GRB 130610A

Klotz A. (IRAP-CNRS-OMP), Gendre B. (IRAP-CNRS-OMP),
Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA),
Atteia J.L. (IRAP-CNRS-OMP) report:

We imaged the field of GRB 130610A detected by SWIFT
(trigger 557845) with the TAROT robotic telescope (D=25cm)
located at the European Southern Observatory,
La Silla observatory, Chile.

The observations started 91s after the GRB trigger
(17s after the notice). The elevation of the field
decreased from 31 degrees above horizon and weather conditions
were good.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We recorded the rise of the afterglow discovered by
Melandri et al. (GCNC 14843).

We used the star NOMAD1 1182-0257977 R.A.=224.3892908
DEC=+28.2065917 R=14.11 to extract the light curve
of the rise of the afterglow:

start end     Rmag
(sec) (sec)
   91   97   > 17.8
   97  103   > 17.8
  103  109   > 17.8
  109  115   > 17.8
  115  121   > 17.8
  121  127     17.7
  127  133     16.9
  133  139     16.5
  139  145     16.6
  145  151     16.1

Magnitudes are not corrected for galactic dust extinction.

After the trailed image a technical problem prevented
to obtain next images.

V. Rumyantsev (CrAO), A. Pozanenko (IKI) report on behalf of  larger GRB 
  follow-up collaboration:

We observed of  the field of  the Swift GRB 130610A (Cummings et al.,
GCN 14842
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 ) with Shajn telescope of CrAO starting on June, 10 (UT)
19:03:05. Several exposures of 120 s were obtained in R-filter. In the
combined image we clearly detected bright point-like source
superimposed on an extended object. Coordinates of the bright object
(J2000) 14 57 40.85 +28 12 25.5 (uncertainty of 0.2" in both
coordinates)  coincide with the afterglow coordinates (Cummings et al.,
GCN 14842
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 ; Melandri et al., GCN 14843
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 ). The extended object could be a
host galaxy with brightness of R ~ 23.8.

Preliminary photometry might be biasedby the extended object and  based 
  on the USNO B1.0 star 1182-0253576 14 57 45.41 +28 12 57.7 assuming 
R=18.98:


UT start,            T0+      Filter  Exposure, OT,             UL
                      mid,days          s
2013-06-10T19:03:05  0.6860   R       35*120    21.70 +/- 0.05  23.9


A finding chart can be found at
http://grb.rssi.ru/GRB130610A/GRB130610a_20130610_R_ZTSh.GIF

Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill
Observatory, Varkaus, Finland) report:

We have detected GRB 130610A optical afterglow at iTelescope observatory
T21 (Mayhill, New Mexico) 0.43m/6.8 astrograph and FLI-PL6303E CCD
camera. Three unfiltered images and three photometric R filter images with 
300 sec exposure time were made.

The afterglow was detected at following position RA 14:57:40.86 and 
DEC +28:12:26.0

The following magnitudes were obtained from the observations using 
NOMAD1 1182-0257977 (R=14.110) as the comparison:

Tmid(sec)+T0    Filter          Exp. time    Mag              Mag err. 
2442                  unfiltered      300            19.09CR     0.15
2759                  unfiltered      300            19.34CR     0.19
3076                  unfiltered      300            19.17CR     0.16
3717                  R                 300            19.58R        0.32
4034                  R                 300            19.93R        0.44
4351                  R                 300            19.93R        0.43

L. Elenin (KIAM),  V. Savanevych (KNURE),  A. Bryukhovetskiy (NSFCTC), 
I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of  larger GRB 
follow-up collaboration:

We observed of  the field of  the Swift GRB 130610A (Cummings et al., 
GCN 14842
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 )  with 0.45-m telescope of ISON-NM observatory starting on 
June, 10 (UT) 03:53:49. Series of 30 s  exposures were obtained in clear 
filter. In the combined images we detect afterglow  (Cummings et al., 
GCN 14842
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 ; Melandri et al., GCN 14843
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 ; Trotter et al., GCN 14844
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 ). 
Preliminary photometry  is based  on the SDSS nearby  stars:


UT start,   T0+       Filter  Exposure,  OT,
             days              s
03:53:49    0.03531   none    25*30     19.33 �� 0.07
04:12:33    0.04831   none    25*30     19.56 �� 0.10

M. H. Siegel (PSU) and J. R. Cummings (NASA/UMBC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 130610A
140 s after the BAT trigger (Cummings et al., GCN Circ. 14842
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 ).
A fading source consistent with the XRT position (Cummings et al. GCN Circ. 14842
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 )
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
   RA  (J2000) =  14:57:40.88 = 224.42034 (deg.)
   Dec (J2000) = +28:12:25.8  =  28.20717 (deg.)
with an estimated uncertainty of 0.51 arc sec. (radius, 90% confidence).

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 listed below.
The lack of detection in the NUV filters would be consistent with the z=2.1 redshift 
reported by Smette et al. (GCN Circ. 14848
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 ).

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

white (fc)       140         290        147     17.85+-0.04
white           1491        1857         58     19.56+-0.19
white           5267        6902        393     20.47+-0.15
v               1540        7312        451    >20.07
b               1467        2005         77     19.12+-0.20
b               6498       19320       1754     21.72+-0.38
u                298         441        140     17.67+-0.09
u               1614        1980         58     19.00+-0.30
uvw1            1589        1956         58    >19.05
uvm2            1911       23463       1298    >21.09
uvw2            1863        7108        412    >20.63

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).

G. Fitzpatrick (UCD) and V. Pelassa (UAH)
report on behalf of the Fermi GBM Team:

At 03:12:10.50 UT on 10 June 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 130610A (trigger 392526733 /130610133)
which was also detected by the Swift/BAT (Cummings et al., GCN Circ. 14842
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 ).
The GBM on-ground location is consistent with the Swift position.

The GBM light curve consists of a single peak
with a duration (T90) of about 28 s (50-300 keV).
The time-averaged spectrum from T0-2.6 s to T0+25.7 s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.0 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 294.9 +/- 42.9 keV

The event fluence (10-1000 keV) in this time interval is
(6.1 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+8.0 s in the 10-1000 keV band is 4.5 +/- 0.9 ph/s/cm^2.

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

M. Im (CEOU/SNU), H.-I. Sung(KASI), and Y. Urata (NCU) 
on behalf of EAFON

We observed the field of GRB 130610A (Cummings et al. GCN 14842
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 ),
using a 1-m telescope at Mt. Lemmon Optical Observatory (LOAO) in
Arizona, US. The observation started at 2013-06-10 05:54:16 UT,
about 2.7 hrs after the burst alert, and a series of images were 
taken in B, R, and I-band for about 40 min.

We identify the afterglow (Melandri et al. GCN 14843
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 ), in all the 
three bands, with approximate magnitude of B = 21.35 +- 0.12, 
V=20.90 +- 0.26, and R=20.35 +- 0.18, all in Vega magnitude, calibrated 
against a star in the vicinity using SDSS photometry converted to BVR.

We thank the LOAO operator, In-Kyung Baek for performing 
the observation.

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

We have analysed 11 ks of XRT data for GRB 130610A (Cummings  et al.
GCN Circ. 14842
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 ),  from 139 s to 25.1 ks after the  BAT trigger. The
data comprise 116 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Osborne et al. (GCN. Circ 14851).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=1.17 (+/-0.03).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.04 (+/-0.15). The
best-fitting absorption column is  2.6 (+2.8, -2.6) x 10^21 cm^-2, at a
redshift of 2.092, in addition to the Galactic value of 1.9 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 (3.9 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 1.9 x 10^20 cm^-2
Intrinsic column:    2.6 (+2.8, -2.6) x 10^21 cm^-2 at z=2.092
Photon index:	     2.04 (+/-0.15)

If the light curve continues to decay with a power-law decay index of
1.17, the count rate at T+24 hours will be 3.2 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-13 (1.3 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/00557845.

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

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

Using 7625 s of XRT Photon Counting mode data and 8 UVOT
images for GRB 130610A, 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 = 224.42032, +28.20711 which is equivalent
to:

RA (J2000): 14h 57m 40.88s
Dec (J2000): +28d 12' 25.6"

with an uncertainty of 1.4 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.

C. B. Markwardt (GSFC), 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), D. M. Palmer (LANL),
T. Sakamoto (AGU), 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-60 to T+243 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 130610A (trigger #557845)
(Cummings, et al., GCN Circ. 14842
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 ).  The BAT ground-calculated position is
RA, Dec = 224.414, 28.187 deg which is
    RA(J2000)  =  14h 57m 39.3s
    Dec(J2000) = +28d 11' 13.8"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 96%.
  
The mask-weighted light curve shows a single FRED peak.  T90 (15-350 keV) is
46.4 +- 11.2 sec (estimated error including systematics).
  
The time-averaged spectrum from T-7.04 to T+61.02 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.27 +- 0.08.  The fluence in the 15-150 keV band is 2.5 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+4.53 sec in the 15-150 keV band
is 1.7 +- 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/557845/BA/

A. Smette (ESO), C. Ledoux (ESO), P. Vreeswijk (Weizmann), A. De Cia 
(Weizmann)**,
P. Petitjean (IAP),  J. Fynbo (DARK/NBI), D. Malesani (DARK/NBI), A. Fox 
(STSCI) report:

  We have observed GRB 130610A  (Cummings et al., GCN 14842
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 ) with UVES
on the ESO-VLT, in Rapid Response Mode. Preliminary analysis of the 
automatically
reduced spectra reveals the presence of an absorption line system at z ~ 
2.092
including a damped Ly-alpha line, CIV 1548 &1550, SiIV 1393 & 1402, SiII 
1260 & 1526
FeII 1608, 2382, 2600, AlII1670, AlIII 1854 & 1862. This absorption line 
system
can be identified with the gamma-ray burst redshift.

We are grateful to the excellent support provided by Christophe Martayan
and Felipe Gaete.

S. B. Cenko (NASA/GSFC) and D. A. Perley (Caltech) report on behalf of a
larger collaboration:

We have imaged the optical afterglow of the Swift GRB 130610A (Cummings et
al., GCN 14842
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 ) with the robotic Palomar 60 inch telescope.  A series of
90 s exposures in the g', r', i', and z' filters were begun starting at
04:23 UT on 2013 Jun 10 (1.18 hr after the Swift trigger).  We detect the
afterglow in individual exposures in all 4 filters.  Using nearby point
sources from SDSS for calibration, we measure a magnitude of r' = 19.8 in
our initial images.  Compared with earlier observations with the Liverpool
telescope (Melandri et al., GCN 14843
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 ), this suggests a power-law decay
index of ~ 1.2.

A. N. Morgan & C. R. Klein (UC Berkeley) report:

We observed the field of GRB 130610A (Cummings et al., GCN 14842
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 ) with the
1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at
2013-Jun-07 03h35m37s UT, 0.39 hr after the Swift Trigger.  In  mosaics
(effective exposure time of ~5.85 minutes) taken simultaneously in the J,
H, and Ks filters, we detect the optical afterglow (Cummings et al., GCN
14842
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 ; Melandri et al., GCN 14843
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 ; Trotter et al. GCN 14844
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 ). The
preliminary K-band reduction is corrupted.

The preliminary photometry yields:

post burst
t_mid (hr) exp.(m)  filt  mag   m_err
0.47       5.85     J     17.49  0.16
0.47       5.85     H     16.95  0.20

Observations are ongoing. All magnitudes are given in the Vega system,
calibrated to 2MASS. No correction for Galactic extinction has been made to
the above reported values.

A. Trotter, J. Haislip, A. LaCluyze, D. Reichart, T. Berger, M. Carroll, 
H. T. Cromartie, R. Egger, A. Foster, C. Foster, N. Frank, K. Ivarsen, 
D. James, M. Maples, J. Moore, M. Nysewander, E. Speckhard, P. Taylor 
and J. A. Crain report

Skynet observed the Swift/XRT localization of GRB 130610A (Cummings et 
al., GCN 14842
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 , Swift trigger #557845), starting at 2013-06-10, 03:14:05 
UT (t=2.03m post-trigger), with three 16" telescopes of the PROMPT array 
at CTIO, Chile.  We detect a fading afterglow in B, V and I bands at: RA 
= 14:57:40.9, Dec = 28:12:25.5 (J2000.0), consistent with the UVOT 
source position reported in GCN 14842
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 .

The afterglow rises until t~3.4m, at which time the apparent magnitudes 
are B~18.1, V~17.1, I~16.6.  A preliminary light curve is at:
http://www.skynet.unc.edu/grb/grb130610a.png

Magnitudes are in the Vega system and photometry is calibrated to 4 SDSS 
stars in the field.

Skynet observations are ongoing.

A. Melandri (INAF-OAB), F.J. Virgili(LJMU), C.G. Mundell (LJMU) and A. 
Gomboc (U. Ljubljana) report:

The 2-m Liverpool Telescope robotically followed up GRB130610A (Swift 
trigger 557845, Cummings et al., GCN 14842
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 ) 15.5  min after the GRB 
trigger time observing with SLOAN-gri filters.

The automatic LT-TRAP procedure detected an uncatalogued fading source 
candidate at:

RA = 14:57:40.89
Dec = +28:12:25.5    (J2000)

with magnitude R~17.9 mag (vs USNOB1) ~16 min after the burst trigger.  
The object is clearly fading in all filters.

Observations and analysis are ongoing.

[GCN OPS NOTE(10jun13):  The GRB name in the firt sentence was changed
from "130410A" to "130610A".]

J. R. Cummings (NASA/UMBC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC), J. A. Kennea (PSU),
H. A. Krimm (CRESST/GSFC/USRA), D. Malesani (DARK/NBI),
C. B. Markwardt (NASA/GSFC), A. Maselli (INAF-IASFPA),
A. Melandri (INAF-OAB), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. H. Siegel (PSU) and T. N. Ukwatta (MSU) report on behalf of the
Swift Team:

At 03:12:13 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 130610A (trigger=557845).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 224.416, +28.191 which is 
   RA(J2000) = 14h 57m 40s
   Dec(J2000) = +28d 11' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a total duration of about 30 sec.  The peak count rate
was ~2700 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 03:14:26.3 UT, 133.0 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 224.4218, 28.2048 which is equivalent to:
   RA(J2000)  = +14h 57m 41.23s
   Dec(J2000) = +28d 12' 17.3"
with an uncertainty of 6.6 arcseconds (radius, 90% containment). This
location is 52 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. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 140 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =	14:57:40.89 = 224.42037
  DEC(J2000) = +28:12:25.7  =  28.20715
with a 90%-confidence error radius of about 0.62 arc sec. This position is 9.6
arc sec. from the center of the XRT error circle. The estimated magnitude is
17.91 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.02. 

Burst Advocate for this burst is J. R. Cummings (jayc AT milkyway.gsfc.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.)