- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Wed 11 May 22 13:42:26 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 45
TRIGGER_NUM: 673969321
GRB_RA: 305.400d {+20h 21m 36s} (J2000),
305.640d {+20h 22m 34s} (current),
304.863d {+20h 19m 27s} (1950)
GRB_DEC: +24.617d {+24d 37' 00"} (J2000),
+24.689d {+24d 41' 20"} (current),
+24.456d {+24d 27' 23"} (1950)
GRB_ERROR: 5.83 [deg radius, statistical plus systematic]
GRB_INTEN: 1582 [cnts/sec]
DATA_SIGNIF: 39.00 [sigma]
INTEG_TIME: 1.024 [sec]
GRB_DATE: 19710 TJD; 131 DOY; 22/05/11
GRB_TIME: 49316.87 SOD {13:41:56.87} UT
GRB_PHI: 183.00 [deg]
GRB_THETA: 130.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO: 0.59
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 73% GRB
2nd_MOST_LIKELY: 23% Cyg X-1
DETECTORS: 0,0,0, 0,0,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN: 48.42d {+03h 13m 41s} +17.97d {+17d 57' 59"}
SUN_DIST: 93.58 [deg] Sun_angle= 6.9 [hr] (West of Sun)
MOON_POSTN: 173.23d {+11h 32m 55s} +7.98d {+07d 58' 58"}
MOON_DIST: 123.29 [deg]
MOON_ILLUM: 75 [%]
GAL_COORDS: 65.17, -6.90 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 315.68, 42.61 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_lc_medres34_bn220511571.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 124.05,17.03 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Wed 11 May 22 13:42:44 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 58
TRIGGER_NUM: 673969321
GRB_RA: 285.360d {+19h 01m 26s} (J2000),
285.609d {+19h 02m 26s} (current),
284.804d {+18h 59m 13s} (1950)
GRB_DEC: +17.510d {+17d 30' 36"} (J2000),
+17.543d {+17d 32' 36"} (current),
+17.438d {+17d 26' 15"} (1950)
GRB_ERROR: 3.54 [deg radius, statistical only]
DATA_SIGNIF: 66.30 [sigma]
DATA_INTERVAL: 2.048 [sec]
GRB_DATE: 19710 TJD; 131 DOY; 22/05/11
GRB_TIME: 49316.87 SOD {13:41:56.87} UT
GRB_PHI: 184.00 [deg]
GRB_THETA: 110.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4173 (Gnd S/W Version number)
SUN_POSTN: 48.42d {+03h 13m 41s} +17.97d {+17d 57' 59"}
SUN_DIST: 113.49 [deg] Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN: 173.23d {+11h 32m 55s} +7.98d {+07d 58' 53"}
MOON_DIST: 108.52 [deg]
MOON_ILLUM: 75 [%]
GAL_COORDS: 49.68, 5.75 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 289.23, 39.93 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_lc_medres34_bn220511571.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_673969321.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.
COMMENTS:
COMMENTS: NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9912).
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Wed 11 May 22 13:51:25 UT
NOTICE_TYPE: Fermi-GBM Final Position
RECORD_NUM: 0
TRIGGER_NUM: 673969321
GRB_RA: 285.370d {+19h 01m 29s} (J2000),
285.619d {+19h 02m 28s} (current),
284.814d {+18h 59m 15s} (1950)
GRB_DEC: +17.540d {+17d 32' 24"} (J2000),
+17.573d {+17d 34' 24"} (current),
+17.468d {+17d 28' 03"} (1950)
GRB_ERROR: 1.00 [deg radius, statistical only]
GRB_DATE: 19710 TJD; 131 DOY; 22/05/11
GRB_TIME: 49316.87 SOD {13:41:56.87} UT
GRB_PHI: 184.00 [deg]
GRB_THETA: 110.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 41731 (Gnd S/W Version number)
SUN_POSTN: 48.43d {+03h 13m 43s} +17.97d {+17d 58' 05"}
SUN_DIST: 113.47 [deg] Sun_angle= 8.2 [hr] (West of Sun)
MOON_POSTN: 173.30d {+11h 33m 12s} +7.95d {+07d 56' 49"}
MOON_DIST: 108.47 [deg]
MOON_ILLUM: 75 [%]
GAL_COORDS: 49.71, 5.75 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 289.25, 39.96 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_lc_medres34_bn220511571.gif
LOC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_locplot_all_bn220511571.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.
COMMENTS:
COMMENTS: NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=9912).
- GCN Circular #32018
The Fermi GBM team reports the detection of a likely LONG GRB
At 13:41:56 UT on 11 May 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220511A (trigger 673969321.870432 / 220511571).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 285.4, Dec = 17.5 (J2000 degrees, equivalent to J2000 19h 01m, 17d 30'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 110.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_skymap_all_bn220511571.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_healpix_all_bn220511571.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220511571/quicklook/glg_lc_medres34_bn220511571.gif
- GCN Circular #32019
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 673969321
at 13:41:56 on 11 May 2022 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) = 291.9+/-1.4 deg
Decl.(2000.0) = 19.7+/-1.0 deg
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB220511571/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB220511571/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB220511571/json
- GCN Circular #32021
A. Ursi (INAF/IAPS), C. Pittori, F. Verrecchia (SSDC, and INAF/OAR), M.
Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C.
Casentini, Y. Evangelista, E. Menegoni, L. Foffano, G. Piano (INAF/IAPS),
F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, A. Di Piano, V. Fioretti,
F. Fuschino, G. Panebianco, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), M. Romani (INAF/OA-Brera), I. Donnarumma (ASI), F.
Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report
on behalf of the AGILE Team:
The AGILE satellite detected the GRB 220511A at T0 = 2022-05-11 13:41:57
(UTC), reported by Fermi GBM (GCN #32018).
The burst is clearly visible in the AGILE scientific ratemeters of the
SuperAGILE (SA; 20-60 keV), MiniCALorimeter (MCAL; 0.4-100 MeV), and
AntiCoincidence (AC; 50-200 keV) detectors. The event lasted about 3 s and
it released a total number of 410 counts in the SA detector (above a
background rate of 70 Hz), 5150 counts in the MCAL detector (above a
background rate of 1230 Hz), and 15270 counts in the AC detector (above a
background rate of 3500 Hz). The AGILE ratemeter light curves can be found
at http://www.agilescienceapp.it/notices/GRB220511A_AGILE_RM.png .
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.
- GCN Circular #32022
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko,
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin
(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
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(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 GRB 220511A ( Fermi GBM team, GCN 32018) errorbox 11983 sec after notice time and 12018 sec after trigger time at 2022-05-11 17:02:15 UT, with upper limit up to 13.3 mag. The observations began at zenith distance = 42 deg. The sun altitude is -18.9 deg.
The galactic latitude b = 5 deg., longitude l = 50 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1969847
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
12109 | 2022-05-11 17:02:15 | MASTER-Amur | (19h 05m 21.07s , +17d 46m 28.2s) | C | 180 | 12.1 |
12455 | 2022-05-11 17:08:01 | MASTER-Amur | (19h 05m 20.14s , +17d 47m 39.0s) | C | 180 | 13.3 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
- GCN Circular #32023
James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Jamie A.
Kennea (PSU), Gayathri Raman (PSU) report:
Swift/BAT did not trigger on GRB 220511A (T0: 2022-05-11T13:47:57
UTC, Fermi/GBM GCN 32018, INTEGRAL/SPI-ACS trig#9912, GECAM trig #
utn220511_134156_GECAMb, AGILE GCN 32021).
The GECAM and INTEGRAL notices, 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 duration of ~5 seconds.
The burst occurred during a Swift slew.
The burst location was found in a mosaiced slew image with an SNR of ~10.
The BAT position is
RA, Dec = 287.446, 17.739 deg which is
RA(J2000) = 19h 09m 47.04s
Dec(J2000) = 17d 44′ 20.4″
with an estimated uncertainty of 7 arcmin.
This position is consistent with the Ferm/GBM localization (GCN 32018).
XRT and UVOT follow-up has been requested. 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 b
found at: https://www.swift.psu.edu/guano/
- GCN Circular #32024
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 220511A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021498
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 Swift/BAT-GUANO 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 #32027
Y.-D. Hu, E. Fernandez-Garcia, T.-R. Sun, A. J. Castro-Tirado, M.D. Caballero-Garcia, R. Sanchez-Ramirez, I. Perez-Garcia (IAA-CSIC), C. Perez del Pulgar, A. Castellon, M. A. Castro Tirado (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC) and M. Jelinek (ASU-CAS), on behalf of a larger collaboration, report:
Following the detection of GRB 220511A by Fermi (GBM team GCNC 32018), AGILE (Ursi et al. CNCN 32021) and Swift (DeLaunay et al. GCNC 32023), the 0.6m BOOTES-2/TELMA robotic telescope in Algarrobo Costa (Malaga, Spain) pointed to the Swift/BAT-GUANO position on May. 11 at 22:48:06 UT (~9.1 hrs after trigger). No new source is detected in a 11' x 11' FOV within the BAT-GUANO error region in the co-added image (60 x 10 s, clear filter) down to 18.7 mag. This non-detection is consistent with the MASTER results (Lipunov et al. GCNC 32022).
We thank the staff at IHSM/UMA-CSIC La Mayora for its excellent support.
- GCN Circular #32028
R. Gopalakrishnan (IUCAA), V. Prasad (IUCAA), G. Waratkar (IITB), A.
Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao
(IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat
CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al.,
2021, JApA, 42, 73) showed detection of GRB 220511A which was also
reported by Fermi GBM (GCN #32018), AGILE (Ursi et al., GCN #32021), and
Swift/BAT-GUANO (DeLaunay et al., GCN #32023).
The source was clearly detected in the 20-200 keV energy range. The
light curve peaked at 2022-05-11 13:41:57.45 UT. The measured peak count
rate associated with the burst is 802 (+197, -74) counts/s above the
background in the combined data of four quadrants, with a total of 1126
(+156, -184) counts. The local mean background count rate was 525 (+9,
-9) counts/s. Using cumulative rates, we measure a T90 of 1.8 (+0.8,
-0.4) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector
in the 100-500 keV energy range.
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 Circular #32029
V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU),
J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),
J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 220511A (DeLaunay et al. GCN Circ.
32023), collecting 5.0 ks of Photon Counting (PC) mode data between
T0+37.4 ks and T0+49.1 ks. The burst was also detected by Fermi-GBM
(GCN Circ. 32018), AGILE (Ursi et al., GCN 32021) and AstroSat CZTI
(Gopalakrishnan et al., GCN 32028).
Two uncatalogued X-ray sources have been detected, 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): 287.4316 = 19:09:43.59
Dec (J2000.0): +17.7297 = +17:43:46.9
Error: 5.4 arcsec (radius, 90% conf.)
Count-rate: (4.7 +/- 1.2)e-3 ct s^-1
Distance: 59 arcsec from Swift/BAT-GUANO position.
Flux: (1.94 +/- 0.51)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 3:
RA (J2000.0): 287.5100 = 19:10:2.41
Dec (J2000.0): +17.7394 = +17:44:21.8
Error: 4.0 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: (3.9 [+1.2, -1.0])e-3 ct s^-1
Distance: 219 arcsec from Swift/BAT-GUANO position.
Flux: (7.9 [+2.5, -2.1])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
A catalogued source was also detected.
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/00021498.
This circular is an official product of the Swift-XRT team.
- GCN Circular #32030
P. Veres and C. Meegan (both UAH)
report on behalf of the Fermi GBM Team:
"At 13:41:56.87 UT on 11 May 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220511A (trigger 673969321 / 220511571)
which was also detected by Swift/BAT-GUANO (DeLaunay et al., GCN 32023).
The Fermi GBM Final Real-time Localization (GCN 32018) is consistent
with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 112 degrees.
The GBM light curve consists of a single FRED-like pulse
with a duration (T90) of about 4.2 s (50-300 keV).
The time-averaged spectrum from T0 to T0+5.7 s is best fit by
a power law function with an exponential
high-energy cutoff. The power law index is -0.85 +/- 0.05 and
the cutoff energy, parameterized as Epeak, is 199 +/- 11 keV.
The event fluence (10-1000 keV) in this time interval is
(7.62 +/- 0.23)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.58 s in the 10-1000 keV band
is 20.3 +/- 0.5 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 155 +/- 14 keV, alpha = -0.70 +/- 0.08 and beta = 2.18 +/- 0.12.
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 #32033
D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 220511A (AGILE detection: Ursi et al., GCN 32021;
AstroSat CZTI detection: Gopalakrishnan et al., GCN 32028;
Fermi-GBM observation: Veres & Meegan, GCN 32030)
triggered Konus-Wind (KW) at T0=49319.624 s UT (13:41:59.624).
The burst light curve shows a single emission pulse,
which starts at ~T0-1 s and has a total duration of ~6 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220511_T49319/
As observed by Konus-Wind, the burst had
a fluence of (7.8 ± 1.5)x10^-6 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 0.832 s,
of (4.2 ± 0.7)x10^-6 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 - 1.5 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.75 (-0.19,+0.42),
the high energy photon index beta = -3.1 (-6.9,+0.8),
the peak energy Ep = 159 (-34,+21) keV,
chi2 = 57/59 dof.
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
- GCN Circular #32052
V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU),
J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),
J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB) 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
Swift/BAT-GUANO-detected burst GRB 220511A (Ursi et al. GCN Circ.
32021). The observations now extend from T0+37.5 ks to T0+285.4 ks.
Of the sources reported by D'Elia et al. (GCN Circ. 32029), "Source 1"
is fading with 2.4 sigma significance and thus is believed to be the
GRB afterglow. The position of this source is RA, Dec=287.4316,
+17.7297 which is equivalent to:
RA (J2000): 19:09:43.59
Dec(J2000): +17:43:46.9
with an uncertainty of 5.4 arcsec (radius, 90% confidence). This
position is 59 arcsec from the Swift/BAT-GUANO position.
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.9 (+0.9, -0.6).
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021498.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021498.
This circular is an official product of the Swift-XRT team.
Previous IAU Circulars 
