- GCN/BACODINE POSITION NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Fri 01 Aug 14 18:59:57 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 47
TRIGGER_NUM: 428612396
GRB_RA: 46.333d {+03h 05m 20s} (J2000),
46.548d {+03h 06m 12s} (current),
45.597d {+03h 02m 23s} (1950)
GRB_DEC: +25.667d {+25d 40' 00"} (J2000),
+25.723d {+25d 43' 22"} (current),
+25.473d {+25d 28' 23"} (1950)
GRB_ERROR: 3.85 [deg radius, statistical plus systematic]
GRB_INTEN: 1741 [cnts/sec]
DATA_SIGNIF: 53.50 [sigma]
INTEG_TIME: 0.512 [sec]
GRB_DATE: 16870 TJD; 213 DOY; 14/08/01
GRB_TIME: 68393.26 SOD {18:59:53.26} UT
GRB_PHI: 83.00 [deg]
GRB_THETA: 75.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO: 0.71
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 88% GRB
2nd_MOST_LIKELY: 9% GRO_J0422_32
DETECTORS: 0,1,1, 0,0,0, 0,0,0, 0,1,0, 0,0,
SUN_POSTN: 131.89d {+08h 47m 33s} +17.89d {+17d 53' 11"}
SUN_DIST: 78.29 [deg] Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN: 192.18d {+12h 48m 43s} -5.97d {-05d 58' 29"}
MOON_DIST: 141.70 [deg]
MOON_ILLUM: 28 [%]
GAL_COORDS: 157.25,-28.14 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 51.07, 7.93 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2014/bn140801792/quicklook/glg_lc_medres34_bn140801792.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 235.98,5.80 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Fri 01 Aug 14 19:00:09 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 57
TRIGGER_NUM: 428612396
GRB_RA: 46.350d {+03h 05m 24s} (J2000),
46.565d {+03h 06m 16s} (current),
45.614d {+03h 02m 27s} (1950)
GRB_DEC: +25.600d {+25d 36' 00"} (J2000),
+25.656d {+25d 39' 21"} (current),
+25.407d {+25d 24' 24"} (1950)
GRB_ERROR: 4.10 [deg radius, statistical plus systematic]
GRB_INTEN: 1232 [cnts/sec]
DATA_SIGNIF: 76.50 [sigma]
INTEG_TIME: 2.048 [sec]
GRB_DATE: 16870 TJD; 213 DOY; 14/08/01
GRB_TIME: 68393.26 SOD {18:59:53.26} UT
GRB_PHI: 83.00 [deg]
GRB_THETA: 75.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO: 0.81
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 91% GRB
2nd_MOST_LIKELY: 7% GRO_J0422_32
DETECTORS: 0,1,1, 0,0,0, 0,0,0, 0,1,0, 0,0,
SUN_POSTN: 131.89d {+08h 47m 33s} +17.89d {+17d 53' 11"}
SUN_DIST: 78.29 [deg] Sun_angle= 5.7 [hr] (West of Sun)
MOON_POSTN: 192.18d {+12h 48m 43s} -5.98d {-05d 58' 31"}
MOON_DIST: 141.71 [deg]
MOON_ILLUM: 28 [%]
GAL_COORDS: 157.31,-28.19 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 51.07, 7.87 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2014/bn140801792/quicklook/glg_lc_medres34_bn140801792.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 235.98,5.80 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Fri 01 Aug 14 19:00:23 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 56
TRIGGER_NUM: 428612396
GRB_RA: 45.250d {+03h 01m 00s} (J2000),
45.471d {+03h 01m 53s} (current),
44.492d {+02h 57m 58s} (1950)
GRB_DEC: +30.890d {+30d 53' 24"} (J2000),
+30.947d {+30d 56' 49"} (current),
+30.693d {+30d 41' 34"} (1950)
GRB_ERROR: 1.20 [deg radius, statistical only]
DATA_SIGNIF: 84.60 [sigma]
DATA_INTERVAL: 2.048 [sec]
GRB_DATE: 16870 TJD; 213 DOY; 14/08/01
GRB_TIME: 68393.26 SOD {18:59:53.26} UT
GRB_PHI: 81.00 [deg]
GRB_THETA: 80.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4143 (Gnd S/W Version number)
SUN_POSTN: 131.89d {+08h 47m 33s} +17.89d {+17d 53' 11"}
SUN_DIST: 77.94 [deg] Sun_angle= 5.8 [hr] (West of Sun)
MOON_POSTN: 192.18d {+12h 48m 44s} -5.98d {-05d 58' 33"}
MOON_DIST: 140.05 [deg]
MOON_ILLUM: 28 [%]
GAL_COORDS: 153.21,-24.26 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 51.64, 13.21 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2014/bn140801792/quicklook/glg_lc_medres34_bn140801792.gif
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: This Notice was ground-generated -- not flight-generated.
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN Circular #16653
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.
- GCN Circular #16654
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 #16655
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 #16656
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 #16657
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 #16658
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 #16659
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 #16660
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 #16661
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 #16662
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 #16663
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 #16665
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 #16666
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 #16667
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).
- 1510.07807 from 28 Oct 15
V. M. Lipunov et al.: The optical identifcation of events with poorly defined locations: The case of the Fermi GBM GRB140801A
We report the early discovery of the optical afterglow of gamma-ray burst (GRB) 140801A in the 137 deg$^2$ 3-$\sigma$ error-box of the Fermi
Gamma-ray Burst Monitor (GBM). MASTER is the only observatory that automatically react to all Fermi alerts. GRB 140801A is one of the few GRBs
whose optical counterpart was discovered solely from its GBM localization. The optical afterglow of GRB 140801A was found by MASTER Global
Robotic Net 53 sec after receiving the alert, making it the fastest optical detection of a GRB from a GBM error-box. Spectroscopy obtained with
the 10.4-m Gran Telescopio Canarias and the 6-m BTA of SAO RAS reveals a redshift of $z=1.32$. We performed optical and near-infrared
photometry of GRB 140801A using different telescopes with apertures ranging from 0.4-m to 10.4-m. GRB 140801A is a typical burst in many ways.
The rest-frame bolometric isotropic energy release and peak energy of the burst is $E_\mathrm{iso} = 5.54_{-0.24}^{+0.26} \times 10^{52}$ erg
and $E_\mathrm{p, rest}\simeq280$ keV, respectively, which is consistent with the Amati relation. The absence of a jet break in the optical
light curve provides a lower limit on the half-opening angle of the jet $\theta=6.1$ deg. The observed $E_\mathrm{peak}$ is consistent with the
limit derived from the Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis shows that GRB 140801A could belong to the class of
intermediate duration. The rapid detection of the optical counterpart of GRB 140801A is especially important regarding the upcoming experiments
with large coordinate error-box areas.
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