- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Tue 01 Oct 19 06:41:54 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 44
TRIGGER_NUM: 591604915
GRB_RA: 301.600d {+20h 06m 24s} (J2000),
301.829d {+20h 07m 19s} (current),
301.020d {+20h 04m 05s} (1950)
GRB_DEC: +14.417d {+14d 25' 00"} (J2000),
+14.474d {+14d 28' 28"} (current),
+14.272d {+14d 16' 19"} (1950)
GRB_ERROR: 7.83 [deg radius, statistical plus systematic]
GRB_INTEN: 208 [cnts/sec]
DATA_SIGNIF: 9.60 [sigma]
INTEG_TIME: 2.048 [sec]
GRB_DATE: 18757 TJD; 274 DOY; 19/10/01
GRB_TIME: 24110.58 SOD {06:41:50.58} UT
GRB_PHI: 242.00 [deg]
GRB_THETA: 100.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO: 1.21
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 97% GRB
2nd_MOST_LIKELY: 1% Generic SGR
DETECTORS: 0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN: 187.17d {+12h 28m 41s} -3.10d {-03d 05' 50"}
SUN_DIST: 114.64 [deg] Sun_angle= -7.6 [hr] (East of Sun)
MOON_POSTN: 221.58d {+14h 46m 19s} -11.46d {-11d 27' 50"}
MOON_DIST: 83.63 [deg]
MOON_ILLUM: 9 [%]
GAL_COORDS: 54.55, -9.40 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 307.65, 33.82 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_lc_medres34_bn191001279.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 247.53,-24.80 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Tue 01 Oct 19 06:42:12 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 68
TRIGGER_NUM: 591604915
GRB_RA: 306.417d {+20h 25m 40s} (J2000),
306.646d {+20h 26m 35s} (current),
305.837d {+20h 23m 21s} (1950)
GRB_DEC: +15.283d {+15d 16' 60"} (J2000),
+15.349d {+15d 20' 55"} (current),
+15.119d {+15d 07' 09"} (1950)
GRB_ERROR: 5.88 [deg radius, statistical plus systematic]
GRB_INTEN: 675 [cnts/sec]
DATA_SIGNIF: 16.80 [sigma]
INTEG_TIME: 0.512 [sec]
GRB_DATE: 18757 TJD; 274 DOY; 19/10/01
GRB_TIME: 24110.58 SOD {06:41:50.58} UT
GRB_PHI: 236.98 [deg]
GRB_THETA: 100.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO: 0.93
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 91% GRB
2nd_MOST_LIKELY: 6% Cyg X-1
DETECTORS: 0,0,0, 0,0,0, 0,1,1, 0,0,0, 0,0,
SUN_POSTN: 187.17d {+12h 28m 41s} -3.10d {-03d 05' 50"}
SUN_DIST: 119.21 [deg] Sun_angle= -8.0 [hr] (East of Sun)
MOON_POSTN: 221.58d {+14h 46m 19s} -11.47d {-11d 27' 54"}
MOON_DIST: 88.36 [deg]
MOON_ILLUM: 9 [%]
GAL_COORDS: 57.83,-12.88 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 313.32, 33.41 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_lc_medres34_bn191001279.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 247.53,-24.80 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Tue 01 Oct 19 06:42:08 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 58
TRIGGER_NUM: 591604915
GRB_RA: 308.760d {+20h 35m 02s} (J2000),
308.990d {+20h 35m 58s} (current),
308.179d {+20h 32m 43s} (1950)
GRB_DEC: +15.280d {+15d 16' 48"} (J2000),
+15.349d {+15d 20' 56"} (current),
+15.107d {+15d 06' 24"} (1950)
GRB_ERROR: 2.65 [deg radius, statistical only]
DATA_SIGNIF: 17.00 [sigma]
DATA_INTERVAL: 4.096 [sec]
GRB_DATE: 18757 TJD; 274 DOY; 19/10/01
GRB_TIME: 24110.58 SOD {06:41:50.58} UT
GRB_PHI: 235.00 [deg]
GRB_THETA: 99.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4173 (Gnd S/W Version number)
SUN_POSTN: 187.17d {+12h 28m 41s} -3.10d {-03d 05' 50"}
SUN_DIST: 121.46 [deg] Sun_angle= -8.1 [hr] (East of Sun)
MOON_POSTN: 221.58d {+14h 46m 19s} -11.47d {-11d 27' 53"}
MOON_DIST: 90.57 [deg]
MOON_ILLUM: 9 [%]
GAL_COORDS: 59.12,-14.76 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 315.90, 32.75 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_lc_medres34_bn191001279.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_591604915.fits
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: This Notice was ground-generated -- not flight-generated.
COMMENTS: The LC_URL file will not be created/available until ~15 min after the trigger.
COMMENTS: The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Tue 01 Oct 19 06:49:22 UT
NOTICE_TYPE: Fermi-GBM Final Position
RECORD_NUM: 0
TRIGGER_NUM: 591604915
GRB_RA: 308.930d {+20h 35m 43s} (J2000),
309.154d {+20h 36m 37s} (current),
308.362d {+20h 33m 27s} (1950)
GRB_DEC: +18.510d {+18d 30' 36"} (J2000),
+18.579d {+18d 34' 45"} (current),
+18.336d {+18d 20' 10"} (1950)
GRB_ERROR: 3.32 [deg radius, statistical only]
GRB_DATE: 18757 TJD; 274 DOY; 19/10/01
GRB_TIME: 24110.58 SOD {06:41:50.58} UT
GRB_PHI: 234.00 [deg]
GRB_THETA: 102.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 41731 (Gnd S/W Version number)
SUN_POSTN: 187.18d {+12h 28m 42s} -3.10d {-03d 05' 57"}
SUN_DIST: 121.23 [deg] Sun_angle= -8.1 [hr] (East of Sun)
MOON_POSTN: 221.65d {+14h 46m 36s} -11.49d {-11d 29' 21"}
MOON_DIST: 91.32 [deg]
MOON_ILLUM: 9 [%]
GAL_COORDS: 61.95,-13.07 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 317.27, 35.78 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_lc_medres34_bn191001279.gif
LOC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_locplot_all_bn191001279.png
COMMENTS: Fermi-GBM Final Position.
COMMENTS: This Notice was ground-generated -- not flight-generated.
COMMENTS: The LC_URL file should be available by the time this FINAL notice is produced.
COMMENTS: This notice was generated completely by automated pipeline processing.
COMMENTS: This is likely a Long GRB.
- GCN Circular #25893
The Fermi GBM team reports the detection of a likely LONG GRB
At 06:41:50 UT on 1 Oct 2019, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 191001A (trigger 591604915.579128 / 191001279).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 308.9, Dec = 18.5 (J2000 degrees, equivalent to J2000 20h 35m, 18d 30'), with a statistical uncertainty of 3.3 degrees.
The angle from the Fermi LAT boresight is 102.0 degrees.
The skymap can be found here:
http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_skymap_all_bn191001279.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_healpix_all_bn191001279.fit
The GBM light curve can be found here:
http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2019/bn191001279/quicklook/glg_lc_medres34_bn191001279.gif
- GCN Circular #25894
J. Burgess , F. Kunzweiler, B. Biltzinger, F. Berlato, & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
591604915 at 06:41:50 on 01 Oct. 2019 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 313.4+/-6.0 deg
Decl.(2000.0) = 15.1+/-1.4 deg
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB191001279/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB191001279/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB191001279/json
- GCN Circular #25896
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
(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-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB191001.28 (trigger No 591604915,20h 35m 02.400s , +15d 16m 48.00s, R=2.65) errorbox 13621 sec after trigger time at 2019-10-01 10:28:51 UT, with upper limit up to 17.9 mag. Observations started at twilight. The observations began at zenit distance = 38 deg. The sun altitude is -13.2 deg.
The galactic latitude b = -60 deg., longitude l = 98 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1153873
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
13711 | 2019-10-01 10:28:51 | MASTER-Amur | (20h 30m 34.532s , +13d 42m 12.24s) | C | 180 | 17.7 |
13931 | 2019-10-01 10:32:31 | MASTER-Amur | (20h 42m 10.157s , +15d 42m 03.39s) | C | 180 | 17.9 |
14144 | 2019-10-01 10:36:03 | MASTER-Amur | (20h 37m 01.556s , +11d 42m 04.62s) | C | 180 | 17.6 |
14357 | 2019-10-01 10:39:36 | MASTER-Amur | (20h 30m 33.577s , +13d 41m 59.48s) | C | 180 | 17.7 |
14568 | 2019-10-01 10:43:07 | MASTER-Amur | (20h 38m 48.687s , +13d 41m 51.66s) | C | 180 | 17.7 |
14778 | 2019-10-01 10:46:38 | MASTER-Amur | (20h 42m 11.003s , +15d 41m 52.39s) | C | 180 | 17.7 |
14990 | 2019-10-01 10:50:10 | MASTER-Amur | (20h 50m 30.447s , +15d 42m 06.69s) | C | 180 | 17.5 |
15203 | 2019-10-01 10:53:42 | MASTER-Amur | (20h 37m 00.578s , +11d 41m 53.47s) | C | 180 | 17.5 |
15414 | 2019-10-01 10:57:14 | MASTER-Amur | (20h 45m 11.757s , +11d 41m 45.90s) | C | 180 | 17.6 |
15626 | 2019-10-01 11:00:46 | MASTER-Amur | (20h 38m 49.836s , +13d 41m 41.01s) | C | 180 | 17.6 |
15845 | 2019-10-01 11:04:25 | MASTER-Amur | (20h 50m 30.568s , +15d 41m 58.99s) | C | 180 | 17.3 |
16058 | 2019-10-01 11:07:58 | MASTER-Amur | (20h 45m 11.775s , +11d 41m 50.61s) | C | 180 | 17.3 |
16277 | 2019-10-01 11:11:37 | MASTER-Amur | (20h 38m 44.628s , +17d 41m 35.51s) | C | 180 | 17.2 |
16492 | 2019-10-01 11:15:11 | MASTER-Amur | (20h 25m 31.336s , +15d 41m 34.10s) | C | 180 | 17.0 |
16705 | 2019-10-01 11:18:45 | MASTER-Amur | (20h 36m 43.935s , +19d 41m 30.18s) | C | 180 | 17.0 |
16922 | 2019-10-01 11:22:21 | MASTER-Amur | (20h 38m 44.350s , +17d 41m 37.65s) | C | 180 | 17.5 |
17136 | 2019-10-01 11:25:55 | MASTER-Amur | (20h 47m 08.577s , +17d 41m 41.54s) | C | 180 | 17.3 |
17366 | 2019-10-01 11:29:45 | MASTER-Amur | (20h 22m 09.725s , +16d 17m 50.06s) | C | 180 | 16.0 |
17577 | 2019-10-01 11:33:17 | MASTER-Amur | (20h 22m 10.504s , +16d 17m 39.25s) | C | 180 | 16.5 |
17788 | 2019-10-01 11:36:47 | MASTER-Amur | (20h 30m 29.471s , +16d 17m 50.86s) | C | 180 | 17.1 |
18658 | 2019-10-01 11:51:18 | MASTER-Amur | (20h 43m 39.449s , +18d 17m 49.88s) | C | 180 | 17.6 |
18871 | 2019-10-01 11:54:51 | MASTER-Amur | (20h 30m 25.765s , +16d 17m 32.29s) | C | 180 | 17.7 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
- GCN Circular #25911
Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L.
Becerra (UNAM), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD),
illiam H. Lee (UNAM), Eleonora Troja (GSFC/UMD), Gabriele Minervini
(INAF/IAPS-Rome) and Tanner Wolfram (ASU), Simone Dichiara (GSFC/UMD)
report:
We observed the field of GRB 191001A (trigger 591604915, Fermi GBM Team,
GCN Circ. 25893) from 2019 Oct 1 06:48:21 UTC (391 seconds after the
trigger) to 06:59:52 UTC with the DDOTI wide-field imager at the
Observatorio Astronomico Nacional on Sierra San Pedro Martir (
http://ddoti.astroscu.unam.mx/). We calibrated our images against the APASS
catalog and obtained a 10-sigma limiting magnitude of w = 18.6.
Comparing our 10-sigma detections against the USNO-B1 and Pan-STARRS DR1
catalogues, we detect an uncatalogued source at 20:20:47.65 +15:05:03.4
that fades at the 2.4 sigma level from w = 16.7 to 17.0. Specifically, it
fades as a power-law in time since trigger with an index of -0.53 +/- 0.23.
Independently and roughly simultaneously, the source was detected at a
similar magnitude by ATLAS as ATLAS19wxr and is cataloged in the Transient
Name Server as AT2019rog (TNS Astronomical Transient Report 48331). The
discovery report states that it was not detected on 2019 Sep 29.
No known minor planets, brighter than V = 24.0, were found in the 5 arcmin
region around the source position at the time our observations were
performed.
The source is about 1 sigma from the Fermi Final Real-Time Localization and
BALROG positions (Fermi GBM Team, GCN Circ. 25893; Burgess et al., GCN
Circ. 25894). We suggest that it might be the optical counterpart of the
GRB and encourage further observations.
We thank the staff of the Observatorio Astronomico Nacional in San Pedro
Martir.
- GCN Circular #25918
Margarita Pereyra (UNAM), Alan M. Watson (UNAM), Eleonora Troja (GSFC), Nat
Butler (ASU), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Diego
Gonzalez (UNAM), Michael G. Richer (UNAM), Ori Fox (STScI), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UVI), Owen
Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jesús González (UNAM),
Carlos Román-Zúñiga (UNAM), Harvey Moseley (GSFC), John Capone (UMD), V.
Zach Golkhou (U. Wash.), and Vicki Toy (UMD) report:
We observed the field of the candidate afterglow of GRB 191001A (trigger
591604915, Fermi GBM Team, GCN Circ. 25893, Pereyra et al. GCN Circ.
25911), centered at 20:20:47.65 +15:05:03.4, with the Reionization and
Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold
Johnson Telescope at the Observatorio Astronómico Nacional on Sierra San
Pedro Mártir from 2019/10 2.12 to 2019/10 2.17 UTC (20.08 to 21.45 hours
after the Fermi trigger), obtaining a total of 0.34 hours exposure in the g
and r bands, 0.67 hours exposure in the i band and 0.37 hours exposure in
the i, Z, Y, J, and H bands.
At the position of the transient source AT2019rog discovered independently
by ATLAS and DDOTI, in comparison with the USNO-B1, PS1 and 2MASS catalogs,
we obtain the following upper limits (3-sigma):
g > 23.20
r > 23.01
i > 23.26
Z > 21.40
Y > 21.49
J > 21.22
H > 20.92
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
The non-detection implies that the source has faded by about 6 magnitudes
in 20 hours. This is consistent with it being the afterglow of GRB 191001A.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro
Mártir.
- GCN Circular #25919
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to the GBM GRB 191001A (Fermi GBM team,
GCN 25893) starting at ~21.8 hours after the burst. We observed
the afterglow candidate AT2019rog, which was discovered independently
by ATLAS (Tonry et al., TNSTR 1954) and DDOTI (Pereyra et al., GCN 25911),
obtaining 17 x 60s images in the clear (roughly R) filters. We do not
detect the afterglow candidate in our co-add images with limiting mag
of ~21.5. Our non-detection result is consistent with observations from
RATIR (Pereyra et al., GCN 25918).
- GCN Circular #25924
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/GBM GRB 191001A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00020949
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Fermi/GBM event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
- GCN Circular #25926
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova,
and T. Cline on behalf of the Konus-Wind team,
K. Hurley, on behalf of the IPN, and
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team, report:
The long duration GRB 191001A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 25893;
BALROG localization: Burgess et al., GCN Circ. 25894)
was detected by Fermi (GBM trigger 591604915), Konus-Wind,
and Swift (BAT) at about 24110 s UT (06:41:50).
The burst was outside the coded field of view of the BAT.
We have triangulated this GRB to a Konus-GBM annulus centered at
RA(2000)=346.113 deg (23h 04m 27s) Dec(2000)=-7.939 deg (-7d 56' 21"),
whose radius is 46.475 +/- 2.251 deg (3 sigma).
The distance between the optical transient ATLAS19wxr
(Smartt, et al., GCN Circ. 25922; Pereyra et al., GCN Circ. 25911)
and the annulus center line is 9.3 arcmin,
supporting the association of the transient and the GRB.
This annulus may be improved.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB191001_T24130/IPN
- GCN Circular #25938
E. Bissaldi (Politecnico & INFN Bari), R. Hamburg (UAH)
and C. Meegan (UAH) report on behalf of the Fermi GBM Team:
"At 06:41:50.58 UT on 1 October 2019, the Fermi Gamma-Ray
Burst Monitor (GBM) triggered and located GRB 191001A
(trigger 591604915 / 191001279). The on-ground calculated
location has been reported in GCN #25893, and an IPN
annulus consistent with the GBM localization was reported
in GCN #25926. The ATLAS and DDOTI (GCN #25911) optical
counterpart position are consistent with the GBM localization.
The GBM light curve consists of several pulses
with a duration (T90) of about 24 s (50-300 keV).
The time-averaged spectrum from T0-4.99 s to T0+25.73 s
is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.8 +/- 0.1
and the cutoff energy, parameterized as Epeak, is 114 +/- 9 keV.
The event fluence (10-1000 keV) in this time interval is
(4.7 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+15.7 s in the 10-1000 keV band
is 10.5 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support
Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
- GCN Circular #25942
D.N. Burrows (PSU), J. D. Gropp (PSU), A. Tohuvavohu (U. Toronto), K.L.
Page (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo
(INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) and
P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Fermi/GBM
detected burst GRB 191001A (GCN Circ. 25893, 25894), collecting 5.2 ks
of Photon Counting (PC) mode data between T0+114.2 ks and T0+161.3 ks.
No X-ray sources have been detected consistent with being within 2.0
arcsec of the likely associated optical transient AT2019rog (GCN Circ.
25911, 25918, 25919 and Tonry et al., TNSTR 1954). The 3-sigma upper
limit in the field ranges from ~0.002 to ~0.003 ct s^-1, corresponding
to a 0.3-10 keV observed flux of 8.6e-14 to 1.0e-13 erg cm^-2 s^-1
(assuming a typical GRB spectrum).
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00020949.
This circular is an official product of the Swift-XRT team.
Previous IAU Circulars 
