GRB170830A

This page lists all entries on GRB170830A in GRBweb

Summary Fermi GBM IPN GCN 21761 GCN 21764 GCN 21773 GCN 21776

Summary table
Variable Value Source
GRB_name_Fermi GRB170830135
T0 3:14:00 UTC GCN_circulars,AstroSat CZTI
ra 267.2417° IPN
decl -2.0000° IPN
pos_error 8.33e-02° IPN
T90 117.25 s Fermi_GBM
T90_error 2.318 s Fermi_GBM
T90_start 3:14:02.205 UTC Fermi_GBM
fluence 8.28e-06 erg/cm² Fermi_GBM
fluence_error 4.93e-08 erg/cm² Fermi_GBM
T100 119.455 s
GBM_located False
mjd 57995.134722222225 GCN_circulars,AstroSat CZTI
Fermi GBM table
GRB_name_Fermi GRB170830135
trigger_name bn170830135
ra 267.2442°
decl -2.0000°
pos_error 3.92e+00°
datum 2017-08-30
t_trigger 3:14:01.949 UTC
T90 117.25 s
T90_error 2.318 s
T90_start 3:14:02.205 UTC
fluence 8.28e-06 erg/cm²
fluence_error 4.93e-08 erg/cm²
flux_1024 5.54e+00 erg/cm²/s
flux_1024_error 3.38e-01 erg/cm²/s
flux_1024_time 8.94e+01 erg/cm²/s
flux_64 9.04e+00 erg/cm²/s
flux_64_error 1.83e+00 erg/cm²/s
IPN table
GRB_name GRB170830A
ra 267.2417°
decl -2.0000°
pos_error 8.33e-02°
GCN 21761 table
GRB_name GRB170830A
GCN_number 21761
Detection_method MAXI Det
t_trigger 3:15:29 UTC
ra 267.2440°
decl -2.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21761 SUBJECT: GRB 170830A: MAXI/GSC detection DATE: 17/08/30 05:53:04 GMT FROM: H. Negoro at Nihon U. T. Yoneyama (Osaka U.), S. Nakahira (RIKEN), S. Sugita (Tokyo Tech), T. Mihara, M. Sugizaki, M. Serino, W. Iwakiri, M. Shidatsu, M. Matsuoka (RIKEN), H. Negoro, M. Nakajima, T. Kawase, A. Sakamaki (Nihon U.), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai (JAXA), N. Kawai, T. Yoshii, Y. Tachibana, S. Harita, Y. Muraki, K. Morita (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka, T. Hashimoto (AGU), H. Tsunemi, (Osaka U.), Y. Ueda, T. Hori, A. Tanimoto, S. Oda (Kyoto U.), Y. Tsuboi, Y. Nakamura, R. Sasaki, H. Kawai (Chuo U.), M. Yamauchi, C. Hanyu, K, Hidaka (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.) GRB 170830A: MAXI/GSC detection The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at UT 03:15:29 UT on 2017 August 30. Assuming that the source flux was constant over the transit, we obtain the source position at (R.A., Dec) = (267.244 deg, -2.000 deg) = (17 48 58, -02 00 00) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.09 deg and 0.05 deg, respectively. The roll angle of long axis from the north direction is 41.0 deg counterclockwise. We estimated a rectangular error box for the transient source with the following corners: (266.590, -1.392) deg = (17 46 21, -01 23 31) (J2000) (266.518, -1.475) deg = (17 46 04, -01 28 30) (J2000) (267.633, -2.210) deg = (17 50 31, -02 12 36) (J2000) (267.637, -2.281) deg = (17 50 32, -02 16 50) (J2000). There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 1330 +- 75 mCrab (4.0-10.0keV, 1 sigma error). There was no significant excess flux in the previous transit at UT 01:42 and in the next transit at UT 04:48 with an upper limit of 20 mCrab for each.
GCN 21764 table
GRB_name GRB170830A
GCN_number 21764
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 21764 SUBJECT: GRB 170830A: iTelescope optical observations DATE: 17/08/30 09:48:50 GMT FROM: Denis Denisenko at SAI MSU D. Denisenko (Sternberg Astronomical Institute, Moscow State University) reports: MAXI/GSC error box of GRB 170830A (T. Yoneyama et al., GCN 21761) was observed remotely by iTelescope.Net T32 instrument (0.43-m f/6.8 reflector + FLI Proline 16803 CCD) in Siding Spring, Australia, at 08:55-08:58 UT on 2017 Aug. 30 (5.7 hours after the trigger time). The telescope was centered at R.A. = 17 48 20, Decl. = -01 50 00 with a 43'x43' field of view covering the entire rectangular error box by MAXI/GSC. Observations were performed at the zenith distance of 31 degree, only 18 deg from the waxing Moon (phase 0.60). Visual inspection of the combined image (3x60-sec unfiltered exposures) against 1991-06-15 DSS Red plate shows no optical transient to the 3-sigma upper limit of 18.5m (calibrated against USNO-B1.0 Red magnitudes). In particular, there is no new object in the vicinity of the unidentified ROSAT X-ray source 1RXS J174835.3-014843 which falls inside the gamma-ray burst error box.
GCN 21773 table
GRB_name GRB170830A
GCN_number 21773
Detection_method AstroSat CZTI
t_trigger 3:14:00 UTC
T90 57.6 s
Circular_text TITLE: GCN CIRCULAR NUMBER: 21773 SUBJECT: GRB 170830A: Astrosat CZTI detection DATE: 17/08/31 13:22:08 GMT FROM: Vidushi Sharma at IUCAA V. Bhalerao (IITB), V. Sharma and D. Bhattacharya (IUCAA), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed clear detection of GRB 170830A (MAXI/GSC detection: Yoneyama T. et al., GCN Circ. 21761) in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 03:14:00 UT, ~89 s before the MAXI/GSC trigger. The measured peak count rate is 66.3 counts/sec above the background in combined data of four quadrants, with a total of 91.4 counts. The local mean background count rate was 395.1 counts/sec. Using cumulative rates, we measure a T90 of 57.6 secs. 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 21776 table
GRB_name GRB170830A
GCN_number 21776
Detection_method Fermi GBM Det
t_trigger 3:14:01.950 UTC
ra 275.9000°
decl -4.0000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 21776 SUBJECT: GRB 170830A: Fermi GBM observation DATE: 17/08/31 17:04:28 GMT FROM: Elisabetta Bissaldi at U.Innsbruk/IAPP M. Stanbro (UAH), E. Bissaldi (Politecnico & INFN Bari) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 03:14:01.95 UT on 30 August 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170830A (trigger 525755646 / 170830135). This trigger is likely associated with the transient source reported by MAXI/GSC (Yoneyama et al., GCN 21761), which was also detected by AstroSat (Bhalerao et al., GCN 21773). The on-ground calculated location, using the GBM trigger data, is RA = 275.9, DEC = -4.0, with an uncertainty of 2.6 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 100 degrees. The GBM light curve shows two peaks with a duration (T90) of about 110 s (50-300 keV). The time-averaged spectrum from T0 to T0+92 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.54 +/- 0.07 and the cutoff energy, parameterized as Epeak, is 180 +/- 40 keV. The event fluence (10-1000 keV) in this time interval is (4.20 +/- 0.11)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0 in the 10-1000 keV band is 4.6 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."