GRB 140423A
GCN Circular 16318
Subject
GRB 140423A: TShAO optical observations
Date
2014-05-22T16:23:31Z (11 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), A.V. Kusakin (Fesenkov Astrophysical Institute) A.V.
Khruslov (INASAN), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:
We observed the optical afterglow (Elenin et al., GCN 16143; Kaur et
al., GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147;
Maehara et al., GCN 16151) of the Swift GRB 140423A (Sonbas et al.,
GCN 16142) with Zeiss-1000 (East) 1m telescope of Tien Shan Astronomical
Observatory on Apr., 23 and Apr., 24. We took several images in R-filter
of 300 and 540 s exposures in three epochs.
Details of the photometry are following:
date UT start t-T0 Filter Exp. OT
(mid, days) (s)
2014-04-23 R 15:04:19 0.291036 R 8*300 20.47 0.14
2014-04-23 R 19:04:44 0.450758 R 6*300 20.70 0.20
2014-04-24 R 15:20:01 1.322830 R 12*540 22.17 0.10
The photometry is based on SDSS stars, R (gri -> R transformations by
Lupton 2005):
SDSS id R
J130914.51+494636.5 18.661+/-0.019
J130911.04+494854.6 20.209+/-0.053
J130924.79+494946.6 19.533+/-0.038
The light curve of the afterglow based on our previous an later
observations (GCNs 16143, 16148, 16168, 16247, 16264) can be found in
http://grb.rssi.ru/GRB140423A/grb140423a-lc.png
GCN Circular 16272
Subject
GRB 140423A: HCT optical observations
Date
2014-05-15T16:31:36Z (12 years ago)
From
D.K. Sahu at Indian Inst of Astrophysics,Bangalore <dks@iiap.res.in>
D.K. Sahu (Indian Institute of Astrophysics, Bangalore, India) reports:
The optical afterglow of Swift detected GRB 140423A (E.Sonbas et al.,
GCN 16142) was observed in Bessell R band, with the 2m. Himalayan
Chandra Telescope of the Indian Astronomical Observatory, Hanle, India.
Observations were made between 15:12 UT and 20:48 UT on 23/04/2014.
The optical afterglow (Elenin et al., GCN 16143; Kaur et al.,
GCN 16144; Ferrante et al., GCN 16145) was detected in our
individual frames. The preliminary R magnitudes of the optical
afterglow calibrated using nearby USNO B1 stars is as under.
Date Mid UT Exp R Magnitude
(sec)
23-04-2014 15:03 180+300 20.35 +/- 0.05
23-04-2014 17:44 2x300 20.68 +/- 0.06
23-04-2014 20.40 2x300 21.08 +/- 0.06
GCN Circular 16264
Subject
GRB 140423A: AAO optical upper limits
Date
2014-05-14T14:27:00Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), R. Inasaridze (AAO), O. Kvaratskhelia (AAO), V.
Ayvazian (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed the optical afterglow (Elenin et al., GCN 16143; Kaur et
al., GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147;
Maehara et al., GCN 16151) of the Swift GRB 140423A (Sonbas et al., GCN
16142) with AS-32 (0.7m) telescope of Abastumani Observatory on Apr. 24
at (UT) 00:29-01:16 and Apr. 24 (UT) 17:46-19:16. We obtained several
unfiltered frames with exposures of 120 s. Within the enhanced XRT
circle (Beardmore et al., GCN 16155) in the stacked images from both
epochs we do not detect the afterglow.
The details of the photometry are the following:
UT start t-T0 Filter Exp. Uplim
(mid, days) (s) (3 sigma)
00:29:23 0.68139 None 16*120 20.3
The photometry is based on SDSS stars, R mag (R mag obtained using ugriz
transformations in BVRI (Lupton, 2005):
SDSS id R_Lupton
J130858.37+494547.9 15.418 �� 0.018
J130914.51+494636.5 18.661 �� 0.019
GCN Circular 16247
Subject
GRB 140423A: Mondy optical observations
Date
2014-05-12T17:32:49Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up
collaboration:
We observed the optical afterglow (Elenin et al., GCN 16143; Kaur et
al., GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147;
Maehara et al., GCN 16151) of the Swift GRB 140423A (Sonbas et al.,
GCN 16142) with AZT-33IK telescope of Sayan observatory (Mondy). We took
several images in R-filter of 60 s exposure on Apr., 25 and
of 120 s exposure on Apr., 26 and 27.
The details of the photometry are the following:
date UT start t-T0 Filter Exp. OT
(mid, days) (s)
2014-04-25 16:36:21 2.36772 R 90*60 22.63+/-0.10
2014-04-26 15:56:26 3.34068 R 46*120 23.46+/-0.18
2014-04-27 14:15:32 4.27964 R 54*120 > 22.9
The photometry is based on two SDSS stars, R (gri -> R transformations
by Lupton 2005):
SDSS id R
J130911.04+494854.6 20.209+/-0.053
J130924.79+494946.6 19.533+/-0.038
GCN Circular 16213
Subject
Konus-Wind observation of GRB 140423A
Date
2014-05-05T07:43:26Z (12 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team report:
The long GRB 140423A (Swift-BAT trigger #596901: Sonbas, et al., GCN
Circ. 16142, Cummings, et al., GCN Circ. 16161) was detected by
Konus-Wind in the waiting mode.
The burst light curve shows a single episode started at ~T0(BAT)-46 s
with a duration of ~130 s.
As observed by Konus-Wind, the burst had a fluence of
1.87(-0.17,+0.13)x10^-5 erg/cm2 (in the 20 - 1200 keV energy range).
Modeling the K-W 3-channel time-integrated spectrum (from T0(BAT)-46 s
to T0(BAT)+84 s) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.1 +/- 0.1, and Ep = 196(-20,+30) keV.
All the quoted errors are estimated at the 1 sigma confidence level.
All the presented results are preliminary.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB140423A/
GCN Circular 16185
Subject
GRB 140423A: RTT150 optical observations
Date
2014-04-29T19:47:26Z (12 years ago)
From
Rodion Burenin at IKI, Moscow <rodion@hea.iki.rssi.ru>
I. Bikmaev (KFU/AST), I. Khamitov (TUG),
S. Melnikov, N. Sakhibullin (KFU/AST),
R. Burenin, M. Pavlinsky, R. Sunyaev (IKI),
H. Kirbiyik (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.)
report:
The field of the optical afterglow of GRB 140423A (Sonbas et al., GCN
16142) was observed with Russian-Turkish 1.5-m telescope (RTT150,
Bakirlitepe, TUBITAK National Observatory, Turkey) using the TFOSC
instrument.
We obtained series of 300 sec exposures in B and Rc filters with mean
time in April 24, 00:34 UT (B) and April 24, 01:58 UT (Rc). The
afterglow is clearly detected in combined images.
Using the USNO-B1 (1398-0233739) star at RA = 13:09:13.1, DEC =
+49:53:11, with B1_mag = 16.70, R1_mag = 14.76 as a reference, we
estimated the B and R-magnitudes of the afterglow:
Filter T-T0, hours Mag. +/- Mag.err
B 16.03 23.21 +/- 0.09
Rc 17.43 21.29 +/- 0.06
GCN Circular 16176
Subject
GRB 140423A: MITSuME Akeno upper limits
Date
2014-04-28T12:03:53Z (12 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
Y. Ono, Y. Tachibana, Y. Saito, H. Ohuchi, T. Yoshii,
S. Kurita, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We performed the follow-up observation for optical afterglow of GRB140423A(E.Sonbas et al., GCN Circular #16142, Elenin et al.,GCN Circular #16143 etc.) 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 started on 2014-04-24 14:10:46 UT (31.1h after the burst).
We did not find the optical source on the position of GRB140423A.
The measured magnitudes were listed below.
T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
-------------------------------------------------------------------------
44700 14-04-24 15:42:02 9600 >21.3 >21.2 >20.6
-------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
GCN Circular 16175
Subject
GRB 140423A Third epoch pODI photometry
Date
2014-04-27T03:42:42Z (12 years ago)
From
Dieter Hartmann at Clemson.U <hdieter@clemson.edu>
D. Harbeck (WIYN Observatory), A. Kaur (Clemson U.), A. Delgado-Navarro
(Clemson U.), M. Orio (INAF, UW Madison), D. H. Hartmann (Clemson U.)
report:
We re-imaged the location of the Swift detected GRB 140423A (Sonbas et al.,
GCN 16142) with the pODI instrument on the 3.5 m WIYN telescope at KPNO (
http://www.wiyn.org/ODI/About/wiynpODI.html).
Observations in the sdss r' band on 25 April 2014 consisted of one 300s
exposure, and one 600s exposures. The optical counterpart of the burst
(Elenin et al., GCN 16143; Kaur et al., GCN 16144; Ferrante et al., GCN
16145; Chester et al., GCN 16147) was detected under good conditions.
OBS DATE [UTC at start] T_Exp r' AB stat-error seeing
2014-04-25 07:17:45.434 300.0 22.58 0.1 0.7"
2014-04-25 07:24:59.654 600.0 22.64 0.08 0.75"
Calibration was the same as described in our previous report. Calibration
rms without color correction is < 0.1", consistency check with nearby SDSS
star shows calibration variations < 0.02 mag. No color / foreground
extinction correction was applied.
GCN Circular 16174
Subject
GRB 140423A: Continued RATIR Optical and NIR Observations
Date
2014-04-25T22:10:59Z (12 years ago)
From
Nat Butler at Az State U <natbutler@asu.edu>
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William
H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB),
J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico
Ramirez-Ruiz (UCSC), Jos�� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes��s
Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:
We observed the field of GRB 140423A (Sonbas, et al., GCN 16142) with the
Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the
1.5m Harold Johnson Telescope at the Observatorio Astron��mico Nacional on
Sierra San Pedro M��rtir from 2014/04 25.15 to 2014/04 25.47 UTC (43.01 to
50.78 hours after the BAT trigger), obtaining a total of 4.07 hours
exposure in the r and i bands and 1.73 hours exposure in the Z, Y, J, and H
bands.
For a source within the Swift-UVOT error circle (Chester, et al., GCN
16147), in comparison with the SDSS DR9 and 2MASS, we obtain the following
detections and upper limit (3-sigma):
r 22.70 +/- 0.11
i 22.67 +/- 0.12
Z 22.49 +/- 0.35
Y 22.17 +/- 0.29
J > 21.66
H 21.87 +/- 0.35
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB. Compared to our observations last
night (Littlejohns et al., GCN 16170), the source has faded approximately
as t^(-1.3).
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 16173
Subject
GRB 140423A: MITSuME Akeno Optical observation
Date
2014-04-25T14:28:40Z (12 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
T. Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi,
S. Kurita, Y.Ono , Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 140423A (E. Sonbas et al., GCN Circular #16142) 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 started on 2014-04-23 12:38:42 UT (4.1h after the burst).
We detected the previously reported optical afterglow of GRB140423A (D.Kuroda et al., GCN Circular #16160) in the Rc and Ic band.
The measured magnitudes were listed below.
T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
-------------------------------------------------------------------------------------------------------------------
19710 14:00:28 7740 20.49+/-0.23 19.83+/-0.15 19.72+/-0.22
31955 17:24:28 7560 >21.3 20.35+/-0.19 19.89+/-0.23
-------------------------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
GCN Circular 16170
Subject
GRB 140423A: RATIR Optical and NIR Observations
Date
2014-04-24T17:13:50Z (12 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC),
Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos�� A. de
Diego (UNAM), Leonid Georgiev (UNAM), Jes��s Gonz��lez (UNAM),
Carlos Rom��n-Z����iga (UNAM), Neil Gehrels (GSFC), and Harvey
Moseley (GSFC) report:
We observed the field of GRB 140423A (Sonbas, et al., GCN 16142) with
the Reionization and Transients Infrared Camera (RATIR; www.ratir.org)
on the 1.5m Harold Johnson Telescope at the Observatorio Astron��mico
Nacional on Sierra San Pedro M��rtir from 2014/04 24.29 to 2014/04
24.49 UTC (22.48 to 27.13 hours after the BAT trigger), obtaining a
total of 2.56 hours exposure in the r and i bands and 1.07 hours
exposure in the Z, Y, J, and H bands.
We detect the previously reported optical counterpart candidate
(Elenin, et al., GCN 16143; Chester, et al., GCN 16147; Chester, et
al., GCN 16157). For a source within the UVOT error circle (Chester,
et al., GCN 16147), in comparison with the SDSS DR9 and 2MASS, we
obtain the following detections:
r 21.90 +/- 0.08
i 21.79 +/- 0.07
Z 21.65 +/- 0.19
Y 21.39 +/- 0.17
J 20.98 +/- 0.20
H 21.33 +/- 0.26
These magnitudes are in the AB system and are not corrected for
Galactic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron��mico Nacional in San
Pedro M��rtir.
GCN Circular 16169
Subject
GRB 140423A: NOT Afterglow Observations
Date
2014-04-24T16:49:40Z (12 years ago)
From
Zach Cano at U of Iceland <zewcano@gmail.com>
Z. Cano (U. Iceland), D. Malesani (DARK), S. Geier (NOT), J. J. Jensen
(DARK), F. Taddia, C. Fremling (Stockholm U.)
We observed the field of GRB 140423A (Sonbas et al., GCN 16142) with the
2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC starting at 23:32
UT on 23-Apr-2014. We obtained 2x150 s, 6x200 s and 7x200 s frames in
SDSS-r, SDSS-i and SDSS-z respectively.
The optical afterglow (
���e.g. ���
Elenin et al., GCN 16143) is clearly detected in our co
���-���
added images.
A summary of our photometry:
filter t-t0 (hr) mag
---------------------------------------------
r 15.06 21.46 +- 0.03
i 15.33 21.28 +- 0.03
z 15.78 21.36 +- 0.07
Our photometry has been calibrated using an SDSS star in the FOV
(13:09:09.56 +49:52:13.38, r=19.76 +- 0.02, i=19.23 +- 0.02, z=18.92 +-
0.04), it has not been corrected for foreground extinction, and the errors
include the uncertanity in the SDSS calibration star.
Comparing our observations with those in the GCNs, we derive a decay
constant of alpha~-1.0 relative to the photometry published by Cenko &
Perley (GCN 16153;
���from ���
+1.4 hr to +15 hr), and alpha~-1.2 relative to the z-band photometry
published by Maehara et al. (GCN 16151;
���from ���
+2hr to +15.8 hr) and the R-band photometry published by Pandey et al. (GCN
16164;
���from ���
+6 hr to +15 hr), where a colour term of r-Rc~0.19 has been assumed in the
latter. These decay rates are slower than those derived from the early
KAIT observations (Zheng et al., GCN 16156), who find alpha~-1.7 up to
about 6000 s.
GCN Circular 16167
Subject
GRB 140423A: Nishi-Harima NIR Observations
Date
2014-04-24T13:44:50Z (12 years ago)
From
Akira Arai at Nishi-Harima Astro. Obs/U of Hyogo <arai@nhao.jp>
J. Takahashi and A. Arai (Univ. of Hyogo)
report on behalf of the Nayuta team and the OISTER collaboration:
We observed the field of GRB 140423A (Sonbas et al., GCN 16142)
with Nishiharima Infrared Camera (NIC) attached to the Nayuta 2-m
telescope at the Nishi-Harima Astronomical Observatory.
The observations were conducted on 2014-04-23 at 10:05-10:29 UT and
13:03-13:53 UT.
We detected the near-infrared afterglow in H and Ks bands.
Photometric results of our observations are listed below.
We used 2MASS 13085994+4951082 as a reference star for photometry.
# MID-UT Tmid-T0 T-EXP H_mag Ks_mag*
-----------------------------------------------------------------------
10:17:20 1.76 300 17.0 +/- 0.2 16.6 +/- 0.2
10:25:50 1.90 300 17.2 +/- 0.2 16.6 +/- 0.2
13:11:00 4.65 480 17.7 +/- 0.2 17.1 +/- 0.3
13:27:16 4.93 480 17.7 +/- 0.2 --**
13:44:50 5.22 600 17.7 +/- 0.2 17.3 +/- 0.3
------------------------------------------------------------------------
Tmid-T0: Elapsed time after the burst (hours)
T-EXP: Total Exposure time (seconds)
* 2MASS Ks error for the reference star is not given, and thus it is
not included in our error estimates for the GRB afterglow,
** Photometry was not possible.
GCN Circular 16166
Subject
GRB 140423A: TNG NIR observations
Date
2014-04-24T13:35:25Z (12 years ago)
From
Stefano Covino at Brera Astronomical Observatory <stefano.covino@brera.inaf.it>
P. D'Avanzo, S. Covino, D. Malesani, A. Rossi, G. Tagliaferri, M. Pedani on behalf of the CIBO report:
We observed the field of GRB 140423A (Sonbas et al., GCN 16142) using the NICS
near-Infrared camera on the 3.6m TNG Telescope (La Palma, Canary Islands).
We obtained a series of imaging observations in the J, H and K' bands(16 minutes per filter)
at a mean epoch of 14.8 hours from the burst. The GRB afterglow is clearly detected in all bands.
The observed J-band magnitude is 19.7 +- 0.1 (calibrated against the 2MASS catalogue).
[GCN OPS REPORT(24apr14): Per author's request, MP was added to the author list.]
GCN Circular 16165
Subject
GRB 140423A pODI/WIYN afterglow photometry
Date
2014-04-24T11:00:08Z (12 years ago)
From
Dieter Hartmann at Clemson.U <hdieter@clemson.edu>
D. Harbeck (WIYN Observatory), A. Kaur (Clemson U.), A. Delgado-Navarro
(Clemson U.), M. Orio (INAF, UW Madison), D. H. Hartmann (Clemson U.)
report on behalf of a larger collaboration:
We imaged the location of the Swift detected GRB 140423A (Sonbas et al.,
GCN 16142) at two epochs with the pODI instrument on the 3.5 m WIYN
telescope at KPNO (http://www.wiyn.org/ODI/About/wiynpODI.html).
Observations in the sdss r' band on 23 April 2014 consist of a single 300s
exposure, and on 24 April 2014 we performed two 600s exposures. The optical
counterpart of the burst (Elenin et al., GCN 16143; Kaur et al., GCN 16144;
Ferrante et al., GCN 16145; Chester et al., GCN 16147) was detected under
fair seeing conditions (~ 1 arcsec) in all single exposures.
Date Exp. Start Time Magnitude
2014-04-23 UT 09:52:50.400 r' = 18.85
2014-04-24 UT 08:29:12.393 r' = 21.90
2014-04-24 UT 08:41:12.901 r' = 21.85
The photometric error is dominated by calibration and is 0.07 mag (in r')
rms for a secondary reference star ensemble (but not accounting for color
terms or galactic foreground extinction).
The photometric calibration is based on
(i) cross-correlating with the sdss dr9 star catalog in the r' band over
the entire field of view (24' X 24')
(ii) consistency check on exemplary star SDSS J130915.57+494948.5 at sdss
r' = 19.98. The photometric error based on this reference star is < 0.02
mag rms.
GCN Circular 16164
Subject
GRB 140423A, Optical Observations
Date
2014-04-24T10:12:16Z (12 years ago)
From
Shashi Bhushan Pandey at ROTSE <shaship@umich.edu>
S. B. Pandey, Brajesh Kumar and Aditi Agarwal (ARIES Nainital India,
on behalf of larger Indian GRB collaboration)
We observed the Swift GRB 140423A field (Sonbas et al., GCN 16142)
using 1.3m DFOT telescope at Devasthal operated by ARIES Nainital, India.
Observations were started at 14:36:07 UT on 2014-04-23 (~6 h after the
burst).
The optical counterpart of the burst (Elenin et al., GCN 16143; Kaur et
al.,
GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147) was
clearly
detected in individual frames of exposure time 300s each.
The preliminary photometry is as following:
(UT)Start filter exp(sec) mag
14:36:07 R_c 300 20.12 +/- 0.08
14:42:50 I_c 300 19.76 +/- 0.15
The photometry was performed in comparison to nearby USNO stars.
This message may be cited.
GCN Circular 16163
Subject
GRB 140423A: Kanata/HONIR Optical and NIR Observations
Date
2014-04-24T08:15:36Z (12 years ago)
From
Michitoshi Yoshida at HASC,Hiroshima U <yoshidam@hiroshima-u.ac.jp>
Hiroshi Akitaya, Yuki Moritani, Takahiro Ui, Yuka Kanda, and Michitoshi
Yoshida (Hiroshima Univ.) on behalf of the OISTER collaboration:
We observed the field of GRB140423A (Sonbas et al., GCNC 16142) with
the optical and near-infrared simultaneous imager HONIR (Sakimoto et
al. 2012, Proc.SPIE 8446, 844673) attached to the 1.5-m Kanata
Telescope at Higashi-hiroshima Observatory, Japan.
We detected the afterglow at R_C and J bands at 2014-04-23 10:46 UT
(~2.2 hours after the burst). Photometric results are as follows.
MID-UT Total exp[sec] Band Mag Mag_err
----------------------------------------------------------
2014-04-23 10:46 720 Rc 19.4 0.3
2014-04-23 10:46 792 J 17.3 0.2
----------------------------------------------------------
GCN Circular 16162
Subject
GRB 140423A: Swift-XRT refined Analysis
Date
2014-04-24T05:24:46Z (12 years ago)
From
Kim Page at U.of Leicester <klp5@leicester.ac.uk>
A. Amaral-Rogers (U. Leicester), K.L. Page (U. Leicester) and E. Sonbas
(NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift-XRT team:
We have analysed 11 ks of XRT data for GRB 140423A (Sonbas et al. GCN
Circ. 16142), from 3.0 ks to 40.0 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Beardmore et al. (GCN Circ. 16155).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.00 (+/-0.05).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.08 (+/-0.09). The
best-fitting absorption column is 5.0 (+2.0, -1.8) x 10^20 cm^-2, in
excess of the Galactic value of 1.1 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 3.1 x 10^-11 (3.6 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 5.0 (+2.0, -1.8) x 10^20 cm^-2
Galactic foreground: 1.1 x 10^20 cm^-2
Excess significance: 3.5 sigma
Photon index: 2.08 (+/-0.09)
If the light curve continues to decay with a power-law decay index of
1.00, the count rate at T+24 hours will be 0.027 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.5 x
10^-13 (9.8 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/00596901.
This circular is an official product of the Swift-XRT team.
GCN Circular 16161
Subject
GRB 140423A: Swift-BAT refined analysis
Date
2014-04-24T04:43:09Z (12 years ago)
From
Tilan Ukwatta at MSU <tilan.ukwatta@gmail.com>
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), E. Sonbas (NASA/GSFC/Adiyaman Univ.),
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 140423A (trigger #596901) (Sonbas, et al., GCN Circ. 16142).
The BAT ground-calculated position is
RA, Dec = 197.276, 49.838 deg which is
RA(J2000) = 13h 09m 06.2s
Dec(J2000) = +49d 50' 18.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat,
90% containment). The partial coding was 39%.
The mask-weighted light curve shows a multi-peak episode
starting ~T-50 sec, highest peak at ~T+45 sec, and the episode
ends around ~T+140 sec. T90 (15-350 keV) is 134 +- 23 sec
(estimated error including systematics).
The time-averaged spectrum from T-130.13 to T+108.91 sec
is best fit by a simple power-law model. The power law index
of the time-averaged spectrum is 1.33 +- 0.06. The fluence
in the 15-150 keV band is 9.4 +- 0.3 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+44.19 sec in
the 15-150 keV band is 2.1 +- 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/596901/BA/
GCN Circular 16160
Subject
GRB 140423A: MITSuME Okayama Optical Observation
Date
2014-04-24T04:30:15Z (12 years ago)
From
Daisuke Kuroda at OAO/NAOJ <dikuroda@oao.nao.ac.jp>
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:
We observed the field of GRB 140423A (Sonbas et al., GCNC 16142)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2014-04-23 10:43:36 UT (~2.2 h after the burst).
We detected the previously reported afterglow (Elenin et al., GCNC 16143;
Kaur et al., GCNC 16144; Ferrante et al., GCNC 16145) in all the three bands.
Photometric results of the OT are listed below.
We used SDSS catalog for flux calibration.
#T0+[day] MID-UT T-EXP[sec] g' g'_err Rc Rc_err Ic Ic_err
-----------------------------------------------------------------------
0.21728 13:44:45 5880.0 20.1 0.3 20.1 0.2 19.5 0.3
------------------------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
GCN Circular 16157
Subject
GRB 140423A: Further Observations with Swift/UVOT
Date
2014-04-23T21:12:24Z (12 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
M. M. Chester (PSU), E. Sonbas (NASA/GSFC/Adiyaman Univ.), and
F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team:
Further analysis confirms UVOT's detection of the afterglow of GRB 140423A
(Sonbas et al., GCN Circ. 16142) reported by Elenin et al. (GCN Circ. 16143).
The UVOT position based on the initial exposure is:
RA (J2000) = 13:09:08.54 = 197.28558 (deg.)
Dec (J2000) = +49:50:29.4 = 49.84150 (deg.)
with an estimated uncertainty of 0.48 arc sec. (radius, 90% confidence).
This position is consistent with the enhanced XRT position reported by
Beardmore et al. (GCN Circ. 16155).
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 2947 3097 147 19.80 +/- 0.09
v 3104 3303 197 19.33 +/- 0.19
b 3924 4123 197 19.96 +/- 0.16
u 3719 5353 393 >21.3
w1 3513 5148 393 >21.7
m2 4743 4943 197 >20.7
w2 4334 11161 808 >22.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 16156
Subject
GRB 140423A: KAIT Optical Detection
Date
2014-04-23T18:58:38Z (12 years ago)
From
Weikang Zheng at UC Berkeley <zwk@astro.berkeley.edu>
WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and
S. B. Cenko (NASA/Goddard Space Flight Center) 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 140423A (Sonbas et al.,
GCN 16142) starting at 08:33:55 UT, 122 s after the burst.
Observations were performed with an automatic sequence in the
V, I, and clear (roughly R) filters, and the exposure time was
20 s per image. The bright optical afterglow (Elenin et al., GCN
16143; Kaur et al., GCN 16144; Ferrante et al., GCN 16145; Chester
et al., GCN 16147; Maehara et al., GCN 16151; Cenko et al., GCN
16153) was well detected in all three filters. Preliminary analysis
shows that the afterglow had a rather broad peak at t = 150-250 s with
R ~ 14.3 mag. It decayed faster after ~1000 s, with a single power
law having alpha about -1.7. A preliminary light curve is posted at
http://astro.berkeley.edu/~zwk/grb/GRB140423A/GRB140423A_kait.png
GCN Circular 16155
Subject
GRB 140423A: Enhanced Swift-XRT position
Date
2014-04-23T18:17:20Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.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 5971 s of XRT Photon Counting mode data and 15 UVOT
images for GRB 140423A, 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 = 197.28544, +49.84152 which is equivalent
to:
RA (J2000): 13h 09m 8.51s
Dec (J2000): +49d 50' 29.5"
with an uncertainty of 1.4 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 16154
Subject
GRB 140423A: Nanshan optical upper limit
Date
2014-04-23T17:26:52Z (12 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), X. Zhang, C.-H. Bai, A. Esamdin, L. Ma (XAO) report:
We observed the optical afterglow field of GRB 140423A (Sonbas et al.,
GCN 16142; Elenin et al., GCN 16143; Kaur et al., GCN 16144;) using
the 1m telescope located at Nanshan, Xinjiang, China. Three R-band
frames were obtained under rather bad weather. The afterglow has
decayed down to a limiting magnitude of m(R)>19.4 mag at a mean time
of 8.216 hr post-burst, calibrated with nearby SDSS stars.
GCN Circular 16153
Subject
GRB 140423A: P60 Observations
Date
2014-04-23T17:09:05Z (12 years ago)
From
S. Bradley Cenko at NASA/GSFC <brad.cenko@nasa.gov>
S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a larger collaboration:
We observed the optical afterglow (Elenin et al., GCN 16143; Kaur et al., GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147; Maehara et al., GCN 16151) of the Swift GRB 140423A (Sonbas et al., GCN 16142) with the robotic Palomar 60 inch telescope. Observations were obtained in the r', i', and z' filters beginning at 9:55 UT on 2014 April 23 (84 minutes after the Swift trigger).
The optical afterglow is clearly detected in all three filters. Using nearby point sources from SDSS for calibration, we measure the following magnitudes in our initial images:
r' = 18.87 +/- 0.05 at dt = 84.0 min
i' = 18.71 +/- 0.05 at dt = 87.0 min
z' = 18.67 +/- 0.11 at dt = 88.4 min
Further observations are planned.
GCN Circular 16152
Subject
GRB 140423A: Fermi GBM observation
Date
2014-04-23T15:29:40Z (12 years ago)
From
Andreas von Kienlin at MPE <azk@mpe.mpg.de>
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team:
"At 08:32:38.54 UT on 23 April 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140423A (trigger 419934761 / 140423356)
which was also detected by the Swift/BAT (Sonbas et al. 2014, GCN 16142)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 44 degrees.
The GBM light curve shows a multiple-peak structure
with a duration (T90) of about 95 s (50-300 keV).
The time-averaged spectrum from T0-61.440 s to T0+32.768 s is
best fit by a Band function with Epeak = 125 +/- 9 keV,
alpha = -0.25 +/- 0.11, and beta = -1.97 +/- 0.06.
The event fluence (10-1000 keV) in this time interval is
(2.0 +/-0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+5.44 s in the 10-1000 keV band
is 3.0 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 16151
Subject
GRB 140423A: KWFC z-band photometry
Date
2014-04-23T13:55:20Z (12 years ago)
From
Nozomu Tominaga at Konan U <tominaga@konan-u.ac.jp>
Hiroyuki Maehara (Univ. of Tokyo), Nozomu Tominaga (Konan Univ.), Tomoki Morokuma (Univ. of Tokyo) and Masaomi Tanaka (NAOJ) on
behalf of OISTER collaboration:
We observed the field of GRB 140423A (Sonbas et al., GCN 16142) with the 1.05-m Schmidt telescope and KWFC (Sako et al. 2012, Proc.
SPIE 8446, 84466L) at Kiso Observatory in Japan.
The observation was made in the Sloan z-band at 2014-04-23 10:30 (UT), approximately 2 hours post burst.
We have also detected the optical source (Elenin et al., GCN 16143, 16148; Kaur et al. GCN 16144; Ferrante et al., GCN 16145;
Chester et al., GCN 16147) at RA=13:09:08.54, DEC=+49:50:29.3 (J2000).$B!!(BPreliminary photometry of the source is as follows.
obs. date (mid time) Tmid-T0 (hr) exp. time filter mag limiting mag
2014-04-23 10:30:11 1.97 300 sec z 18.6+/-0.1 19.5
The photometry is based on z-mag of SDSS stars in the observed field.
GCN Circular 16150
Subject
GRB 140423A: Gemini-N redshift
Date
2014-04-23T12:14:10Z (12 years ago)
From
Nial Tanvir at U.Leicester <nrt3@star.le.ac.uk>
N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), K. Wiersema (U. Leicester),
A. Petric, K. Chiboucas, J. Miller (Gemini) report:
We observed the afterglow of GRB 140423A (Sonbas et al. GCN 16142;
Elenin et al. GCN 16143; Kaur et al. GCN 16144; Ferrante et al. GCN 16145;
Chester et al. GCN 16147) with the GMOS-N spectrograph on Gemini-N.
Observations began at 10:25 UT, approximately 1.9 hr post burst.
The spectra show absorption lines due to Ly-alpha, SiII (1251/1254),
SiII* (1265), OI (1302), SiII (1304), CII (1334), SiIV (1394/1403),
SiII (1527), CIV (1548/1551) at a common redshift of z=3.26, which
we infer is the redshift of the GRB.
GCN Circular 16148
Subject
GRB 140423A: ISON-MN early photometry and correction to the GCN circ. 16143
Date
2014-04-23T11:01:48Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
L. Elenin (KIAM), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI)
report on behalf of larger GRB follow-up collaboration:
After detection of the optical afterglow of GRB 140423A (Elenin et al., GCN
16143; Kaur et al., GCN 16144; Ferrante et al., GCN 16145) and X-ray
afterglow (Burrows et al., GCN 16146) we report initial photometry of our
first images taken with ISON-NM observatory:
UT start t-T0 Exp. Filter OT
(mid.,days) (s)
09:01:18 0.02043 30 Clear 17.11 +/- 0.17
09:06:49 0.02426 30 Clear 17.60 +/- 0.21
The photometry is based on star SDSS J130858.37+494547.9 (assuming R =
15.418 +/- 0.018).
The finding chart of GRB 140423A afterglow can be found in
http://grb.rssi.ru/GRB140423A/GRB140423A_ISON-NM_fc.png
Also we report the corect time of observation of the first image in GCN
16143. It should be April, 23, (UT) 09:01:03.
We apologize for the misprint.
GCN Circular 16147
Subject
GRB 140423A: Swift/UVOT detection of a possible counterpart
Date
2014-04-23T10:49:48Z (12 years ago)
From
Margaret Chester at PSU <chester@swift.psu.edu>
M. M. Chester (PSU), E. Sonbas (NASA/GSFC/Adiyaman Univ.), K. L. Page
(U Leicester), D. Malesani (DARK/NBI), and S. R. Oates (UCL-MSSL)
report on behalf of the Swift/UVOT team:
Swift/UVOT took a finding chart exposure of 150 seconds with the White filter
starting 2946 seconds after the BAT trigger. A faint source (19.6 +/- 0.4 mag)
is detected in the White filter which is consistent with the candidate reported
by Elenin et al. (GCN Circ. 16143) but not consistent with the Swift/XRT position
reported by D. N. Burrows et al. (GCN Circ. 16146). The separation from the XRT
position is 9.6 arcsec. The preliminary UVOT position is
RA (J2000) 197.28546 (13:09:08.51)
Dec (J2000) 49.84133 (+49:50:28.8)
with an estimated uncertainty of 1.1 arcsec (radius, 90% confidence,
statistical + systematic). No correction has been made for the
expected extinction corresponding to E(B-V) of 0.01.
GCN Circular 16146
Subject
GRB 140423A: Swift-XRT observations
Date
2014-04-23T10:13:31Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
D.N. Burrows (PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB), G.
Cusumano (INAF-IASF PA), P.A. Evans (U. Leicester) and J.P. Osborne (U.
Leicester) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 140423A at 09:20:56.7 UT,
2943.5 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source located at RA, Dec 197.28927,
49.84233 which is equivalent to:
RA(J2000) = 13h 09m 09.42s
Dec(J2000) = +49d 50' 32.4"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 98 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 in excess of the Galactic value (1.09 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.4
(+2.57/-1.42) x 10^21 cm^-2 (90% confidence).
GCN Circular 16145
Subject
GRB 140423A: ROTSE-III Detection of Optical Counterpart
Date
2014-04-23T10:01:48Z (12 years ago)
From
Farley V. Ferrante at Southern Methodist U/ROTSE <fferrante@smu.edu>
F. V. Ferrante (SMU), T. Guver (Istanbul Univ.), H. Flewelling (IfA/Hawaii), R. Kehoe (SMU),
and G. Dhungana (SMU) report on behalf of the ROTSE GRB team:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 140423A
(Swift trigger 596901, GCN 16142; Elenin et al., GCN 16143; A. Kaur et al., GCN 16144).
The first image was at 08:32:45.1 UT, 51.5 s after the burst (0.1 s after the GCN notice time).
The unfiltered images are calibrated relative to USNO A2.0. We detect a 14.2 magnitude,
fading source with coordinates:
13:09:08.08 +49:50:26.5 (J2000), with positional uncertainty of 1" or better
start UT mag mlim(of image)
----------------------------------
08:33:39.6 14.2 16.0
This source is not visible in DSS (second epoch), 2MASS or the MPChecker database.
The object decayed from ~14.2 magnitude to ~15.0 magnitude in ~100 seconds.
A jpeg image is available at http://www.rotse.net/images/gsq596901_3b01_img.jpg
Continuing observations are in progress.
GCN Circular 16144
Subject
GRB 140423A optical observations with pODI/WIYN at KPNO
Date
2014-04-23T09:49:53Z (12 years ago)
From
Dieter Hartmann at Clemson.U <hdieter@clemson.edu>
A. Kaur (Clemson U.), A. Delgado-Navarro (Clemson U.), D. Harbeck (WIYN
Observatory), M. Riabokin (NOAO), M. Orio (INAF, UW Madison), D. H.
Hartmann (Clemson U.) report on behalf of a larger collaboration:
We imaged the location of the Swift detected GRB 140423A (Sonbas et al.,
GCN 16142) with the pODI instrument on the 3.5 m WIYN telescope at KPNO (
http://www.wiyn.org/ODI/About/wiynpODI.html).
Observations in the ODI r' band began at 09:40:38 UT on 23 April 2014. We
clearly detect the optical afterglow candidate indicated by Elenin et al.
(GCN 16143) in individual exposures beginning at this time.
GCN Circular 16143
Subject
GRB 140423A: optical afterglow candidate
Date
2014-04-23T09:32:14Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
L. Elenin (KIAM), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI)
report on behalf of larger GRB follow-up collaboration:
We observed of the field of the Swift GRB 140423A (Sonbas et al., GCN
16142) with 0.4-m telescope of ISON-NM observatory starting
on Mar., 20 (UT) 09:01:03. The start of observation was delayed due to bad
weather. We took unfiltered images of 30 s exposures. We detect a fading
optical source in coordinates
(J2000) 13 09 08.50 +49 50 29.4
(with initial accuracy of about 1 arcsec). Preliminary photometry of the
source in the first images is ~ 17.2m. the photometry is based on nearby
USNO-B1.0 stars (R2 mag). Since the source is absent in USNO-B1.0 catalog
and clearly fading we suggest it as GRB 140423A afterglow candidate.
[GCN OPS NOTE(23apr14): Please see 16148 for the correction on the start date.
Also added the "A" on the GRB name in the first and last sentences.]
GCN Circular 16142
Subject
GRB 140423A: Swift detection of a burst
Date
2014-04-23T08:44:16Z (12 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
E. Sonbas (NASA/GSFC/Adiyaman Univ.), M. M. Chester (PSU),
K. L. Page (U Leicester) and T. N. Ukwatta (MSU) report on behalf of
the Swift Team:
At 08:31:53 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140423A (trigger=596901). Swift did not slew immediately
due to an observing constraint. The BAT on-board calculated location is
RA, Dec 197.290, +49.815 which is
RA(J2000) = 13h 09m 10s
Dec(J2000) = +49d 48' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a multi-peak
structure with a duration of about 80 sec. The peak count rate
was ~2000 counts/sec (15-350 keV), at ~20 sec after the trigger.
Due to an observing constraint, Swift will not slew until T0+47.2
minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com).
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 OPS NOTE(23apr14): The second sentence was corrected to indicate
a delayed (not immediate) slew.]