GRB 111022B
GCN Circular 12472
Subject
GRB 111022B: Swift detection of a burst
Date
2011-10-22T17:31:34Z (14 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
S. T. Holland (CRESST/USRA/GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
M. M. Chester (PSU), V. D'Elia (ASDC), N. Gehrels (NASA/GSFC),
C. Guidorzi (U Ferrara), J. A. Kennea (PSU),
C. B. Markwardt (NASA/GSFC), A. Melandri (INAF-OAB),
K. L. Page (U Leicester) and G. Stratta (ASDC) report on behalf of the
Swift Team:
At 17:13:04 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 111022B (trigger=506074). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 108.951, +49.666 which is
RA(J2000) = 07h 15m 48s
Dec(J2000) = +49d 39' 59"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows nothing which is typical
for an image trigger.
The XRT began observing the field at 17:15:21.8 UT, 137.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
108.9646, 49.6835 which is equivalent to:
RA(J2000) = 07h 15m 51.49s
Dec(J2000) = +49d 41' 00.4"
with an uncertainty of 2.5 arcseconds (radius, 90% containment). This
location is 69 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 http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 7.32
x 10^20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 8.17e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 144 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag.
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.07.
Burst Advocate for this burst is S. T. Holland (Stephen.T.Holland AT nasa.gov).
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/too.html.)
GCN Circular 12475
Subject
GRB 111022B: MASTER-Net early limit
Date
2011-10-22T18:07:27Z (14 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, D.Kuvshinov,
N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov,
D.Zimnukhov, M. Kornilov, A.Sankovich
Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V. Senik
Kislovodsk Solar Station of the Pulkovo Observatory
K.Ivanov, S.Yazev, N.M.Budnev, E.Konstantinov, V.Lenok, O.Gres,
O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Kislovodsk was pointed to the GRB111022B 22 sec after
notice time and 583 sec after GRB time at 2011-10-22 17:22:48 UT in two
polarization bands. On our first (120s exposure) set we haven`t found
optical transient within SWIFT error-box.
The 5-sigma upper limit has been about 17.0 mag
MASTER II robotic telescope located in Tunka(Siberia) was pointed to
GRB111022B 183 sec after notice time and 748 sec after GRB time at
2011-10-22 17:25:32 UT in two polarization bands. On
our first (150s exposure) set we haven`t found optical transient within
SWIFT error-box. So long time of pointing in this site is caused by a
mount problem.
The 5-sigma upper limit has been about 18.3 mag
The message may be cited.
GCN Circular 12478
Subject
GRB 111022B: Enhanced Swift-XRT position
Date
2011-10-22T21:50:44Z (14 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 885 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 111022B, 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 = 108.96498, +49.68362 which is equivalent
to:
RA (J2000): 07h 15m 51.59s
Dec (J2000): +49d 41' 01.0"
with an uncertainty of 1.8 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 12479
Subject
GRB 111022B: NOT observations
Date
2011-10-23T04:42:13Z (14 years ago)
Edited On
2024-11-07T19:19:59Z (7 months ago)
From
Paul Vreeswijk at U of Iceland <pmv@raunvis.hi.is>
Edited By
Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov> on behalf of Leo P. Singer at NASA/GSFC <leo.p.singer@nasa.gov>
Paul Vreeswijk, Annalisa De Cia (U. Iceland), Dong Xu (WIS), Daniele
Malesani (DARK), Páll Jakobsson (U. Iceland) report on behalf of a
larger collaboration:
Using ALFOSC on the Nordic Optical Telescope (NOT) we have obtained R
(3 x 300 s) and I-band (5 x 400 s) imaging of the field of the Swift
GRB 111022B (Holland et al., GCN 12472), starting on 2011 October
23.097 UT (roughly 9.3 hours after the burst). The seeing during the
observations was around 1".
We do not detect any object within the enhanced XRT error circle
(Beardmore et al., GCN 12478), down to limiting magnitudes of about
R>23.2 and I>21.9 (calibrated against the USNO-B1 catalog).
We are grateful to the NOT observer, Terese Hansen (U. Copenhagen),
for obtaining these observations.
GCN Circular 12480
Subject
GRB 111022B: MITSuME Akeno Optical upper limits
Date
2011-10-23T07:51:48Z (14 years ago)
From
Yoichi Yatsu at Tokyo Tech. <yatsu@hp.phys.titech.ac.jp>
Y. Aoki, R. Usui, K. Tokoyoda, Y. Yatsu, K. Kawakami, M. Hayashi, S.
Song, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME
collaboration:
We observed GRB 111022B (S.T. Holland et al, GCN12472)
with the optical three color (g, Rc, and Ic) CCD camera attached
to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The follow-up observation was started at 18:09:58, ~ 57 min after the
BAT trigger because of bad weather.
We did not find any new point source within the enhanced XRT error
circle (A.P. Beardmore et al, GCN12478) in three bands.
Photometric results and are listed below. We used GSC2.3 catalog for
flux calibration.
T0+[s] MID-UT T-EXP[sec] g' Rc Ic
---------------------------------------------------------------------------------
+7317 19:54:13 540 >17.8 >17.7 ---
+10426 20:12:52 360 --- --- >16.5
---------------------------------------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]
GCN Circular 12481
Subject
GRB 111022B: Gemini infrared observations
Date
2011-10-23T13:19:30Z (14 years ago)
From
Andrew Levan at U.of Leicester <A.J.Levan@warwick.ac.uk>
A.J. Levan (U. Warwick), D. Fox (PSU), N.R. Tanvir (U. Leicester)
report for a larger collaboration:
"We observed the localization of GRB 111022B (Holland et al. GCN
12472) with the Gemini-North telescope, equipped with NIRI.
Observations were obtained in poor conditions (2.5" seeing) and
began 17 hours after the burst in the YJHK filters.
We find a single source within the refined XRT error circle (Beardmore
et al. GCN 12478). The source is well detected in both H and K,
with K~19.0 +/- 0.2, but only very weakly in J. Given the earlier
non-detections in the optical (Vreeswijk et al. GCN 12479) the
inferred optical-IR colour is red (R-K > 4.2), coupled with the
lack of apparent excess N_H this could be indicative of a high
redshift burst.
Analysis is ongoing, and further observations are planned."
GCN Circular 12484
Subject
GRB 111022B: Swift-XRT refined Analysis
Date
2011-10-23T15:38:04Z (14 years ago)
From
Valerio D'Elia at ASDC <delia@asdc.asi.it>
V. D'Elia, G. Stratta (ASDC), S. T. Holland (CRESST/USRA/GSFC) report
on behalf of the Swift-XRT team:
We have analysed 8.5 ks of XRT data for GRB 111022B (Holland et al.
GCN Circ. 12472), from 127 s to 18.5 ks after the BAT trigger. The
data comprise 134 s in Windowed Timing (WT) mode (the first 8 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The enhanced XRT position for this burst was given by
Beardmore et al. (GCN. Circ 12478).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.7 (+/-0.9). At T+176 s the decay
steepens to an alpha of 3.64 (+0.26, -0.22) before breaking again at
T+404 s to a final decay with index alpha=2.05 (+0.26, -0.21).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.41 (+0.14, -0.13). The
best-fitting absorption column is 1.46 (+0.27, -0.26) x 10^21 cm^-2,
in excess of the Galactic value of 7.3 x 10^20 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 1.59 (+0.15, -0.12)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 4.5 x 10^-11 (5.0 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 0 (+2.7, -0) x 10^20 cm^-2
Galactic foreground: 7.3 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.59 (+0.15, -0.12)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00506074.
This circular is an official product of the Swift-XRT team.
GCN Circular 12485
Subject
GRB 111022B, Swift-BAT refined analysis
Date
2011-10-23T18:40:50Z (14 years ago)
From
Tilan Ukwatta at GSFC/GWU <tilan.ukwatta@gmail.com>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC),
S. T. Holland (CRESST/USRA/GSFC), H. A. Krimm (GSFC/USRA),
D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(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 111022B (trigger #506074)
(Holland, et al., GCN Circ. 12472). The BAT ground-calculated position is
RA, Dec = 108.927, 49.663 deg which is
RA(J2000) = 07h 15m 42.4s
Dec(J2000) = +49d 39' 45.9"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 82%.
The mask-weighted light curve shows a multi-peak structure starting at
~T-50 sec and ending at ~T+60 sec. T90 (15-350 keV) is 79.1 +/- 13.5
sec (estimated error including systematics).
The time-averaged spectrum from T-47.84 to T+53.80 sec is best fit by a
simple
power-law model. The power law index of the time-averaged spectrum is
1.59 +/- 0.20. The fluence in the 15-150 keV band is 9.0 +/- 1.2 x 10^-07
erg/cm2.
The 1-sec peak photon flux measured from T+49.54 sec in the 15-150 keV band
is 0.4 +/- 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/506074/BA/
GCN Circular 12488
Subject
GRB 111022B: Swift/UVOT upper limits
Date
2011-10-23T21:29:31Z (14 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (MSSL-UCL) and S. T. Holland (CRESST/USRA/GSFC)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 111022B
145 s after the BAT trigger (Holland et al., GCN Circ. 12472).
The upper limit of detection was determined at the enhanced XRT position
(Beardmore et al., GCN 12478).
Preliminary 3-sigma upper limits in the UVOT photometric system (
Poole et al. 2008, MNRAS, 383, 627) for the first finding
chart (FC) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 145 294 147 >20.8
u_FC 303 552 246 >20.0
v 635 6091 452 >19.8
b 559 6912 452 >20.3
u 302 6707 678 >20.4
uvw1 685 6501 432 >20.3
uvm2 659 6296 452 >20.3
uvw2 608 5886 255 >20.1
white 145 6975 606 >21.3
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.07 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 12491
Subject
GRB 111022B: BTA Optical Observations
Date
2011-10-24T19:37:43Z (14 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
A. S. Moskvitin, V. N. Komarova, V. V. Sokolov and T. N. Sokolova
(SAO RAS GRB follow-up team) report:
The field of GRB 111022B (Holland et al., GCN#12472) was observed
with the 6-m BTA/Scorpio on October, 23, 2011. We obtained 3 x 180 sec.
frames in the Rc band and 25 x 120 sec. in the Ic band.
Observations in Rc began at 00:40:10 (7.5 hours after the trigger),
ended at 00:50:21 UT; in Ic began at 01:23:11 UT (8.2 hours after the
trigger), ended at 02:22:40 UT. Conditions were clear with a seeing
of about 1".2 (FWHM of stellar objects in the Ic co-added image).
The possible optical counterpart is clearly detected in the Ic band
within the 1".5 XRT error circle (according to
http://www.swift.ac.uk/xrt_positions/) at the coordinates:
R.A. (J2000) = 07:15:51.56
Decl. (J2000) = +49:41:01.7
with the uncertainty 0".2.
The object magnitude is I = 23.6 +/- 0.3 as compared to USNO-B1.0 Imag
of six nearby stars. The high error is due to calibration, the 3-sigma
limit of the Ic co-added image is about 24.7. We do not detect the object
in the Rc-band down to the 3-sigma level limiting magnitude of about 24.3.
The Ic image can be found at
ftp://ftp.sao.ru/pub/grb/GRB111022B/GRB111022B_BTA.jpg
Our results are in agreement with the previously reported NOT observations
(Vreeswijk et al., GCN#12479) and do not contradict the idea of a high
redshift burst according to Gemini infrared observations (Levan et al.,
GCN#12481).
We are grateful to T. A. Fatkhullin
and the BTA staff for the help in observations.
GCN Circular 12493
Subject
GRB111022B: D50 optical limit
Date
2011-10-25T02:58:35Z (14 years ago)
From
Martin Jelinek at Inst.Astrophys.Andalucia,Granada <mates@iaa.es>
M. Blazek (AsU AV), R. Hudec (AsU AV), M. Jelinek (IAA-CSIC),
C. Polasek (AsU AV) and J. Strobl (AsU AV)
"We observed the field of GRB 111022B (Holland et al., GCN
12472) with 0.5m robotic telescope D50 in Ondrejov observatory
(Czech Republic). The observation started at 23:55:06 UT on
October 22, 2011, approx. 6.5 hours after the Swift trigger.
We report no detection of the optical counterpart on the
unfiltered images within the error circle given by SWIFT-XRT
(Beardmore et al., GCN 12478). The limiting magnitude of about
R>20.0 mag in R-band was estimated using nearby sources from
GSC2.2 catalogue."
GCN Circular 12494
Subject
GRB 111022B: 10.4m GTC z'-band observations
Date
2011-10-25T10:15:40Z (14 years ago)
From
Javier Gorosabel at IAA-CSIC <jgu@iaa.es>
J. Gorosabel (IAA-CSIC), A. Cabrera Lavers (GTC), R. Sanchez-Ramirez
(IAA-CSIC), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), A.J. Levan (U.
Warwick), C.C. Thoene (IAA-CSIC), N.R. Tanvir (U. Leicester), A.J.
Castro-Tirado (IAA-CSIC), P. Kubanek (IAA-CSIC, U. Valencia), report
on behalf of a larger collaboration:
We acquired z'-band images of the GRB 111022B field (Holland et al.,
GCNC 12472; Beardmore et al., GCNC 12478) with the 10.4m GTC(+OSIRIS)
telescope. The observations were carried out on Oct 24.1105--24.1453
UT (33.4--34.3 hours post GRB) with a total exposure time of
31x60s=1860s and a seeing of 1.0-1.5". A faint object is detected
coincident with the near-IR and optical candidate (Levan et al. GCNC
12481; Moskvitin et al. GCNC 12491). This source has a very
preliminary AB magnitude of z'~25.5. In the XRT error circle
(Beardmore et al., GCNC 12478) we note the presence of an additional
object with a similar magnitude located 1.5" eastwards from the
afterglow candidate.
GCN Circular 12495
Subject
GRB 111022B: EVLA observations
Date
2011-10-26T03:49:15Z (14 years ago)
From
Ashley Zauderer at CfA <bevinashley@gmail.com>
A. Zauderer and E. Berger (Harvard) report:
"We observed the position of GRB 111022B (GCN 12472) with the EVLA at
5.8 and 22 GHz beginning on 2011 Oct 23.64 UT (0.92 days after the
burst). No radio source is detected at 5.8 GHz to a 3-sigma upper limit
of 30 uJy. At 22 GHz, a potential radio counterpart was detected with a
flux of 45+/-14 uJy, consistent with the most up-to-date 1.5'' Swift-XRT
position (GCN 12478, http://www.swift.ac.uk/xrt_positions). The
potential radio source centroid is (J2000):
RA = 07:15:51.53 +/- 0.05
Dec = 09:41:01.18 +/- 0.37
Follow-up observations at 22 GHz are planned."
GCN Circular 12496
Subject
GRB 111022B: EVLA observations - correction to GCN 12495
Date
2011-10-26T04:35:32Z (14 years ago)
From
Ashley Zauderer at CfA <bevinashley@gmail.com>
A. Zauderer and E. Berger (Harvard) report:
The declination given in GCN 12495 was incorrect.
"We observed the position of GRB 111022B (GCN 12472) with the EVLA at
5.8 and 22 GHz beginning on 2011 Oct 23.64 UT (0.92 days after the
burst). No radio source is detected at 5.8 GHz to a 3-sigma upper limit
of 30 uJy. At 22 GHz, a potential radio counterpart was detected with a
flux of 45+/-14 uJy, consistent with the most up-to-date 1.5'' Swift-XRT
position (GCN 12478, http://www.swift.ac.uk/xrt_positions). The
potential radio source centroid is (J2000):
RA = 07:15:51.53 +/- 0.05
Dec = +49:41:01.18 +/- 0.37
Follow-up observations at 22 GHz are planned."
GCN Circular 12521
Subject
GRB 111022B: MASTER OT observations
Date
2011-11-03T11:46:35Z (14 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
A.V. Parhomenko, A. Tlatov, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory
K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Gres,
O.Chuvalaev,E.Konstantinov,
Irkutsk State University
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina,
N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M.
Kornilov,A.Sankovich
Sternberg Astronomical Institute, Moscow State University
V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov
Ural State University, Kourovka
V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina
Blagoveschensk Educational State University, Blagoveschensk
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in
Tunka(Siberia) was pointed to the GRB110801A 101 sec after GRB time at
2011-08-01 19:51:23 UT. Unfortunatelly the objects was not in focus because
recently photometer modification. On our first (20s
exposure) set we haven`t found optical transient within SWIFT error-box
(De Pasquale et al., GCN 12228).
The 3-sigma upper limit has been about 14.0 mag (white+polarizator).
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located
near Kislovodsk (Caucasus Mountains) closed roof 20 min before trigger due to
cloudy condidtions. The telescope was repointed to the
GRB110901A only 47 min 40 sec after trigger time at 2011-08-01 20:37:22 UT.
We found OT at UVOT postion (De Pasquale et al., GCN 12228).
The results of our photometry are:
Time_Start T_mean-T_trig exp time m error Band UT
s s 20:37:22 2950 180 16.13 0.06
R
20:44:29 3377 180 16.12 0.06 R 20:48:01
3589 180 16.29 0.08 R
20:48:01 3589 180 16.03 0.06 White 20:51:24
3792 180 16.43 0.06 R
20:51:24 3792 180 16.19 0.06 White
23:20:14 12722 180 17.75 0.10 R
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).
The power low index (F~t^-aplha) apha ~1.0+-0.1 during this observations in
R-band.
The message may be cited.
GCN Circular 12619
Subject
GRB 111022B: CrAO optical limit
Date
2011-12-04T22:27:27Z (14 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:
We observed the field of GRB 111022B (Holland et al. GCN 12472) with Shajn
telescope of CrAO observatory starting on Oct. 22 (UT) 20:44:36 under a
mean seeing (FWHM) of 3.2 arsces. We took several frames with exposure of
60 s in R-band. Within enhanced Swift-XRT position (Beardmore et al. GCN
12478) we do not detected any optical source. A photometry is based on the
USNO B1.0 star 1396-0186811 (07 15 51.05 +49 40 13.0) assuming R=17.07
.
T_start UT T0+ Filter, Exposure, OT, uplim (3 sigma)
(mid, d) (s)
20:44:36 0.1711 R 64x60 n/d 22.8