- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 08 Oct 20 10:37:42 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 45
TRIGGER_NUM: 623846261
GRB_RA: 165.433d {+11h 01m 44s} (J2000),
165.736d {+11h 02m 57s} (current),
164.701d {+10h 58m 48s} (1950)
GRB_DEC: +51.867d {+51d 52' 00"} (J2000),
+51.755d {+51d 45' 17"} (current),
+52.136d {+52d 08' 09"} (1950)
GRB_ERROR: 7.90 [deg radius, statistical plus systematic]
GRB_INTEN: 387 [cnts/sec]
DATA_SIGNIF: 13.30 [sigma]
INTEG_TIME: 0.512 [sec]
GRB_DATE: 19130 TJD; 282 DOY; 20/10/08
GRB_TIME: 38256.71 SOD {10:37:36.71} UT
GRB_PHI: 292.00 [deg]
GRB_THETA: 55.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO: 0.85
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 98% GRB
2nd_MOST_LIKELY: 1% Generic Transient
DETECTORS: 0,0,0, 1,0,0, 1,0,0, 0,0,0, 0,0,
SUN_POSTN: 194.38d {+12h 57m 32s} -6.14d {-06d 08' 39"}
SUN_DIST: 62.87 [deg] Sun_angle= 1.9 [hr] (West of Sun)
MOON_POSTN: 87.10d {+05h 48m 24s} +23.94d {+23d 56' 40"}
MOON_DIST: 64.52 [deg]
MOON_ILLUM: 66 [%]
GAL_COORDS: 155.22, 57.83 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 142.69, 41.29 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201008443/quicklook/glg_lc_medres34_bn201008443.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 48.50,2.55 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Thu 08 Oct 20 10:37:55 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 58
TRIGGER_NUM: 623846261
GRB_RA: 165.120d {+11h 00m 29s} (J2000),
165.417d {+11h 01m 40s} (current),
164.401d {+10h 57m 36s} (1950)
GRB_DEC: +46.760d {+46d 45' 36"} (J2000),
+46.648d {+46d 38' 53"} (current),
+47.029d {+47d 01' 43"} (1950)
GRB_ERROR: 6.23 [deg radius, statistical only]
DATA_SIGNIF: 17.20 [sigma]
DATA_INTERVAL: 2.048 [sec]
GRB_DATE: 19130 TJD; 282 DOY; 20/10/08
GRB_TIME: 38256.71 SOD {10:37:36.71} UT
GRB_PHI: 297.00 [deg]
GRB_THETA: 58.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4173 (Gnd S/W Version number)
SUN_POSTN: 194.38d {+12h 57m 32s} -6.14d {-06d 08' 40"}
SUN_DIST: 58.71 [deg] Sun_angle= 1.9 [hr] (West of Sun)
MOON_POSTN: 87.10d {+05h 48m 25s} +23.94d {+23d 56' 41"}
MOON_DIST: 65.03 [deg]
MOON_ILLUM: 66 [%]
GAL_COORDS: 163.54, 60.67 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 145.73, 36.76 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201008443/quicklook/glg_lc_medres34_bn201008443.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_623846261.fits
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: In the LAT Field-of-view.
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: Thu 08 Oct 20 10:39:00 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 0
TRIGGER_NUM: 623846261
GRB_RA: 142.740d {+09h 30m 58s} (J2000),
143.058d {+09h 32m 14s} (current),
141.972d {+09h 27m 53s} (1950)
GRB_DEC: +36.850d {+36d 51' 00"} (J2000),
+36.758d {+36d 45' 28"} (current),
+37.070d {+37d 04' 14"} (1950)
GRB_ERROR: 5.75 [deg radius, statistical only]
DATA_SIGNIF: 13.30 [sigma]
DATA_INTERVAL: 10.240 [sec]
GRB_DATE: 19130 TJD; 282 DOY; 20/10/08
GRB_TIME: 38256.71 SOD {10:37:36.71} UT
GRB_PHI: 293.00 [deg]
GRB_THETA: 77.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 41731 (Gnd S/W Version number)
SUN_POSTN: 194.38d {+12h 57m 32s} -6.14d {-06d 08' 41"}
SUN_DIST: 64.30 [deg] Sun_angle= 3.4 [hr] (West of Sun)
MOON_POSTN: 87.11d {+05h 48m 27s} +23.95d {+23d 56' 44"}
MOON_DIST: 49.24 [deg]
MOON_ILLUM: 66 [%]
GAL_COORDS: 186.91, 46.90 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 133.00, 20.95 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201008443/quicklook/glg_lc_medres34_bn201008443.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_623846261.fits
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: This is likely a Long GRB.
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 Circular #28577
F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
623846261 at 10:37:36 on 08 Oct. 2020 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) = 167.1+/-4.3 deg
Decl.(2000.0) = 42.1+/-3.9 deg
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB201008443/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB201008443/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB201008443/json
- GCN Circular #28581
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),
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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB201008.44 (trigger No 623846261,10h 41m 55.20s , +47d 39m 00.0s, R=3.33) errorbox 27862 sec after notice time and 27870 sec after trigger time at 2020-10-08 18:22:07 UT, with upper limit up to 15.8 mag. The observations began at zenith distance = 70 deg. The sun altitude is -41.6 deg.
The galactic latitude b = 58 deg., longitude l = 165 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1458009
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
27900 | 2020-10-08 18:22:07 | MASTER-Tunka | (10h 38m 38.56s , +47d 47m 29.8s) | C | 60 | 14.5 |
27980 | 2020-10-08 18:23:26 | MASTER-Tunka | (10h 39m 49.70s , +49d 47m 34.0s) | C | 60 | 15.8 |
28059 | 2020-10-08 18:24:46 | MASTER-Tunka | (11h 01m 08.85s , +45d 45m 21.4s) | C | 60 | 13.9 |
28139 | 2020-10-08 18:26:05 | MASTER-Tunka | (10h 14m 38.76s , +47d 47m 51.2s) | C | 60 | 13.1 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
- GCN Circular #28583
James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Jamie Kennea (PSU),
Peter Veres (UAH) report:
Swift/BAT did not trigger on GRB 201008A (T0: 2020-10-08 10:37:36 UTC,
Fermi/GBM Team TRIGGER 623846261).
The Fermi/GBM notice, distributed in near real-time triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert
Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150]
seconds around the time of the burst. All the requested event mode data was
delivered to the ground.
The burst is detected in BAT with a T90 duration of ~2.5 seconds.
With a maximum likelihood analysis (DeLaunay et al. 2020, in prep.) on
the event-mode data we detect a location for the burst with a square
root of the test statistic, sqrt(TS), of 13.22. The sqrt(TS) behaves
similarly to SNR.
Using the normal BAT imaging technique, we find the location of the GRB
with an SNR of 4.2.
Since this is a low significance detection near the edge of the coded field
of view there is a chance that this localization may be incorrect.
The BAT ground-calculated position is
RA, Dec = 161.744, 46.101 deg which is
RA(J2000) = 10h 46m 58.56s
Dec(J2000) = 46d 06’ 03.6”
with an uncertainty of 5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 3.5%.
This position is consistent with the Fermi GBM localization (
https://gcn.gsfc.nasa.gov/other/623846261.fermi) and BALROG localization
(GCN 28577).
XRT and UVOT follow-up has been triggered. Results of follow-up
observations will be reported in future circulars.
GUANO is a fully autonomous, extremely low latency, spacecraft commanding
pipeline designed for targeted recovery of BAT event mode data around the
times of compelling astrophysical events to enable more sensitive GRB
searches.
A live reporting of Swift/BAT event data recovered by GUANO can be found
at: https://www.swift.psu.edu/guano/
- GCN Circular #28585
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Fermi/GBM GRB 201008A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021034
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 #28587
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M.G.
Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi
(INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B.
Sbarufatti (PSU) 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 and
Swift/BAT-GUANO detected burst GRB 201008A (DeLaunay et al. GCN Circ.
28583), collecting 4.5 ks of Photon Counting (PC) mode data between
T0+46.9 ks and T0+60.1 ks.
Two uncatalogued X-ray sources have been detected consistent with being
within 296 arcsec of the BAT/GUANO position, however none of them is
above the RASS limit or shows definitive signs of fading. Therefore, at
the present time we cannot identify which, if any, is the afterglow.
Details of these sources are given below:
Source 1:
RA (J2000.0): 161.7543 = 10:47:1.02
Dec (J2000.0): +46.1475 = +46:08:51.1
Error: 5.1 arcsec (radius, 90% conf.)
Count-rate: (1.79 [+1.09, -0.80])e-3 ct s^-1
Distance: 169 arcsec from BAT position.
NB, this position is consistent with SDSS J104701.20+460848.8,
a likely quasar in the SDSS Quasar Catalogue. If this association
and ID is accurate, this source is unlikely to be related to the GRB.
Source 4:
RA (J2000.0): 161.8588 = 10:47:26.10
Dec (J2000.0): +46.1019 = +46:06:06.9
Error: 4.8 arcsec (radius, 90% conf.)
Count-rate: (4.1 [+1.3, -1.1])e-3 ct s^-1
Distance: 286 arcsec from BAT position.
Flux: (1.68 [+0.52, -0.44])e-10 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Two uncatalogued sources were also detected too far from the GRB
position to be likely afterglow candidates.
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/00021034.
This circular is an official product of the Swift-XRT team.
- GCN Circular #28648
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M.G.
Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , M. Capalbi
(INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B.
Sbarufatti (PSU) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:
Swift-XRT has conducted further observations of the field of the
Fermi/GBM and Swift-BAT/GUANO detected burst GRB 201008A (DeLaunay et
al. GCN Circ. 28583). The observations now extend from T0+47.0 ks to
T0+650.8 ks.
Of the sources reported by Page et al. (GCN Circ. 28587), "Source 4" is
fading with 3-sigma significance, and is therefore likely the GRB
afterglow. The position of this source is RA, Dec=161.8588, +46.1019
which is equivalent to:
RA (J2000): 10:47:26.10
Dec(J2000): +46:06:06.9
with an uncertainty of 4.8 arcsec (radius, 90% confidence). This
position is 4.8 arcmin from the BAT/GUANO position. The source is
fading with alpha >0.8.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021034.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021034.
This circular is an official product of the Swift-XRT team.
- GCN Circular #30242
E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 10:37:36.71 UT on 8 October 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 201008A (trigger 623846261 / 201008443),
which was also detected by the Swift/BAT-GUANO (DeLaunay et al. 2020, GCN 28583).
The Fermi GBM Final Real-time Localization is consistent with the Swift position.
The angle from the Fermi LAT boresight
at the GBM trigger time is 60 degrees.
The GBM light curve consists of a multi-peaked emission episode
with a duration (T90) of about 2 s (50-300 keV).
The time-averaged spectrum from T0-0.26 s to T0+2.11 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.80 +/- 0.13 and
the cutoff energy, parameterized as Epeak, is 166 +/- 21 keV.
The event fluence (10-1000 keV) in this time interval is
(1.17 +/- 0.09)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+1.28 s in the 10-1000 keV band
is 7.3 +/- 1.3 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/"
Previous IAU Circulars 