GRB 140430A

T. Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi,
S. Kurita, Y.Ono , Y. Yatsu, and N. Kawai (Tokyo Tech)

report on behalf of the MITSuME collaboration:
We observed the field of GRB 140430A (Siegel et al. , GCN Circular #16190
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 ) with the 
optical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 2014-05-01 10:57:06 UT ( 14.4 h after the burst).
We did not find any new point source within the enhanced XRT circle (Evans et al., GCNC 16195) in all the three bands.
The measured magnitudes were listed below.

T0+[sec]    MID-UT    T-EXP[sec]    g'         Rc         Ic
---------------------------------------------------------------------------------------
   54229  11:37:25     3540        >19.2    >19.5     >19.2
---------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.

T. Sakamoto, D. Kawamura, A. Yoshida (AGU)

We observed the field of GRB 140430A detected by Swift (trigger #597722; 
Siegel et al., GCN Circ. 16190
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 ) with the iTelescope.Net (http://www.itelescope.net) 
T16 (15 cm Takahashi TOA-150) telescope located at the AstroCamp Observatory 
(Nerpio, Spain).  

Due to the elevation constraint, we were able to collect only 4 images of 60 sec 
exposures in the R filter starting from April 30 20:46:42 (UT) about 13 minutes 
after the trigger and stopped on April 30 20:52:42 (UT).  We do not detect the optical afterglow 
both in the individual images and the stacked image at the reported optical 
afterglow position (Siegel et al., GCN Circ. 16190
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 ; Malesani et al., GCN Circ. 16193
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 ).  
The estimated five sigma upper limit of the combined image (total exposure of 240 sec) 
is ~18.6 using the USNO-B1 catalog.

A. J�rvinen (AIP) and J. Gorosabel (IAA-CSIC/UPV-EHU), report on behalf 
of larger collaborations:

"The field of GRB 140430A (Siegel et al. GCN 16190
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 ) was observed with 
WiFSIP on STELLA-I telescope located at Observatorio del Teide,
Tenerife, Spain.  The automatic observations were carried out on April
30., 2.9-32.5 min post trigger using the r'-band filter. The object is 
clearly detected in all 52 images with preliminary r'(AB) magnitudes
ranging from ~17.0 to ~18.6 calibrated against the USNO B1.0 catalogue."

[GCN OPS NOTE(03may14):  The distribution was delayed by 3 hours
due to a stale address in the vetting list.]

J. Gorosabel (IAA-CSIC/UPV-EHU), E. Gomez (IAC), P.A. Gonzalez-Morales (IAC), J. Cepa (IAC), report on behalf of a larger collaboration:

"We observed the field of GRB 140430A (Siegel et  al. GCN 16190
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 ) with the 0.82m IAC80 telescope located at Observatorio del Teide, Tenerife, Spain. The observations were carried on April 30.87401-30.88509 UT (25.0-40.9 min post burst) using the BVR-band filters. The optical afterglow is clearly detected in the three bands with a preliminary Vega magnitude of B=19.3 against the USNO B1.0 catalogue."

M. Kennedy (University College Cork), P. Garnavich (Notre Dame)

We again observed the field around GRB 140430A with the 1.8m Vatican
Advanced Technology Telescope (VATT; GCN 16196
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 ). Observations with the
VATT4K CCD were centered around 3:22 UT on 2014 May 2 (1848 minutes after
the burst). We obtained 5x300s exposures with the R-band filter in good
seeing. We detect the previously reported afterglow in the combined images.

With the same USNO comparison star used by Malesani et al (GCN 16193
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 )
and Kennedy et al. (GCN 16196
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 ) we estimate the afterglow brightness
as R=21.7 +/- 0.1 at 30.81 hours after the burst. This is fainter
than the extrapolation of the power-law decay rate estimated for the
first seven hours and we conclude that optical power-law decay index has
steepened to 1.0 over the past day.

H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. H. Siegel (PSU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-152 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140430A (trigger #597722)
(Siegel, et al., GCN Circ. 16190
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 ).  The BAT ground-calculated position is
RA, Dec = 102.942, 23.033 deg, which is 
   RA(J2000)  =  06h 51m 46.0s 
   Dec(J2000) = +23d 01' 58.2" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows several well separated peaks.
The first (and brightest) starts at ~T-1 sec, peaks at ~T+4 sec,
and ends at ~T+9 sec.  The 2nd and 3rd peaks peak at ~T+30 and ~T+180,
respectively.  T90 (15-350 keV) is 173.6 +- 3.7 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-0.30 to T+177.58 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.00 +- 0.22.  The fluence in the 15-150 keV band is 1.1 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+2.44 sec in the 15-150 keV band
is 2.5 +- 0.2 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/597722/BA/

A. A. Breeveld (UCL-MSSL) and M. H. Siegel (PSU) report on behalf of the 
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140430A 
183 s after the BAT trigger (Siegel et al., GCN Circ. 16190
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 ). A fading 
source consistent with the refined XRT position (Evans et al. GCN Circ. 
16195
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 ) is confirmed in the initial UVOT exposures. The detection in the 
uvw1 filter, but not in uvm2 and uvw2 is consistent with the redshift of 
1.6 given by Kruehler et al., (GCN Circ. 16194
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 ).

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

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

white_FC           183          333          147         18.17 � 0.09
white             4020         4220          197         19.61 � 0.17
v                  417         4630          216        >18.6
b                 3815         4015          197         19.77 � 0.34
u                10431        10933          490         19.46 � 0.19
uvw1              6178        10424          966         20.40 � 0.31
uvm2               442         4835          216        >19.9
uvw2               393         4425          216        >19.4

The magnitudes in the table are not corrected for the Galactic 
extinction due to the reddening of E(B-V) = 0.14 in the direction of the 
burst (Schlegel et al. 1998).

M.C. Stroh (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), C.
Pagani (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri
(INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), J.A.
Kennea (PSU) and M.H. Siegel report on behalf of the Swift-XRT team:

We have analysed 7.0 ks of XRT data for GRB 140430A (Siegel  et al. GCN
Circ. 16190
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 ),  from 132 s to 23.5 ks after the	BAT trigger. The data
comprise 382 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. 16195
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 ).

The late-time light curve (from T0+3.8 ks) can be modelled with  a
power-law decay with a decay index of alpha=0.68 (+0.12, -0.13).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 2.05 (+/-0.04). The
best-fitting absorption column is  3.7 (+1.4, -1.3) x 10^21 cm^-2, at a
redshift of 1.6, in addition to the Galactic value of 2.1 x 10^21 cm^-2
(Willingale et al. 2013). The PC mode spectrum has a photon index of
2.21 (+0.20, -0.19) and a best-fitting absorption column of 5.3 (+6.5,
-5.3) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV
flux conversion factor deduced from this spectrum  is 3.3 x 10^-11 (5.2
x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 2.1 x 10^21 cm^-2
Intrinsic column:    5.3 (+6.5, -5.3) x 10^21 cm^-2 at z=1.6
Photon index:	     2.21 (+0.20, -0.19)

If the light curve continues to decay with a power-law decay index of
0.68, the count rate at T+24 hours will be 0.018 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 6.0 x
10^-13 (9.6 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00597722.

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

M. Kennedy (University College Cork), P. Garnavich (Notre Dame)

We observed the region around GRB 140430A with the 1.8m Vatican Advanced
Technology Telescope (VATT) on 2014 May 1 (UT). With the VATT4K CCD we
obtained 5x120s exposures in the R-band centered around 03:22UT (408 mins
after the GRB). A source not seen in the Digitized Sky Survey is
well-detected at the coordinates reported by Malesani et al (GCN 16193
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 ).
Relative photometry was carried out using the same nearby star used by
Malesani et al. which has an R-band magnitude of R=15.13.

Our R-band magnitude for the GRB, 6.81 hours after the initial outburst,
is R=20.07 +- 0.03. Combining our results with the magnitude from GCN
16193
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  we estimate an optical power-law decay index of 0.76.

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

Using 1017 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 140430A, 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 = 102.93576, +23.02375 which is equivalent
to:

RA (J2000): 06h 51m 44.58s
Dec (J2000): +23d 01' 25.5"

with an uncertainty of 1.9 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.

T. Kruehler (ESO Santiago), D. Malesani (DARK/NBI), A. de Ugarte Postigo 
(IAA/CSIC and DARK/NBI), A. Melandri (INAF/OABr), J. P. U. Fynbo 
(DARK/NBI), report on behalf of a larger collaboration:

We observed the optical afterglow of GRB 140430A (Siegel et al., GCN 
16190
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 ) with the ESO VLT equipped with X-shooter. Observations started at 
23:09 UT on 2014 April 30 (2.5 hr after the GRB), still in twilight, and 
two 10-minute spectra were secured. The covered wavelength range is 
3000-25000 AA.

We detect a clear continuum, and several absorption features, which we 
interpret as due, among others, to Si II, C IV, Al II, Fe II, and Mg II 
at a common redshift z = 1.60. In the infrared arm, we also detect the 
[O III] 5008 nebular line in emission at the same redshift.

We acknowledge excellent support from the ESO staff at Paranal, in 
particular Andrea Mehner, Rodrigo Romero, and Stephane Brillant.

D. Malesani (DARK/NBI), T. Kruehler (ESO Santiago), A. de Ugarte Postigo 
(IAA/CSIC and DARK/NBI), H. Dahle (Univ. Oslo), E. Soto (CUA), report on 
behalf of a larger collaboration:

We observed the optical afterglow of GRB 140430A (Siegel et al., GCN 
16190
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 ; Melandri et al., GCN 16192
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 ) with the Nordic Optical Telescope 
equipped with ALFOSC. We took a single 100-s image in the R filter 
starting at 22:00 UT (86.5 min after the GRB). The optical afterglow is 
well detected at coordinates (J2000):

RA = 06:51:44.61
Dec = +23:01:25.1

with an uncertainty of 0.3". Assuming R = 15.13 for the USNO star at RA 
= 06:51:41.3, Dec = +23:01:44.0, we measure for the optical afterglow a 
magnitude R = 18.78 +- 0.02 (statistical error only).

A 1800-s spectrum was acquired starting at 22:11 UT, at airmass 2.2-2.8, 
covering the wavelength range 3200-9100 AA. From a preliminary analysis, 
no absorption or emission features are seen in the spectrum. From the 
lack of a DLA feature down to ~4000 AA, we can set a redshift limit z < 2.3.

A. Melandri (INAF-OAB), C. Guidorzi (U. Ferrara), A. Gomboc (U. Ljubljana), R. J. Smith and C. G. Mundell (LJMU), on behalf of a large collaboration report:

The 2-m Liverpool Telescope with the RINGO3 polarimeter robotically followed up Swift GRB 140430A (Siegel et al., GCN 16190
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 ) at 20:35:40 UT (~2 min after the burst trigger).

We detect the optical afterglow at the UVOT position. In a coadded 3x10s SDSS-r image, we estimate a preliminary magnitude R = 18.4 +/- 0.1 at t_mid = 33.1 min since the Swift/BAT trigger time. The magnitude is calibrated against nearby USNO-B1 stars.

Observations are ongoing.

M. H. Siegel (PSU), W. H. Baumgartner (GSFC/UMBC),
M. M. Chester (PSU), V. D'Elia (ASDC), S. T. Holland (STScI),
J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL),
C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC) and
T. N. Ukwatta (MSU) report on behalf of the Swift Team:

At 20:33:36 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140430A (trigger=597722).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 102.929, +23.009 which is 
   RA(J2000)  =  06h 51m 43s
   Dec(J2000) = +23d 00' 34"
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 10 sec.  The peak count rate
was ~4500 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 20:34:27.3 UT, 50.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 102.9359, 23.0227 which is equivalent to:
   RA(J2000)  = +06h 51m 44.62s
   Dec(J2000) = +23d 01' 21.7"
with an uncertainty of 4.9 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 2.5 s image was 3.99e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 183 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	06:51:44.61 = 102.93589
  DEC(J2000) = +23:01:25.2  =  23.02367
with a 90%-confidence error radius of about 0.62 arc sec. This position is 3.5
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.16 with a 1-sigma error of about  0.15. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.14. 

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.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.)