GRB 140512A

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, 
D.Denisenko, A.Sankovich
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow 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  GRB140512A   171 sec after trigger 
time at 2014-05-12 19:34:40.212 UT. On our first (30s exposure) set we 
haven`t found optical transient  within SWIFT error-box (ra=19 17 28 
dec=-15 06 00 r=0.050000).
The 5-sigma upper limit has been about 16.2 mag
Observations were made in twilight.
The message may be cited.

C. Pagani (U Leicester), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC),
J. A. Kennea (PSU), V. Mangano (PSU), C. J. Mountford (U Leicester),
K. L. Page (U Leicester), B. Sbarufatti (INAF-OAB/PSU),
M. H. Siegel (PSU), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report
on behalf of the Swift Team:

At 19:31:49 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140512A (trigger=598819).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 289.371, -15.100 which is 
   RA(J2000)  =  19h 17m 29s
   Dec(J2000) = -15d 05' 59"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a multi-peak event
with a total duration of about 170 sec.  The peak count rate
was ~8000 counts/sec (15-350 keV), at ~122 sec after the trigger. 

The XRT began observing the field at 19:33:27.5 UT, 98.4 seconds after
the BAT trigger. The position determined from promptly downlinked data
differs significantly from the on-board position, suggesting that the
XRT may have centroided on a cosmic ray; the initial XRT position
notice should be treated with caution. Using promptly downlinked data
we find an uncatalogued X-ray source located at RA, Dec 289.36925,
-15.09492 which is equivalent to:
   RA(J2000)  = 19h 17m 28.62s
   Dec(J2000) = -15d 05' 41.7"
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This
location is 19 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. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 106 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	19:17:28.78 = 289.36991
  DEC(J2000) = -15:05:39.2  = -15.09423
with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.4
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.01 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.16. 

Burst Advocate for this burst is C. Pagani (cp232 AT star.le.ac.uk). 
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.)

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, 
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  GRB140512A   171 sec after trigger time at 2014-05-12 
19:34:40.212 UT in two polarizations. We definetly see OT (Pagani et. al. 
GCN 16249
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 )  on our images in bosh polarizations.

The preliminary automatic light curve available at Tab.1 and here:
http://master.sai.msu.ru/static/GRB/GRB140512A_lc.png

Table 1. GRB140512B early automatic light curve.

        T_start         T-T_trig   mag
  2014-05-12 19:34:44.3  175 sec  13.5
  2014-05-12 19:36:36.3  287 sec  13.9
  2014-05-12 19:38:21.9  392 sec  14.5
  2014-05-12 19:39:43.7  474 sec  14.8
  2014-05-12 19:41:05.3  556 sec  15.1
  2014-05-12 19:42:26.3  637 sec  15.2
  2014-05-12 19:43:47.3  718 sec  15.5
  2014-05-12 19:45:56.8  847 sec  16.2

Our unfiltered magnitude is well described by a parity 0.8R + 0.2B 
(USNO-B1)

The power low index alpha from 175 to 847 seconds after the trigger  is
1.5 +- 0.1  (F ~ t-apha).

We erraticly reported (Ivanov et. al. GCN 16248
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 ) that we don't see object 
earlier because of the wrong identification. We are sorry for it.

The message may be cited.

E. Klunko (ISTP), A. Volnova (IKI), M. Eselevich (ISTP), I. Korobtsev
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the field of GRB 140512A (Pagani et al., GCN 16249
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 )   with 
AZT-33IK telescope of Sayan observatory (Mondy). We took several images 
in R-filter of 60 s exposure starting on May, 12 (UT) 19:56:58. We 
clearly detect a fading optical transient in the position reported early 
(Pagani et al., GCN 16249
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 ). A brightness of the OT in the first image is 
about R=16.7 (at (UT) 19:57:28, mid time). Observation is continuing.

The finding chart can be found in 
http://grb.rssi.ru/GRB140512A/GRB140512A_AZT33IK_R_fc.png

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J. Gorosabel (IAA-CSIC,
UPV-EHU), D. Xu (DARK/NBI), T. Kruehler (ESO), A.A. Djupvik (NOT),
E. Gafton (OKC, Stockholm Univ.) and T. Libbrecht (Stockholm Univ.)
report on behalf of a larger collaboration:

We have observed the field of GRB 140512A (Pagani et al. GCN 16249
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 )
with the AlFOSC instrument on the 2.5 m Nordic Optical Telescope (La
Palma, Spain), as part of the Stockholm remote observing school.
Observations consisted of 3x300s imaging in R, starting at 02:10 UT
(6.65 hrs after the burst). Observations were performed under variable
seeing conditions of 2.0-2.5". Preliminary photometry, based on the
USNO-B1.0 catalogue yields R~19.5 mag. Spectroscopic observations
are ongoing.

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester)
report on behalf of the Swift-XRT team.

Using 5222 s of XRT Photon Counting mode data and 10 UVOT
images for GRB 140512A, 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 = 289.37006, -15.09430 which is equivalent
to:

RA (J2000): 19h 17m 28.81s
Dec (J2000): -15d 05' 39.5"

with an uncertainty of 1.5 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.

P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester), V. D'Elia
(ASDC), M. de Pasquale (INAF-IASFPA), A. Maselli  (INAF-IASFPA), V.
Mangano (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.P. Osborne (U.
Leicester) and C. Pagani report on behalf of the Swift-XRT team:

We have analysed 6.1 ks of XRT data for GRB 140512A (Pagani  et al. GCN
Circ. 16249
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 ),  from 87 s to 12.6 ks after the  BAT trigger. The data
comprise 841 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. 

The late-time light curve (from T0+4.6 ks) can be modelled with  a
power-law decay with a decay index of alpha=1.06 (+/-0.09).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.460 (+0.029, -0.016). The
best-fitting absorption column is  consistent with the Galactic value
of 1.5 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.80 (+/-0.07) and a best-fitting absorption column
of 2.02 (+0.28, -0.26) x 10^21 cm^-2. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 4.0 x 10^-11 (5.1 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     2.02 (+0.28, -0.26) x 10^21 cm^-2
Galactic foreground: 1.5 x 10^21 cm^-2
Excess significance: 3.4 sigma
Photon index:	     1.80 (+/-0.07)

If the light curve continues to decay with a power-law decay index of
1.06, the count rate at T+24 hours will be 0.15 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.8 x
10^-12 (7.4 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00598819.

This circular is an official product of the Swift-XRT team.

J. Graham, K. Varela, C. Delvaux and J. Greiner (all MPE
Garching) report on behalf of the GROND team:

We observed the field of GRB 140512A (Pagani et al., GCN 16249
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 )
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120,
405) mounted at the 2.2m MPG telescope at La Silla Observatory (Chile).

Observations started at 03:36 UT on May 13, about 8.0 hrs after the GRB
trigger. They were performed at an average seeing of 1.7" and at an
average airmass
of 2.3.

The afterglow discovered by Gorbovskoy et al. (GCN 16250
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 )
is detected in all optical bands and the JH bands. At a mean time of 04:02
UT, with
a 264 s exposure in g�r�i�z� bands and 240 s in JHK, we measure the following
preliminary AB magnitudes:

g'= 20.3 +/- 0.1 mag,
r'= 19.7 +/- 0.1 mag,
i'= 19.5 +/- 0.1 mag,
z'= 19.3 +/- 0.1 mag,
J = 19.0 +/- 0.1 mag,
H = 18.6 +/- 0.1 mag, and
K > 18.2 mag.

The given optical and NIR magnitudes are calibrated against GROND
zeropoints and
2MASS field stars in g'r'i'z and JHK respectively, and are not corrected
for the
Galactic foreground extinction corresponding to a reddening of E(B-V)=0.16
in the
direction of the burst (Schlegel et al. 1998).

T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), C. Pagani (U Leicester),
D. M. Palmer (LANL), 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 140512A (trigger #598819)
(Pagani, et al., GCN Circ. 16249
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 ).  The BAT ground-calculated position is
RA, Dec = 289.366, -15.087 deg which is
    RA(J2000)  =  19h 17m 27.9s
    Dec(J2000) = -15d 05' 14.8"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 35%.

The mask-weighted light curve shows a complex structure.  The first group of 
multiple peaks begins at ~T-15 sec, reaches maximum at T+0 sec, and returns to 
background by ~T+40 sec.  Then a second longer, brighter group of multiple peaks 
begins at ~T+85 sec, reaches maximum at T+120 sec and falls to background by 
T+170 sec. T90 (15-350 keV) is 154.8 +- 4.88 sec (estimated error including 
systematics).

The time-averaged spectrum from T-22.84 to T+186.29 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.45 +- 0.04.  The fluence in the 15-150 keV band is 1.4 +- 0.03 x 10^-5 
erg/cm2. The 1-sec peak photon flux measured from T+121.96 sec in the 15-150 keV 
band is 6.8 +- 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/598819/BA/

L. P. Xin,   X. F. Wang,  J. Y. Wei,  Y. L. Qiu, J. S. Deng,  
J. Wang, X. H. Han and C. Wu on behalf of EAFON report:

We began to observe GRB 140512A (Pagani et al., GCN 16429
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 )  with Xinglong 
0.8-m TNT telescope at 19:33:54  (UT) , 126 sec after the burst.

The optical counterpart (Pagani et al., GCN 16429
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 ) was clearly detected
 in our white and R band images.  A preliminary analysis shows that 
the brightness of the OT was fading from 13.0 mag to 17.0 mag, 
calibrated by nearby USNO B1.0 R2mag, during our observation epoch,  
with an index of  1.54  after fitting by a single power law.

The message may be cited.

Matthew Stanbro (UAH) reports on behalf of the Fermi GBM Team:

"At 19:31:42.50 UT on 12 May 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140512A (trigger 421615905 / 140512814)
which was also detected by Swift (C. Pagani et al. 2014, GCN 16249
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 ).
The GBM on-ground location, using the Fermi GBM trigger data,
is consistent with the Swift/BAT location.

The GBM light curve shows a complex structure, consisting of two main
separated episodes with a total duration (T90) of about 148.0 s (50-300
keV).
The time-averaged spectrum from T0-10.240 s to T0+152.578 s is well fit
by a power law function with an exponential high-energy cutoff.
The power law index is -1.33 +/- 0.03 and the cutoff energy,
parameterized as Epeak, is 588 +/- 84 keV.


The event fluence (10-1000 keV) in this time interval is
(4.30 +/- 0.10)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+128.70 s in the 10-1000 keV band is 11.0 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

B. Porterfield (PSU) and C. Pagani (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140512A
106 s after the BAT trigger (Pagani et al., GCN Circ. 16249
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 ).
We can confirm the detection of a fading source  with the
UVOT position
  RA(J2000)  =	19:17:28.78 = 289.36991
  DEC(J2000) = -15:05:39.2  = -15.09423

Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the
finding chart (FC) exposures and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white (fc)         106          256          293       14.91 +/- 0.07
white              106         1022          186       16.99 +/- 0.07
white             1175         6197          412       19.07 +/- 0.08
v                   88         1072           68       15.97 +/- 0.09
v                 4973         6608          393       18.68 +/- 0.15
b                  574         1344           76       16.84 +/- 0.08
b                 5793         5992          196       19.56 +/- 0.19
u (fc)             319          568          491       15.37 +/- 0.07
u                 5587         7102          275       19.08 +/- 0.18
uvw1               697         1295           58       17.52 +/- 0.19
uvw1              5383         7018          393       20.10 +/- 0.34
uvm2               672         1270           77      >18.71
uvm2              5177         6812          393      >20.17
uvw2               624         1220           77      >19.05
uvw2              4769         6403          393      >20.47

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.162 in the direction of the burst
(Schlegel et al. 1998).

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:

A long-duration GRB 140512A (Swift-BAT trigger 598819: Pagani et al., 
GCN 16249
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 ; Sakamoto et al., GCN 16258
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 ; Fermi-GBM detection: Stanbro, GCN 
16262
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 ) triggered Konus-Wind at T0=70310.769 s UT (19:31:50.769).

The light curve shows two separated multipeaked episodes: the first from 
~T0-21 s to ~T0+12 s and the second longer and brighter from ~T0+88 s to 
~T0+158 s. A total duration of the burst is ~179 s.

As observed by Konus-Wind, the burst had a fluence
of 4.8(-0.8,+2.0)x10^-5 erg/cm2, and a 256-ms peak flux,
measured from T0+121.856 s, of 3.7(-1.2,+1.3)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the first bursting episode
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 1.2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.85 (-0.47,+0.61)
and Ep = 279 (-69,+148) keV (chi2 = 62/60 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy
photon index: beta < -2.1 (chi2 = 62/59 dof).

The time-averaged spectrum of the second bursting episode
(measured from T0+90.368 to T0+155.904 s)
is best fit in the 20 keV - 6 MeV range
by a power law with exponential cutoff model with the following parameters:
alpha = -1.30 (-0.18,+0.21)
and Ep = 466 (-124, +287) keV (chi2 = 79/79 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy
photon index: beta < -1.9 (chi2 = 78/78 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140512_T70310/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, D.Denisenko, 
A.Sankovich
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory

V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

V.Krushinski, I.Zalozhnih,  A. Popov
Ural Federal University, 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  began observations of   GRB140512A  (Pagani et. al. GCN 
16249
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 ) from  pointing  on several FERMI alerts.
During the second set of observations by FERMI coordinates the GRB140512A 
error box was covered by our  very wide field cameras MASTER VWF 
(FOV=2x384 square degrees, D=72mm, f/1.2, 1 pix = 22 arcsec) which 
installed on  MASTER-II telescope. So we have 5 images with 5 second 
exptime without time gap since 2014-05-12 19:32:38 i.e. 29 sec. after the 
trigger and 49 sec. after the burst. We did not see optical transient 
(Pagani et. al. GCN 16249
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 )  at GRB140512A place. The  5-sigma upper limit 
on coadd of 5 MASTER-VWF images since 49 sec. till 74 sec. after the burst 
has been about 12.3 mag. The prompt images available here 
http://master.sai.msu.ru/static/GRB/GRB140512A.png .

After several repointing by FERMI alerts MASTER II was pointed to the 
GRB140512A 171 sec after trigger time at 2014-05-12 19:34:40.212 UT in two 
polarizations by Swift coordinates. We definitely see OT on our images in 
both polarizations.

Out final light curve  is  available in Tab. 1

        Start time       Exptime T-T_mid     P/      eP/      P\    eP\
2014-05-12T19:34:40.212     30     186    14,45    0,04    14,37  0,03
2014-05-12T19:36:37.643     60     318    14,72    0,05    14,74  0,04
2014-05-12T19:38:24.484     60     425    15,60    0,12    15,35  0,06
2014-05-12T19:39:47.447     60     508    15,41    0,10    15,65  0,07
2014-05-12T19:41:10.651     60     591    15,75    0,13    15,75  0,08
2014-05-12T19:42:32.663     60     673    15,98    0,16    15,94  0,09
2014-05-12T19:43:54.083     60     754    16,46    0,22    16,42  0,12
2014-05-12T19:45:56.002    170     931    16,37    0,20    16,79  0,15
2014-05-12T19:50:30.564    180    1211    17,50    0,39    16,84  0,15
2014-05-12T19:56:11.667    180    1552    16,82    0,27    17,57  0,22

P/ and P\ is a polarization filter which are oriented at an angle 45 and 
135 degrees to RA axis respectivel.  eP/ and eP\ is a error of P/ and P\ 
values.  T is a  GRB trigger time.

The dimensionless Stokes parameter averaged over 5 first expositions is 
estimated to be less than observational error which equals to 2.9% (i.e. q 
= 0.3 +- 2.9%). So big error is connected to observation in a morning 
twilight (sun altitude ~ 12 d) and high object zenith distance (z ~ 70 d).

Our  unfiltered magnitude is well described by a parity 0.8R + 0.2B  (USNO-B1)

The message may be cited.

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J. Gorosabel (IAA-CSIC,UPV-EHU),
D. Xu (DARK/NBI), D. Malesani (DARK/NBI), G. Leloudas (DARK/NBI),P.
Jakobsson (U. Iceland), T. Kruehler (ESO), A.A. Djupvik (NOT), E. Gafton
(OKC, Stockholm Univ.) and T. Libbrecht (Stockholm Univ.) report on behalf
of a larger collaboration:


Following the photometric observations of the counterpart of GRB 140512A
(Pagani et al. GCN 16249
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 ) from the 2.5 m NOT (+ALFOSC) reported by de
Ugarte Postigo et al. (GCN 16253
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 ) we obtained spectroscopic data.
Observations consisted in 2x1800s exposures using Grism #4, which covers
the range from 3800 to 9100. The mean observing epoch was May 13, 3:18:50
UT (7.78 hrs after the burst).


The spectrum presents absorption features consistent with FeII and MgII at
a common redshift of z=0.725, which we consider the most probable redshift
for this event.