GRB 211024B
GCN Circular 30980
Subject
GRB 211024B: Swift detection of a burst
Date
2021-10-24T22:34:22Z (4 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
J.D. Gropp (PSU), N. J. Klingler (GSFC/UMBC/CRESSTII),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), D. M. Palmer (LANL),
T. M. Parsotan (GSFC/UMBC/CRESSTII), M. H. Siegel (PSU) and
A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 22:20:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 211024B (trigger=1081073). Swift slewed immediately to
the burst, but immediately slewed away due to a conflicting observation.
The BAT on-board calculated location is
RA, Dec 154.688, +24.579 which is
RA(J2000) = 10h 18m 45s
Dec(J2000) = +24d 34' 43"
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 70 sec. The peak count rate
was ~1500 counts/sec (15-350 keV), at ~7 sec after the trigger.
Because of a conflicting preplanned observation, there was
no immediate XRT or UVOT observation. A target of opportunity
observation is planned.
Burst Advocate for this burst is J.D. Gropp (jdg44 AT 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/)
GCN Circular 30981
Subject
Swift GRB 211024B: Global MASTER-Net observations report
Date
2021-10-25T00:10:41Z (4 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, T.Pogrosheva, E.Minkina,
A.Chasovnikov, V.Topolev, V.Grinshpun, 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
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(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 211024B ( J.D. Gropp et al., GCN 30980) errorbox 5877 sec after notice time and 5966 sec after trigger time at 2021-10-25 00:00:02 UT, with upper limit up to 15.6 mag. The observations began at zenith distance = 70 deg. The sun altitude is -44.2 deg.
The galactic latitude b = 56 deg., longitude l = 209 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1764215
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
6056 | MASTER-Tavrida | C | 180 | 15.6 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 30984
Subject
GRB 211024B: Nanshan/NEXT optical afterglow detection
Date
2021-10-25T01:27:33Z (4 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 211024B (Gropp et al., GCN 30980) using the
NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.
Observations automatically started at 22:23:13 UT on 2021-10-24, i.e.,
157 s after the BAT trigger. A series of 3x40 s, 3x60 s and 12x90 s
frames in the Sloan r-filter were obtained.
An uncatalogued evolving optical transient is detected within the
Swift/BAT error circle (Gropp et al., GCN 30980), at coordinates
R.A. = 10:18:51.12
Dec. = +24:34:05.16
with an uncertainty of 0.5 arcsec. The OT had r = 18.4 +/- 0.1 mag in
our first image, brightened to a peak of r ~ 17.6 at ~ 378 s, and then
faded with a powerlaw decay as F(t) ~ t^-0.94, all calibrated with
nearby PS1 stars. We thus conclude that the OT is the optical afterglow
of the burst.
GCN Circular 30989
Subject
GRB 211024B: Swift-BAT refined analysis
Date
2021-10-25T13:03:36Z (4 years ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), J.D. Gropp (PSU),
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-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 211024B (trigger #1081073)
(Gropp, et al., GCN Circ. 30980). The BAT ground-calculated position is
RA, Dec = 154.708, 24.566 deg which is
RA(J2000) = 10h 18m 49.9s
Dec(J2000) = +24d 33' 57.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows three episodes. The first episode
starts from T-60 s, peaks at T+10 s and ends at T+100 s. The second, and
weakest, episode runs from T+250 to T+400 sec and the third episode starts
around T+500 s, peaks at T+580 s and ends at T+620 s. The burst came into
the BAT field of view around T-100 sec during a pre-planned slew.
T90 (15-350 keV) is 603.5 +- 20.7 sec (estimated error including systematics).
The time-averaged spectrum from T-56.37 to T+613.08 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.63 +- 0.09. The fluence in the 15-150 keV band is 6.8 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+5.17 sec in the 15-150 keV band
is 0.9 +- 0.2 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/1081073/BA/
GCN Circular 30994
Subject
GRB 211024B: Swift-XRT refined Analysis
Date
2021-10-25T15:12:58Z (4 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), E. Ambrosi
(INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR),
J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L.
Page (U. Leicester) and J.D. Gropp report on behalf of the Swift-XRT
team:
We have analysed 6.2 ks of XRT data for GRB 211024B (Gropp et al. GCN
Circ. 30980), from 105 s to 24.7 ks after the BAT trigger. The data
comprise 6 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. Using 6214 s
of PC mode data and 12 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 = 154.71268, +24.56825 which is equivalent
to:
RA (J2000): 10h 18m 51.04s
Dec(J2000): +24d 34' 05.7"
with an uncertainty of 1.9 arcsec (radius, 90% confidence).
The late-time light curve (from T0+5.6 ks) can be modelled with a
power-law decay with a decay index of alpha=2.69 (+0.13, -0.12).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.08 (+0.11, -0.10). The
best-fitting absorption column is 9.7 (+2.7, -2.5) x 10^20 cm^-2, in
excess of the Galactic value of 2.1 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 3.2 x 10^-11 (3.9 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 9.7 (+2.7, -2.5) x 10^20 cm^-2
Galactic foreground: 2.1 x 10^20 cm^-2
Excess significance: 5.0 sigma
Photon index: 2.08 (+0.11, -0.10)
If the light curve continues to decay with a power-law decay index of
2.69, the count rate at T+24 hours will be 5.0 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.6 x
10^-13 (2.0 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/01081073.
This circular is an official product of the Swift-XRT team.
GCN Circular 30995
Subject
GRB 211024B: CAHA 2.2m Detection; ultra-long GRB?
Date
2021-10-25T15:45:51Z (4 years ago)
From
Alexander Kann at IAA-CSIC <kann@iaa.es>
D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH, DARK/NBI), C. C.
Thoene, M. Blazek, J. F. Agui Fernandez (all HETH/IAA-CSIC), A.
Guijarro, and P. Martin-Fernandez (both CAHA) report:
We observed the optical afterglow of the very long Swift GRB 211024B
(Gropp et al., GCN #30980; Zhu et al., GCN #30984) with CAFOS mounted on
the 2.2m Telescope at Calar Alto, Almeria, Spain. We obtained 30 x 90 s
in the SDSS i' band under mediocre conditions.
At the position of the GRB afterglow discovered by Nanshan/NEXT (Zhu et
al., GCN #30984), we detect a source. Against one Pan-STARRS comparison
star, we measure:
i' = 20.27 +\- 0.05 mag (AB) at 0.2485 d after the GRB.
We note the XRT light curve at time of writing
(https://www.swift.ac.uk/xrt_curves/01081073/ Evans et al., GCN #30994)
shows a certain resemblance to that of the ultra-long GRB 111209A, being
relatively flat until 10 ks before dropping off very steeply. The lack
of early data prevents further conclusions for now. Further follow-up is
warranted.
GCN Circular 31005
Subject
GRB 211024B: Swift/UVOT detection
Date
2021-10-26T13:13:02Z (4 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and J. Gropp (PSU) reports on behalf of the
Swift/UVOT team:
We report here the early Swift/UVOT photometry of GRB 211024B (Gropp et
al.,
GCN Circ. 30980; Zhu et al. GCN Circ. 30984; Lien et al. GCN Circ 30989;
Evans et al. GCN Circ 30994; Kann et al. GCN Circ. 30995) at the position
reported by Zhu et al. (GCN Circ. 30984).
Preliminary detections 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
v 6237 6437 197 19.2 +/- 0.4
v 12395 24343 1665 20.4 +/- 0.4
b 5826 5927 197 20.0 +/- 0.4
u 5621 5821 197 18.8 +/- 0.2
u 6852 7052 197 19.3 +/- 0.3
w1 6647 6847 197 19.2 +/- 0.3
m2 6442 6642 197 19.3 +/- 0.3
w2 6032 6232 197 20.1 +/- 0.5
w2 7260 7360 98 19.5 +/- 0.5
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening in the direction of the burst.
GCN Circular 31028
Subject
GRB 211024B: Optical afterglow observation by Ondrejov D50
Date
2021-11-01T21:12:09Z (4 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 very long GRB 211024B (Gropp et al., GCN
30980, Lien et al. GCN 30989 and Evans et al. GCN 30994) with the D50
telescope of the Astronomical Institute Ondrejov, near Prague, Czech
Republic. We obtained a set of 175x 60s exposures in Sloan i' filter as
soon as the position became accessible above the local horizon, between
3.16 and 6.35h after the trigger.
The optical afterglow (Lipunov et al., GCN 30981; Zhu et al., GCN 30984;
Kann et al., GCN 30995; Kuin et al., GCN 31005) is clearly detected in
weight-combined images. In particular, we measure i'=19.94+/-0.11 in a
38x60s frame with an exposure mid time T0+0.152d. The calibration was done
against Atlas stars in the field.
GCN Circular 31800
Subject
GRB 211024B: Host galaxy redshift from X-shooter/VLT
Date
2022-03-28T15:57:26Z (3 years ago)
From
Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>
A. de Ugarte Postigo (Artemis/OCA), B. Schneider (CEA Paris-Saclay),
D. B. Malesani (Radboud Univ. and DAWN/NBI), D. A. Kann (IAA-CSIC)
report on behalf of the Stargate collaboration:
We observed the location of the ultra-long GRB 211024B (Gropp et al.
GCN 30980, Zhu et al. GCN 30984) using the X-shooter spectrograph
mounted on the UT3 of ESO���s Very Large Telescope. The observation
was performed on 27 March 2022 (153 days after the GRB) and
consisted of 4x1200 s in the UVB and VIS arms and 8x600 s in the NIR
arm. We used the JH-slit that blocks part of the K-band and in return
increases the efficiency of the J and H bands, resulting in a wavelength
coverage between 3000 to 21000 AA.
In a preliminary reduction we detect two weak emission lines that we
identify as [OII]3727 and [OIII] 5008, as well as a marginal detection of
[OII]4960 at a common redshift of z=1.1137+/-0.0002. The other line of
the OII doublet, [OII]3729 is affected by a sky line and is consequently
not detected. H-alpha falls within a telluric absorption and H-beta in a
spectral region of low sensitivity, both resulting in non detections. Given
the spatial coincidence of these emissions with the afterglow, we identify
the underlying object as the host galaxy and propose this as the redshift
of the GRB.
We acknowledge expert support from the ESO staff in Paranal, in
particular Cedric Ledoux and Michael Abdul-Masih.