GRB 130627B

S. R. Oates (UCL-MSSL), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
V. D'Elia (ASDC), P. A. Evans (U Leicester), S. T. Holland (STScI),
A. Y. Lien (NASA/GSFC/ORAU), D. Malesani (DARK/NBI),
K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Swift Team:

At 12:00:50 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130627B (trigger=559139).  Due to an Earth limb constraint
Swift could not immediately slew to the burst. 
The BAT on-board calculated location is 
RA, Dec 181.932, -55.730 which is 
   RA(J2000) = 12h 07m 44s
   Dec(J2000) = -55d 43' 47"
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 40 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+48.4
minutes. There will be no XRT or UVOT data until this time. 

Burst Advocate for this burst is S. R. Oates (samantha.oates AT ucl.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.)

S. Campana (INAF-OAB), G. Cusumano (INAF-IASF PA), P.A. Evans (U.
Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU) and J.A.
Kennea (PSU) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 130627B at 12:50:47.2 UT,
2996.6 seconds after the BAT trigger. No source was detected in 1.8 ks
of promptly downlinked data, which covered 96% of the BAT error circle.
We are waiting for the full dataset to detect and localise the XRT
counterpart.

S. R. Oates & M. De Pasquale (UCL-MSSL) report on behalf of the Swift/UVOT Team:

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 3754 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 25%
of the BAT 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 BAT error circle. The list of sources is typically complete down to about 18
mag. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.40.

P.A. Evans (U. Leicester) & S.R. Oates (MSSL-UCL) report on behalf of
the Swift-XRT team:

In 3.3 ks of XRT data for GRB 130627B (Oates  et al. GCN Circ. 14936
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 ),
from 3.7 ks to 11.2 ks after the  BAT trigger we find an uncatalogued
X-ray sources at  RA, Dec = 181.91308, -55.7008 which is equivalent to:

RA (J2000): 12 07 39.14
Dec(J2000): -55 42 02.9

with an uncertainty of 4.2 arcsec (radius, 90% confidence). The mean
count rate in this interval is 8.8(+/-2.0) x 10^-3 ct/sec, and we cannot
determine at the present time whether the source is fading.

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

N. P. M. Kuin and S. R. Oates (UCL-MSSL) report on behalf of
the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 130627B  3755 s after the BAT trigger (Oates et al.,
GCN Circ. No. 14936 and 14939).

No optical afterglow consistent with the XRT position
Evans et al. GCN Circ. No. 14947 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          3755         3905          147         >20.3
white             3755         5137          344         >20.9
v                 3911         5474          320         >19.5
b                 4733         4932          197         >20.1
u                 4526         4726          197         >19.7
w1                4321        11240          757         >20.3
m2                4116        10664         1082         >20.4
w2                5143         5343          197         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.40 in the direction of the burst
(Schlegel et al. 1998).

M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),
H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC),
S. R. Oates (UCL-MSSL), D. M. Palmer (LANL), T. Sakamoto (AGU),
G. Sato (ISAS), 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 130627B (trigger #559139)
(Oates, et al., GCN Circ. 14936
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 ).  The BAT ground-calculated position is
RA, Dec = 181.914, -55.706 deg which is
  RA(J2000)  =  12h 07m 39.3s
  Dec(J2000) = -55d 42' 20.3"
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 95%.

The mask-weighted light curve shows a single peak starting at ~T-6 sec,
peaking at ~T+2 sec, and ending at ~T+22 sec.
T90 (15-350 keV) is 28.6 +- 5.8 sec (estimated error including systematics).

The time-averaged spectrum from T-10.5 to T+26.0 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.13 +- 1.03,
and Epeak of 47.6 +- 8.7 keV (chi squared 56.72 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 6.1 +- 0.8 x 10^-07 erg/cm2
and the 1-sec peak flux measured from T+1.82 sec in the 15-150 keV band is
0.8 +- 0.2 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.79 +- 0.16 (chi squared 68.34 for 57 d.o.f.).  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/559139/BA/

P.A. Evans (U. Leicester) and S. R. Oates (UCL-MSSL) report on behalf of
the Swift-XRT team:

Swift performed a second epoch observation of GRB 130627B (Oates et al.,
GCN Circ. 14936
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 ) on 2013 July 2nd, collecting 7.3 ks of Photon Counting
mode data from T0+390 ks to T0+415 ks. The X-ray object reported by
Evans et al. (GCN Circ. 14947
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 ) is no longer detected. The 3-sigma upper 
limit is 1.7 x 10^-3 ct/sec, which is well below the level of 
8.8(+/-2.0) x 10^-3 ct/sec at which the source was previously detected.

We therefore confirm that this object was the afterglow of GRB 130627B.

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