GRB 120215A

E. A. Hoversten (PSU), W. H. Baumgartner (GSFC/UMBC),
D. N. Burrows (PSU), N. Gehrels (NASA/GSFC),
A. Y. Lien (NASA/GSFC/ORAU), V. Mangano (INAF-IASFPA),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU), T. N. Ukwatta (MSU)
and B.-B. Zhang (PSU) report on behalf of the Swift Team:

At 00:41:15 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 120215A (trigger=515015).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is RA, Dec 30.032, +8.792 which is 
   RA(J2000) = 02h 00m 08s
   Dec(J2000) = +08d 47' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 15 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 00:43:01.8 UT, 106.5 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source located at RA, Dec 30.04753, 8.80220 which is
equivalent to:
   RA(J2000)  = 02h 00m 11.41s
   Dec(J2000) = +08d 48' 07.9"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 66 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 consistent with the Galactic value of 5.40
x 10^20 cm^-2 (Kalberla et al. 2005). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 110 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
0.08. 

Burst Advocate for this burst is E. A. Hoversten (hoversten AT astro.psu.edu). 
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.)

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), E. A. Hoversten (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 120215A (trigger #515015)
(Hoversten, et al., GCN Circ. 12954
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 ).  The BAT ground-calculated position is
RA, Dec = 30.057, 8.790 deg, which is 
   RA(J2000)  =  02h 00m 13.7s 
   Dec(J2000) = +08d 47' 25.4" 
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 83%.
 
The mask-weighted light curve shows 2 or 3 overlapping peaks starting at ~T-2 sec,
peaking at ~T+4 sec, and ending at ~T+35 sec.  T90 (15-350 keV) is 26.5 +- 8.9 sec
(estimated error including systematics).
 
The time-averaged spectrum from T-0.36 to T+29.27 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.62 +- 0.22.  The fluence in the 15-150 keV band is 4.0 +- 0.6 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+4.87 sec in the 15-150 keV band
is 0.6 +- 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/515015/BA/

A. LaCluyze, J. Haislip, K. Ivarsen, D. Reichart, J. Moore, M. Nysewander, 
A. Trotter, R. Egger, A. Foster, A. Oza, H. T. Cromartie, E. Speckhard, and 
J. A. Crain report:

Skynet observed the field of GRB 120215A with the PROMPT telescopes located 
at CTIO in Chile. Observations in B, R, and I began at 00:42:24 UT, 69 
seconds after the burst. While no source is detected in early images, 
stacks of later images do find an optical source of roughly 20th magnitude 
consistent with the XRT position reported by Hoversten et. al. (GCN 12954
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 ).


mean-t	#exp 	explen	filt	mag	+(1sig)	-(1sig)
19.27m	4	80s	I	19.095	0.287	0.228
20.88m  6	80s	B	20.320	0.361	0.274

Analysis is ongoing, although no further observations are planned as the 
field has set in Chile.

A preliminary light curve can be found at: 
http://skynet.unc.edu/grb/grb120215a.png

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

Using 1619 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 120215A, 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 = 30.04752, +8.80178 which is equivalent
to:

RA (J2000): 02h 00m 11.41s
Dec (J2000): +08d 48' 06.4"

with an uncertainty of 2.0 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.

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

We have analysed 9.4 ks of XRT data for GRB 120215A (Hoversten	et al.
GCN Circ. 12954
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 ), from 110 s to 19.3 ks after the  BAT trigger. The
data comprise 36 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN. Circ 12957).

The light curve can be modelled with an initial power-law decay with an
index of alpha=3.38 (+0.26, -0.23), followed by a break at T+699 s to
an alpha of -0.28 (+0.15, -0.18).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.10 (+0.24, -0.22). The
best-fitting absorption column is  8.4 (+5.1, -3.0) x 10^20 cm^-2,
consistent with the Galactic value of 5.4 x 10^20 cm^-2 (Kalberla et
al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux
conversion factor deduced from this spectrum  is 3.4 x 10^-11 (4.4 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     8.4 (+5.1, -3.0) x 10^20 cm^-2
Galactic foreground: 5.4 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.10 (+0.24, -0.22)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00515015.

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

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 collaboration:

We observed the field of GRB 120215A (Hoversten et al., GCNC 12954)
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 2012-02-15 10:16:42 UT (9.6 h after the burst)
We did not find any new point source within the enhanced XRT circle
(Evans et al., GCNC 12957) in all the three bands.
We also could not detect the previously reported afterglow (LaCluyze et al.,
GCNC 12956).


Three sigma upper limits of the OT are listed below. We used
GSC2.3 catalog for flux calibration.

T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.40591    10:25:46    1140.0   >19.1  >19.0  >18.5
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

E. A. Hoversten (PSU) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 120215A
110 s after the BAT trigger (Hoversten et al., GCN Circ. 12954
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 ).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 12957
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 ) is detected in the initial UVOT  
exposures.
The optical source reported by LaCluyze et al. (GCN Circ. 12956
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 ) was not
seen in the first orbit of observations, however our upper limits are  
higher than
their detections. 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           110          260          147         >20.5
u_FC               322          572          246         >20.3
white              110          795          186         >20.8
v                  652          672           19         >17.6
b                  578          771           39         >19.2
u                  322          746          265         >20.3
w1                 702          721           19         >18.9
m2                 677          869           39         >19.6

The magnitudes in the table are not corrected for the Galactic  
extinction
due to the reddening of E(B-V) = 0.08 in the direction of the burst
(Schlegel et al. 1998).

Y. Saito, Y. Aoki, S. Song, M. Hayashi, K. Kawakami, K. Tokoyoda,
R. Usui, Y. Yatsu, and N. Kawai (Tokyo Tech)  report on behalf of
the MITSuME collaboration:

We observed GRB 120219A (Swenson et al., GCNC 12964) with the
optical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME
50 cm telescope of Akeno Observatory, Yamanashi, Japan.

We started the observation 134 sec after the BAT trigger
from 2012-02-19 14:32:22 UT.  And we did not find any new point source
within the XRT error circle (Goad et al., GCNC 12967) in the three bands.
The results of photometry (3sigma upper limits) are listed below.

The photon flux were calibrated against GSC2.3 catalog.

T0+[sec]      MID-UT     T-EXP[sec]       g'              Rc           Ic
----------------------------------------------------------------------------------------
   275      14:34:43       240         > 19.5        > 19.5       > 18.2
 12005     17:54:41     18060         > 21.5        > 21.4       > 20.5
----------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]