M. Perri (ASDC), V. D'Elia (ASDC), J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester) and E. Ambrosi report on behalf of the Swift-XRT team: We have analysed 5.9 ks of XRT data for GRB 200806A (Ambrosi et al. GCN Circ. 28211), from 84 s to 22.1 ks after the BAT trigger. The data comprise 372 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 28214). The light curve can be modelled with a power-law decay with a decay index of alpha=1.01 (+/-0.04). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.58 (+/-0.07). The best-fitting absorption column is 3.6 (+/-0.4) x 10^21 cm^-2, in excess of the Galactic value of 2.6 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.85 (+/-0.14) and a best-fitting absorption column of 4.8 (+0.9, -0.8) 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 (6.6 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.8 (+0.9, -0.8) x 10^21 cm^-2 Galactic foreground: 2.6 x 10^21 cm^-2 Excess significance: 4.5 sigma Photon index: 1.85 (+/-0.14) If the light curve continues to decay with a power-law decay index of 1.01, the count rate at T+24 hours will be 0.023 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.9 x 10^-13 (1.5 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/00987016. This circular is an official product of the Swift-XRT team.
GCN 28222 table
GRB_name GRB200806A
GCN_number 28222
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 28222 SUBJECT: GRB 200806A: Swift/UVOT Possible Detection DATE: 20/08/07 17:37:59 GMT FROM: Frank Marshall at Swift/UVOT F. E. Marshall (NASA/GSFC) and E. Ambrosi (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 200806A 86 s after the BAT trigger (Ambrosi et al., GCN Circ. 28211). A source consistent with the enhanced XRT position (Beardmore et al. GCN Circ. 28214) is marginally detected in the initial UVOT exposures. The preliminary detection 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 86 236 147 20.26 +/- 0.28 v 629 821 39 >17.9 b 555 747 39 >19.3 u 300 722 265 >19.5 w1 678 870 39 >18.8 m2 653 845 39 >19.4 w2 604 1052 58 >19.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.42 in the direction of the burst (Schlegel et al. 1998).
GCN 28223 table
GRB_name GRB200806A
GCN_number 28223
Detection_method Swift-BAT Det
ra 52.9330°
decl 37.0760°
Circular_text TITLE: GCN CIRCULAR NUMBER: 28223 SUBJECT: GRB 200806A: Swift-BAT refined analysis DATE: 20/08/07 18:10:15 GMT FROM: Hans Krimm at NSF/NASA-GSFC A. Y. Lien (GSFC/UMBC), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200806A (trigger #987016) (Ambrosi, et al., GCN Circ. 28211). The BAT ground-calculated position is RA, Dec = 52.933, 37.076 deg which is RA(J2000) = 03h 31m 43.9s Dec(J2000) = +37d 04' 33.5" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 57%. The mask-weighted light curve shows a multi-peaked structure, with a sharp rise close to T+0 sec. The emission peaked at T+22 sec and declined to background by T+50 sec. T90 (15-350 keV) is 38.8 +- 1.1 sec (estimated error including systematics). The time-averaged spectrum from T-0.13 to T+61.22 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.72 +- 0.12, and Epeak of 148.1 +- 18.6 keV (chi squared 40.06 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.6 +- 0.02 x 10^-5 erg/cm2 and the 1-sec peak flux measured from T+22.24 sec in the 15-150 keV band is 14.1 +- 0.4 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.27 +- 0.03 (chi squared 111.98 for 57 d.o.f.). 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/987016/BA/
GCN 28224 table
GRB_name GRB200806A
GCN_number 28224
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28224 SUBJECT: GRB 200806A: VIRT optical observations DATE: 20/08/07 18:21:00 GMT FROM: Priyadarshini Gokuldass at U. of the Virgin Islands P. Gokuldass (UVI), R. Strausbaugh (UVI), D. Morris (UVI), N. Orange (OrangeWave Innovative Science, LLC), A. Cucchiara (UVI/College of Marin) report: We observed the field of GRB200806A (Ambrosi et al, GCN 28211) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 08-06-2020 starting at 06:22:50 UT (T+15 hrs). We performed a series of exposures in R filter with a total exposure of 5810 s. The weather conditions were clear during the hours of observation with an average airmass of 1.6. We find no new source within the enhanced XRT position error circle (Beardmore et al., GCN 28214) and report the following 3-sigma upper limit: T_mid ||Exposure ||Filter ||Limit T+16 hrs ||5810s ||R ||19.6 The limit is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. The VIRT is still in the commissioning phase. This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR AST Award 1901296, and NSF HBCU-UP AST Award 1831682. This message can be cited.
GCN 28227 table
GRB_name GRB200806A
GCN_number 28227
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28227 SUBJECT: GRB 200806A: CAHA optical afterglow confirmation DATE: 20/08/07 22:19:18 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. C. Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), and L. Montoya (CAHA) report: We observed the afterglow position (Beardmore et al., GCN #28214; Marshall et al., GCN #28222) of the bright Swift GRB 200806A (Ambrosi et al., GCN #28211; Lien et al., GCN #28223) with CAFOS at the 2.2m telescope at Calar Alto, Almeria, Spain, in the SDSS i' band. We obtained 20 x 180 s exposures, centered at 0.49185 days after the GRB, under good conditions but moonlight. At the position of the potential UVOT afterglow (Marshall et al., GCN #28222), we detect a faint source not visible in PanSTARRS archival imaging, at position (J2000) RA = 03:31:43.76, Dec. = +37:04:43.90, with an estimated error of 0".75. Photometry is made complicated by an uneven background, but measured against two nearby SDSS stars, we derive i' = 22.95 +/- 0.25 mag. As this is significantly fainter than the UVOT detection, we consider this to be the afterglow of GRB 200806A. We note foreground extinction is rather high (E(B-V)=0.3564 mag according to the maps of Schlafly & Finkbeiner 2011), and there is additional hydrogen column density along the line-of-sight (Page et al., GCN #28221), implying this is likely a dark GRB.
GCN 28229 table
GRB_name GRB200806A
GCN_number 28229
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 28229 SUBJECT: GRB 200806A: Nanshan/NEXT optical upper limit DATE: 20/08/08 06:35:51 GMT FROM: Dong Xu at NAOC/CAS S.Y. Fu, Z.P. Zhu, 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 200806A (Ambrosiet al., GCN 28211) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 8x100s frames in the Sloan r-band, starting at 19:42:36 UT on 2020-08-07, i.e., 28.22 hr after the burst. No optical source is detected in our stacked image at the enhanced XRT position (Beardmore et al., GCN 28214), down to a limiting magnitude of r~20.2, calibrated with the nearby PanSTARRS field.
GCN 28234 table
GRB_name GRB200806A
GCN_number 28234
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 28234 SUBJECT: GRB 200806A: CALET Gamma-Ray Burst Monitor detection DATE: 20/08/09 12:42:57 GMT FROM: Valentin Pal'shin at AGU Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U), T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena), and the CALET collaboration: The long GRB 200806A (Swift detection: Ambrosi et al., GCN Circ. 28211, Lien et al., GCN Circ. 28223; AstroSat CZTI detection: Gupta et al., GCN Circ. 28216; https://gcn.gsfc.nasa.gov/other/200806A.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 15:28:52.289 UTC on 6 August 2020. The burst signal was seen by all CGBM detectors. No real-time CGBM GCN notice was distributed about this trigger because the real-time communication from the ISS was off (loss of signal). The burst light curve shows a multi-peaked structure which starts at T-2.7 sec, peaks at T+20.0 sec and ends at T+40.9 sec. The T90 and T50 durations measured by the SGM data are 33.4 +- 3.1 sec and 14.5 +- 2.0 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1280762930/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University.