GRB 210222B
GCN Circular 31753
Subject
GRB 210222B: TAROT Reunion observatory optical light curve
Date
2022-03-13T22:11:11Z (4 years ago)
From
Alain Klotz at IRAP-CNRS-OMP <Alain.Klotz@free.fr>
A. Klotz (CNRS-OMP-IRAP),
M. Fortune, R. Augerai (Universite de la Renuion),
P. Thierry�� (AGORA),
L. Eymar, S. Antier, M. Boer, A. de Ugarte Postigo (CNRS-OCA-ARTEMIS),
We analyzed archive images of the SWIFT trigger 1034325 (GRB 210222B,
BAT detection by Gropp et al. GCN Circ. 29545,
early optical ground observations by Fernandez-Garcia et al. GCN Circ.
29546,
redshift by Agui Fernandez et al. GCN Circ. 29552)
with the TAROT robotic telescope (D=18cm) located
at Les Makes Observatory, Reunion Island, France.
Images were acquired without any filter, camera FLI PL16803
and Takahashi Epsilon 180ED.
According the reference star NOMAD-1 0750-0237314 R=15.43
we give the photometry of the GRB optical transient:
t1(s) t2(s)�������� R�� dmag
�� 342���� 433 15.76�� 0.06
�� 439���� 529 16.08�� 0.07
�� 536���� 626 16.14�� 0.08
�� 658���� 748 16.28�� 0.09
�� 755���� 845 16.38�� 0.09
�� 853���� 942 16.38�� 0.09
��1526�� 1706 16.98�� 0.12
��1714�� 1894 17.28�� 0.15
��1902�� 2543 17.32�� 0.13
��2550�� 3317 17.74�� 0.21
��3347�� 4843 17.92�� 0.25
��4852�� 6755 18.52�� 0.47
t1 and t2 are start and stop acquisition since the trigger.
Magnitudes are not corrected for Galactic dust extinction.
GCN Circular 29569
Subject
GRB 210222B: 1.3m DFOT Optical upper limit
Date
2021-02-26T06:14:15Z (5 years ago)
From
Rahul Gupta at ARIES, India <rahulbhu.c157@gmail.com>
Rahul Gupta, A. Kumar, Dimple, A. Ghosh, A. Aryan, V. Negi, B. Kumar,
S. B. Pandey, and K. Misra (ARIES) report:
We observed the field of Swift detected GRB 210222B (Gropp et al., GCN
29545) 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 2021-02-23 at ~ 19:15 UT, i.e., ~ 20.6 hours after the BAT trigger.
We have taken multiple frames having an exposure time of 120 s in the
R and I filters. We stacked the images after the alignment. We did
not detect the optical afterglow reported previously (Gropp et al. GCN
29545; Hu et al. GCN 29546; Strausbaugh et al. GCN 29547; Mong et al.
GCN 29548, 29550; Perley et al. GCN 29549; Zhu et al. GCN 29551,
Fernandez et al. GCN 29552; Lipunov et al. GCN 29554; Jelinek et al.
GCN 29557; Siegel et al. GCN 29559; Gokuldass et al. GCN 29562; Belkin
et al. GCN 29563; and D'Avanzo et al. GCN 29567) in our stacked image.
We obtain the following 3-sigma upper limit in the stacked image.
Date Start_UT T_start-T0 (hour) Filter Exp time (s) Limiting magnitude
====================================================
2021-02-23 19:15 ~20.6 R 120*30 > 21.1
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 29567
Subject
GRB 210222B: REM observations of the optical/NIR afterglow
Date
2021-02-25T21:29:46Z (5 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
P. D'Avanzo, S. Covino, D. Fugazza, A. Melandri (INAF-OAB) on behalf of the REM team, report:
We observed the field of GRB 210222B (Gropp et al., GCN Circ. 29545) with the REM 60cm robotic telescope
located at the ESO premise of La Silla (Chile). The observations were performed starting on 2021 February 23
at 00:18:20 UT (i.e. 1.68 hours after the burst) and were carried in the g, r, i, z, J and H bands.
The optical afterglow (Gropp et al., GCN Circ. 29545) is detected in all bands.
From preliminary photometry we obtain for the optical/NIR afterglow the following magnitudes:
r = 18.85 +/- 0.13 (AB; calibrated against the Pan-STARRS catalogue)
H = 16.39 +/- 0.20 (Vega; calibrated against the 2MASS catalogue)
at a mid time of t-t0 = 1.93 hours.
GCN Circular 29565
Subject
GRB 210222B: MITSuME Akeno optical upper limits
Date
2021-02-25T08:30:41Z (5 years ago)
From
Ryohei Hosokawa at Tokyo Institute of Technology <hosokawa@hp.phys.titech.ac.jp>
R. Hosokawa, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa, N.
Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N.
Kawai (TokyoTech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 210222B (Lipunov et al. GCN #29544, Gropp
et al. GCN #29545, Hu et al. GCN #29546, Strausbaugh et al. GCN
#29547, Mong et al. GCN #29548, Perley et al. GCN #29549, Mong et al.
GCN #29550, Zhu et al. GCN #29551, Fernandez et al. GCN #29552,
Lipunov et al. GCN #29554, Jelinek et al. GCN #29557, Zheng et al. GCN
#29558, Siegel et al. GCN #29559, Page et al. GCN #29560, Ukwatta et
al. GCN #29561, Gokuldass et al. GCN #29562, Belkin et al. GCN #29563)
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 at
2021-02-23 11:00:13 UT(12.4hours after the Swift BAT trigger). We
stacked the images with good conditions. We did not detect the optical
afterglow reported previously (Gropp et al. GCN #29545, Hu et al. GCN
#29546, Strausbaugh et al. GCN #29547, Mong et al. GCN #29548, Perley
et al. GCN #29549, Mong et al. GCN #29550, Zhu et al. GCN #29551,
Fernandez et al. GCN #29552, Lipunov et al. GCN #29554, Jelinek et al.
GCN #29557, Siegel et al. GCN #29559, Gokuldass et al. GCN #29562,
Belkin et al. GCN #29563) in all three bands.
We obtained the 5-sigma limits of the stacked images as follows.
T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
12.4 15:18:25 14100 g'>19.6, Rc>19.9, Ic>19.2
------------------------------------------------------------------------------------------------
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. 2021, PASJ, Vol.73, Issue 1, Pages
4-24; https://github.com/MNiwano/Eclaire).
GCN Circular 29563
Subject
GRB 210222B: Zeiss-1000 of Koshka observatory, optical observations
Date
2021-02-24T11:08:10Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), A. Novichonok (Petrozavodsk State
University, KIAM), A. Zhornichenko (KIAM), N. Pankov (HSE) report on
behalf of IKI GRB FuN:
We observed the field of GRB 210222B (Gropp et al., GCN 29545) with
Zeiss-1000 telescope of Koshka observatory starting on Feb. 22 (UT)
22:46:13, i.e. about 12.8 minutes after GRB trigger. We clearly detect
optical afterglow (Gropp et al., GCN 29545; Hu et al., GCN 29546;
Strausbaugh et al., GCN 29547; Mong et al., GCNs 29548, 29550; Perley et
al., GCN 29549; Zhu et al., GCN 29551; Lipunov et al., GCN 29554;
Jelinek et al., GCN 29557; Zheng et al., GCN 29558; Siegel et al., GCN
29559; Gokuldass et al., GCN 29562). Observations were performed under
non-optimal weather conditions.
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2020-12-03 20:50:46 0.58216 R 120*25 n/d n/d 20.5
Date, UT start Exptime,s t-T0,d Filter OT Err UL(3sigma)
2021-02-22 22:46:13 240 0,00748842 R 16.27 0.09 18.3
2021-02-22 22:50:18 240 0,01032407 R 16.49 0.11 18.2
2021-02-22 22:55:50 240 0,01416666 R 16.71 0.11 18.2
2021-02-22 22:59:54 5*240 0,02254629 R 17.18 0.18 18.7
2021-02-22 23:20:18 7*240 0,03949074 R 17.60 0.15 18.9
The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
0750-0233028 14.52
0750-0233056 15.22
0750-0233031 15.24
The light curve can be found in
http://grb.rssi.ru/GRB210222B/GRB210222B_LC.png
Based only on our photometry we estimated power law index of the
afterglow light curve of -0.74.
We are grateful to the ���Terskol Observatory��� Center of the Institute of
Astronomy of the Russian Academy of Sciences (INASAN) for the
observations with the Zeiss-1000 telescope on Mount Koshka at the Simeiz
Observatory.
GCN Circular 29562
Subject
GRB 210222B: VIRT optical detection
Date
2021-02-24T04:10:56Z (5 years ago)
From
Priyadarshini Gokuldass at U. of the Virgin Islands <priyadass.94@gmail.com>
P. Gokuldass (UVI), N. Orange (OrangeWave Innovative Science, LLC), R.
Strausbaugh (UVI), A. Cucchiara (UVI/College of Marin),
D. Morris (UVI) report:
We observed the field of GRB210222B (Gropp et al, GCN 29545) with the
0.5m Virgin Island Robotic Telescope (VIRT)
at the University of the Virgin Islands' Etelman Observatory on
02-23-2021 starting at 02:14:31 UT (T+3.6hrs).
We performed a series of exposures in R filter with a total exposure
of 4600 s. The weather conditions were clear
during the hours of observation with an average air masses as shown in
the table below.
We detect the optical transient reported by others (Gropp et al., GCN
29545, Hu et al., GCN 29546,Strausbaugh et al.,
GCN 29547, Mong et al., GCN 29548, Perley, GCN 29549, Aqui Fernandez
et al., GCN 29552, Lipunov et al., GCN 29554,
Jelinik et al., GCN 29557) at > 3-sigma confidence with magnitudes as
reported below:
T_mid ||Exposure ||Filter ||Limit ||Airmass
T+4.5 hrs ||2000s ||R ||18.5 +/- 0.1 ||1.7
T+8.5 hrs ||2600s ||R ||20.0 +/- 0.2 ||1.5
The magnitude is estimated from comparison to nearby USNO B1 stars and
is not corrected for Galactic extinction.
Further analysis is in progress. The VIRT is still in the commissioning phase.
This work is supported by NASA-MUREP-MIRO grant NNX15AP95A, NSF EiR
AST Award 1901296, and NSF HBCU-UP AST Award 1831682.
This message can be cited.
GCN Circular 29561
Subject
GRB 210222B: Swift-BAT refined analysis
Date
2021-02-23T22:42:22Z (5 years ago)
From
Sibasish Laha at GSFC <sibasish.laha@nasa.gov>
T. N. Ukwatta (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), D. M. Palmer (LANL),
T. Sakamoto (AGU), B. Sbarufatti (PSU)
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 210222B (trigger #1034325)
(Gropp et al., GCN Circ. 29545). The BAT ground-calculated position is
RA, Dec = 154.631, -14.946 deg which is
RA(J2000) = 10h 18m 31.4s
Dec(J2000) = -14d 56' 45.7"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 38%.
The BAT light curve showed a two peaked structure with a duration of about ~20 sec.
T90 (15-350 keV) is 12.82 +- 1.28 sec (estimated error including systematics).
The time-averaged spectrum from T-11.37 to T+2.72 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.37 +- 0.33. The fluence in the 15-150 keV band is 3.4 +- 0.7 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.87 sec in the 15-150 keV band
is 1.4 +- 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/1034325/BA/
GCN Circular 29560
Subject
GRB 210222B: Swift-XRT refined Analysis
Date
2021-02-23T19:23:17Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), E. Ambrosi
(INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR),
J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU),
P.A. Evans (U. Leicester) and J.D. Gropp report on behalf of the
Swift-XRT team:
We have analysed 6.2 ks of XRT data for the Swift-BAT-detected burst
GRB 210222B (Gropp et al. GCN Circ. 29545), from 111 s to 63.2 ks after
the Swift-BAT trigger. The data are entirely in Photon Counting (PC)
mode. Using 2754 s of PC mode data and 4 UVOT images, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 154.60574, -14.93170
which is equivalent to:
RA (J2000): 10h 18m 25.38s
Dec(J2000): -14d 55' 54.1"
with an uncertainty of 1.4 arcsec (radius, 90% confidence). This
position is 2.2 arcmin from the Swift-BAT position.
The light curve can be modelled with an initial power-law decay with an
index of alpha=0.19 (+/-0.16), followed by a break at T+827 s to an
alpha of 1.30 (+0.12, -0.08).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.98 (+0.15, -0.14). The
best-fitting absorption column is 1.4 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 8.9 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.5 x 10^-11 (4.4 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.4 (+0.5, -0.4) x 10^21 cm^-2
Galactic foreground: 8.9 x 10^20 cm^-2
Excess significance: 1.9 sigma
Photon index: 1.98 (+0.15, -0.14)
If the light curve continues to decay with a power-law decay index of
1.30, the count rate at T+24 hours will be 3.1 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-13 (1.4 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/01034325.
This circular is an official product of the Swift-XRT team.
GCN Circular 29559
Subject
GRB 210222B: Swift/UVOT Detection
Date
2021-02-23T18:57:39Z (5 years ago)
From
Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>
M. H. Siegel (PSU) and J. D. Gropp (PSU)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210222B
101 s after the BAT trigger (Gropp et al., GCN Circ. 29545).
A source consistent with the XRT position (Gropp et al. GCN Circ. 29545)
is detected in the initial UVOT exposures. This source is also consistent
with previously reported optical detections (Hu et al., GCN Circ. 29546;
Strausbaugh, GCN Circ. 29547; Mong et al., GCN Circ. 29548; Parley, GCN Circ.
29549; Zhu et al., GCN Circ. 29551, Lipunov et al., GCN Circ. 29554). We note
that the lack of detection in the NUV passbands would be consistent with the
redshift of 2.198 reported by Agui Fernandez et al. (GCN Circ. 29552).
The preliminary UVOT position is:
RA (J2000) = 10:18:25.43 = 154.60595 (deg.)
Dec (J2000) = -14:55:55.1 = -14.93198 (deg.)
with an estimated uncertainty of 0.42 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 101 250 147 16.89 +/- 0.03
v 588 608 19 16.80 +/- 0.17
b 515 534 20 17.24 +/- 0.12
u 259 508 246 16.82 +/- 0.04
w1 639 1793 124 >18.8
m2 614 1606 78 >20.1
w2 564 1732 136 >19.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.102 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 29558
Subject
GRB 210222B: KAIT Optical Upper Limit
Date
2021-02-23T16:48:01Z (5 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 210222B (Gropp et al.,
GCN 29545) starting at ~0.44 days after the burst. A total of
30x60s images were obtained in the clear (roughly R) filters.
We do not detect the optical afterglow (Gropp et al., GCN 29545;
Hu et al., GCNC 29546; Strausbaugh et al., GCNC 29547; Mong et al.,
GCNC 29548; Perley, GCNC 29549; Agui Fernandez et al., GCNC 29552;
Lipunov et al., GCNC 29554; Jelinek et al., GCN 29557) in the
co-add images, down to a limiting magnitude of ~20.0 mag calibrated
to the USNOB1.0 catalog.
GCN Circular 29557
Subject
GRB 210222B: FRAM-ORM afterglow detection
Date
2021-02-23T15:53:50Z (5 years ago)
From
Martin Jelinek at Astro.Inst-AVCR,Ondrejov <martin.jelinek@asu.cas.cz>
Martin Jelinek and Jan Strobl (ASU CAS Ondrejov, CZ),
Sergey Karpov, Martin Masek, Petr Janecek, Jakub Jurysek,
Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza
(Institute of Physics, Prague, CZ)
report:
The 25cm robotic telescope FRAM-ORM at La Palma (Spain) reacted robotically
to the alert of GRB210222B (Gropp et al. GCNC 29545, Marrocchesi et al.
GCNC 29553), obtaining a series of 20 s unfiltered images starting at
22:38:21.1 UT, i.e. 55.1s post trigger.
We clearly detect the source reported by other telescopes (Hu et al. GCNC
29546, Strausbaugh et al. GCNC 29547, Mong et al. GCNC 29548, Perley GCNC
29549, Agui Fernandez et al. GCNC 29552, and Lipunov et al. GCNC 29554). As
seen by FRAM, the brightness of the object reached a maximum of about
R(Vega) ~ 15.5, similarly to the value of BOOTES, and then slowly changed
to a decay with an index alpha = ~1.1.
Would the decay stay at this rate, the afterglow may have a brightness of
R~22.0 24h post trigger.
GCN Circular 29554
Subject
GRB 210222B: MASTER OT observation
Date
2021-02-23T11:10:04Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy,N.Tiurina,P.Balanutsa,F.Balakin,
V.Vladimirov, A.Kuznetsov,K.Zhirkov,D. Vlasenko, I.Gorbunov, D.Zimnukhov,
V.Senik, A.Chasovnikov,A.Pozdnyakov,V.Topolev, D.Cheryasov(Lomonosov Moscow State University, SAI, Physics Department),
D. Buckley (South African Astronomical Observatory),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico FelixAguilar OAFA),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
MASTER Global robotic net (MASTER-Net:http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L)
automatically started (Lipunov et al. GCN 29544)
Swift GRB 200222B (J.Gropp et al. GCN 29545,Ttrigger=22:37:26 UT)
optical observations at MASTER-Kislovodsk at 2021-02-22 22:38:07UT (41s
after trigger time in clouds),
at MASTER-SAAO at 2021-02-22 22:42:03UT (GCN 29544).
MASTER auto-detection system found MASTER OT J101825.41-145554.9,
also detected by Swift (GCN 29545), and observed by BOOTES-1 (GCN 29546),
LCO (29547), GOTO(29548), Liverpool Telescope (GCN 29549), NEXT (29551),VLT (GCN 29551)
This OT was also observed by MASTER-IAC.
The reduction of MASTER wide field and very wide field cameras images will be
continued.
This message may be cited.
GCN Circular 29552
Subject
GRB 210222B: Redshift from FORS2/VLT
Date
2021-02-23T08:49:55Z (5 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
J. F. Agui Fernandez (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), L. Izzo (DARK/NBI), D. Xu (NAOC), D.A. Kann (HETH/IAA-CSIC), D.B. Malesani (DTU Space), J.P.U. Fynbo (DAWN/NBI), K. Wiersema (Warwick U.) report:
We observed the afterglow of GRB 210222B (Gropp et al. GCN 29545; Hu et al. GCN 29546; Strausbaugh et al. GCN 29547; Mong et al. GCN 29548 and GCN 29550; Perley GCN 29549; Zhu et al. GCN 29551) with FORS2, mounted at the Unit Telescope 1 of the Very Large Telescope, at Paranal Observatory, Chile. The observation started at 3:00 UT (4.376 hr after the burst) and consisted of 2x700 s exposures using grism 300V and 2x700 s exposures using grism 300I, which together cover the full range between 3300 and 10100 AA.
In the acquisition image, the afterglow is well detected at V = 19.6 +/- 0.1 mag (Vega).
The spectrum shows continuum over the full range with strong absorption features that we identify as due to Lyman alpha, SII, SiII, SiII*, OI, CII, SiIV, CIV, FeII, AlII and MgII at a common redshift of 2.198, which we identify as the redshift of the GRB. This is consistent with the moderately high redshift already reported by Perley (GCN 29549) based on the photometric decline in the u-band.
We acknowledge excellent support from the ESO staff, in particular Jose Velasquez, Chiara Mazzucchelli, and Jonathan Smoker.
GCN Circular 29551
Subject
GRB 210222B: NEXT early optical afterglow observations
Date
2021-02-23T05:05:58Z (5 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi
No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 210222B (Gropp et al., GCN 29545) using the
NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.
Observations automatically started at 22:39:01 UT on 2021-02-22, i.e.,
95 s after the BAT trigger. We obtained a series of 40 s and 60 s frames
during the local morning twilight in the Sloan r-filter.
The previously reported optical afterglow (Gropp et al., GCN 29545; Hu
et al., GCN 29546; Strausbaugh et al., GCN 29547; Mong et al., GCN
29548, 29550; Perley et al., GCN 29549) is detected in the stacked
images of the first three exposures, with r = 14.5 +/- 0.3 mag,
calibrated with nearby PS1 stars.
GCN Circular 29550
Subject
GRB 210222B: GOTO confirmation of afterglow detection (correction to GCN29548)
Date
2021-02-23T01:05:06Z (5 years ago)
From
Travis Mong at Monash University <yik.mong@monash.edu>
Y-L Mong (1); K. Wiersema (2); K. Tse (1); K. Ackley (1); D. K. Galloway
(1); M. Dyer (3); J. Lyman (2); K. Ulaczyk (2); D. Steeghs (2); V. Dhillon
(3); P. O'Brien (4); G. Ramsay (5); S. Poshyachinda (6); R. Kotak (7); L.
Nuttall (8); D. Pollacco (2); R. Breton (9)
((1) Monash University, (2) Warwick University, (3) University of
Sheffield, (4) University of Leicester, (5) Armagh Observatory &
Planetarium, (6) National Astronomical Research Institute of Thailand, (7)
University of Turku, (8) University of Portsmouth, (9) University of
Manchester) report on behalf of the GOTO collaboration:
The declination (Dec) of the afterglow candidate reported in GCN29548 is
incorrect. The correct position of the detection is
RA 10:18:25.42
Dec -14:55:54:63
We apologize for any confusion.
GOTO is operated at the La Palma observing facilities of the University of
Warwick on behalf of a consortium including the University of Warwick,
Monash University, Armagh Observatory, the University of Leicester, the
University of Sheffield, the National Astronomical Research Institute of
Thailand (NARIT), Turku University, Portsmouth University, Manchester
University and the Instituto de Astrofisica de Canarias (IAC) (
https://goto-observatory.org)
GCN Circular 29549
Subject
GRB 210222B: Liverpool Telescope optical detection
Date
2021-02-23T00:32:17Z (5 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley (LJMU) reports:
A short ugriz imaging sequence of the optical afterglow of GRB 210222A
(Gropp et al. 29545) was obtained using IO:O on the robotic Liverpool
Telescope between 23:39 and 23:50 UT on 2021-02-22. Photometry relative
to PS1 standards in the field gives the following magnitudes:
t-t0 (d) magnitude
0.04333 : g = 18.67 +/- 0.04
0.04440 : r = 18.21 +/- 0.03
0.04544 : i = 18.01 +/- 0.03
0.04971 : z = 17.83 +/- 0.06
The g-band photometry lies below an extrapolation of the other bands and
the source is not detected in u-band, which may suggest a moderately
high redshift.
DisclaimerNone
GCN Circular 29548
Subject
GRB 210222B: GOTO confirmation of afterglow detection
Date
2021-02-23T00:25:43Z (5 years ago)
From
Travis Mong at Monash University <yik.mong@monash.edu>
Y-L Mong (1); K. Wiersema (2); K. Tse (1); K. Ackley (1); D. K. Galloway
(1); M. Dyer (3); J. Lyman (2); K. Ulaczyk (2); D. Steeghs (2); V. Dhillon
(3); P. O'Brien (4); G. Ramsay (5); S. Poshyachinda (6); R. Kotak (7); L.
Nuttall (8); D. Pollacco (2); R. Breton (9)
((1) Monash University, (2) Warwick University, (3) University of
Sheffield, (4) University of Leicester, (5) Armagh Observatory &
Planetarium, (6) National Astronomical Research Institute of Thailand, (7)
University of Turku, (8) University of Portsmouth, (9) University of
Manchester) report on behalf of the GOTO collaboration:
We carried out observations with the Gravitational-wave Optical
Transient Observer (GOTO) on La Palma in response to GRB 210222B
(Gropp et al; GCN 29545).
We made a series of 4x90 s exposures using our wide L-band filter
(400-700 nm) covering the Swift XRT error box, beginning around 54 s after
the trigger, with midtime of the first observation 22:42:05.21 UT on 22
February 2021.
We detect an uncatalogued source located at (J2000):
RA 10:18:25.42
Dec +53:24:55.89
confirming the OT reported by MASTER (Lupinov et al.; GCN 29544),
BOOTES-1 (Malesani et al.; GCN 29546) and LCO (Strausbaugh et al.; GCN
29547). We find an equivalent magnitude of g = (16.58 +/- 0.03) mag based
on calibration against PanSTARRS DR1 photometry in ATLAS_REFCAT2 (Tonry et
al. 2018).
Observations are continuing.
GOTO is operated at the La Palma observing facilities of the University
of Warwick on behalf of a consortium including the University of
Warwick, Monash University, Armagh Observatory, the University of
Leicester, the University of Sheffield, the National Astronomical
Research Institute of Thailand (NARIT), Turku University, Portsmouth
University,
Manchester University and the Instituto de Astrofisica
de Canarias (IAC) (https://goto-observatory.org)
GCN Circular 29547
Subject
GRB210222B: LCO Optical Afterglow Detection
Date
2021-02-22T23:42:26Z (5 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 210222B (Gropp et al., GCN 29545) with the LCO 1-m Sinistro instrument at the Sutherland, South Africa site, on February 22, from 22:53 to 23:06 UT (corresponding to 0.27 to 0.43 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 3x120s exposures in R and I. We clearly detect an optical source in R and I band in stacked images at a location consistent with the initial UVOT detection (Gropp at al., GCN 29444); this source is not present in either USNO or 2MASS catalogs. Using the USNO-B.1 catalog as reference, we calculate the following magnitudes:
R = 16.95 +/- 0.01
I = 16.32 +/- 0.01
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
GCN Circular 29546
Subject
GRB210222B: BOOTES-1 optical afterglow detection
Date
2021-02-22T23:16:50Z (5 years ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, M. A. Castro Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco, A. Reina (Univ. de Malaga) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:
Following the Swift trigger of GRB 210222B (Gropp et al. GCNC 29545), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva), southern Spain, automatically responded to this burst. Images were taken starting at 22:40:53 UT (~3.5 min after trigger). In the first 10s image, the afterglow reported by UVOT (Gropp et al. GCNC 29545) is detected with magnitude of 15.6 +/- 0.15 (clear filter). Further observations are ongoing.
We thank the staff at INTA-CEDEA for their excellent support.
GCN Circular 29545
Subject
GRB 210222B: Swift detection of a burst with an optical counterpart
Date
2021-02-22T23:02:05Z (5 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU),
N. P. M. Kuin (UCL-MSSL), F. E. Marshall (NASA/GSFC),
M. J. Moss (GWU), D. M. Palmer (LANL) and B. Sbarufatti (PSU) report
on behalf of the Neil Gehrels Swift Observatory Team:
At 22:37:26 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 210222B (trigger=1034325). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 154.621, -14.898 which is
RA(J2000) = 10h 18m 29s
Dec(J2000) = -14d 53' 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 20 sec. The peak count rate
was ~1250 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 22:39:02.1 UT, 95.9 seconds after
the BAT trigger. Using promptly downlinked data we find an X-ray source
with an enhanced position: RA, Dec 154.6062, -14.9316 which is
equivalent to:
RA(J2000) = 10h 18m 25.50s
Dec(J2000) = -14d 55' 53.7"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 131 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.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (8.87 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3
(+1.87/-1.66) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of nominal 150.000 seconds with the White
filter starting 100 seconds after the BAT trigger. There is a candidate
afterglow in the list of sources generated on-board at
RA(J2000) = 10:18:25.45 = 154.60606
DEC(J2000) = -14:55:55.7 = -14.93215
with a 90%-confidence error radius of about 1.10 arc sec. This position is 2.0
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.65. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.101.
This source lies within the current (Sector 35) field-of-view of TESS camera 1.
We note that this source is 32 arcseconds from the known ROSAT All-Sky
X-ray Survey source 1RXS J101827.6-145604. This is outside of the nominal
joint error radius and so we believe that the ROSAT source is a
coincidental alignment unrelated to the new GRB and its optical counterpart.