GRB 120213A

T. Sakamoto (NASA/UMBC), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester),
D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), E. A. Hoversten (PSU),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (NASA/GSFC),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and
M. C. Stroh (PSU) report on behalf of the Swift Team:

At 00:27:19 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 120213A (trigger=514767).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 301.032, +65.397, which is 
   RA(J2000)  =  20h 04m 08s
   Dec(J2000) = +65d 23' 51"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single FRED pulse
with a duration of about 40 sec.  The peak count rate
was ~3200 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 00:28:09.0 UT, 49.5 seconds after
the BAT trigger. XRT found a bright, uncatalogued, fading  X-ray source 
located at RA, Dec 301.0105, 65.4092 which is equivalent to:
   RA(J2000)  = +20h 04m 2.52s
   Dec(J2000) = +65d 24' 33.1"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 54 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 0.1 s image was 4.08e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 58 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.22. 

Burst Advocate for this burst is T. Sakamoto (Taka.Sakamoto AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Using  promptly downlinked XRT event data for GRB 120213A, we find an
enhanced XRT position of the afterglow: RA, Dec: 301.0128, 65.4110
which is equivalent to:
   RA (J2000)  = 20 04 03.07
   Dec (J2000) = +65 24 39.6
with an uncertainty of 2.1 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/514767.

Position enhancement is is described by Goad et al. (2007, A&A, 476,
1401) and Evans et al. (2009, MNRAS, 397, 1177).

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

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov, 
P.V.Kortunov, A.Kuznetsov, M.Kornilov, A.Sankovich
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.Krushinski, I.Zalozhnich,  A. Popov
Ural State University, Kourovka

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

H.Levato, C.Mallamaci, C.Saffe
ICATE (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio), San 
Juan, San Juan University, Felix Aguilar Observatory, Argentina

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Kislovodsk was pointed to the  GRB120213A 26 sec. after  notice 
time and 49 sec. after GRB time at 2012-02-13 00:28:08.528 UT in two 
polarizations.
  On our first (10s exposure) set we haven`t found optical transient 
within SWIFT  error-box (ra=20 04 07 dec=+65 23 59 r=0.050000).
The 5-sigma upper limit has been about 16.15mag
The message may be cited.

W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+841 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 120213A (trigger #514767)
(Sakamoto, et al., GCN Circ. 12942
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 ).  The BAT ground-calculated position is
RA, Dec = 300.987, 65.413 deg, which is 
   RA(J2000)  =  20h 03m 56.8s 
   Dec(J2000) = +65d 24' 48.0" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows a single FRED-like pulse starting
at ~T-7 sec, peaking at ~T+5 sec, and ending at ~T+75 sec.  T90 (15-350 keV) is
48.9 +- 12.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T-6.31 to T+74.46 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.37 +- 0.09.  The fluence in the 15-150 keV band is 1.9 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+5.44 sec in the 15-150 keV band
is 1.7 +- 0.1 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/514767/BA/

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

Using 2431 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 120213A, 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 = 301.01211, +65.41135 which is equivalent
to:

RA (J2000): 20h 04m 2.91s
Dec (J2000): +65d 24' 40.9"

with an uncertainty of 1.7 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.

S. R. Oates (MSSL-UCL) and T. Sakamoto (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 120213A
59 s after the BAT trigger (Sakamoto et al., GCN Circ. 12942
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 ).
No optical afterglow consistent with the XRT position
(Beardmore et al., GCN Circ. 12948
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 ) 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 first
finding chart (FC) exposure and subsequent exposures are:

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

white_FC            59          209          147         >19.8
u_FC               271          521          246         >19.7
white               59        12944         1454         >21.6
v                  602         6546          294         >20.4
b                  527        12032         1219         >20.5
u                  271         7161          717         >20.6
w1                 653         6956          471         >19.8
m2                6551         6751          197         >19.8
w2                 578        13010          332         >20.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.22 in the direction of the burst
(Schlegel et al. 1998).

J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P. Beardmore
(U. Leicester), P.A. Evans (U. Leicester), O.M. Littlejohns (U.
Leicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), G.
Stratta (ASDC) and T. Sakamoto report on behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 120213A (Sakamoto  et al.
GCN Circ. 12942
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 ), from 53 s to 22.8 ks after the  BAT trigger. The data
comprise 886 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Beardmore et al. (GCN. Circ 12944).

The late-time light curve (from T0+5.3 ks) can be modelled with  a
power-law decay with a decay index of alpha=3.02 (+0.19, -0.18).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 3.28 (+/-0.07). The
best-fitting absorption column is  3.52 (+0.15, -0.14) x 10^21 cm^-2,
in excess of the Galactic value of 1.0 x 10^21 cm^-2 (Kalberla et al.
2005). The PC mode spectrum has a photon index of 2.22 (+/-0.15) and a
best-fitting absorption column of 1.7 (+/-0.4) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.4 x 10^-11 (5.4 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     1.7 (+/-0.4) x 10^21 cm^-2
Galactic foreground: 1.0 x 10^21 cm^-2
Excess significance: 3.2 sigma
Photon index:	     2.22 (+/-0.15)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00514767.

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