GRB 200829A
GCN Circular 28404
Subject
GRB 200829A: T100 observations
Date
2020-09-09T08:28:19Z (5 years ago)
From
Massimiliano De Pasquale at Istanbul U/FOGTWA <m.depasquale@ucl.ac.uk>
De Pasquale, M. (Istanbul Univ.) Sonbas, E. (Adiyaman Univ.), Ozdonmez, A., Er, H. (Ataturk Univ.), Ivantsov, A., (Akdeniz Univ.), Eryilmaz, S. (TUG) on behalf of a larger collaboration:
We observed the field of GRB 200829A (Siegel et al., GCN #28307) with the
1.0 meter T100 telescope (TUBITAK National Observatory, Antalya - Turkey),
starting on 2020-09-01, at 20:36:18 UT (~78 hours after the trigger). We obtained 12 x 300 s exposures with R filter under good weather conditions. The Moon was present in the sky during observations.
We do not detect an optical afterglow within the reported XRT error circle down to a 3 sigma limiting magnitude of 21 in the combined R band image.
We are grateful to the TUBITAK National Observatory staff for promptly scheduling the observations and their technical support.
GCN Circular 28359
Subject
GRB 200829A: optical observations, a light curve in R-filter
Date
2020-09-03T15:15:47Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), N. Pankov (HSE), S. Belkin (IKI), A. Volnova (IKI),
I. Reva (FAPHI), A. Zhornichenko (KIAM), A. Novichonok (Petrozavodsk
State University, KIAM), S. Naroenkov (INASAN), K. Antoniuk (CrAO),
R.Ya. Inasaridze (AbAO), E. Mazaeva (IKI), Sh. Ehgamberdiev (UBAI)
report on behalf of larger GRB IKI FuN collaboration:
We observed the the field of GRB 200829A (Siegel et al., GCN 28307; Ursi
et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage & Meegan, GCN
28326) with Zeiss-1000 telescope of TShAO observatory, RC-36 telescope
of Kitab observatory, Zeiss-1000 telescope of Koshka Observatory, AZT-11
telescope of CrAO observatory, and AS-23 telescope of AbAO observatory.
The optical afterglow (Siegel et al., GCN 28307, Pozanenko et al., GCN
28308; Kuin & Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et
al., GCN 28316; Hentunen et al., GCN 28318; Moskvitin et al., GCNs
28322, 28328, Zhu et al., GCNs 28324, 28330; Pankov et al., GCN 28329;
Izzo, GCN 28331; Volnova et al., GCN 28333) is detected on first two
days after GRB trigger. Preliminary light curve of the afterglow in
R-filter can be found at
http://grb.rssi.ru/GRB200829A/GRB200829A_LC1_R.png
One can tentatively assume a jet break in the light curve at ~0.33 days.
(The photometry is based on nearby USNO-B1.0 stars identical for all
observations.)
GCN Circular 28338
Subject
GRB 200829A: Swift/UVOT-XRT photometric redshift
Date
2020-09-01T11:55:48Z (5 years ago)
From
Samantha Oates at MSSL <samantha.oates@alumni.ucl.ac.uk>
S. R. Oates (U.Birmingham), N.P.M. Kuin (MSSL-UCL),
M. De Pasquale (Istanbul U.), S. Campana (INAF-OAB),
A. Tohuvavohu (U Toronto) and M. H. Siegel (PSU)
report on behalf of the Neil Gehrels Swift
Observatory Team:
We have performed a joint spectral analysis of Swift UVOT and XRT
observations of GRB 200829A (Siegel et al., GCN Circ. 28307; Kuin et al.
GCN Circ. 28311, Goad et al., GCN Circ. 28313), based on the methodology
of Schady et al. (2010, MNRAS, 401, 2773). Using this method, we created
an SED at 900s after the BAT trigger consisting of 6 UVOT filters and
WT mode XRT data. The model with the best fit, broken power-law with a
Milky Way extinction curve for the host extinction, gives a photometric
redshift for GRB 200829A of 1.25 +\- 0.02 (1 sigma uncertainty;
chi^2/dof = 586/538).
This circular is an official product of the Swift team.
GCN Circular 28333
Subject
GRB 200829A: Koshka Zeiss-1000 optical observations
Date
2020-08-31T19:52:13Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), S. Naroenkov (INASAN), A. Pozanenko (IKI), N. Pankov
(HSE), S. Belkin (IKI), E. Mazaeva (IKI) report on behalf of larger GRB
IKI FuN collaboration:
We observed the the field of GRB 200829A (Siegel et al., GCN 28307; Ursi
et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage & Meegan, GCN
28326) with Zeiss-1000 1-m telescope of Koshka Observatory on August,
30 starting (UT) 19:18:21 in I- and R-filters. The optical afterglow
(Siegel et al., GCN 28307, Pozanenko et al., GCN 28308; Kuin & Siegel,
GCN 28311; Lipunov et al., GCN 28315; Vinko et al., GCN 28316; Hentunen
et al., GCN 28318; Moskvitin et al., GCNs 28322, 28328, Zhu et al., GCN
28324, GCN 28330; Pankov et al., GCN 28329; Izzo, GCN 28331) is
detected in stacked images of both filters. Preliminary photometry of
the afterglow is following.
Date UT start t-T0 Filter Exp. OT Err. UL
(mid, days) (s)
2020-08-30 19:18:21 1.29067 I 47*120 20.14 0.20 20.8
2020-08-30 19:20:31 1.29217 R 47*120 21.0 0.25 21.4
The photometry is based on nearby USNO-B1.0 stars.
GCN Circular 28331
Subject
GRB 200829A: Liverpool Telescope observations
Date
2020-08-31T11:52:24Z (5 years ago)
From
Luca Izzo at DARK/NBI <luca.izzo@gmail.com>
L. Izzo (DARK/NBI) reports:
We observed the field of GRB 200829A (Siegel et al., GCN #28307; Ursi et al., GCN #28314; Ridnaia et al., GCN #28323; Lesage & Meegan, GCN #28326) with the IO:O camera mounted on the 2-m Liverpool Telescope located in La Palma, Spain. Observations started on August 29 at 20:31:39 UT (0.272 days after the GRB trigger) and a second epoch was obtained on August 30 at 22:38:42 UT (1.362 days). In both epochs, we obtained a series of 5x60s images in the griz filters.
The optical afterglow (Siegel et al., GCN #28307, Pozanenko et al., GCN #28308; Kuin & Siegel, GCN #28311; Lipunov et al., GCN #28315; Vinko et al., GCN #28316; Hentunen et al., GCN #28318; Moskvitin et al., GCN #28322, GCN #28328, Zhu et al., GCN #28324, GCN #28330; Pankov et al., GCN #28329) is visible in the stacked images in both epochs. We measure the following preliminary AB magnitudes, calibrated against Pan-STARRS catalog stars:
Filter mag err MJD
SDSS-g 18.91 0.05 (59090.855)
SDSS-g 21.17 0.09 (59091.944)
SDSS-r 18.76 0.04 (59090.860)
SDSS-r 21.34 0.10 (59091.948)
SDSS-i 18.65 0.04 (59090.865)
SDSS-i 21.25 0.09 (59091.953)
SDSS-z 18.57 0.04 (59090.870)
SDSS-z 20.50 0.08 (59091.958)
GCN Circular 28330
Subject
GRB 200829A: Continued Nanshan/NEXT optical observations
Date
2020-08-31T07:52:40Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu, S.Y Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High
School), X. Zhang, J.Z. Liu (XAO) report:
We continued to observe the optical afterglow (e.g., Siegel et al., GCN
28307; Pozanenko et al., GCN 28308; Kuin and Siegel, GCN 28311; Lipunov
et al., GCN 28315; Vinko et al., 28316; Hentunen et al., GCN 28318; Zhu
et al., GCN 28324; Moskvitin et al., GCNs 28322, 28328; Pankov et al.,
GCN 28329) of GRB 200829A (Siegel et al., GCN 28307; Ursi et al., GCN
28314; Ridnaia et al., GCN 28323; Lesage et al., GCN 28326), using the
NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 28
frames in the Sloan r band, starting at 15:24:17 UT on 2020-08-30, i.e.,
about 1.058 d after the BAT trigger.
Preliminary photometric measurements are as follows:
Filter T_exp/s T_mid/d Mag Mag_err
SDSS-r 8x120 1.062 >20.6
SDSS-r 20x120 1.307 21.20 0.16
calibrated with nearby Pan-STARRS stars.
GCN Circular 28329
Subject
GRB 200829A: Kitab optical upper limit
Date
2020-08-30T21:20:06Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Novichonok (Petrozavodsk State University, KIAM), A.
Zhornichenko (KIAM), A. Pozanenko (IKI), S. Belkin (IKI), E. Mazaeva
(IKI), A. Volnova (IKI), Sh. Ehgamberdiev (UBAI) report on behalf of
IKI-GRB-FuN:
We observed the field of a GRB 200829A (Siegel et al., GCN 28307; see
also Ursi et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage et
al., GCN 28326) with Kitab-ISON RC-36 telescope in R-filter. We do not
detect optical afterglow (Siegel et al., GCN 28307; Pozanenko et al.,
GCN 28308; Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko
et al., 28316; Hentunen et al., GCN 28318; Zhu et al., GCN 28324;
Moskvitin et al., GCNs 28322, 28328). Preliminary photometry of the
filed is following
Date, UT start, t-T0, Exp., Filter, OT, Err., UL
(mid, days)
2020-08-30 15:57:25 1.08184 3600 R n/d n/d 18.8
The photometry is based on nearby USNO-B1.0 star, R2 magnitude
USNO_B10_id R2
1626-0124132 14.76
GCN Circular 28328
Subject
GRB 200829A: further SAO RAS optical observations
Date
2020-08-30T20:17:46Z (5 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. S. Moskvitin, V. N. Aitov (SAO RAS)
on behalf of GRB follow-up team report.
We observed the field of the GRB 200829A (Siegel et al., GCN 28307)
with Zeiss-1000 (1-m telescope of SAO RAS) equipped with
Multi-Mode Photometer-Polarimeter (MMPP) on August 30. We obtained
5 x 300 sec. frames in Rc band and similar sequence in Ic band.
The OT (Siegel et al., GCN 28307; Pozanenko et al., GCN 28308;
Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al.,
28316; Hentunen and Nissinen, GCN 28318; Zhu et al., GCN 28324)
is clearly detected in individual images as well as stacked frames
with the brightness of R = 20.37 +/- 0.13 (T_mid - T0 = 1.1492 days),
I = 20.14 +/- 0.10 (T_mid - T0 = 1.1662 days).
Preliminary photometry is based on R2 and I magnitudes
of the same nearby USNO-B1 stars (Moskvitin and Aitov, GCN 28322).
GCN Circular 28326
Subject
GRB 200829A: Fermi GBM detection
Date
2020-08-30T17:12:33Z (5 years ago)
From
Stephen Lesage at Fermi-GBM Team <sjl0014@uah.edu>
S. Lesage (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 13:58:14.66 UT on 29 August 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 200829A (trigger 620402299 / 200829582)
which was also detected by the Swift Burst Alert Telescope (BAT)
(M. H. Siegel et al. 2020, GCN 28307). GBM initially triggered on a weak
spike ~15-20 s before the very bright emission. The GBM on-ground location
is consistent with the Swift BAT position.
The angle from the Fermi LAT boresight at the GBM trigger time is ~148
degrees.
The GBM light curve shows an exceptionally bright long GRB
with a duration (T90) of about 6.9 s (50-300 keV).
The time-averaged spectrum from T0+16.64 s to T0+25.856 s is
best fit by a Band function with Epeak = 336.8 +/- 4.3 keV,
alpha = -0.43 +/- 0.01, and beta = -2.4 +/- 0.02
The event fluence (10-1000 keV) in this time interval is
(2.069 +/- 0.009)E-04 erg/cm^2.
The 1.024-sec peak photon flux measured starting from T0+19.7 s in
the 10-1000 keV band is 213.9 +/- 1.7 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 28325
Subject
GRB 200829A: Swift-BAT refined analysis
Date
2020-08-30T17:01:36Z (5 years ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. H. Siegel (PSU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 200829A (trigger #993768)
(Siegel, et al., GCN Circ. 28307). The BAT ground-calculated position is
RA, Dec = 251.136, 72.363 deg which is
RA(J2000) = 16h 44m 32.7s
Dec(J2000) = +72d 21' 45.6"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 88%.
The mask weighted light curve shows a peak at ~ T-60 s followed by an extended emission.
The duration of the initial bright peak is ~15 sec. We note that Swift was slewing from T-150 s to T s.
The overall structure starts at ~T-75 s and lasts till ~T+200 s.
T90 (15-350 keV) is 13.04 +- 2.91 sec (estimated error including systematics).
The time-averaged spectrum from T-74 to T+204 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
0.83 +- 0.03. The fluence in the 15-150 keV band is 5.1 +- 0.1 x 10^-5 erg/cm2.
The 1-sec peak photon flux measured from T-60.07 sec in the 15-150 keV band
is 98.7 +- 1.6 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/993768/BA/
GCN Circular 28324
Subject
GRB 200829A: Nanshan/NEXT optical observations
Date
2020-08-30T15:27:43Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu, S.Y Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High
School), X. Zhang, J.Z. Liu (XAO) report:
We observed the field of GRB 200829A (Siegel et al., GCN 28307) using
the NEXT-0.6m
telescope located at Nanshan, Xinjiang, China. We obtained a series of
frames in the Sloan g-/r-/i- bands, starting at 19:55:23 UT on
2020-08-29, i.e., 5.93 hr after the BAT trigger.
The GRB optical afterglow (e.g., Pozanenko et al., GCN 28308; Kuin et
al., GCN 28311; Ursi et al., GCN 28314; Lipunov et al., GCN 28315; Vinko
et al., GCN 28316; Hentunen & Nissinen, GCN 28318; Moskvitin et al., GCN
28322) is clearly detected in our images.
Preliminary photometric measurements are as follows:
Filter T-mid(hr) Mag Mag_err
SDSS-g 6.72 18.89 0.04
SDSS-r 5.98 18.77 0.04
SDSS-i 6.40 18.50 0.05
calibrated with nearby Pan-STARRS stars.
GCN Circular 28323
Subject
Konus-Wind detection of GRB 200829A (a clone of GRB 200826B?)
Date
2020-08-30T14:52:11Z (5 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration, very bright GRB 200829A
(Swift detection: Siegel et al., GCN 28307;
Goad et al., GCN 28313; Gropp et al., GCN 28317;
AGILE/MCAL detection: Ursi et al., GCN 28314)
triggered Konus-Wind at T0=50309.99 s UT (13:58:29.990).
The burst light curve shows a bright, multi-peaked pulse
which started at ~T0-24 s and had a total duration of ~39 s.
A weak post-burst emission is visible in the 18-70 keV band
up to the end of the KW trigger record at ~T0+250 s.
The emission is seen up to ~10 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200829_T50309/
As observed by Konus-Wind, the burst
had a fluence of 3.02(-0.07,+0.07)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+3.456 s,
of 1.08(-0.07,+0.07)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+16.384 s)
can be described, in the 20 keV - 15 MeV range,
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.49(-0.03,+0.03),
the high energy photon index beta = -2.34(-0.05,+0.04),
the peak energy Ep = 336(-11,+11) keV
(chi2 = 163/98 dof).
The spectrum near the maximum count rate
(measured from T0+3.072 to T0+3.840 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.23(-0.07,+0.08),
the high energy photon index beta = -2.17(-0.06,+0.06),
the peak energy Ep = 372(-26,+27) keV
(chi2 = 78/71 dof).
We note, that this burst is very similar to GRB 200826B,
which, as detected by KW (Ridnaia et al., GCN 28304),
had the time-integrated spectrum with alpha = -0.54, beta = -2.38,
Ep = 337 keV; a factor of ~1.5 smaller energy fluence (~2.0x10^-4 erg/cm^2),
and a factor of ~2 smaller peak energy flux ~5x10^-5 erg/cm^2/s.
Interestingly, light curves of both bursts are also very similar
if we scale the time axis by a factor of ~1.5
(http://www.ioffe.ru/LEA/GRBs/GRB200829_T50309/gWind64_29A_26B.pdf).
Given the angular distance between the directions
to GRB 200829A (Swift-XRT GCN 28307) and GRB 200826B (IPN GCN 28303)
of ~38.6 arcdeg, and the ~3 day difference in the burst arrival times,
an idea of a lensed GRB cannot be excluded.
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 28322
Subject
GRB 200829A: SAO RAS optical observations
Date
2020-08-30T13:45:46Z (5 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. S. Moskvitin, V. N. Aitov (SAO RAS)
on behalf of GRB follow-up team report.
We observed the field of the GRB 200829A (Siegel et al., GCN 28307)
with Zeiss-1000 (1-m telescope of SAO RAS) equipped with
Multi-Mode Photometer-Polarimeter (MMPP). We obtained 4 x 300 sec.
frames in Rc band and similar sequence in Ic band.
The OT (Siegel et al., GCN 28307; Pozanenko et al., GCN 28308;
Kuin and Siegel, GCN 28311; Lipunov et al., GCN 28315; Vinko et al.,
28316; Hentunen and Nissinen, GCN 28318) is clearly detected
with the brightness R = 17.84 +/- 0.09 (T_mid - T0 = 4.587 h),
I = 17.65 +/- 0.09 (T_mid - T0 = 4.204 h).
Preliminary photometry is based on R2 and I magnitudes
of nearby USNO-B1 stars.
GCN Circular 28318
Subject
GRB 200829A: THO optical observatios
Date
2020-08-30T06:36:53Z (5 years ago)
From
Veli-Pekka Hentunen at Taurus Hill Obs,A95 <veli-pekka.hentunen@kassiopeia.net>
Veli-Pekka Hentunen and Markku Nissinen (Taurus Hill
Observatory, Varkaus, Finland) report:
We have detected GRB 200829A optical afterglow at Taurus
Hill Observatory (A95) using C-14SC 0.35-m f/7.3 telescope,
SBIG STT-8300M CCD and RGB filters. The observations were
started at 2020-08-29 18:48:29 (UT).
The afterglow was detected at the position RA 16 44 49.16
and DEC +72 19 45.9.
The following magnitudes were obtained from the observations
using NOMAD1 1623-0124683 (R=17.05, V=17.32, B=17.55)
as a comparison star:
Tmid(h:min:sec)+T0 Filter Exp.time(sec) Mag MagErr
4:53:37 R 3x180 17.98 0.28
5:02:49 R 3x180 18.11 0.34
5:12:36 R 3x180 18.22 0.27
5:25:05 R 5x180 18.26 0.17
6:00:06 R 5x180 18.27 0.14
6:25:44 B 3x180 18.66 0.21
6:35:32 G 3x180 18.69 0.26
URL link for the RGB image:
www.kassiopeia.net/wp-content/uploads/2020/08/GRB200829A_RGB_web.png
GCN Circular 28317
Subject
GRB 200829A: Swift-XRT refined Analysis
Date
2020-08-30T02:47:18Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), T. Sbarrato
(INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), A.
Tohuvavohu (U. Toronto) and M.H. Siegel report on behalf of the
Swift-XRT team:
We have analysed 6.8 ks of XRT data for GRB 200829A (Siegel et al. GCN
Circ. 28307), from 135 s to 24.2 ks after the BAT trigger. The data
comprise 1.7 ks in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN Circ. 28313).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.62 (+0.09, -0.10). At T+279 s the decay
steepens to an alpha of 8.0 (+0.0, -6.9). The light curve breaks again
at T+283 s to a decay with alpha=0.885 (+0.016, -0.017), before a
final break at T+1174 s s after which the decay index is 1.19
(+/-0.04).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.700 (+/-0.014). The
best-fitting absorption column is 9.9 (+/-0.4) x 10^20 cm^-2, in
excess of the Galactic value of 4.7 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.89 (+/-0.09) and a
best-fitting absorption column of 1.36 (+0.28, -0.26) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 3.7 x 10^-11 (4.5 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.36 (+0.28, -0.26) x 10^21 cm^-2
Galactic foreground: 4.7 x 10^20 cm^-2
Excess significance: 5.6 sigma
Photon index: 1.89 (+/-0.09)
If the light curve continues to decay with a power-law decay index of
1.19, the count rate at T+24 hours will be 0.23 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.4 x
10^-12 (1.0 x 10^-11) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00993768.
This circular is an official product of the Swift-XRT team.
GCN Circular 28316
Subject
GRB200829A: optical afterglow detection
Date
2020-08-29T21:05:19Z (5 years ago)
From
Jozsef Vinko at Konkoly Observatory <vinko@konkoly.hu>
GRB200829A: optical afterglow detection from Konkoly Observatory
J. Vinko, K. Vida, A. Pal, L. Kriskovics, R. Szakats, A. Ordasi and K. Sarneczky
(Konkoly Observatory, Hungary) report:
The optical afterglow of GRB 200829A (Siegel et al. GCN 28307) is detected with the
0.8m RC80 robotic telescope at Piszkesteto Station of Konkoly Observatory starting on
Aug 29 19:22:00 UT, 19346 s after the Swift/BAT trigger. The afterglow
is measured on stacked Sloan r'- and i'-band frames of 3x300 s exposure.
Photometry, tied to nearby comparison stars with PS1 magnitudes, gives.
r' = 18.45 +/- 0.09 and i' = 18.49 +/- 0.11 mag, in accord with previous optical
detections (Pozanenko et al. GCN 28308; Kuin et al. GCN 28311; Ursi et al. GCN 28314;
Lipunov et al. GCN 28315)..
GCN Circular 28315
Subject
GRB 200829A: Global MASTER-Net OT detection
Date
2020-08-29T19:50:58Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, N.Tyurina, E. Gorbovskoy, V.Kornilov, 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-Tavrida robotic telescope (Global MASTER-Net:
http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy,
vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical
station) was pointed to the Swift GRB 200829A ( M. H. Siegel et al., GCN
28307) errorbox 12423 sec after notice time and 12502 sec after trigger
time at 2020-08-29 17:27:56 UT, with upper limit up to 18.5 mag.
We see OT at Swift/UVOT position (Kuin et al GCN 28311).
Datetime: 2020-08-29 17:36:40
Coord: 16h 44m 48.88s , +72d 19m 45s.8
Mag: 18.1
Observations started at twilight.
The observations began at zenith
distance = 30 deg. The sun altitude is -11.7 deg.
GCN Circular 28314
Subject
GRB 200829A: AGILE/MCAL detection
Date
2020-08-29T19:23:40Z (5 years ago)
From
Alessandro Ursi at INAF/IAPS <alessandro.ursi@gmail.com>
A. Ursi (INAF/IAPS), C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS,
and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y.
Evangelista, G. Piano (INAF/IAPS), F. Lucarelli, F. Verrecchia (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ.
Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of
the AGILE Team:
The AGILE Mini-CALorimeter (MCAL) detected GRB 200829A at T0 = 2020-08-29
13:58:30.90 +/- 0.01 s (UTC), reported by Swift-BAT (Siegel et al., GCN
#28307) and Swift-UVOT (Kuin et al., GCN #28311).
The event lasted about 5.6 s and it released a total number of ~15550
counts in the detector (in the 0.4-100 MeV energy range), above an average
background rate of 570 Hz.
The time-integrated spectrum of the burst can be fitted in the energy range
0.4-20 MeV with a single power-law with ph.ind. = 2.26 -0.03/+0.03,
resulting in a reduced chi-squared of 1.67 (62 d.o.f.) and a fluence of
6.2e-05 ergs/cm^2 (90% confidence level), in the same energy range.
The MCAL light curve can be found at
http://www.agilescienceapp.it/notices/GRB_069336_525794310.907011.png .
The event is also clearly visible in the scientific ratemeters (RMs) of the
SuperAGILE (18-60 keV), MCAL (0.4-100 MeV), and Anti-Coincidence (50-200
keV) detectors. Their light curves can be found at
http://www.agilescienceapp.it/notices/GRB200829A_AGILE_RMs.png .
The AGILE/MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. 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 28313
Subject
GRB 200829A: Enhanced Swift-XRT position
Date
2020-08-29T19:22:47Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1810 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 200829A, 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 = 251.20605, +72.32921 which is equivalent
to:
RA (J2000): 16h 44m 49.45s
Dec (J2000): +72d 19' 45.2"
with an uncertainty of 1.7 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 28311
Subject
GRB 200829A: Swift/UVOT Detection
Date
2020-08-29T19:10:29Z (5 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N.P.M. Kuin (MSSL-UCL) and M. H. Siegel (PSU) report on behalf of
the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 200829A
138 s after the BAT trigger (Siegel et al., GCN Circ. 28307).
The UV-optical source position is RA=251.204709, Dec=72.329356 deg
(J2000) which is in sexagesimal:
RA(J2000) = 16h 44m 49.14s
Dec(J2000) = 72d 19' 45.63"
with a positional uncertainty of 0.35" radius (90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures
are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 138 288 147 14.29 +/- 0.02
white 576 596 19 15.43 +/- 0.04
white 1527 1547 19 16.38 +/- 0.06
v 626 646 19 15.50 +/- 0.10
b 552 572 19 15.68 +/- 0.07
u 296 546 246 14.54 +/- 0.03
u 700 720 19 15.12 +/- 0.07
w1 675 696 19 15.19 +/- 0.12
m2 1080 1100 19 16.25 +/- 0.25
w2 1032 1398 39 17.64 +/- 0.30
Note that the times are since the BAT trigger time. The main burst took
place around 60s earlier during a Swift Slew.
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.04 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 28309
Subject
Swift GRB 200829A: Global MASTER-Net observations report
Date
2020-08-29T17:36:30Z (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),
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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 200829A ( M. H. Siegel et al., GCN 28307) errorbox 12423 sec after notice time and 12502 sec after trigger time at 2020-08-29 17:27:56 UT, with upper limit up to 18.5 mag. Observations started at twilight. The observations began at zenith distance = 30 deg. The sun altitude is -11.7 deg.
The galactic latitude b = 35 deg., longitude l = 104 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1429750
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
12592 | MASTER-Tavrida | C | 180 | 18.5 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 28308
Subject
GRB 200829A: TSHAO optical observations
Date
2020-08-29T17:02:07Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), I. Reva (FAPHI), A. Serebryanskiy (FAPHI), S.
Belkin (IKI), M. Krugov (FAPHI), E. Mazaeva (IKI), A. Volnova (IKI)
report on behalf of IKI-GRB-FuN:
We are observing the afterglow of GRB 200829A (Siegel et al. GCN 28307)
with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory
starting on Aug. 29 (UT) 14:49:05. The afterglow is clearly visible in
single images of 60 s exposure. Preliminary photometry of the afterglow
is R=16.8 +/- 0.1 at mid time (UT) 15:00:41.
Observations is continuing.
GCN Circular 28307
Subject
GRB 200829A: Swift detection of a burst with an optical afterglow
Date
2020-08-29T14:18:33Z (5 years ago)
From
Boris Sbarufatti at PSU <bxs60@psu.edu>
M. H. Siegel (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), S. Laha (GSFC/UMBC/CRESST) and
B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 13:59:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200829A (trigger=993768). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 251.212, +72.335 which is
RA(J2000) = 16h 44m 51s
Dec(J2000) = +72d 20' 07"
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 30 sec. The peak count rate
was ~1335 counts/sec (15-350 keV), at ~6 sec after the trigger.
The XRT began observing the field at 14:01:43.1 UT, 128.7 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 251.2096, 72.3273 which is equivalent to:
RA(J2000) = 16h 44m 50.30s
Dec(J2000) = +72d 19' 38.3"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 27 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
The initial flux in the 2.5 s image was 9.30e-09 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 138 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 16:44:49.05 = 251.20439
DEC(J2000) = +72:19:45.3 = 72.32924
with a 90%-confidence error radius of about 0.61 arc sec. This position is 9.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
14.28 with a 1-sigma error of about 0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.04.
Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.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/)