GRB 220403B
GCN Circular 31820
Subject
GRB 220403B: Swift detection of a burst with an optical counterpart
Date
2022-04-03T20:54:46Z (3 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
N. J. Klingler (GSFC/UMBC/CRESSTII), E. Ambrosi (INAF-IASFPA),
V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), J.D. Gropp (PSU),
H. A. Krimm (NSF), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL),
T. M. Parsotan (GSFC/UMBC/CRESSTII) and T. Sakamoto (AGU) report on
behalf of the Neil Gehrels Swift Observatory Team:
At 20:42:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220403B (trigger=1101053). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 191.025, +89.170 which is
RA(J2000) = 12h 44m 06s
Dec(J2000) = +89d 10' 13"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a single-peaked
structure with a duration of about 30 sec and a possible precursor just before.
The peak count rate was ~2800 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 20:44:18.9 UT, 96.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 191.50031, 89.18362 which
is equivalent to:
RA(J2000) = 12h 46m 00.07s
Dec(J2000) = +89d 11' 01.0"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 54 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 1.20
x 10^21 cm^-2 (Willingale et al. 2013).
The initial flux in the 2.5 s image was 4.65e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 105 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
RA(J2000) = 12:45:53.30 = 191.47207
DEC(J2000) = +89:11:06.6 = 89.18518
with a 90%-confidence error radius of about 0.67 arc sec. This position is 6.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.80 with a 1-sigma error of about 0.17. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.208.
Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.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 31821
Subject
GRB 220403B: optical detection by D50
Date
2022-04-03T22:14:20Z (3 years ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
M. Jelinek, J. Strobl, R. Hudec, C. Polasek (ASU CAS Ondrejov) report:
We observed the position of the Swift-detected GRB 220403B (Klingler et
al. GCNC 31820) with the D50 telescope of the Astronomical Institute
Ondrejov, near Prague, Czech Republic. Our observation started at 21:04 UT,
i.e. 22 min after the initial trigger and was performed without a filter.
We detect the optical afterglow (Klingler et al. GCNC 31820) in a combined
image with exp. mean time 31.3 min after trigger (exposed 21:05--21:22UT)
with an AB magnitude RC = 19.02 +/- 0.04.
GCN Circular 31823
Subject
GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
Date
2022-04-03T23:17:19Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu (NAOC,HUST), S.Q. Jiang, X. Liu, S.Y. Fu, D. Xu (NAOC), X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220403B detected by Swift (Klingler et al.,
GCN 31820) using the NEXT-0.6m telescope located at Nanshan, Xinjiang,
China. Observations started at 21:10:31 UT on 2022-04-03 (i.e., 27.8 min
after the BAT trigger), and a series of 300 s frames were obtained in
the Sloan r-filters.
The optical afterglow (Klingler et al., GCN 31820) is clearly detected
in each of our images. The preliminary photometric analysis shows that
the afterglow decays from r ~ 19.04 to r ~ 19.64 in 47 minutes, with a
decay index of \alpha ~ 0.6 (F_t ~ t^-\alpha), calibrated the nearby PS1
stars.
Our measurement is consistent with that in other reports (Jelinek et
al., GCN 31821; Nicuesa Guelbenzu et al., GCN 31822).
GCN Circular 31825
Subject
Swift GRB 220403B: Global MASTER-Net observations report
Date
2022-04-04T02:37:02Z (3 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
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-OAGH robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) was pointed to the Swift GRB 220403B ( N. J. Klingler et al., GCN 31820) errorbox 20759 sec after notice time and 20778 sec after trigger time at 2022-04-04 02:29:01 UT, with upper limit up to 17.7 mag. Observations started at twilight. The observations began at zenith distance = 59 deg. The sun altitude is -11.3 deg.
The galactic latitude b = 28 deg., longitude l = 123 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1931497
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
20869 | MASTER-OAGH | C | 180 | 17.2 |
20869 | MASTER-OAGH | C | 180 | 17.7 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 31826
Subject
GRB 220403B: LBT observations
Date
2022-04-04T06:11:24Z (3 years ago)
From
Andrea Rossi at INAF <andrea.rossi@inaf.it>
A Rossi (INAF-OAS) report on behalf of the CIBO collaboration:
We observed the field of GRB 220403B (Klingler et al., GCN 31820)
simultaneously in the g',r',i' and z' bands with the LBC imager mounted
on LBT (Mt Graham, AZ, USA). We obtained 10min of imaging at the midtime
04:02 UT on 2022-04-04, 0.3 days after the burst trigger. Observations
were performed under good weather conditions with an average seeing of
~1.5".
We clearly detect the afterglow and we preliminary measure
r=20.9+-0.1 (AB system),
calibrated against Pan-STARRS field stars.
We acknowledge the excellent support from the LBTO and LBT-INAF staff,
particularly A. Cardwell and S. Allanson in obtaining these observations.
GCN Circular 31827
Subject
GRB 220403B: Swift-XRT refined Analysis
Date
2022-04-04T07:08:18Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), E. Ambrosi
(INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR),
A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU),
J.P. Osborne (U. Leicester) and N.J. Klingler report on behalf of the
Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 220403B (Klingler et al.
GCN Circ. 31820), from 86 s to 28.9 ks after the BAT trigger. The data
comprise 50 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The refined XRT position is RA, Dec = 191.4734, +89.1846 which is
equivalent to:
RA (J2000): 12 45 53.62
Dec(J2000): +89 11 04.6
with an uncertainty of 3.5 arcsec (radius, 90% confidence).
The light curve can be modelled with an initial power-law decay with an
index of alpha=4.4 (+/-0.4), followed by a break at T+229 s to an alpha
of 0.35 (+0.04, -0.05).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.86 (+0.16, -0.14). The
best-fitting absorption column is 1.47 (+0.51, -0.27) x 10^21 cm^-2,
consistent with the Galactic value of 1.2 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 3.7 x 10^-11 (4.6 x
10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.47 (+0.51, -0.27) x 10^21 cm^-2
Galactic foreground: 1.2 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.86 (+0.16, -0.14)
If the light curve continues to decay with a power-law decay index of
0.35, the count rate at T+24 hours will be 0.057 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.1 x
10^-12 (2.6 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01101053.
This circular is an official product of the Swift-XRT team.
GCN Circular 31829
Subject
GRB 220403B: Fermi GBM detection
Date
2022-04-04T15:12:37Z (3 years ago)
From
Rachel Hamburg at UAH <rkh0007@uah.edu>
Rachel Hamburg (UAH) and Boyan Hristov (UAH)
report on behalf of the Fermi GBM Team:
"At 20:42:39.05 UT on 03 April 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220403B (trigger 670711364 / 220403863), which
was also detected by the Swift/BAT and the Swift/XRT (Klingler et al. 2022,
GCN 31820). Additionally, the optical afterglow was detected by the
Swift/UVOT (Klingler et al. 2022, GCN 31820), D50 (Jelinek et al. 2022,
GCN 31821), Nanshan/NEXT (Zhu et al. 2022, GCN 31823) and LBT (Rossi 2022,
GCN 31826).
The angle from the Fermi LAT boresight at the GBM trigger time is 43
degrees.
The GBM light curve shows broad rise with multiple peaks with a
duration (T90) of about 28 s (50-300 keV).
The time-averaged spectrum from T0-6.1 s to T0+21.5 s is best fit by a
power law function with an exponential high-energy cutoff. The power law
index is -1.2 +/- 0.1 and the cutoff energy, parameterized as Epeak,
is 79 +/- 3 keV. The spectrum is also well fit by a Band function with
Epeak = 70 +/- 5, alpha = -1.1 +/- 0.1, and beta = -2.6 +/- 0.2.
The event fluence (10-1000 keV) in this time interval is
(5.2 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.6 s in the 10-1000 keV band is 4.3 +/- 0.2 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 31830
Subject
GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
Date
2022-04-04T17:28:51Z (3 years ago)
From
Toktarkhan Komesh at Nazarbayev University <toktarkhan.komesh@nu.edu.kz>
SUBJECT: GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
B. Grossan (UCB, NU), T. Komesh (NU), Z. Maksut (NU), M. Krugov (FAI), E. Linder (UCB, NU), E. Abdikamalov (NU), K. Baigarin (NU), G. F. Smoot (HKUST, UCB, NU), report on behalf of the Energetic Cosmos Laboratory:
The Nazarbayev University Transient Telescope at Assy-Turgen Astrophysical Observatory (NUTTelA-TAO) observed the field of GRB 220403B 11 s after receipt an automated GCN / BAT position alert, observing in Sloan i' band, with the Burst Simultaneous Three-Channel Imager (BSTI; Grossan, Kumar & Smoot 2019, JHEA, 32, 14).
We started observations at 20:43:09 UT on 2022-04-03, 27 s after the BAT trigger. Observations were made in partially cloudy conditions starting at about 43 deg. target altitude. No source consistent with the XRT (A.P. Beardmore et al., GCN Circ.31827) was detected.�� We report the following results:
start time����t-t0(s)�� end time�������������� ULi'������������ exposure_time (s)
---------�� ----�� --------- ���������� ------ --------------------
20:43:09 ������ 27 �� 20:44:09 ���������������� 17.6 ������������������ 60
20:44:24 ������ 87 �� 20:46:54 ���������������� 18.4 �������������� 150
start time is in UT. t-t0(s) gives the time since trigger, in seconds. UL i', gives the 5 sigma upper limit sensitivity in magnitudes, for images co-added to the given exposure time. The first row in the table corresponds to co-adds of an initial short exposure image sequence of 7.5 s. The second row corresponds to co-adds from a continuing series of 15 s exposures.�� Calibration was done with the 2 bright Pan-STARRS catalog stars on our images.
We caution the reader that these are preliminary results, without color or other corrections. Please also note that times are approximate.
----------------------------------
NU = Nazarbayev University, Nur-Sultan, Kazakhstan
UCB = University of California, Berkeley, USA
HKUST = Hong Kong University of Science and Technology
FAI = Fesenkov Astrophysical Institute, Kazakhstan
The NUTTelA-TAO Team acknowledges the support of the staff of the Assy-Turgen Astrophysical Observatory, Almaty, Kazakhstan, and the Fesenkov Astrophysical Institute, Almaty, Kazkhstan.
GCN Circular 31834
Subject
GRB 220403B: Swift-BAT refined analysis
Date
2022-04-05T13:29:33Z (3 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), N. J. Klingler (GSFC/UMBC/CRESSTII)
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
T. Sakamoto (AGU), M. Stamatikos (OSU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220403B (trigger #1101053)
(Klingler, et al., GCN Circ. 31820). The BAT ground-calculated position is
RA, Dec = 190.974, 89.180 deg which is
RA(J2000) = 12h 43m 53.9s
Dec(J2000) = +89d 10' 49.0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 60%.
The mask-weighted light curve shows a bright peak structure that starts
at T-19 s, peaks at T-1 s and ends at T+40 s. T90 (15-350 keV) is
27.0 +- 3.4 sec (estimated error including systematics).
The time-averaged spectrum from T-14.42 to T+27.96 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.94 +- 0.06. The fluence in the 15-150 keV band is 3.7 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.06 sec in the 15-150 keV band
is 2.7 +- 0.3 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/1101053/BA/
GCN Circular 31837
Subject
GRB 220403B: Kitab optical observations
Date
2022-04-05T21:24:30Z (3 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Zhornichenko (KIAM), A. Pozanenko (IKI), V.
Agletdinov (KIAM), S. Belkin (IKI), Sh. Ehgamberdiev (UBAI) report on
behalf of IKI-GRB-FuN:
We observed the field of GRB 220403B (Klingler et al., GCN 31820)
with Kitab RC-36 telescope in Clear filter. Observation started on
April, 03 (UT) 21:23:55 and ended on April, 04 (UT) 00:00:11. We
clearly detect the optical afterglow (Klingler et al., GCN 31820;
Jelinek et al., GCN 31821; Zhu et al., GCN 31823; Rossi et al., GCN
31826; see also early upper limits in Lipunov et al., GCN 31825; Grossan
et al., GCN 31830) in the combined images of an initial part of
observations and do not detect it in the final part.
Preliminary photometry of the combined images is following
Date, UT start, t-T0, Exp., Filter, OT, Err, UL(3 sigma)
(mid, days)
2022-04-03 21:23:55 0.05178 40*60 CR 19.24 0.19 20.2
2022-04-03 22:30:39 0.10640 87*60 CR n/d n/d 20.5
The photometry is based on nearby USNO-B1.0 stars, R2 magnitude
USNO-B1.0_id R2
1791-0003982 16.77
1791-0003984 17.83
GCN Circular 31841
Subject
GRB 220403B: 1.5m OSN optical observation
Date
2022-04-06T11:59:32Z (3 years ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Y.-D. Hu, A. Sota, A. J. Castro-Tirado, T.-R. Sun, M. D. Caballero-Garcia, R. Sanchez-Ramirez and E. Fernandez-Garcia (IAA-CSIC), on behalf of a larger collaboration, report:
Following the detection of GRB 220403B by Swift (Klingler et al. GCNC 31820) and Fermi (Hamburg et al. GCNC 31829), we triggered the 1.5m OSN telescope in Granada (Spain) starting on Apr 4 at 02:49 UT (i.e. ~6.1 h post burst). A series of images in the I band with 60 s exposure were obtained in cloudy weather. In the co-added image of selected high S/N frames, the optical afterglow is weakly detected within the position reported by UVOT (Klingler et al. GCNC 31820) and XRT (Beardmore et al. GCNC 31827) with I=20.45+-0.30 at a median time of 03:20 UT, which is consistent with previous reports of detection by Jelinek et al. (GCNC 31821), Zhu et al. (GCNC 31823), Rossi et al. (GCNC 31826) and Pankov et al. (GCNC 31837), also upper limits by Lipunov et al. (GCNC 31825), Grossan et al. (GCNC 31830). Further observations are ongoing.
We thank the staff at OSN for their excellent support.
GCN Circular 31844
Subject
GRB 220403B: Mondy optical upper limit
Date
2022-04-06T16:37:01Z (3 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI)
report on behalf of GRB IKI FuN:
We observed the field of GRB 220403B (Klingler et al., GCN 31820)
with AZT-33 telescope of Mondy observatory starting on April, 05 (UT)
15:00:54. We do not detect the optical afterglow (Klingler et al.,
GCN 31820; Jelinek et al., GCN 31821; Zhu et al., GCN 31823; Rossi
et al., GCN 31826; Pankov et al., GCN 31837; Hu et al., GCN 31841; see
also early upper limits in Lipunov et al., GCN 31825; Grossan et al.,
GCN 31830) in the combined image.
Preliminary photometry of the combined image is following
Date, UT start, t-T0, Exp., Filter, OT, Err, UL(3 sigma)
(mid, days)
2022-04-05 15:00:54 1.77723 20*120 R n/d n/d 23.2
The photometry is based on nearby USNO-B1.0 stars, R2 magnitude
USNO-B1.0_id R2
1791-0003982 16.77
1791-0003984 17.83
GCN Circular 31869
Subject
GRB 220403B: 1.3m DFOT Optical upper limit
Date
2022-04-10T12:39:32Z (3 years ago)
From
Rahul Gupta at ARIES, India <rahulbhu.c157@gmail.com>
Amit Kumar Ror, Rahul Gupta, Amit Kumar, Dimple, Ankur Ghosh, Amar Aryan,
Brajesh Kumar, S. B. Pandey, and Kuntal Misra (ARIES) report:
We observed the Swift-BAT and Fermi-GBM detected GRB 220403B (Klingler et
al., GCN 31820; Hamburg et al., GCN 31829) with 1.3m Devasthal Fast Optical
Telescope (DFOT) located at Devasthal observatory of Aryabhatta Research
Institute of Observational Sciences (ARIES), India. The observations were
started on 2022-04-04 at ~ 17:32 UT, i.e., ~ 20.82 hours after the BAT
trigger. We have taken multiple frames having an exposure time of 300 sec
in the R filter. We stacked the images after the alignment. We did not
detect the optical afterglow (Klingler et al., GCN 31820; Jelinek et al.,
GCN 31821; Zhu et al., GCN 31823; Lipunov et al., GCN 31825; Rossi GCN
31826; Pankov et al., GCN 31837; and Hu et al., GCN 31841) in our stacked
image.
We obtain the following 3-sigma upper limit in the stacked image.
Date Start_UT T_start-T0 (hours) Filter Exp time (sec) Limiting magnitude
=============================================================
2022-04-04 17:32:01 ~20.82 R 300 sec*24
> 21.6
The magnitude is not corrected for the Galactic extinction in the direction
of the burst. Photometric calibration is performed using the standard stars
from the USNO-B1.0 catalog.
This circular may be cited.
GCN Circular 31876
Subject
GRB 220403B: Swift/UVOT Detection
Date
2022-04-11T17:51:22Z (3 years ago)
From
Noel Klingler at NASA-GSFC / UMBC <njk5441@psu.edu>
N. J. Klingler (NASA-GSFC/UMBC/CRESST II) reports on behalf of the
Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220403B
105 s after the BAT trigger (Klingler et al., GCN Circ. 31820).
A source consistent with the XRT position
is detected in the initial UVOT exposures.
The UVOT position is:
RA (J2000) = 12:45:53.46 = 191.47274 (deg.)
Dec (J2000) = +89:11:06.5 = 89.18515 (deg.)
with an estimated uncertainty of 0.52 arc sec. (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 105 255 147 19.86 +/- 0.12
v 647 1074 58 >18.6
b 573 766 39 >19.3
u 318 741 265 19.93 +/- 0.22
w1 697 716 19 >18.9
w2 797 1049 39 >19.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.208 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 31883
Subject
GRB 220403B: GRANDMA observations
Date
2022-04-12T08:21:29Z (3 years ago)
From
Sarah Antier at OCA <sarah.antier@oca.eu>
X. Song, J. Zhu (BJP), I. Tosta e Melo (INFN-LNS), J.-G. Ducoin (IAP),
N. Guessoum (AUS), W. Corradi (LNA), T. Culino (OCA), E. Gurbanov (ShAO),
E. Hesenov (ShAO), A. de Ugarte Postigo, S. Antier (OCA/Artemis), L. Wang,
A. Iskandar (XAO), X. F. Wang (TSU/BJP), X. Zeng (CTGU), D. Marchais (KNC),
P.A. Duverne, N. Leroy (IJCLAB), D. A. Kann (HETH/IAA-CSIC), A. Simon,
A. Baransky (Kyiv univ), V. Godunova (IC ICAMER),
report on behalf of GRANDMA collaboration:
The GRANDMA telescope network responded to the alert of GRB 220403B
(Klingler et al., GCN 31820). The first observations started 8 min after
the BAT trigger time.
We clearly detect the afterglow within the first hour.
We also report our 3-sigma upper limits. Magnitudes are given in the
AB system.
T-T0 (hr)| MJD���� | Obser.���� |Exposure| Filter | Mag +/- err�� | Upp.Lim. (AB)
___________________________________________________________________________
0.13 |59672.86832| ALi-50���� | 5x20s�� | Clear�� | 18.4 +/- 0.1 | -
0.35 |59672.8775 | ALi-50���� | 20x20s | SDSS g'| 19.7 +/- 0.1 | -
0.48 |59672.88298| ALi-50���� | 20x20s | SDSS r'| 18.6 +/- 0.1 | -
17.67|59673.59939| SNOVA������ | 15x300s| Clear�� |������������ -���������� | 19.4
24.72|59673.89285| KNC-T-CAT| 240x32s| Blue���� |������������ -���������� | 20.9
24.72|59673.89285| KNC-T-CAT| 240x32s| Green�� |������������ -���������� | 20.9
24.72|59673.89285| KNC-T-CAT| 240x32s| Red������ |������������ -���������� | 19.9
These detections and limits are consistent with the detections and limits
previously reported in Klingler et al. (GCN 31820), Jelinek et al.
(GCN 31821),Nicuesa Guelbenzu et al. (GCN 31822), Zhu et al. (GCN 31823),
Lipunov et al. (GCN 31825),�� Rossi et al. (GCN, 31826), Grossan et al.
(GCN 31830), Pankov et al. (GCN 31837, 31844), Hu et al. (GCN 31841),
and Kumar et al. (GCN 31869).
The photometry of Ali-50 was performed using field stars from the
PanSTARRs-DR1 catalog for images with SDSS g' and r' filters, and from the
Gaia gmag catalog for images with no filters. The SNOVA and T-CAT data have
been processed using field stars from the PanSTARRS-DR1 catalog and with
the
MUPHOTEN pipeline (Duverne et al. 2021).
GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr)
devoted to the observation of transients in the context of multi-messenger
astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is
the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).