GRB170728B

This page lists all entries on GRB170728B in GRBweb

Summary Fermi GBM IPN Swift GCN 21371 GCN 21372 GCN 21373 GCN 21374 GCN 21375 GCN 21376 GCN 21377 GCN 21380 GCN 21381 GCN 21383 GCN 21384 GCN 21387 GCN 21388 GCN 21389 GCN 21391 GCN 21393 GCN 21394 GCN 21395 GCN 21398 GCN 21399 GCN 21401 GCN 21419 GCN 21441 GCN 21466 GCN 21932

Summary table
Variable Value Source
GRB_name_Fermi GRB170728961
T0 23:03:18.412 UTC GCN_circulars,Konus-Wind Det
ra 237.9812° Swift
decl 70.1223° Swift
pos_error 1.81e-04° Swift
T90 46.336 s Fermi_GBM
T90_error 0.81 s Fermi_GBM
T90_start 23:03:19.434 UTC Fermi_GBM
fluence 4.02e-06 erg/cm² Fermi_GBM
fluence_error 3.18e-08 erg/cm² Fermi_GBM
T100 48.288 s
GBM_located False
mjd 57962.96062976852 GCN_circulars,Konus-Wind Det
Fermi GBM table
GRB_name_Fermi GRB170728961
trigger_name bn170728961
ra 237.9808°
decl 70.1222°
pos_error 2.97e+00°
datum 2017-07-28
t_trigger 23:03:19.434 UTC
T90 46.336 s
T90_error 0.81 s
T90_start 23:03:19.434 UTC
fluence 4.02e-06 erg/cm²
fluence_error 3.18e-08 erg/cm²
flux_1024 1.27e+01 erg/cm²/s
flux_1024_error 3.20e-01 erg/cm²/s
flux_1024_time -1.28e-01 erg/cm²/s
flux_64 2.31e+01 erg/cm²/s
flux_64_error 1.43e+00 erg/cm²/s
IPN table
GRB_name GRB170728B
ra 238.0458°
decl 70.1500°
pos_error 5.00e-02°
Swift table
GRB_name GRB170728B
t_trigger 23:03:19 UTC
ra 237.9812°
decl 70.1223°
pos_error 1.81e-04°
T90 47.7 s
fluence 6.20e-07 erg/cm²
GCN 21371 table
GRB_name GRB170728B
GCN_number 21371
Detection_method Swift Det
t_trigger 23:03:19 UTC
ra 238.0440°
decl 70.1420°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21371 SUBJECT: GRB 170728B: Swift detection of a short burst DATE: 17/07/28 23:24:58 GMT FROM: Scott Barthelmy at NASA/GSFC S. B. Cenko (GSFC), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), A. Cholden-Brown (PSU), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 23:03:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 170728B (trigger=765130). Due to an observing constraint, Swift executed a 6-min delayed slew to the burst. The BAT on-board calculated location is RA, Dec 238.044, +70.142, which is RA(J2000) = 15h 52m 11s Dec(J2000) = +70d 08' 32" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 1 sec. The peak count rate was ~5500 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 23:11:08.2 UT, 468.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 237.9813, 70.1222 which is equivalent to: RA(J2000) = 15h 51m 55.52s Dec(J2000) = +70d 07' 19.9" with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 104 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 http://www.swift.ac.uk/sper. No spectrum from the promptly downlinked event data is yet available to determine the column density. UVOT took a finding chart exposure of 150 seconds with the White filter starting 473 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 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 0.03. Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN 21372 table
GRB_name GRB170728B
GCN_number 21372
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21372 SUBJECT: GRB 170728B: TNG optical afterglow candidate DATE: 17/07/29 01:16:51 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo (INAF-OAB), V. D'Elia (INAF/OAR & ASI/ASDC), M. Cecconi, H. Stoev (INAF-TNG) report on behalf of the CIBO collaboration: We observed the field of the short GRB 170728B (Cenko et al., GCN Circ. 21371) with the 3.6m Telescopio Nazionale Galileo (TNG) equipped with DOLoRes. Observations were carried out in the r-sdss filter. Observations started Jul 28 at 23:55:49 UT (~52.5 minutes after the burst) and consist in a single image lasting 300 seconds. Inside the enhanced XRT position (http://www.swift.ac.uk/xrt_positions/) we detect a candidate optical afterglow. From preliminary photometry we estimate a magnitude r(AB)~20.6 (calibrated against nearby stars reported in the PAN-STARSS catalogue).
GCN 21373 table
GRB_name GRB170728B
GCN_number 21373
Detection_method Optical
ra 237.9811°
decl 70.1225°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21373 SUBJECT: GRB 170728B: position of the TNG optical counterpart DATE: 17/07/29 01:49:24 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo (INAF-OAB), H. Stoev, M. Cecconi (INAF-TNG, V. D'Elia (INAF/OAR & ASI/ASDC) report on behalf of the CIBO collaboration: We report here the position of the optical afterglow candidate of the short GRB 170728B (D’Avanzo et al. GCN Circ. 21372). The source position is: RA (J2000): 15:51:55.47 Dec (J2000): +70:07:21.1 +/- 0.3”. We apologize for the delay in sending this information.
GCN 21374 table
GRB_name GRB170728B
GCN_number 21374
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21374 SUBJECT: GRB 170728B: NOT optical afterglow confirmation DATE: 17/07/29 02:14:13 GMT FROM: Kasper Elm Heintz at Univ. of Iceland and DARK/NBI K. E. Heintz (Univ. Iceland and DARK/NBI), N. R. Tanvir (Univ. Leicester), D. A. Perley (LJMU) and R. T. Rasmussen (NOT) report on behalf of a larger collaboration: We observed the field of the short GRB 170728B (Cenko et al., GCN 21371) using the ALFOSC instrument equipped at the 2.56-m Nordic Optical Telescope (NOT). We obtained a single image with the SDSS r-band consisting of a 60 s exposure at 00:10:53 UT on 29 July, 2017 (i.e., 67.3 minutes after the burst). We confirm the presence of the optical afterglow (P. D'Avanzo et al., GCN 21372/21373) and from the single image we measure a magnitude of r(AB) = 20.9 +/- 0.1 mag calibrated against nearby stars from the Pan-STARRS survey. In addition, we obtained spectroscopy of the afterglow consisting of 3x1200 s exposures using grism no. 4, covering a spectral wavelength range of 3200 — 9600 Å, and a slit width of 1.3 arcsec. The trace is faint and at this point we can not robustly determine a redshift. A separate GCN will be submitted later based on the reduced spectroscopic data. The observations were carried out under good weather conditions at an airmass of ~ 1.6 and a measured seeing of 0.74 arcsec.
GCN 21375 table
GRB_name GRB170728B
GCN_number 21375
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21375 SUBJECT: GRB 170728B: LT afterglow confirmation DATE: 17/07/29 04:50:11 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), C.G. Mundell (U. Bath), A. Gomboc (U. Nova Gorica), S. Kobayashi, I.A. Steele (LJMU) on behalf of a large collaboration report: We began observing Swift GRB 170728B (Cenko et al. GCN 21371) on July 28, 23:06:47 UT (208 seconds since the GRB trigger) with 2-m Liverpool Telescope with RINGO3 polarimeter and IO:O camera in the SDSS R filter. We clearly detect the optical counterpart (D'Avanzo et al. GCN 21373; Heintz et al. GCN 21374) with r'=20.43 +- 0.12 mag in a 6x10s frame at a mid time of 36.5 minutes since GRB, as calibrated against nearby Pan-STARRS1 sources.
GCN 21376 table
GRB_name GRB170728B
GCN_number 21376
Detection_method Swift-XRT Other
ra 237.9806°
decl 70.1227°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21376 SUBJECT: GRB 170728B: Swift-XRT refined Analysis DATE: 17/07/29 05:05:26 GMT FROM: Phil Evans at U of Leicester V. D'Elia (ASDC), S. J. LaPorte (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB) and S.B. Cenko report on behalf of the Swift-XRT team: We have analysed 7.3 ks of XRT data for GRB 170728B (Cenko et al. GCN Circ. 21371), from 454 s to 14.4 ks after the BAT trigger. The data comprise 231 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The best available XRT position (using the promptly downlinked event data, the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue) is RA, Dec = 237.9806, 70.1227 which is equivalent to: RA (J2000): 15 51 55.35 Dec(J2000): +70 07 21.7 with an uncertainty of 2.0 arcsec (radius, 90% confidence). The light curve can be modelled with an initial power-law decay with an index of alpha=0.66 (+0.08, -0.12), followed by a break at T+1874 s to an alpha of 1.20 (+/-0.07). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.94 (+/-0.12). The best-fitting absorption column is 1.7 (+0.5, -0.4) x 10^21 cm^-2, in excess of the Galactic value of 3.2 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.81 (+/-0.08) and a best-fitting absorption column of 2.5 (+/-0.3) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 2.5 (+/-0.3) x 10^21 cm^-2 Galactic foreground: 3.2 x 10^20 cm^-2 Excess significance: 11.6 sigma Photon index: 1.81 (+/-0.08) If the light curve continues to decay with a power-law decay index of 1.20, the count rate at T+24 hours will be 0.043 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x 10^-12 (2.3 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/00765130. This circular is an official product of the Swift-XRT team.
GCN 21377 table
GRB_name GRB170728B
GCN_number 21377
Detection_method Swift-XRT Det
ra 237.9812°
decl 70.1223°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21377 SUBJECT: GRB 170728B: Enhanced Swift-XRT position DATE: 17/07/29 05:33:24 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 7030 s of XRT Photon Counting mode data and 10 UVOT images for GRB 170728B, 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 = 237.98125, +70.12230 which is equivalent to: RA (J2000): 15h 51m 55.50s Dec (J2000): +70d 07' 20.3" 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.
GCN 21380 table
GRB_name GRB170728B
GCN_number 21380
Detection_method Fermi LAT Det
t_trigger 23:33:32 UTC
ra 238.9700°
decl 69.7400°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21380 SUBJECT: GRB 170728B: Fermi-LAT detection DATE: 17/07/29 13:03:36 GMT FROM: Manal Yassine at IN2P3/LUPM/CNRS M. Yassine (LUPM,CNRS,IN2P3) and J. L. Racusin (NASA/GSFC) report on behalf of the Fermi-LAT team: On July 28, 2017, Fermi-LAT detected high-energy emission from GRB 170728B, which triggered the Fermi-GBM (trigger 522975804) at 23:33:32 UT July, 28 2017. This burst was also detected by Swift (Cenko et al., GCN Circ. 21371). The best LAT on-ground location is found to be RA, Dec 238.97, 69.74 (degrees, J2000) with an error radius of 0.53 deg (90% containment, statistical error only). This was 30 deg from the LAT boresight at the time of the trigger and triggered an autonomous repoint of the spacecraft. The data from the Fermi-LAT is spatially and temporally correlated with the GBM emission with high significance. More than 10 photons above 100 MeV are observed within 100 seconds. The highest-energy photon is a 0.6 GeV event which is observed 9.3 seconds after the GBM trigger. The Fermi-LAT point of contact for this burst is Manal Yassine (manal.yassine@lupm.in2p3.fr). 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.
GCN 21381 table
GRB_name GRB170728B
GCN_number 21381
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21381 SUBJECT: GRB 170728B: I-band detection from 1.5m OSN DATE: 17/07/29 14:31:54 GMT FROM: Luca Izzo at IAA-CSIC L. Izzo, D.A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), C. C. Thoene (HETH/IAA-CSIC) and A. Sota (IAA-CSIC) report on behalf of a larger collaboration: We observed the field of GRB 170728B (Cenko et al., GCN 21371) with the 1.5m OSN telescope of the Sierra Nevada Observatory (Granada, Spain). Observation consisted of a series of 300 s Ic-band exposures, starting at 00:06:02.7 UT (1.05 hr after the burst). The afterglow is detected at a position consistent with the one reported by D’Avanzo et al., (GCN 21373). In the combination of the first 7x300s exposures we measure a magnitude of Ic(Vega) = 19.8+/- 0.2 as compared to USNO-B1 stars.
GCN 21383 table
GRB_name GRB170728B
GCN_number 21383
Detection_method Fermi GBM Det
t_trigger 23:03:19.430 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 21383 SUBJECT: GRB 170728B: Fermi GBM detection DATE: 17/07/29 15:47:09 GMT FROM: Matthew Stanbro at UAH/Fermi M. Stanbro and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 23:03:19.43 UT on 28 July 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170728B (trigger 522975804 / 170728961) which was also detected by the Swift/BAT (S. B. Cenko et al. 2017, GCN 21371) and Fermi LAT (M. Yassine et al. 2017, GCN 21380). The GBM on-ground location is consistent with the Swift position. The Swift/BAT reported a short GRB in GCN 21371. Fermi GBM sees the initial short peak at trigger time but is followed up by several peaks up the ~50s later. The trigger resulted in an Autonomous Repoint Request (ARR) by the GBM Flight Software owing to the high peak flux of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight location. The initial angle from the Fermi LAT boresight to the best location is 30 degrees. The GBM light curve consists of several episodes with a duration (T90) of about 46 s (50-300 keV). The time-averaged spectrum from T0-.90 s to T0+47.23 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.10 +/- 0.10 and the cutoff energy, parameterized as Epeak, is 175 +/- 26 keV The event fluence (10-1000 keV) in this time interval is (4.59 +/- 0.34)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.13 s in the 10-1000 keV band is 12.7 +/- 0.32 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 124 +/- 30 keV, alpha = -0.93 +/- 0.19 and beta = -2.12 +/- 0.22. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 21384 table
GRB_name GRB170728B
GCN_number 21384
Detection_method Swift-BAT Det
ra 238.0190°
decl 70.1110°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21384 SUBJECT: GRB 170728B, Swift-BAT refined analysis DATE: 17/07/29 19:04:42 GMT FROM: Amy Lien at GSFC T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), (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 170728B (trigger #765130) (Cenko et al., GCN Circ. 21371). The BAT ground-calculated position is RA, Dec = 238.019, 70.111 deg which is RA(J2000) = 15h 52m 04.5s Dec(J2000) = +70d 06' 40.0" with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 5%. The mask-weighted light curve shows a short multi-peaked structure from ~T-0.1 s to ~T+0.7 s, followed by some weak emission till ~T+50 s, Fermi/GBM also reports emission till ~T+47 s (Stanbro et al., GCN Circ. 21383). T90 (15-350 keV) is 47.7 +- 25.2 sec (estimated error including systematics). The time-averaged spectrum for the short pulse from T-0.1 to T+0.7 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index -1.10 +- 1.71, and Epeak of 82.0 +- 24.2 keV (chi squared 51.71 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 6.2 +- 1.1 x 10^-7 erg/cm2. A fit to a simple power law gives a photon index of 1.21 +- 0.24 (chi squared 61.25 for 57 d.o.f.). The time-averaged spectrum for the extended emission from T+0.7 to T+50.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.25 +- 0.57. The fluence in the 15-150 keV band is 9.8 +- 3.9 x 10^-7 erg/cm2. 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/765130/BA/
GCN 21387 table
GRB_name GRB170728B
GCN_number 21387
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21387 SUBJECT: GRB 170728B iTelescope observation DATE: 17/07/29 23:19:08 GMT FROM: Takanori Sakamoto at AGU Y. Kitaoka, T. Sakamoto (AGU) We observed the field of GRB 170728B detected by Swift (Cenko et al., GCN Circ. 21371) with the iTelescope.Net (http://www.itelescope.net) T16 (Takahashi TOA-150) telescope located at the AstroCamp Observatory (Nerpio, Spain). 20 images of 60 sec exposures were taken in the R filter starting from July 28 23:03:19 (UT) about 36 mimute after the trigger and stopped on July 29 00:17:48 (UT). We do not detect the optical afterglow both in the individual images and the stacked image at the X-ray afterglow position. The estimated five sigma upper limit of the combined image (total exposure of 1200 sec) is ~15.8 using the USNO-B1 catalog.
GCN 21388 table
GRB_name GRB170728B
GCN_number 21388
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21388 SUBJECT: GRB 170728B: Swift/UVOT Upper Limits DATE: 17/07/30 01:46:56 GMT FROM: Sam LaPorte at PSU GRB 170728B: Swift/UVOT Upper Limits S. J. Laporte (PSU) and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170728B 473 s after the BAT trigger (Cenko et al., GCN Circ. 21371). No optical afterglow consistent with the optical position (D'Avanzo et al. GCN Circ. 21373) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 473 623 147 >19.8 white 473 7867 908 >20.8 v 630 8278 627 >19.6 b 728 14417 1117 >21.3 u 703 13868 1276 >21.2 w1 679 19251 2000 >21.6 m2 6847 18681 1279 >22.1 w2 6437 8073 393 >21.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN 21389 table
GRB_name GRB170728B
GCN_number 21389
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21389 SUBJECT: GRB 170728B: COATLI Observations And Confirmation of Fading DATE: 17/07/30 02:20:58 GMT FROM: Alan M. Watson at Instituto de Astronomia UNAM Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), Carlos Román-Zúñiga (UNAM), and William H. Lee (UNAM) report: We observed the field of the short GRB 170728B (Cenko et al., GCN Circ. 21371) with the COATLI 50-cm telescope and interim imager (Watson et al. 2016, Proc. SPIE, 9908, 50) at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir from 2017-07-29 04:21 to 08:19 obtaining a total of 2.76 hours of observation in the clear filter. We detect the source reported by D’Avanzo et al. (GCN Circ. 21372). Calibrating with respect to the USNO-B1 catalog, we estimate a preliminary magnitude of R = 22.40 +/- 0.16. This magnitude is in the USNO-B1 Vega system and is corrected for Galactic extinction in the direction of the GRB. The source has faded by around two magnitudes between the observations in the first hour or so (D’Avanzo et al., GCN Circ. 21372; Heintz et al, GCN Circ. 21374; and Guidorzi et al., GCN Circ. 21375) and our observations. This confirms that the source is the optical transient associated with the GRB. We thank the COATLI technical team (Fernando Ángeles, Oscar Chapa, Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosalía Langarica, Fernando Quirós, and Carlos Tejada) and the staff of the Observatorio Astronómico Nacional.
GCN 21391 table
GRB_name GRB170728B
GCN_number 21391
Detection_method Optical
ra 237.9792°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21391 SUBJECT: GRB 170728B: MASTER-IAC first minute short GRB early OT detection DATE: 17/07/30 13:25:56 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA), National University of San Juan, Argentina H. Levato, C. Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, Irkutsk State University V.Yurkov, Yu.Sergienko Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB170728B (Cenko et al., GCN Circ. #21371) 28 sec after notice time and 39 sec after trigger time at 2017-07-28 23:04:01 UT. On our first (10s exposure) set we found optical transient within SWIFT XRT error-box ( D'Elia et al., GCN #21376; ) in two polarizations! The 5-sigma upper limit has been about 16.9 mag We 100% found faiding OT on first 10 minutes images with m ~ 16.5 up to 18 mag. RA, DEC = 15h 51m 55s.5 , +70d 7m 19s.3 Error = +- 1.4 arcsec The faiding OT may be coincide with D'Avanzo et al. position (GCN #21372) and Heintz et al., (GCN #21374) and Izzo et al., (GCN #21381) and The observations made on zenit distance = 47 degrees, galaxy latitude b = 40 degree. The moon (34 % bright part) is 8 degrees above the horizon. The distance between moon and object is 78 The sun altitude is -33.7 degree. The error box can be observed till sunrise at 2017-07-29 06:25:17. The message may be cited.
GCN 21393 table
GRB_name GRB170728B
GCN_number 21393
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21393 SUBJECT: GRB 170728B: BOOTES-2/TELMA optical detection during the extended gamma-ray phase DATE: 17/07/30 17:00:39 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia A. J. Castro-Tirado (IAA-CSIC Granada & ISA-UMA Málaga), A. González-Rodríguez, Y. Hu, R. Cunniffe, J. C. Tello, B.-B. Zhang (IAA-CSIC Granada), A. Castellón, I. Carrasco (UMA Málaga), M. Jelínek (ASU-CAS Ondrejov), S. Guziy (Nikolaev Univ.), S. B. Pandey (ARIES Nainital), S. Jeong (SKKU Seoul), M. D. Caballero-García (ASU-CAS Prague), M. Wildi (Vermes Obs.) and P. Kubánek (IP-ASCR Prague), on behalf of a larger collaboration, report: Following the detection of GRB 170728B by Swift (Cenko et al. GCNC 21371), the TELMA 0.6m robotic telescope at the BOOTES-2 astronomical station at IHSM/UMA-CSIC in Málaga (Spain) pointed to the GRB location 26 sec after the notice time and 40 sec after trigger time, i.e. at 23:03:59 UT on July 28. The first exposures (3 sec, unfiltered) were taken simultaneously to the extended gamma-ray emission phase (Stanbro et al. GCNC 21383, Ukwatta et al. GCNC 21384), confirming the optical transient within the Swift/XRT error box (D'Elia et al., GCNC 21376) being coincident with the optical afterglow position (D'Avanzo et al. GCN 21373) with magnitudes in the range reported by Lipunov et al. (GCNC et al. 21391) starting 2 sec after. A detailed analysis is ongoing. This message can be quoted. [GCN OPS NOTE(31jul17): Per author's request, the date was corrected from "July 2" to "July 28"]
GCN 21394 table
GRB_name GRB170728B
GCN_number 21394
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21394 SUBJECT: GRB 170728B: Optical observations at Crni Vrh DATE: 17/07/30 20:13:20 GMT FROM: Bojan Dintinjana at OCV B. Dintinjana and H. Mikuz on behalf of PIKA observing program at Crni Vrh Observatory: We observed the afterglow of GRB 170728B (Cenko et al., GCN Circ. 21371) with 60 cm Cichocki robotic telescope at Crni Vrh Observatory, Slovenia. The series of twenty-six 60 second exposures with Rc filter started at 23:04:41UT, 81 seconds after the burst. We confirm optical afterglow at coordinates reported by DAvanzo et al. (GCN Circ. 21372, 21373). Photometry results are given in table below. The table contains the mid time of exposure in MJD, time since the Swift GRB detection to the middle of exposure in seconds, Rc magnitude and photometric error. The magnitudes are derived using comparison stars from the APASS catalog. The 3-sigma limiting magnitude in Rc filter is around magnitude 20.2 0.2. The light curve of the GRB 170728B: http://www.observatorij.org/vstars/GRB170728B/GRB170728B.png MJD t-T0 Rc err (s) (mag) (mag) ------------------------------------- 57962.961574 81 17.410 0.04 57962.962407 153 17.867 0.05 57962.963252 226 18.077 0.06 57962.964097 299 18.412 0.08 57962.964931 371 18.638 0.10 57962.965775 444 18.830 0.11 57962.966620 517 18.827 0.11 57962.967454 589 19.123 0.14 57962.968299 662 19.054 0.13 57962.969144 735 19.142 0.14 57962.969977 807 19.181 0.15 57962.970822 880 19.217 0.16 57962.971667 953 19.714 0.26 57962.972512 1026 19.505 0.22 57962.973345 1098 19.507 0.20 57962.974190 1171 19.586 0.23 57962.975023 1243 19.674 0.27 57962.975868 1316 19.456 0.23 57962.976713 1389 19.981 0.35 57962.977558 1462 19.734 0.25 57962.978391 1534 20.227 0.42 57962.979236 1607 19.736 0.25 57962.980081 1680 19.878 0.32 57962.980926 1753 20.200 0.38 57962.981759 1825 19.519 0.21 57962.982604 1898 19.913 0.31 -------------------------------------
GCN 21395 table
GRB_name GRB170728B
GCN_number 21395
Detection_method Optical
ra 237.9810°
decl 70.1226°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21395 SUBJECT: GRB 170728B: VLA radio afterglow detection DATE: 17/07/31 04:27:16 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (University of Arizona), T. Laskar (NRAO/UC Berkeley), K. D. Alexander (Harvard) and E. Berger (Harvard) report: "We observed the position of GRB 170728B (Cenko et al., GCN 21371; Yassine et al., GCN 21380; Stanbro & Meegan, GCN 21383) with the Karl G. Jansky Very Large Array (VLA) beginning on 2017 Jul 29.075 UT (2.75 hr post-burst) at a mean frequency of 6 GHz. We obtained a second set of observations beginning on 2017 Jul 29.811 UT (20.4 hr post-burst) at mean frequencies of 6 and 10 GHz. We do not detect any radio counterpart in our first set of observations at 2.75 hr, while we clearly detect a radio source in our second set of observations at both frequencies at 20.4 hr at the position: RA(J2000) = 15:51:55.45 Dec(J2000) = +70:07:21.2 with an uncertainty of 0.2" in each coordinate. This position is coincident with the reported optical source (D'Avanzo et al., GCN 21372, GCN 21373; Heintz et al., GCN 21374; Guidorzi et al., GCN 21375; Watson et al., GCN 21389). Given the rapid variability and positional coincidence with the X-ray (Osborne et al., GCN 21377) and optical afterglows, we consider this to be the radio afterglow of GRB 170728B. Further observations are planned. We thank the VLA staff for quickly executing these observations."
GCN 21398 table
GRB_name GRB170728B
GCN_number 21398
Detection_method Konus-Wind Det
t_trigger 23:03:18.412 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 21398 SUBJECT: Konus-Wind observation of GRB 170728B DATE: 17/07/31 15:51:16 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 170728B (Swift-BAT trigger 765130: Cenko et al., GCN 21371; Ukwatta et al., GCN 21384; Fermi-LAT detection: Yassine et al., GCN 21380; Fermi-GBM observation: Stanbro et al., GCN 21383) triggered Konus-Wind at T0=82998.412 s UT (23:03:18.412). The burst light curve shows an initial short multi-peaked structure with a duration of ~0.5 s, followed by a weaker emission seen up to ~48 s. The emission is seen up to ~2 MeV. As observed by Konus-Wind, the burst had a fluence of 3.96(-0.75,+0.93)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0-0.016 s, of 4.38(-0.91,+0.93)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.13(-0.37,+0.45) and Ep = 160(-43,+103) keV (chi2 = 66/62 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -3.1 (chi2 = 66/61 dof) The spectrum near the maximum count rate (measured from T0+0.000 to T0+0.256 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model with alpha = -0.22(-0.33,+0.39) and Ep = 166(-22,+26) keV (chi2 = 22/36 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -3.0 (chi2 = 22/35 dof) The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170728_T82998/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN 21399 table
GRB_name GRB170728B
GCN_number 21399
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21399 SUBJECT: GRB 170728B: Swift/UVOT Further Analysis DATE: 17/07/31 19:31:50 GMT FROM: Sam LaPorte at PSU GRB 170728B: Swift/UVOT Detection S. J. LaPorte (PSU), S.W.K. Emery (MSSL), and S. B. Cenko (GSFC) report on behalf of the Swift/UVOT team: After detailed analysis of initial data reported in LaPorte and Cenko, GCN Circ. 21388, we do find a significant detection in initial optical filter exposures. The Swift/UVOT began settled observations of the field of GRB 170728B 473 s after the BAT trigger (Cenko et al., GCN Circ. 21371). A fading source consistent with the optical position (D'Avanzo et al. GCN Circ. 21373) is detected in the initial UVOT exposures. 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 876 1026 147 20.56 +/- 0.20 v 630 8278 627 20.23 +/- 0.27 b 728 2561 194 20.60 +/- 0.29 u 703 13868 1276 >21.2 w1 679 19251 2000 >21.6 m2 6847 18681 1279 >22.1 w2 6437 8073 393 >21.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN 21401 table
GRB_name GRB170728B
GCN_number 21401
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 21401 SUBJECT: GRB 170728B: time correction to MASTER GCN Circular 21391 DATE: 17/08/01 08:32:12 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs N.Tyurina, V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA), National University of San Juan, Argentina H. Levato, C. Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, Irkutsk State University V.Yurkov, Yu.Sergienko Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory We found additional image in MASTER-IAC DataBase with more early time. So the begining of our GCN Circular #21391 must be readed as: MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in IAC was pointed to the GRB170728B 19 sec after notice time and 30 sec after trigger time at 2017-07-28 23:03:49 UT. On our first (10s exposure) image we found optical transient within SWIFT error-box (Cenko et al., GCN Circ. #21371). The 5-sigma upper limit has been about 16.6 mag The message may be cited.
GCN 21419 table
GRB_name GRB170728B
GCN_number 21419
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21419 SUBJECT: GRB 170728B: TShAO, SAO RAS and AbAO optical observations DATE: 17/08/07 10:23:04 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), A. Kusakin (Fesenkov Astrophysical Institute), A.S. Moskvitin (SAO RAS), O.I. Spiridonova (SAO RAS), R. Inasaridze (AbAO), I. Reva (Fesenkov Astrophysical Institute), E. Mazaeva (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 170728B (Cenko et al., GCN 21371) with Zeiss-1000 of SAO RAS (July 29, August 4,5 ), AS-32 telescope of AbAO (July 29) and Zeiss-1000 telescope of Tien Shan Astronomical Observatory (July 30,31 August 1,6). Below we report the photometry of the optical afterglow (D'Avanzo et al., GCNs 21372, 21373; Heintz et al., GCN 21374; Guidorzi et al., GCN 21375) and upper limits of our observations. Preliminary photometry is following: Date UT start t-T0 Filter Exp. OT Err. UL Telescope (mid, days) (s) (3 sigma) 2017-07-29 00:41:51 0.07228 R 600 n/d n/d 18.6 Z-1000 SAO 2017-07-29 17:27:49 0.79594 CR 43*60 n/d n/d 20.4 AS-32 AbAO 2017-07-30 16:12:56 1.79815 R 97*120 21.93 0.25 22.1 Z-1000 TSHAO 2017-08-01 15:12:51 3.72304 R 60*120 n/d n/d 21.6 Z-1000 TSHAO 2017-08-04 00:41:51 5.98081 R 41*300 22.6 0.23 22.8 Z-1000 SAO The photometry is based on nearby USNO-B1.0 stars 1601-0108291 15:52:31.54 +70:09:31.7 R2 17.95 1601-0108289 15:52:28.99 +70:09:26.3 R2 18.08 1601-0108260 15:51:57.87 +70:09:53.8 R2 16.87 1601-0108254 15:51:50.88 +70:08:41.2 R2 15.04 1601-0108262 15:52:03.24 +70:07:32.0 R2 16.01 Coordinates of the afterglow obtained from observation on July 30 are (J2000) 15 51 55.5179 +70 07 21.123 with uncertainties on both coordinates of 0.2 arces which is compatible with coordinates of TNG (D'Avanzo et al., GCN 21373) and VLA (Fong et al., GCN 21395). The finding chart can be found in http://grb.rssi.ru/GRB170728B/GRB170728B_TShAO_R_170730.png The light curve of the afterglow based on observations above and photometry reported in GCNs (Dintinjana et al., GCN 21394; Watson GCN 21389; D'Avanzo et al., GCN 21372; Heintz et al., GCN 21374; Guidorzi et al., GCN 21375) can be found in http://grb.rssi.ru/GRB170728B/GRB170728B_lc+GCNs_v2.png Based on our observation on July, 30 (~ 1.8 days after burst onset) one can suggest that the OT experienced rebrightening at that epoch.
GCN 21441 table
GRB_name GRB170728B
GCN_number 21441
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21441 SUBJECT: GMRT upper limit on the radio afterglow of GRB 170728B DATE: 17/08/10 06:40:18 GMT FROM: Poonam Chandra at TIFR Poonam Chandra & A. J. Nayana (NCRA-TIFR, India) report: We observed the short hard burst GRB 170728B (Cenko et al., GCN Circ. 21371) with the Giant Metre Wave Radio Telescope (GMRT) at 1390 MHz band on 2017 August 09.61 UT, i.e. 11.65 days after the burst. We do not see any significant radio emission at the burst position (D’Avanzo et al. GCN Circ. 21373). The 3-sigma upper limit on the GRB radio flux density is 140 uJy. We thank the GMRT staff for scheduling these observations.
GCN 21466 table
GRB_name GRB170728B
GCN_number 21466
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 21466 SUBJECT: GRB 170728B: 15 GHz upper limits from AMI DATE: 17/08/11 18:16:52 GMT FROM: Kunal Mooley at Oxford U K. P. Mooley (Hintze Fellow, Oxford), T. D. Staley, R. P. Fender (Oxford), G. E. Anderson (Curtin), T. Cantwell (Manchester), D. Titterington, S. H. Carey, J. Hickish, Y. C. Perrott, N. Razavi-Ghods, P. Scott (Cambridge), K. Grainge, A. Scaife (Manchester) The AMI Large Array robotically triggered on the Swift alert for the short GRB 170728B (Cenko et al., GCN 21371) as part of the 4pisky program, and subsequent follow up observations were obtained up to 3 days post-burst. Our observations at 15 GHz on 2017 Jul 29.00, Jul 29.80, Jul 30.80 and Jul 31.76 (UT) do not reveal any radio source at the XRT location (Osborne et al., GCN 21377), with 3sigma upper limits of 258 uJy, 201 uJy, 171 uJy and 108 uJy respectively. This upper limit is consistent with the radio afterglow detection on 2017 Jul 29.81 reported by Fong et al. (GCN 21395; much fainter than 300 uJy at 6 GHz). We thank the AMI staff for scheduling these observations. The AMI-GRB database is a log of all GRB follow up observations with the AMI, and is available at http://4pisky.org/ami-grb/.
GCN 21932 table
GRB_name GRB170728B
GCN_number 21932
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21932 SUBJECT: GRB 170728B: Kottamia R-band observation DATE: 17/09/27 06:13:52 GMT FROM: Yasser Hendy at NRIAG TITLE: GCN CIRCULAR NUMBER: SUBJECT: GRB 170728B: Kottamia R-band observation DATE: 17/09/27 6:09 GMT FROM: Yasser Hendy at NRIAG G. B. Ali, Y.H.M. Hendy, A. Takey, N. Essam, and A. Essam National Research institute of Astronomy and Geophysics, NRIAG, Egypt report on behalf of the Kottamia collaboration: We observed the field of the short GRB 170728B: trigger=765130 (Cenko S. B. et al., GCN Circ. 21371) with the 1.88m telescope of the KAO (Kottamia Astronomical Observatory), Egypt. The observation was performed in the Rc-band at the Newtonian camera (F4.8) and started at 2017-07-29 T18:11:19 UT (~ 19.13 hours (0.8 day) after the burst). We obtained four images in the Rc-band each one with 600s exposure time. We clearly detected the optical afterglow (D'Avanzo et al., GCN Circ. 21372/21373; Heintz et al., GCN Circ. 21374; Guidorzi et al., GCN Circ. 21375; Izzo et al., GCN Circ. 21381; Kitaoka et al., GCN Circ. 21387; Watson et al., GCN Circ. 21389; Dintinjana et al., GCN Circ. 21394; Volnova et al., GCN Circ. 21419). We estimate a magnitude Rc 20.625 +/- 0.133, calibrated against nearby USNO-B1.0 stars: USNO-B1.0 R2 1601-0108297 13.35 1600-0109901 13.61 1600-0109913 14.08 1601-0108263 14.58 1601-0108285 14.59 1601-0108292 14.71 1601-0108254 15.04 1600-0109911 15.42 1600-0109861 15.52 1601-0108199 15.66 1600-0109905 15.92 1600-0109885 15.97 -Yasser Hendy, on behalf of tthe Kottamia collaboration GRB followup team. ====================================================================== Dr. Yasser Hassan Mohamed Mohamed Hendy National Research Institute of Astronomy & Geophysics (NRIAG), Astronomy Department, 11421 Helwan, Cairo, Egypt. Phone: +202 25560645 Fax: +202 25548020 Mobile: +20 1007580213 +20 1145385285 Email: y_hendy_yasser@yahoo.com yasserhendy@nriag.sci.eg yasserhendy@mail.ru Homepage: NRIAG ResearchGate GoogleScholar Facebook vk ======================================================================