GRB 140502A

L. Elenin (KIAM),  A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko 
(IKI) report on behalf of larger GRB  follow-up collaboration:

We observed of  the field of  Swift GRB GRB 140502A  with 0.4-m 
telescope of ISON-NM observatory starting on May, 02 (UT)  08:31:32, 
i.e. 72 s after BAT trigger (Swenson et al.,  GCN 16202
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 ). We took series 
of unfiltered images of 30 s - 60 s exposures.  A bright star (USNO-B1.0 
1389-0392112) already mentioned (Oates et al.,  GCN 16210
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 ) lies within 
enhanced XRT error circle (Goad et al.,  GCN 16206
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 ). We investigate 
variability of  a possible OT  in presence in near vicinity of the 
bright star. The upper limit of possible variation of the OT is 16.6m 
within any of 60 s interval of our observations between (UT)  08:31:32 
and 09:24:25 which can be considered as an upper limit on the OT 
associated with GRB 140502A.

Formal photometry and limiting magnitude of point-like source in the 
observed field is following

UT start   t-T0        Exp.    Filter   OT   UL(3 sigma)
           (mid.,days)  (s)
08:31:32  0.00383      10*30   None     n/d  18.8

and based on nearby USNO-B1.0 stars, R2 magnitudes.

S. R. Oates (IAA-CSIC,UCL-MSSL) and C. A. Swenson (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140502A
75 s after the BAT trigger (Swenson et al., GCN Circ. 16202
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 ). Two bright 
USNO-B1 sources lie close to the XRT location, with R magnitudes of 13.48 
and 13.61, lie within 3 and 9 arcseconds, respectively of the XRT position 
(Goad et al., GCN Circ. 16206
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 ). Neither of these sources are observed to 
vary significantly over the duration of the initial UVOT observations.

Ppreliminary 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            75          225          147         >16.0
u_FC               287          537          246         >16.3
white               75         5702          525         >16.0
v                  616         6113          432         >15.0
b                  543        11919          337         >16.0
u                  287        11811         1347         >16.3
w1                 666        17270         1642         >17.9
m2                4681        16734         1262         >20.0
w2                 593         5908          432         >18.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 2.97 in the direction of the burst
(Schlegel et al. 1998).

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 MITSuME collaboration:

We observed the field of GRB 140502A (Swenson et al., GCNC 16202)
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 2014-05-02 16:48:47 UT (~8.3 h after the burst).
We did not find any new point source within the enhanced XRT circle
(Goad et al., GCNC 16206) in all the three bands.

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
-----------------------------------------------------
0.38783    17:48:49    6180.0   >19.5  >19.2  >18.5
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

A. Y. Lien (NASA/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), C. A. Swenson (PSU),
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 recent telemetry downlinks,
we report further analysis of BAT GRB 140502A (trigger #597841)
(Swenson, et al., GCN Circ. 16202
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 ).  The BAT ground-calculated position is
RA, Dec = 319.172, 48.975 deg, which is 
   RA(J2000)  =  21h 16m 41.3s 
   Dec(J2000) = +48d 58' 28.2" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
 
The mask-weighted light curve shows a FRED-shaped peak starting at ~T-3 sec,
peaking at ~T+2 sec, and ending at ~T+20 sec.  T90 (15-350 keV) is
16.9 +- 1.9 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.66 to T+17.39 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.22 +- 0.13.  The fluence in the 15-150 keV band is 6.7 +- 0.5 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.44 sec in the 15-150 keV band
is 0.9 +- 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/597841/BA/

D.N. Burrows (PSU), C. Pagani (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), P.
D'Avanzo (INAF-OAB), V. D'Elia (ASDC), J.A. Kennea (PSU), V. Mangano
(PSU) and C.A. Swenson report on behalf of the Swift-XRT team:

We have analysed 6.3 ks of XRT data for GRB 140502A (Swenson  et al.
GCN Circ. 16202
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 ),  from 84 s to 17.3 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Goad et al. (GCN Circ. 16206
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 ).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=0.85 (+0.23, -0.17).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.7 (+0.8, -0.6). The
best-fitting absorption column is  2.2 (+1.4, -1.1) x 10^22 cm^-2, in
excess of the Galactic value of 9.5 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 7.0 x 10^-11 (1.3 x 10^-10) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     2.2 (+1.4, -1.1) x 10^22 cm^-2
Galactic foreground: 9.5 x 10^21 cm^-2
Excess significance: 1.8 sigma
Photon index:	     1.7 (+0.8, -0.6)

If the light curve continues to decay with a power-law decay index of
0.85, the count rate at T+24 hours will be 7.5 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.3 x
10^-14 (9.5 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00597841.

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

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

Using 1615 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 140502A, 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 = 319.18818, +48.97021 which is equivalent
to:

RA (J2000): 21h 16m 45.16s
Dec (J2000): +48d 58' 12.7"

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.

Hoi-Fung Yu (MPE) reports on behalf of the Fermi GBM Team:

"At 08:30:20.11 UT on 02 May 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140502A (trigger 420712223 / 140502354),
which was also detected by Swift/BAT and XRT (Swenson et al. 2014, GCN 16202
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 ).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight is 64 degrees.

The GBM light curve consists of a single pulse with a duration (T90) 
of about 20 s (50-300 keV). The time-averaged spectrum from T0-2.048 s 
to T0+6.144 s is well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.7 +/- 0.2 and
the cutoff energy, parameterized as Epeak, is 298 +/- 71 keV.

The event fluence (10-1000 keV) in this time interval is
(1.6 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.448 s in the 10-1000 keV band is 1.6 +/- 0.2 ph/s/cm^2.

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

C. A. Swenson (PSU), S. D. Barthelmy (GSFC), M. M. Chester (PSU) and
P. A. Evans (U Leicester) report on behalf of the Swift Team:

At 08:30:20 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140502A (trigger=597841).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 319.155, +49.018 which is 
   RA(J2000)  =  21h 16m 37s
   Dec(J2000) = +49d 01' 04"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
with a duration of about 25 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 08:31:31.3 UT, 70.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 319.18744, 48.97012 which is equivalent
to:
   RA(J2000)  = 21h 16m 44.99s
   Dec(J2000) = +48d 58' 12.4"
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This
location is 188 arcseconds from the BAT onboard position, outside 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 9.47
x 10^21 cm^-2 (Willingale et al. 2013). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 74 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 none of
the XRT error circle. 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 large, but
uncertain extinction expected. 

Burst Advocate for this burst is C. A. Swenson (cswenson 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.)