//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28122 SUBJECT: Swift GRB200716.96: Global MASTER-Net observations report DATE: 20/07/16 23:05:23 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-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the Swift GRB200716.96 (trigger No 982707,13h 04m 03.12s , +29d 37m 48.0s, R=0.05) errorbox 55 sec after notice time and 79 sec after trigger time at 2020-07-16 22:59:00 UT, with upper limit up to 16.1 mag. The observations began at zenith distance = 59 deg. The sun altitude is -31.6 deg. The galactic latitude b = 86 deg., longitude l = 68 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1402659 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 84 | MASTER-IAC | P| | 10 | 15.5 | 121 | MASTER-IAC | P| | 20 | 16.1 | The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28123 SUBJECT: GRB 200716C: Fermi GBM Final Real-time Localization DATE: 20/07/16 23:08:03 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 22:57:41 UT on 16 Jul 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200716C (trigger 616633066.180458 / 200716957). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 192.1, Dec = 35.3 (J2000 degrees, equivalent to J2000 12h 48m, 35d 17'), with a statistical uncertainty of 2.3 degrees. The angle from the Fermi LAT boresight is 36.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200716957/quicklook/glg_skymap_all_bn200716957.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200716957/quicklook/glg_healpix_all_bn200716957.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200716957/quicklook/glg_lc_medres34_bn200716957.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28124 SUBJECT: GRB 200716C: Swift detection of a burst with an optical counterpart DATE: 20/07/16 23:10:50 GMT FROM: David Palmer at LANL T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), J.D. Gropp (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift Observatory Team: At 22:57:41 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200716C (trigger=982707). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 196.013, +29.630 which is RA(J2000) = 13h 04m 03s Dec(J2000) = +29d 37' 47" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 10 sec. The peak count rate was ~30000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 22:59:04.2 UT, 82.9 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 196.0100, 29.6465 which is equivalent to: RA(J2000) = 13h 04m 2.40s Dec(J2000) = +29d 38' 47.4" with an uncertainty of 6.6 arcseconds (radius, 90% containment). This location is 60 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 0.1 s image was 1.10e-08 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 93 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at RA(J2000) = 13:04:02.43 = 196.01011 DEC(J2000) = +29:38:40.6 = 29.64460 with a 90%-confidence error radius of about 0.75 arc sec. This position is 6.85 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.34 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.01. Burst Advocate for this burst is T. N. Ukwatta (tilan.ukwatta AT gmail.com). 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/) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28125 SUBJECT: Swift GRB200716C: Global MASTER-Net OT detection DATE: 20/07/16 23:41:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, F. Balakin, I. Gorbunov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk D. Buckley, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the GRB200716C (Ukwatta et al, GCN 28124) 55 sec after notice time and 79 sec after trigger time at 2020-07-16 22:59:00 UT. On our 5-th (50s exposure) set , obtained 243 sec after tigger time at 2020-07-16 23:01:45 UT, we found an optical transient within Swift error-box (ra=196.012 dec=29.6292 r=0.05) brighter. T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|----- 268 2020-07-16 23:01:45 50 (13h 04m 02.41s , +29d 38m 39.4s) 16.3 The 5-sigma upper limit has been about 16.6mag The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28126 SUBJECT: GRB200716C: BOOTES-1 optical afterglow detection DATE: 20/07/17 03:29:41 GMT FROM: Youdong HU at IAA-CSIC Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report: Following the Swift trigger of GRB 200716C (Ukwatta et al., GCNC 28124), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this burst. Series images were taken started 22:58:53UT (72 s after trigger). In the first 10s image, the afterglow reported by UVOT (Ukwatta et al., GCNC 28124) and MASTER (Lipunov et al., GCNC 28125) is detected with magnitude of 16.8 (clear filter). Further observation are on going. We thank the staff at INTA-CEDEA for their excellent support. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28128 SUBJECT: GRB 200716C: Enhanced Swift-XRT position DATE: 20/07/17 05:32:43 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 1666 s of XRT Photon Counting mode data and 4 UVOT images for GRB 200716C, 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 = 196.01029, +29.64407 which is equivalent to: RA (J2000): 13h 04m 2.47s Dec (J2000): +29d 38' 38.6" with an uncertainty of 1.5 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28129 SUBJECT: GRB 200716C: Swift-XRT refined Analysis DATE: 20/07/17 06:44:34 GMT FROM: Phil Evans at U of Leicester J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and T.N. Ukwatta report on behalf of the Swift-XRT team: We have analysed 6.3 ks of XRT data for GRB 200716C (Ukwatta et al. GCN Circ. 28124), from 86 s to 23.1 ks after the BAT trigger. The data comprise 578 s 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. 28128). We cannot determine at the present time whether the source is fading. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.56 (+/-0.03). The best-fitting absorption column is 5.8 (+1.0, -0.9) x 10^20 cm^-2, in excess of the Galactic value of 1.1 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.45 (+0.13, -0.05) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.4 x 10^-11 (4.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.1 (+2.3, -0.0) x 10^20 cm^-2 Galactic foreground: 1.1 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.45 (+0.13, -0.05) If the light curve continues to decay with a power-law decay index of 1.46, the count rate at T+24 hours will be 8.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.7 x 10^-13 (3.8 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/00982707. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28130 SUBJECT: GRB 200716C: Fermi-LAT detection DATE: 20/07/17 06:53:04 GMT FROM: Nicola Omodei at Stanford U. M. Ohno (Hiroshima Univ/Eotvos Univ.), M. Arimoto (Kanazawa Univ.), N. Di Lalla, N. Omodei (Stanford University), F. Longo (University and INFN, Trieste), report on behalf of the Fermi-LAT Collaboration: On July, 16th, 2020, Fermi-LAT detected high-energy emission from GRB 200716C, which was also detected by Fermi-GBM (trigger 616633066.180458/200716957; Fermi GBM Team GCN 28123) and Swift (Ukwatta et al. GCN 28124). The best LAT on-ground location is found to be RA, Dec = 195.7, 29.9 (degrees, J2000) with an error radius of 0.3 deg (90% containment, statistical error only). The best LAT position is consistent with the Swift position. This was 6 deg from the LAT boresight at the time of the GBM trigger: T0 = 22:57:41 UT. The data from the Fermi-LAT show a significant increase in the event rate after the GBM trigger that is spatially correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0-1000 s after the GBM trigger is 5.3e-6 +/- 2.0e-6 ph/cm2/s. The estimated photon index above 100 MeV is -1.9+/-0.2. The highest-energy photon is a 8.2 GeV event which is observed 152 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Nicola Omodei (nicola.omodei@stanford.edu). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28131 SUBJECT: GRB 200716C: Swift-XRT refined analysis correction DATE: 20/07/17 07:01:57 GMT FROM: Kim Page at U.of Leicester K.L. Page and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: GCN 28129 (Gropp et al.) incorrectly included a sentence that stated it was not possible to tell if the X-ray afterglow of GRB 200716C was fading. In fact, the first snapshot of data shows a complicated structure, which can be modelled by changes in slope and overlapping flares. The late-time light curve (from T0+4.3 ks) can be modelled with a power-law decay with a decay index of alpha=1.56 (+/-0.11). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28132 SUBJECT: GRB 200716C: possible host galaxy from the SDSS DATE: 20/07/17 09:34:53 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D’Avanzo (INAF-OAB), on behalf of the CIBO collaboration report: Inspection of the SDSS reveals the presence of an extended object, classified as a galaxy, at a position consistent (within ~ 1”) with the one reported for the optical afterglow of GRB 200716C (Ukwatta et al., GCN Circ. 28124; Lipunov et al., GCN Circ. 28125; Hu et al., GCN Circ. 28126). According to the SDSS DR16 this galaxy has AB magnitudes: u = 21.48 +/- 0.21, g = 20.46 +/- 0.05, r = 19.29 +/- 0.03, i = 18.88 +/- 0.03, z = 18.54 +/- 0.09 and a photoz = 0.348 +/- 0.053. Further details can be found at the following link: http://skyserver.sdss.org/dr16/en/tools/explore/Summary.aspx?id=1237665442053095703 This object can be the host galaxy of GRB 200716C. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28133 SUBJECT: GRB 200716C: AGILE/MCAL detection DATE: 20/07/17 10:49:24 GMT FROM: Francesco Verrecchia at SSDC,INAF-OAR A. Ursi (INAF/IAPS), F. Verrecchia (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, C. Pittori (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 the GRB 200716C at T0 = 2020-07-16 22:57:41.38 +/- 0.01 s (UTC), reported by Swift-BAT (GCN #28122, #28124), Fermi-GBM (GCN #28123), BOOTES-1 (GCN #28126), Swift-XRT (GCN #28128, #28129, #28131), and Fermi-LAT (GCN #28130). The event consists of two main episodes, lasting ~0.64 s and ~0.26 s, respectively, which released a total number of 623 counts and 416 counts in the detector (in the 0.4-100 MeV energy range), above an average background rate of 650 Hz. The time-integrated spectrum of the first episode can be fitted in the energy range 0.4-20 MeV with single power-law with ph.ind. = 2.40 -0.29/+0.32, resulting in a reduced chi-squared of 1.15 (21 d.o.f.) and a fluence of 4.6e-06 ergs/cm^2 (90% confidence level). The time-integrated spectrum of the second episode can be fitted in the energy range 0.4-20 MeV with single power-law with ph.ind. = 2.51 -0.37/+0.43, resulting in a reduced chi-squared of 1.08 (21 d.o.f.) and a fluence of 5.7e-06 ergs/cm^2 (90% confidence level). The MCAL light curve can be found at http://www.agilescienceapp.it/notices/GRB_068714_522025061.386471.png . The event is also clearly visible in the scientific ratemeters (RMs) of the MCAL (0.4-100 MeV) and Anti-Coincidence (50-200 keV) detectors. Their light curves can be found at http://www.agilescienceapp.it/notices/GRB200716C_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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28135 SUBJECT: GRB 200716C: Fermi GBM detection DATE: 20/07/17 16:02:54 GMT FROM: Peter Veres at UAH P. Veres (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 22:57:41.18 UT on 16 July 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200716C (trigger 616633066 / 200716957) which was also detected by the Swift (Ukwatta et al., GCN 28124), Fermi-LAT (Ohno et al., GCN 28130). The GBM on-ground location is consistent with both the Swift and Fermi-LAT positions. The angle from the Fermi LAT boresight at the GBM trigger time is 37 degrees. The GBM light curve shows two overlapping pulses with a duration (T90) of about 5.3 s (50-300 keV). The time-averaged spectrum from T0-0.26 s to T0+4.9 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.07 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 716 +/- 97 keV. The event fluence (10-1000 keV) in this time interval is (9.57 +/- 0.25)E-6 erg/cm^2. The 1-sec peak photon flux measured starting from T0 + 64 ms in the 10-1000 keV band is 19.3 +/- 0.3 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/" //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28136 SUBJECT: GRB 200716C: Swift-BAT refined analysis DATE: 20/07/17 20:26:57 GMT FROM: Tilan Ukwatta at 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), 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-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 200716C (trigger #982707) (Ukwatta, et al., GCN Circ. 28124). The BAT ground-calculated position is RA, Dec = 196.011, 29.636 deg which is RA(J2000) = 13h 04m 02.5s Dec(J2000) = +29d 38' 08.4" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 57%. The mask-weighted light curve shows two prominent peaks, first at ~T+0.1 s and the second at ~T+2.1. Significant activity is still visible until ~T+90 s. T90 (15-350 keV) is 86 +- 17 sec (estimated error including systematics). The time-averaged spectrum from T-0.42 to T+112.63 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is1.65 +- 0.09. The fluence in the 15-150 keV band is 3.6 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.18 sec in the 15-150 keV band is 10.7 +- 0.5 ph/cm2/sec. All the quoted errors are at the 90% confidencelevel. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/982707/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28138 SUBJECT: GRB 200716C: Optical observations from HCT DATE: 20/07/18 12:03:42 GMT FROM: Brajesh Kumar at Indian Inst. of Astrophysics Brajesh Kumar (ARIES, Nainital), Anirban Dutta, Avinash Singh, G. C. Anupama, D. K. Sahu and Pramod Kumar (IIA, Bengaluru) We observed the field of GRB 200716C (Fermi GBM, GCN #28123; Ukwatta et al., GCN #28124) with the Himalaya Faint Object Spectrograph and Camera (HFOSC) mounted on the 2-m Himalayan Chandra Telescope (IAO, Hanle, India). Multiple frames (each 300 sec) of the GRB field in Bessell R and I bands were obtained under moderate sky conditions. Preliminary PSF photometry on the stacked images was performed and calibrated against USNO-B1 catalogue. The estimated magnitudes are listed below: DATE | UT (mean) | Exposure | Filter | Mag 2020-07-17 17:06:34 300x3 R 17.55 +/- 0.18 2020-07-17 17:23:33 300X3 I 17.19 +/- 0.15 Here, we caution that there is an extended object near the GRB location (possibly the host galaxy, D'Avanzo et al. GCN #28132). However, the extended source is fainter (~19.23 and ~18.67 mag in R and I bands, respectively, USNO-B1). Therefore, the estimated magnitudes likely belong to the OT candidate (Lipunov et al., GCN #28125; Hu et al., GCN #28126), affected by the host contamination. We thank the staff at IAO and CREST for helping with the observations. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28139 SUBJECT: GRB 200716C: CALET Gamma-Ray Burst Monitor detection DATE: 20/07/18 12:06:31 GMT FROM: Valentin Pal'shin at AGU S. Torii (Waseda U), A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN), Y. Asaoka (ICRR), Y. Shimizu, 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 bright GRB 200716C (Swift detection: Ukwatta et al., GCN Circ. 28124, Barthelmy et al., GCN Circ. 28136; Fermi-LAT detection: Ohno et al., GCN Circ. 28130; Fermi GBM detection: Veres and Meegan, GCN Circ. 28135; https://gcn.gsfc.nasa.gov/other/200716C.gcn3) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 22:57:41.346 UTC on 16 July 2020. The burst signal was seen by all CGBM detectors. Because of a problem in one of the ground alert processing script, the GCN notice was not distributed automatically for this event. The burst light curve shows two narrow pulses followed by a weak tail. The emission starts at T-0.1 sec and ends at T+6.8 sec. The T90 and T50 durations measured by the SGM data are 5.3 +- 1.1 sec and 1.9 +- 0.1 sec (40-1000 keV), respectively. The ground processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1278975378/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at the Waseda University. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28145 SUBJECT: GRB 200716C: Insight-HXMT/HE detection DATE: 20/07/19 10:56:08 GMT FROM: Wangchen Xue at IHEP W. C. Xue, S. Xiao, Q. B. Yi, Y. G. Zheng, C. Cai, Q. Luo, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team: At 2020-07-16T22:57:41.18 (T0), Insight-HXMT/HE detected GRB 200716C (trigger ID: HEB200716956) in a routine search of the data, which also triggered Fermi/GBM (Fermi GBM team, GCN #28123), Swift/BAT (Ukwatta et al., GCN #28124), Fermi-LAT (Ohno et al., GCN #28130) and CALET GBM (Torii et al., GCN #28139). The Insight-HXMT/HE light curve mainly consists of multiple pulses with a duration (T90) of 2.16 s measured from T0+0.19 s. The 1-ms peak rate, measured from T0+0.31 s, is 27488 cnts/sec. The total counts from this burst is 6590 counts. URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB200716956_lc.jpg All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope. Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28146 SUBJECT: GRB 200716C: VIRT optical detection. DATE: 20/07/19 22:10:18 GMT FROM: Priyadarshini Gokuldass at U. of the Virgin Islands P. Gokuldass (UVI), D. Morris (UVI), N. Orange (OrangeWave Innovative Science, LLC), A. Cucchiara (UVI/College of Marin), R. Strausbaugh (UVI) report: We observed the field of GRB200716C (Ukwatta et al, GCN 28124) with the 0.5m Virgin Island Robotic Telescope (VIRT) at the University of the Virgin Islands' Etelman Observatory on 07-17-2020 starting at 01:48:10 UT (T+2.8 hrs). We performed a series of exposures in R filter with a total exposure of 1210 s. The weather conditions were clear during the hours of observation with an average airmass of 2.2. We detect a source consistent with the UVOT position (Ukwatta et al, GCN 28124) and optical transient identified by others (Lipunov et al. 28125, Hu et al. 28126, Kumar et al. 28138) with magnitude: R= 17.1 +/- 0.2 The magnitude is estimated from comparison to nearby USNO B1 stars and is not corrected for Galactic extinction. Further analysis is in progress to confirm the decaying nature of the source. 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28147 SUBJECT: Konus-Wind observation of GRB 200716C DATE: 20/07/19 23:32:33 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Frederiks, D. Svinkin, S. Golenetskii, R.Aptekar, A.Lysenko, A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The GRB 200716C (Swift-BAT detection: Ukwatta et al., GCN 28124; Fermi-LAT detection: Ohno et al., GCN 28130; AGILE-MCAL detection: Ursi et al., GCN 28133; Fermi-GBM detection: Veres & Meegan, GCN 28135; CALET-GBM detection: Torii et al., GCN 28139; Insight-HXMT/HE detection: Xue et al., GCN 28145) triggered Konus-Wind (KW) at T0=82658.337 s UT (22:57:38.337). The burst light curve shows two bright, short, hard-spectrum pulses in the interval from ~T0-0.5 s to ~T0+2.5 s. Both pulses are ~0.5 s wide and they are peaked at ~T0-0.128 s and ~T0+2.096 s, respectively. A much weaker post-burst emission is visible in the KW 20-80 keV band up to ~T0+75 s. The emission in the main pulses is seen up to ~7 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/ As observed by Konus-Wind, the burst had a fluence of (1.2 +/- 0.2)x10^-5 erg/cm^2 and a 64-ms peak energy flux, measured from T0+0.128 s, of (3.7 +/- 0.6)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.07(-0.12,+0.14) and Ep = 652(-154,+241) keV (chi2 = 91/97 dof). Fitting by a GRB (Band) model yields similar alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 =91/96 dof). The spectrum near the peak count rate (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.51 (-0.19,+0.31), the high energy photon index beta = -2.23 (-0.58,+0.29), the peak energy Ep = 616 (-200,+226) keV, (chi2 = 48/42 dof). Assuming the photo z=0.348 of a possible host galaxy (D'Avanzo, GCN 28132) and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso ~ 3.9x10^51 erg, the peak luminosity L_iso ~ 1.6x10^52 erg/s, and the rest-frame peak energy of the time-integrated (peak) spectrum Ep,z ~ 880 keV (~830 keV). With these values, GRB 200716C is a clear outlier in the 'Amati' relation built for 138 KW GRBs with known z (Tsvetkova et al., ApJ 850 161, 2017). Meanwile, in both Eiso-Ep,z and Liso-Ep,z planes, the GRB 200716C position is consistent with short-hard (Type I) GRB population, see http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/GRB200716C.pdf All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28148 SUBJECT: Konus-Wind observation of GRB 200716C: correction to GCN 28147 DATE: 20/07/20 12:49:52 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, D. Svinkin, S. Golenetskii, R.Aptekar, A.Lysenko, A. Ridnaia, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: The GRB 200716C (Swift-BAT detection: Ukwatta et al., GCN 28124; Fermi-LAT detection: Ohno et al., GCN 28130; AGILE-MCAL detection: Ursi et al., GCN 28133; Fermi-GBM detection: Veres & Meegan, GCN 28135; CALET-GBM detection: Torii et al., GCN 28139; Insight-HXMT/HE detection: Xue et al., GCN 28145) triggered Konus-Wind (KW) at T0=82658.337 s UT (22:57:38.337). The burst light curve shows two bright, short, hard-spectrum pulses in the interval from ~T0-0.5 s to ~T0+2.5 s. Both pulses are ~0.5 s wide and they are peaked at ~T0+0.128 s and ~T0+2.096 s, respectively. A much weaker extended post-burst emission is visible in the KW 20-80 keV band up to ~T0+75 s. The emission in the main pulses is seen up to ~7 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/ As observed by Konus-Wind, the burst had a fluence of (1.2 +/- 0.2)x10^-5 erg/cm^2 and a 64-ms peak energy flux, measured from T0+0.128 s, of (3.7 +/- 0.6)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by a power law with exponential cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.07(-0.12,+0.14) and Ep = 652(-154,+241) keV (chi2 = 91/97 dof). Fitting by a GRB (Band) model yields similar alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 =91/96 dof). The spectrum near the peak count rate (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.51 (-0.19,+0.31), the high energy photon index beta = -2.23 (-0.58,+0.29), the peak energy Ep = 616 (-200,+226) keV, (chi2 = 48/42 dof). Assuming the photo z=0.348 of a possible host galaxy (D'Avanzo, GCN 28132) and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso ~ 3.9x10^51 erg, the peak luminosity L_iso ~ 1.6x10^52 erg/s, and the rest-frame peak energy of the time-integrated (peak) spectrum Ep,z ~ 880 keV (~830 keV). With these values, GRB 200716C is a clear outlier in the 'Amati' relation built for 138 long KW GRBs with known z (Tsvetkova et al., ApJ 850 161, 2017). Meanwile, in both Eiso-Ep,z and Liso-Ep,z planes, the GRB 200716C position is consistent with short-hard (Type I) GRB population, see http://www.ioffe.ru/LEA/GRBs/GRB200716_T82658/GRB200716C.pdf All the quoted errors are estimated at the 68% confidence level. All the presented results are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28149 SUBJECT: GRB 200716C: FRAM-ORM afterglow detection DATE: 20/07/21 09:04:42 GMT FROM: Martin Jelinek at Astro.Inst-AVCR,Ondrejov Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ), Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek, Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza (Institute of Physics, Prague, CZ) report: The 25cm robotic telescope FRAM-ORM at La Palma (Spain) reacted robotically to the alert of GRB200716C (Ukwatta et al GCNC 28124), obtaining a series of 20s unfiltered images starting at 22:58:17.9 UT, i.e. 36.5s post trigger. We clearly detect the source reported by other telescopes (Ukwatta et al GCN 28124, Lipunov et al GCN 28125, Hu et al GCN 28126) as it rises slowly. The brightness of the object reaches maximum several minutes after the trigger with R = 16.1 and then it decays until the end of our dataset 2.4 h after the trigger. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28151 SUBJECT: GRB 200716C: CrAO, Terskol, Assy-Turgen optical observations DATE: 20/07/21 15:34:11 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), S. Belkin (IKI), V. Rumyantsev (CrAO), A. Gorshkov (INASAN), V. Kim (AFIF, Pulkovo Observatory), N. Pankov (HSE), K. Kamyshnikov (HSE), M. Krugov (AFIF), A. Volnova (IKI), E. Mazaeva (IKI) report on behalf of larger GRB follow-up collaboration: We observed GRB 200716C (Fermi GBM team, GCN 28123; Ukwatta et al GCN 28124; Torii et al., GCN 28139; Xue et al., GCN 28145; Frederiks et al., GCN 28147) with ZTSH 2.6m telescope of CrAO observatory, Zeiss-2000 of Terskol observatory, and AZT-20 telescope of Assy-Turgen observatory. The optical afterglow (Ukwatta et al., GCN 28124; Lipunov et al., GCN 28125; Hu et al., GCN 28126; Kumar et al., GCN 28138; Gokuldass et al., GCN 28146; Jelinek et al., GCN 28149) and possible host galaxy (D’Avanzo et al., GCN 28132) is detected in a stacked image. Preliminary photometry of the (afterglow + possible host galaxy) is following Date UT start t-T0 Filter Exp. OT Err. UL Telescope (mid, days) (s) 2020-07-17 19:17:52 0.84735 R 29*60 19.04 0.03 22.0 ZTSh 2020-07-17 19:50:49 0.87023 R 30*60 19.21 0.03 21.9 ZTSh 2020-07-18 18:33:32 1.83323 R 24*120 19.21 0.06 22.1 Zeiss-2000 2020-07-18 19:25:19 1.85253 R 17*60 19.21 0.06 22.1 ZTSh 2020-07-19 17:15:50 2.78066 r' 52*60 19.31 0.03 22.4 AZT-20 The photometry is based for R-calibration on the star USNO-B1.0_id R 1196-0207871 16.18 and nearby SDSS stars for r' calibration SDSS-DR12_id r J130423.13+294053.3 15.970 J130352.15+293733.9 16.592 J130416.16+293906.8 16.914 The above photometry besides of the first observation is consistent with a brightness of possible host in USNO-B1.0 (R2=19.23) and in SDSS DR12 (r'= 19.301 +/- 0.026). We may conclude that we detected afterglow only in the first observation on 0.84735 days after trigger at R=19.04 +/- 0.03. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28152 SUBJECT: GRB 200716C: CAHA optical observation // Anomalous light curve behavior? DATE: 20/07/21 21:36:27 GMT FROM: Alexander Kann at IAA-CSIC D. A. Kann (HETH/IAA-CSIC), M. Jelinek (ASU CAS Ondrejov), L. Izzo (DARK/NBI), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. C. Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), B. Arroyo, G. Bergond, and S. Pedraz (all CAHA) report: We observed the position of the afterglow (Ukwatta et al., GCN 28124; Lipunov et al., GCN 28125; Hu et al., GCN 28126; Kumar et al., GCN 28138; Gokuldass et al., GCN 28146; Jelinek et al., GCN 28149; Pozanenko et al., GCN 28151) and potential host galaxy (D'Avanzo, GCN 28132) of the bright GRB 200716C (Swift detection: Ukwatta et al., GCN 28124; Fermi GBM/LAT detections: Veres & Meegan, GCN 28135/Ohno et al., GCN 28130; AGILE detection: Ursi et al., GCN 28133; CALET detection: Torii et al., GCN 28139; Insight-HXMT/HE detection: Xue et al., GCN 28145) with the 2.2m telescope at Calar Alto, Almeria, Spain, equipped with CAFOS. We obtained a 180 s image in SDSS r', starting 2020-07-17 20:37:13 UT, (mid-time 0.903495 days after the GRB trigger), at high airmass. The host galaxy is clearly visible, but there is no clear detection of the afterglow. Calibrating against four nearby SDSS stars, we measure r' = 19.67 +/- 0.07 mag (AB mag). This value is fainter than those given by Pozanenko et al., GCN 28151, but we caution that an uneven background nearby may be influencing our magnitude measurement somewhat. Therefore, we are in agreement with Pozanenko et al. that the afterglow was not distinguishable from the host galaxy anymore at this point in time. Combining the above-mentioned sources and the automatically reduced UVOT data (but excluding the point from Kumar et al.), we find the afterglow, starting with the second Swift orbit, decays according to a broken power-law with decay slopes alpha_1 = 0.80 +/- 0.04, alpha_2 = 5.5 +/- 1.3, and break time 0.44 +/- 0.03 days. Hereby, we estimated host galaxy magnitudes in UVOT ubv based on the magnitudes given by D'Avanzo, GCN 28132, and assumed a significantly fainter host in the UV filters. Even compared to this extreme fit, the data point given by Kumar et al. is nearly two magnitudes too bright, as the steep decay should have set on already here assuming it is achromatic. While we caution the second decay slope depends strongly on the assumed host magnitudes, even without a host there is clearly a break to a very steep decay seen in uvw2, b, white, and partially v. This behavior is in strong contrast to the X-rays, which show an unbroken decay at alpha_X = 1.56 across this time span (Page & Evans, GCN 28131). Combined with indications from the Konus-Wind analysis that this may actually be a non-collapsar event (Frederiks et al., GCN 28148), this points to this being an event of interest. Further follow-up is warranted. [GCN OPS NOTE(21jul20): Due to some non-printing characters in the Subject-line of the submission, the MIME processor left a large chunk of the header of the submission email to appear as more of the body of the email. This has been removed from the archive copies.] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28154 SUBJECT: GRB 200716C: Kitab optical observations DATE: 20/07/23 09:34:07 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), A. Zhornichenko (KIAM), A. Novichonok (Petrozavodsk State University, KIAM), Sh. Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN: We observed GRB 200716C (Fermi GBM team, GCN 28123; Ukwatta et al GCN 28124; Ohno et al., GCN 28130; Ursi et al., GCN 28133; Torii et al., GCN 28139; Xue et al., GCN 28145; Frederiks et al., GCN 28147) with RC-36 telescope of Kitab observatory starting July 17 (UT) 17:24:57. The optical afterglow (Ukwatta et al., GCN 28124; Lipunov et al., GCN 28125; Hu et al., GCN 28126; Kumar et al., GCN 28138; Gokuldass et al., GCN 28146; Jelinek et al., GCN 28149; Pozanenko et al., GCN 28151; Kann et al., GCN 28152) is detected in a stacked image. Despite we do not detect possible host galaxy (D’Avanzo et al., GCN 28132) the galaxy may contaminate photometry result. Preliminary photometry of the afterglow is following Date UT start t-T0 Filter Exp. OT Err. UL (mid, days) (s) 2020-07-17 17:24:57 0.78952 R 59*60 18.2 0.3 18.6 The photometry is based on nearby stars of USNO-B1.0 USNO-B1.0_id R2 1196-0207884 15.42 1197-0206830 14.99