GRB 140801A
GCN Circular 16667
Subject
GRB 140801A: AAO optical observations
Date
2014-08-04T01:38:25Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Volnova (IKI), R. Inasaridze (AAO), Molotov (KIAM), A. Pozanenko (IKI)
report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 140801A (Pelassa, GCN 16658) with AS-32 (0.7m)
telescope of Abastumani Observatory starting on Aug. 02 (UT) 21:54:52. We
obtained several unfiltered frames under of 60 s under average FWHM of 2.0
arcsec. The optical afterglow (Gorbovskoy et al., GCN 16653; Xu et al., GCN
16656, Masi, GCN 16659) is well detected on the stacked image.
Details of a photometry of the GRB 140801A are following:
date UT start t-T0 Filter Exp. OT err
(mid, days) (s)
2014-08-02 21:54:52 1.14962 None 26*60 22.13 0.18
The photometry is based on the USNO-B1 star ((J2000) 02:56:16.58 +30:57:02.1
assuming R = 16.06) suggested by Moskvitin et al., (GCN 16663). Our
photometry does not contradict un-broken decay of a light curve of GRB
140801A (Kann et al., GCN 16666).
GCN Circular 16666
Subject
GRB 140801A: GROND Afterglow detection, unbroken decay
Date
2014-08-03T22:14:51Z (12 years ago)
From
Alexander Kann at TLS Tautenburg <kann@tls-tautenburg.de>
D. A. Kann (TLS Tautenburg), C. Delvaux, and J. Greiner (both MPE
Garching) report on behalf of the GROND team:
We observed the field of GRB 140801A (Fermi trigger 428612396; Pelassa,
GCN #16658) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla
Observatory (Chile).
Observations started at 09:43 UT on 2014-08-02, 0.61 days after the GRB
trigger. They were performed at an average seeing of 1".5 and at an
average airmass of 2.1.
Based on images with exposure times of 1584 s in g'r'i'z', we detect the
optical afterglow at the MASTER position reported by Gorbovskoy et al.
(GCN #16653) at the following AB magnitudes:
g' = 22.4 +/- 0.1 mag,
r' = 21.9 +/- 0.1 mag,
i' = 21.8 +/- 0.1 mag, and
z' = 21.2 +/- 0.2 mag.
Observations taken a day later show the afterglow to have decayed by about
0.75 magnitudes. The afterglow continues to decay with a slope of ~0.9 in
comparison to the magnitudes given by Xu et al. (GCN #16656) and Moskvitin
et al. (GCN #16663).
The given magnitudes are derived based on calibrating the images against
the GROND zeropoints and are not corrected for the Galactic foreground
extinction corresponding to a reddening of E_(B-V) = 0.23 in the direction
of the burst (Schlegel et al. 1998).
GCN Circular 16665
Subject
GRB140801A: Swift/XRT further observations
Date
2014-08-03T14:05:25Z (12 years ago)
From
Alessandro Maselli at INAF/IASF Palermo <maselli@ifc.inaf.it>
A. Maselli, M. De Pasquale (INAF-IASFPA) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift-XRT team:
We report on further Swift XRT observations in the field of the
FERMI/GBM-discovered GRB 140801A (Pelassa, GCN Circ. 16658). A new
exposure of 2.0 ks has been obtained, 123 ks after the Fermi/GBM
trigger. The X-ray counterpart reported by Maselli & De Pasquale (GCN
Circ. 16661) is still detected at a count rate of 9.9 (+/-2.5) x 10^-3
cts s^-1. This latest measurement corresponds to a decay slope of 0.8
(+0.5, -0.4): thus we confirm that this source is the afterglow of GRB
140801A.
This circular is an official product of the Swift-XRT team.
GCN Circular 16663
Subject
GRB 140801A: BTA confirmation of redshift
Date
2014-08-02T19:11:44Z (12 years ago)
From
Vladimir Sokolov at SAO RAS <sokolov@sao.ru>
A. Moskvitin, V. Komarova, T. Sokolova (SAO RAS),
A. J. Castro-Tirado (IAA-SCIC), J. Gorosabel (IAA-SCIC, UPV/EHU),
S. B. Pandey (ARIES), M. Glushkov (KFU), S. Boronina (SPbSU),
report on behalf of the larger collaboration:
At the night of August 1/2 we observed the GRB 140801A field (Fermi trigger
428612396) with BTA/Scorpio-I. Observations started at 21:10 UT (2.17 hours
after the GRB). The optical transient (Gorbovskoy et al., GCNC 16653; Xu et
al., GCNC 16656, Masi, GCNC 16659) is clearly detected in our V and Rc images
with the brightness R = 20.2 (2.85 hours after the trigger). Photometry
is based on the USNO-B1 star with the coordinates
R. A. = 02:56:16.58, Dec. = +30:57:02.1 and R2 = 16.06.
The OT magnitude was not corrected for the Galactic extinction
E(B-V) = 0.09 in the direction of the object.
We also obtained an OT spectrum and measured the redshift on basis of several
lines. Our value z =1.319 +/- 0.003 is in a good agreement with that by
de Ugarte Postigo et al. (GCNC 16657).
We thank T. Fatkhullin for his great assistance in observations.
GCN Circular 16662
Subject
GRB 140801A: Swift/UVOT Upper Limits
Date
2014-08-02T18:10:39Z (12 years ago)
From
Lea Hagen at PSU <lea.zernow.hagen@gmail.com>
L. M. Z. Hagen (PSU) and E. Troja (NASA/GSFC/UMCP) report on behalf
of the Swift/UVOT team:
The Swift/UVOT observed the field of the Fermi/GBM-detected burst GRB 140801A
beginning 36.4 ks after the trigger (Pelassa, GCN Circ. 16658). No optical
afterglow consistent with the XRT candidate (Maselli, GCN Circ. 16661) or
MASTER candidate (Gorbovskoy et al., GCN Circ. 16653) is detected in the
initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
uvw1 36391 47996 1944 >20.70
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.226 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 16661
Subject
GRB 140801A: Swift-XRT observations
Date
2014-08-02T14:20:53Z (12 years ago)
From
Alessandro Maselli at INAF/IASF Palermo <maselli@ifc.inaf.it>
A. Maselli and M. De Pasquale (INAF-IASFPA) report on behalf of the
Swift-XRT team:
We have analysed 2.0 ks of XRT data for the FERMI/GBM detected burst GRB
140801A (Pelassa, GCN Circ. 16658), from 36.4 ks to 48.0 ks after the
GBM trigger. The data are entirely in Photon Counting (PC) mode. An
X-ray source is found at the position of the optical transient detected
by MASTER (Gorbovskoy et al., GCN Circ. 16653). Using 1893 s of PC mode
data and 2 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 = 44.06877, +30.93799 which is equivalent to:
RA (J2000): 02h 56m 16.50s
Dec(J2000): +30d 56' 16.8"
with an uncertainty of 2.5 arcsec (radius, 90% confidence). This
position is 0.8 arcsec from the MASTER position. We believe that this
source, which has a mean count rate of 2.3e-02 ct/sec, is the X-ray
afterglow of GRB 140801A but further observations are needed to
determine a decaying behaviour.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020402.
This circular is an official product of the Swift-XRT team.
GCN Circular 16660
Subject
Konus-Wind observation of GRB 140801A
Date
2014-08-02T12:26:02Z (12 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 140801A
(IPN triangulation: Hurley et al., GCN 16655;
Fermi-GBM detection: Pelassa, GCN 16658)
triggered Konus-Wind at T0=68394.769 s UT (18:59:54.769).
The light curve shows a multi-peaked structure with a total duration of ~7.5 s.
The emission is seen up to ~3 MeV.
As observed by Konus-Wind, the burst had a fluence
of 1.10(-0.04,+0.04)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0+0.128 s, of 4.6(-0.6,+0.6)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+7.680 s)
is best fit in the 20 keV - 5 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.44(-0.17,+0.18),
and the peak energy Ep = 108(-4,+5) keV,
chi2 = 75/71 dof.
Fitting this spectrum with the Band model yields the same
values of alpha and Ep with an upper limit on beta of -4.2
The spectrum near the peak count rate (measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 5 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = +0.38(-0.56,+0.69),
and the peak energy Ep = 121(-12,+13) keV,
chi2 = 27/24 dof.
Assuming the redshift z=1.320 (de Ugarte Postigo et al., GCN 16657)
and a standard cosmology model with H_0 = 70 km/s/Mpc,
Omega_M = 0.27, and Omega_Lambda = 0.73,
we estimate the following rest-frame parameters:
the isotropic energy release E_iso is ~4.9x10^52 erg,
the peak luminosity L_iso is ~5.0x10^52 erg/s,
and the rest-frame peak energy of the time-integrated spectrum,
Ep,i, is ~250 keV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140801_T68394/
All the quoted errors are at the 90% sigma confidence level.
All the quoted values are preliminary.
GCN Circular 16659
Subject
GRB 140801A : Virtual Telescope optical observations
Date
2014-08-02T09:44:48Z (12 years ago)
From
Gianluca Masi at Bellatrix Astronomical Obs <gianluca@bellatrixobservatory.org>
G. Masi, the Virtual Telescope Project - Italy, reports:
I observed the field of GRB 140801A (Fermi trigger 428612396) with with the 17"
robotic unit part of the Virtual Telescope (Ceccano, Italy) at 2 Aug. 2014,
00:10:39 UT, 5.15 hours seconds after the burst.
An optical source is visible where described by Gorbovskoy et al. (GCN 16653)
and D. Xu et al (GCN 16656) in a image coming from the sum of three, 180-seconds
exposures, unfiltered. The position of the source is RA: 02 56 16.46 +30 56 17.9
(J2000.0, mean residuals of 0.2") and the magnitude was estimated to be 19.6,
assuming R mags for the reference stars from UCAC-4.
The message may be cited.
GCN Circular 16658
Subject
GRB 140801A: Fermi GBM observation
Date
2014-08-02T05:37:24Z (12 years ago)
From
Veronique Pelassa at UAH <vero.pelassa@gmail.com>
V. Pelassa (UAH) reports on behalf of the Fermi GBM Team:
"At 18:59:53.26 UT on 1 August 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140801A (trigger 428612396 / 140801792).
An optical transient was detected by the MASTER II robotic telescope
(Lipunov et al. 2014, GCN 16653). The GBM on-ground location is
consistent with the OT location, which angle from the Fermi LAT
boresight is 80 degrees.
The GBM light curve consists of two bright pulses followed by a
short tail, with a duration (T90) of about 7 s (50-300 keV).
The time-averaged spectrum from T0-2.048 s to T0+12.288 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.42 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 125 +/- 2 keV
(Castor-statistics 697.99 for 610 d.o.f.).
A Band function fits the spectrum equally well (Castor-statistics
695.14 for 609 d.o.f.) with Epeak= 122 +/- 3 keV,
alpha = -0.40 +/- 0.04 and beta = -3.6 +/- 0.4.
The event fluence (10-1000 keV) in this time interval is
(1.22 +/- 0.01)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+0.832 s in the 10-1000 keV band
is 22.6 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 16657
Subject
GRB 140801A: Redshift from the 10.4m GTC telescope
Date
2014-08-02T04:56:21Z (12 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J. Gorosabel (IAA-CSIC, UPV/EHU),
C.C. Thoene (IAA-CSIC), J.P.U. Fynbo (DARK/NBI), D. Xu (DARK/NBI),
D. Perez-Valladares (GTC), and G. Gomez-Velarde (ULL-IAC, GTC) report on
behalf of a larger collaboration:
We have observed the afterglow of the Fermi GRB140801A (Gorbovskoy et al.
GCN 16653, Xu et al. GCN 16655) with the 10.4m GTC (+OSIRIS). Spectroscopic
observations began at 3:35 UT (8.59 hr after the burst). The first 900 s spectrum
was obtained with the R1000B grism, and covered the range between 3630 and
7500 A, at a resolution of ~1000.
We detect a strong continuum with absorption features that correspond to NiII,
MnII, FeII, MgII, and MgI at a common redshift of z=1.320, which we identify as the
redshift of the GRB.
Further spectroscopic observations are ongoing.
GCN Circular 16656
Subject
GRB 140801A: NOT afterglow confirmation
Date
2014-08-02T03:34:21Z (12 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), S. Schulze (PUC, MAS), M. El-Souri, S. Boye Nissen,
M. Sparre, J. P. U. Fynbo (DARK/NBI), A. de Ugarte Postigo (IAA-CSIC,
DARK/NBI), P. Jakobsson (U. Iceland) report on behalf a larger
collaboration:
We observed the field of GRB 140801A (Fermi trigger 428612396) with
the 2.5-m Nordic Optical Telescope (NOT) equipped with ALFOSC. We
obtained a 200-s exposure in each of V, R, and I bands. Observations
started at 01:07:23 UT on August 2 (i.e. 6.12 hours after the burst).
The optical transient reported by Gorbovskoy et al. (GCN 16653) is
clearly detected in each of our images at the same position. And it
has decayed to R(Vega) ~ 20.6 mag at 6.15 hours post-trigger,
calibrated against two bright nearby USNO B1 stars. This measurement
is not corrected for foreground extinction.
The OT roughly decays as t^-1.5 during the MASTER observations (GCN
16653), and then changes to roughly as t^-0.9 assuming a simple
power-law decline since the MASTER's end-time. The whole behavior is
similar to that of previous GRB optical afterglows. We thus conclude
that this OT is very likely the optical afterglow of GRB 140801A.
GCN Circular 16655
Subject
IPN triangulation of GRB 140801A (Fermi trigger 428612396)
Date
2014-08-01T22:25:55Z (12 years ago)
From
Kevin Hurley at UCBerkeley/SSL <khurley@ssl.berkeley.edu>
K. Hurley, on behalf of the IPN team,
S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks,
D. Svinkin, and T. Cline on behalf of the Konus-Wind team,
J. Goldsten, on behalf of the MESSENGER NS GRB team, and
V. Connaughton, M. S. Briggs, C. Meegan, and V. Pelassa, on behalf of the Fermi
GBM team, report:
GRB140801A (Fermi trigger 428612396) has been observed by Konus-Wind,
Fermi-GBM, and MESSENGER, so far, at around 68393 SOD (18:59:53) UT.
We have triangulated it to a preliminary, 3 sigma annulus centered at
RA, Dec (2000)=123.886, +21.098 degrees, whose radius is 70.951 +/-
0.125 degrees. The bright MASTER OT (Gorbovskoy et al. GCN 16653) lies
0.0093 degrees from the center line of this annulus, and is therefore
likely to be the optical afterglow of this GRB.
A map has been posted at ssl.berkeley.edu/ipn3/140801A. This localization
may be improved.
The spectral and temporal properties of this GRB will be given in
forthcoming GCN Circulars.
GCN Circular 16654
Subject
GRB 140801A: archival upper limits on the host galaxy
Date
2014-08-01T22:09:55Z (12 years ago)
From
Denis Denisenko at SAI MSU <d.v.denisenko@gmail.com>
D. Denisenko, E. Gorbovskoy, V. Lipunov (Sternberg Astronomical
Institute, Moscow State University) report:
Since the error box of GRB 140801A (FERMI trigger 428612396) was not
covered by Sloan Digital Sky Survey, we have used the digitized
Palomar plates of this area to create the color-combined finder chart
and to estimate the upper limits on the host galaxy of this burst.
There are in total 12 plates available (POSS-I red and blue ones from
1953 and 1954, two Quick-V plates from 1982 and six POSS-II plates
from 1991-1995: 2 blue, 2 red and 2 infrared). There is nothing at the
position of MASTER optical transient (Gorbovskoy et al., GCN 16653) on
any individual plates, as well as on their combination to the limiting
magnitude ~22.5.
5'x5' color-combined finder chart centered at MASTER OT
J025616.43+305617.0 is uploaded to
http://master.sai.msu.ru/static/GRB/GRB140801A-BRIR5x5.jpg (position
of the OT is marked with dashes). We also note the nearby white dwarf
44" north of the OT which is marked by an arrow. It has the following
entries in the major catalogues:
USNO-B1.0 1209-0038230 (02 56 16.581 +30 57 02.09 pmRA=88 pmDE=32
B1=15.37 R1=15.54 B2=15.74 R2=16.06 I=16.20)
GALEX J025616.6+305702 (FUV=15.09+/-0.02 NUV=15.41+/-0.01)
2MASS J02561657+3057017 (J=16.12+/-0.09)
There is no mention of its variability in the literature. However, it
should be used with caution in photometric purposes.
This message can be cited.
GCN Circular 16653
Subject
GRB 140801A (FERMI trigger 428612396): MASTER brigth OT discovery
Date
2014-08-01T20:52:09Z (12 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
E. Gorbovskoy, V. Lipunov, D.Denisenko, M.Pruzhinskaya, V.Kornilov,
D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov,
A.Kuznetsov, V.V.Chazov, A.Sankovich
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinsky, I.Zalozhnih, A. Popov
Ural Federal University, Yekaterinburg, Kourovka
Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Tunka was pointed to the GRB140801A (FERMI trig. 428612396) 54
sec after notice time and 100 sec after trigger time at 2014-08-01 19:01:33 UT
in two polarizations.
MASTER-Tunka auto-detection system discovered bright OT
source at (RA, Dec) = 02h 56m 16.44s +30d 56m 16.8s on 2014-08-01.79376
UT. The OT unfiltered magnitude is 14.6m (limit 18.3m) within FERMI
error-box (trig. N 428612396).
Preliminary automatic photometry and astrometry
Date Time Ra Dec Mag
2014-08-01 19:01:31.886 02h 56m 16.42s , +30d 56m 16s.8 14.64
2014-08-01 19:03:02.863 02h 56m 16.43s , +30d 56m 17s.0 15.72
2014-08-01 19:04:38.384 02h 56m 16.43s , +30d 56m 17s.0 16.30
Our band is well described by a parity 0.8R+0.2B (USNO B1).
The discovery and reference images are available at:
http://master.sai.msu.ru/static/GRB/GRB140801_FERMI.png
The 5-sigma upper limit has been about 18.53mag
The message may be cited.