GRB 200819A
GCN Circular 28263
Subject
GRB 200819A: Swift detection of a burst
Date
2020-08-19T16:04:22Z (5 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
S. Dichiara (NASA/GSFC/UMCP), S. D. Barthelmy (GSFC),
D. N. Burrows (PSU), P. A. Evans (U Leicester), C. Gronwall (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU),
N. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), M. J. Moss (GWU),
K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and
A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 15:43:52 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200819A (trigger=992099). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 21.428, +63.048 which is
RA(J2000) = 01h 25m 43s
Dec(J2000) = +63d 02' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of about 10 sec. The peak count rate
was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 15:45:17.4 UT, 84.5 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 21.4240, 63.0614 which
is equivalent to:
RA(J2000) = 01h 25m 41.76s
Dec(J2000) = +63d 03' 40.9"
with an uncertainty of 2.6 arcseconds (radius, 90% containment). This
location is 48 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 https://www.swift.ac.uk/sper. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 9.84
x 10^21 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 88 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 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
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 large, but uncertain, extinction expected.
We note that this source is near the Galactic plane (lat=0.45, lon=126.8
degrees) which raises the possibility that this is a new Galactic transient.
The source is somewhat soft (visible above 50 keV but not above 100 keV).
The lightcurve is consistent with either a GRB or a Galactic transient.
The complete dataset from this event and further observations of
the source will determine the nature of this source.
If it is a Galactic transient we would name it Swift J0125.7+6303 .
Burst Advocate for this burst is S. Dichiara (dichiara AT umd.edu).
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/)
GCN Circular 28264
Subject
Swift GRB 200819A: Global MASTER-Net observations report
Date
2020-08-19T16:58:19Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
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),
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-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) was pointed to the Swift GRB 200819A ( S. Dichiara et al., GCN 28263) errorbox 80 sec after notice time and 149 sec after trigger time at 2020-08-19 15:46:22 UT, with upper limit up to 17.7 mag. The observations began at zenith distance = 39 deg. The sun altitude is -23.8 deg.
The galactic latitude b = 1 deg., longitude l = 127 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1422693
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
165 | MASTER-Tunka | P| | 30 | 16.3 |
465 | MASTER-Tunka | P| | 630 | 17.7 | Coadd
219 | MASTER-Tunka | P| | 40 | 16.5 |
284 | MASTER-Tunka | P| | 50 | 16.7 |
358 | MASTER-Tunka | P| | 60 | 16.9 |
448 | MASTER-Tunka | P| | 80 | 17.0 |
557 | MASTER-Tunka | P| | 100 | 16.8 |
687 | MASTER-Tunka | P| | 120 | 16.6 |
841 | MASTER-Tunka | P| | 150 | 16.1 |
1026 | MASTER-Tunka | P| | 180 | 16.1 |
The observation and reduction will continue.
The message may be cited.
GCN Circular 28265
Subject
GRB 200819A: Enhanced Swift-XRT position
Date
2020-08-19T18:22:27Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.
Using 493 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 200819A, 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 = 21.42421, +63.06092 which is equivalent
to:
RA (J2000): 01h 25m 41.81s
Dec (J2000): +63d 03' 39.3"
with an uncertainty of 2.2 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 Circular 28266
Subject
GRB 200819A: Kitab, TSHAO optical upper limit
Date
2020-08-19T21:04:51Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Kusakin (FAPHI), A. Novichonok (KIAM), A. Pozanenko
(IKI), I. Reva (FAPHI), E. Mazaeva (IKI), A. Volnova (IKI) report on
behalf of larger GRB follow-up collaboration:
We observed the field of GRB 200819A (Dichiara et al., GCN 28263) with
Zeiss-1000 telescope of Tien Shan Astronomical observatory starting on
August 19 (UT) 18:03:47 and with RC-36 of Kitab observatory on (UT)
16:30:50. We do not detect any optical object within enhanced XRT
position (Evans et al., GCN 28265). Preliminary photometry of the field
is following.
Date UT start t-T0 Filter Exp. OT Err. UL Telesope
(mid, days) (s)
2020-08-19 16:30:50 0.05345 CR 3600 n/d n/d 20.0 RC-36
2020-08-19 18:03:47 0.10289 R 990 n/d n/d 21.2 Zeiss-1000
The photometry is based on nearby USNO-B1.0 stars.
Ref.stars
USNO-B1.0_id R2
1530-0056474 15.45
1530-0056771 15.06
GCN Circular 28267
Subject
GRB 200819A / Swift J0125.7+6303: Ondrejov Perek-2m optical limit
Date
2020-08-19T21:25:18Z (5 years ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
Martin Jelinek, Jan Strobl and Ludek Rezba
(ASU CAS Ondrejov, CZ), report:
We observed the location of the GRB 200819A / Swift
J0125.7+6303 (Dichiara et al, GCNC 28263), with the
photometric camera of the 2m Perek telescope of Ondrejov
observatory in the Czech Republic.
The observations consisted of 20 x 120s dithered SDSS-z'
exposures, starting at 20:30:19 UT, with observation mean
time 5.08h after the initial trigger. There is no source
detected within the XRT errorbox (Evans et al, GCN28265), we
estimate the magnitude limit of our combined image as
z'>22.0
GCN Circular 28269
Subject
GRB 200819A: MITSuME Akeno optical upper limits
Date
2020-08-19T23:59:46Z (5 years ago)
From
Katsuhiro L. Murata at Nagoya U <murata@u.phys.nagoya-u.ac.jp>
K. L. Murata, R. Hosokawa, R. Adachi, M. Niwano, F. Ogawa, N.
Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N.
Kawai (Tokyo Tech), Takashi Horiuchi, Hidekazu Hanayama (NAOJ) report
on behalf of the MITSuME collaboration:
We observed the field of GRB 200819A (Dichiara et al., GCN 28263;
Evans et al., GCN 28265) with the optical three color (g���, Rc, and Ic)
CCD cameras attached to the MITSuME 50 cm telescope of Akeno
Observatory, Yamanashi, Japan.
The observation with a series of 60 sec exposures started on
2020-08���19 15:45:44 UT. Some images were heavily affected by bad
weather conditions. We stacked the images with good weather
conditions. We did not find any new point sources within the enhanced
Swift/XRT error circle (Evans et al., GCN 28265) of the stacked
images. We obtained the 5-sigma limits as follows.
T0+[sec] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
~290 2020-08-19T17:36:48 5640 g���>18.4, Rc>19.0, Ic>19.3
------------------------------------------------------------------------------------------------
T0+: Elapsed time after the burst
T-EXP: Total Exposure time
We used the PS1 catalog for flux calibration. The magnitudes are
expressed in the AB system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al., submitted;
https://github.com/MNiwano/Eclaire)
GCN Circular 28271
Subject
GRB 200819A: MITSuME Ishigaki optical upper limits
Date
2020-08-20T04:43:13Z (5 years ago)
From
Katsuhiro L. Murata at Nagoya U <murata@u.phys.nagoya-u.ac.jp>
Takashi Horiuchi, Hidekazu Hanayama (NAOJ), Katsuhiro L. Murata,
Yoichi Yatsu, Nobuyuki Kawai (Tokyo Tech) report on behalf of the
MITSuME collaboration:
We observed the field of GRB 200819A (Dichiara et al., GCN 28263;
Evans et al., GCN 28265) with the optical three color (g', Rc, and Ic)
CCD cameras attached to the 105 cm Murikabushi telescope of
Ishigakijima Astronomical Observatory, Okinawa, Japan.
The observation with a series of 60 sec exposures started on
2020-08���19 16:35:33 UT. Throughout, the images were terribly extended
by the altitude oscillation of the Murikabushi Telescope. We stacked
the 79 images and did not find any new point sources other than the
USNO-B1.0 sources from the stacked images. We obtained the SN = 10
limits as follows.
T0+[min] MID-UT T-EXP[sec] SN=10 limits
------------------------------------------------------------------------------------------------
52 2020-08-19T17:21:38 960 g'>18.7, Rc>19.0, Ic>17.8
------------------------------------------------------------------------------------------------
GCN Circular 28272
Subject
GRB 200819A: Swift-XRT refined Analysis
Date
2020-08-20T08:08:08Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U. Toronto), B.
Sbarufatti (PSU), D.N. Burrows (PSU), P.A. Evans (U. Leicester), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A. Melandri
(INAF-OAB) and S. Dichiara report on behalf of the Swift-XRT team:
We have analysed 7.3 ks of XRT data for GRB 200819A (Dichiara et al.
GCN Circ. 28263), from 94 s to 40.7 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Evans et al. (GCN Circ. 28265).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.83 (+/-0.08).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.6 (+/-0.5). The
best-fitting absorption column is 2.2 (+1.1, -0.9) x 10^22 cm^-2, in
excess of the Galactic value of 9.8 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 7.6 x 10^-11 (1.2 x 10^-10) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 2.2 (+1.1, -0.9) x 10^22 cm^-2
Galactic foreground: 9.8 x 10^21 cm^-2
Excess significance: 2.3 sigma
Photon index: 1.6 (+/-0.5)
If the light curve continues to decay with a power-law decay index of
0.83, the count rate at T+24 hours will be 2.3 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (2.9 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00992099.
This circular is an official product of the Swift-XRT team.
GCN Circular 28273
Subject
GRB 200819A: Optical Observations from HCT
Date
2020-08-20T16:13:01Z (5 years ago)
From
Anirban Dutta at Indian Inst. of Astrophysics <anirban.dutta@iiap.res.in>
Anirban Dutta(IIA, Bengaluru), Brajesh Kumar(ARIES, Nainital), Avinash
Singh, G. C.
Anupama, D. K. Sahu and Pramod Kumar (IIA, Bengaluru)
We observed the field of GRB 200819A (Dichiara et
al., GCN #28263; Evans et al., GCN #28265) with the Himalaya Faint
Object
Spectrograph and Camera (HFOSC) mounted on the 2-m Himalayan Chandra
Telescope (IAO, Hanle, India). Multiple frames (each 300 sec) of the GRB
field in Bessell R and I bands were obtained with an average airmass of
1.3
and a seeing of 2''. Preliminary PSF photometry on the stacked
images was performed and calibrated against USNO-B1 catalogue. We do
not
detect any OT within the enhanced XRT position (Belkin et al., GCN
#28266; Jelinek et al., GCN #28267).
The estimated limiting magnitude is as under -
Date | UT (mean) | Filter | Exp time x no. of
frames | Upper limit (mag)
2020-08-19 19:16:23 R 300 sec x 4
21.5
2020-08-19 19:32:37 I 300 sec X 4
20.3
We thank the staff at IAO and CREST for helping with the observations.
GCN Circular 28276
Subject
GRB 200819A: Swift-BAT refined analysis
Date
2020-08-21T02:37:04Z (5 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), S. Dichiara (NASA/GSFC/UMCP),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 200819A (trigger #992099)
(Dichiara et al., GCN Circ. 28263). The BAT ground-calculated position is
RA, Dec = 21.527, 63.061 deg which is
RA(J2000) = 01h 26m 06.4s
Dec(J2000) = +63d 03' 39.3"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
The mask-weighted light curve shows a double-peaked structure that starts
at ~T0 and ends at ~T+7 s, followed by some tail emission that
lasts until ~T+27 s. T90 (15-350 keV) is 23.62 +- 6.74 sec (estimated
error including systematics).
The time-averaged spectrum from T-0.72 to T+27.12 sec is best fit by a
simple power-law model. The power law index of the time-averaged
spectrum is 2.08 +- 0.31. The fluence in the 15-150 keV band is
3.2 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T+0.31 sec in the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec.
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/992099/BA/
GCN Circular 28281
Subject
GRB 200819A: Swift/UVOT Upper Limits
Date
2020-08-21T20:55:50Z (5 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and S. Dichiara (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 200819A
89 s after the BAT trigger (Dichiara et al., GCN Circ. 28263).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 28265)
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 89 239 147 >20.4
u_FC 301 551 246 >19.0
white 89 601 167 >20.3
b 557 577 19 >17.7
u 301 551 246 >19.0
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 1.59 in the direction of the burst
(Schlegel et al. 1998).