Gamma-ray Burst 140413A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:10:59 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     595616,   Seg_Num: 0
GRB_RA:           65.449d {+04h 21m 48s} (J2000),
                  65.542d {+04h 22m 10s} (current),
                  65.124d {+04h 20m 30s} (1950)
GRB_DEC:         -51.205d {-51d 12' 17"} (J2000),
                 -51.172d {-51d 10' 18"} (current),
                 -51.321d {-51d 19' 16"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1249 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        16760 TJD;   103 DOY;   14/04/13
GRB_TIME:        580.12 SOD {00:09:40.12} UT
GRB_PHI:         -81.09 [deg]
GRB_THETA:        40.77 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    12.49 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +2  +0  +0 -32  +0 
SUN_POSTN:        21.28d {+01h 25m 08s}   +8.94d {+08d 56' 29"}
SUN_DIST:         71.19 [deg]   Sun_angle= -3.0 [hr] (East of Sun)
MOON_POSTN:      174.85d {+11h 39m 23s}   -0.95d {-00d 57' 17"}
MOON_DIST:       101.20 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      259.19,-43.96 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       39.27,-70.35 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 40.41,-18.72 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:13:37 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     595616,   Seg_Num: 0
GRB_RA:           65.449d {+04h 21m 48s} (J2000),
                  65.542d {+04h 22m 10s} (current),
                  65.124d {+04h 20m 30s} (1950)
GRB_DEC:         -51.205d {-51d 12' 17"} (J2000),
                 -51.172d {-51d 10' 18"} (current),
                 -51.321d {-51d 19' 16"} (1950)
GRB_DATE:        16760 TJD;   103 DOY;   14/04/13
GRB_TIME:        580.12 SOD {00:09:40.12} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -81.09 [deg]
GRB_THETA:        40.77 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    12.49 [sigma]
LC_URL:          sw00595616000msb.lc
SUN_POSTN:        21.28d {+01h 25m 08s}   +8.94d {+08d 56' 32"}
SUN_DIST:         71.19 [deg]   Sun_angle= -3.0 [hr] (East of Sun)
MOON_POSTN:      174.87d {+11h 39m 28s}   -0.96d {-00d 57' 44"}
MOON_DIST:       101.21 [deg]
MOON_ILLUM:      94 [%]
GAL_COORDS:      259.19,-43.96 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       39.27,-70.35 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is an image trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 40.41,-18.72 [deg].

GCN Circular #16098
V. D'Elia (ASDC), S. T. Holland (STScI), L. Izzo (URoma/ICRA), F. E. Marshall (NASA/GSFC) and B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:
At 00:09:40 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140413A (trigger=595616). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 65.449, -51.205 which is
```
   RA(J2000) = 04h 21m 48s
   Dec(J2000) = -51d 12' 17"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). This is an image trigger and we cannot say much about the light curve. However, since it is 12.5 sigma detection at 64 sec exposure in the image domain, it is likely to be real.
Due to an observing constraint, Swift will not slew until T0+33.6 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). 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.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:47:04 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     595616,   Seg_Num: 0
GRB_RA:           65.4544d {+04h 21m 49.05s} (J2000),
                  65.5475d {+04h 22m 11.39s} (current),
                  65.1289d {+04h 20m 30.93s} (1950)
GRB_DEC:         -51.1831d {-51d 10' 59.1"} (J2000),
                 -51.1501d {-51d 09' 00.4"} (current),
                 -51.2995d {-51d 17' 58.1"} (1950)
GRB_ERROR:       6.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       6.58e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.09 [sigma]
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2791.37 SOD {00:46:31.37} UT,   2211.2 [sec] since BAT Trigger Time
TAM[0-3]:        327.67 237.22 261.59 243.54
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        21.31d {+01h 25m 13s}   +8.95d {+08d 57' 02"}
SUN_DIST:         71.17 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.14d {+11h 40m 35s}   -1.06d {-01d 03' 26"}
MOON_DIST:       101.30 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.16,-43.96 [deg] galactic lon,lat of the burst
ECL_COORDS:       39.31,-70.33 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.33 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:47:16 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     595616,   Seg_Num: 0
GRB_RA:           65.4544d {+04h 21m 49.0s} (J2000),
                  65.5475d {+04h 22m 11.3s} (current),
                  65.1289d {+04h 20m 30.9s} (1950)
GRB_DEC:         -51.1831d {-51d 10' 59.1"} (J2000),
                 -51.1501d {-51d 09' 00.4"} (current),
                 -51.2995d {-51d 17' 58.1"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       26 [cnts]
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2791.37 SOD {00:46:31.37} UT,   2211.2 [sec] since BAT Trigger Time
CENTROID_X:      336.38,  raw= 336  [pixels]
CENTROID_Y:      295.47,  raw= 295  [pixels]
ROLL:            313.43 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -5.48
GRB_POS_XRT_Z:   73.26
IMAGE_URL:       sw00595616000msxps_rw.img
SUN_POSTN:        21.31d {+01h 25m 13s}   +8.95d {+08d 57' 02"}
SUN_DIST:         71.17 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.15d {+11h 40m 35s}   -1.06d {-01d 03' 28"}
MOON_DIST:       101.30 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.16,-43.96 [deg] galactic lon,lat of the burst
ECL_COORDS:       39.31,-70.33 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:47:27 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     595616,   Seg_Num: 0
GRB_RA:           65.4544d {+04h 21m 49.0s} (J2000),
                  65.5475d {+04h 22m 11.3s} (current),
                  65.1289d {+04h 20m 30.9s} (1950)
GRB_DEC:         -51.1831d {-51d 10' 59.1"} (J2000),
                 -51.1501d {-51d 09' 00.4"} (current),
                 -51.2995d {-51d 17' 58.1"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       26 [cnts]
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2791.37 SOD {00:46:31.37} UT,   2211.2 [sec] since BAT Trigger Time
CENTROID_X:      336.38,  raw= 336  [pixels]
CENTROID_Y:      295.47,  raw= 295  [pixels]
ROLL:            313.43 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -5.48
GRB_POS_XRT_Z:   73.26
IMAGE_URL:       sw00595616000msxps_rw.img
SUN_POSTN:        21.31d {+01h 25m 13s}   +8.95d {+08d 57' 03"}
SUN_DIST:         71.17 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.15d {+11h 40m 35s}   -1.06d {-01d 03' 30"}
MOON_DIST:       101.30 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.16,-43.96 [deg] galactic lon,lat of the burst
ECL_COORDS:       39.31,-70.33 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:52:19 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     595616,   Seg_Num: 0
POINT_RA:         65.429d {+04h 21m 43s} (J2000)
POINT_DEC:       -51.170d {-51d 10' 11"} (J2000)
POINT_ROLL:      313.427d
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2800.78 SOD {00:46:40.78} UT,   2220.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        8.563
N_STARS:         24
X_OFFSET:        208 [pixels]
Y_OFFSET:        584 [pixels]
X_MAX:           1167 [pixels]
Y_MAX:           1543 [pixels]
DET_THRESH:      26
PHOTO_THRESH:    16
SL_URL:          sw00595616000msufc2220.fits
SUN_POSTN:        21.31d {+01h 25m 14s}   +8.95d {+08d 57' 07"}
SUN_DIST:         71.15 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.19d {+11h 40m 45s}   -1.07d {-01d 04' 20"}
MOON_DIST:       101.34 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.15,-43.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       39.29,-70.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:52:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     595616,   Seg_Num: 0
POINT_RA:         65.429d {+04h 21m 43s} (J2000)
POINT_DEC:       -51.170d {-51d 10' 11"} (J2000)
POINT_ROLL:      313.427d
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2800.78 SOD {00:46:40.78} UT,   2220.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        8.563
N_STARS:         24
X_OFFSET:        208 [pixels]
Y_OFFSET:        584 [pixels]
X_MAX:           1167 [pixels]
Y_MAX:           1543 [pixels]
DET_THRESH:      26
PHOTO_THRESH:    16
SL_URL:          sw00595616000msufc2220.fits
SUN_POSTN:        21.31d {+01h 25m 14s}   +8.95d {+08d 57' 07"}
SUN_DIST:         71.15 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.19d {+11h 40m 46s}   -1.07d {-01d 04' 25"}
MOON_DIST:       101.34 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.15,-43.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       39.29,-70.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:53:55 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     595616,   Seg_Num: 0
POINT_RA:         65.429d {+04h 21m 43s} (J2000)
POINT_DEC:       -51.170d {-51d 10' 11"} (J2000)
ROLL:            313.427d
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2800.78 SOD {00:46:40.78} UT,   2220.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     419042812
X_OFFSET:        671 [pixels]
Y_OFFSET:        969 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       831
Y_GRB_POS:       1129
BINNING_INDEX:   1
IM_URL:          sw00595616000msuni2232.fits
SUN_POSTN:        21.31d {+01h 25m 14s}   +8.95d {+08d 57' 08"}
SUN_DIST:         71.15 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.20d {+11h 40m 48s}   -1.08d {-01d 04' 36"}
MOON_DIST:       101.34 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.15,-43.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       39.29,-70.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 13 Apr 14 00:54:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     595616,   Seg_Num: 0
POINT_RA:         65.429d {+04h 21m 43s} (J2000)
POINT_DEC:       -51.170d {-51d 10' 11"} (J2000)
ROLL:            313.427d
IMG_START_DATE:  16760 TJD;   103 DOY;   14/04/13
IMG_START_TIME:  2800.78 SOD {00:46:40.78} UT,   2220.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     419042812
X_OFFSET:        671 [pixels]
Y_OFFSET:        969 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       831
Y_GRB_POS:       1129
BINNING_INDEX:   1
IM_URL:          sw00595616000msuni2232.fits
SUN_POSTN:        21.31d {+01h 25m 14s}   +8.95d {+08d 57' 09"}
SUN_DIST:         71.15 [deg]   Sun_angle= -2.9 [hr] (East of Sun)
MOON_POSTN:      175.20d {+11h 40m 49s}   -1.08d {-01d 04' 40"}
MOON_DIST:       101.34 [deg]
MOON_ILLUM:      95 [%]
GAL_COORDS:      259.15,-43.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       39.29,-70.31 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #16099
K. Varela, C. Delvaux (both MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 140413A (Swift trigger 595616; D'Elia et al., GCN #16098) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory (Chile).
Observations started at 00:13 UT on 13 April 2014, less than 5 min after the GRB trigger, and are continuing. They are performed at a mean airmass of 1.9 and a mean seeing of 0.9".
We find a single point source within the 5.8" Swift/XRT error circle at coordinates
```
   RA(J2000)  =  04:21:49.23
   Dec(J2000) = -51:10:58.0.
```
At a midtime of 00:17 UT we measure the following preliminary AB magnitudes:
```
r' = 20.2 +/- 0.1,
i' = 19.6 +/- 0.1,
z' = 19.3 +/- 0.1.
```
The source is also visible in g. At present we cannot decide if the source is fading. Data processing is still ongoing, observations are continuing.
Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #16101
V. D'Elia (ASDC) and L. Izzo (URoma/ICRA) report for the Swift/XRT team:
The XRT began observing the field of GRB 140413A at 00:46:31.37 UT, 2211.= 2 seconds after the BAT trigger. We find an uncatalogued X-ray source loc= ated at RA, Dec 65.4544, -51.1831 which is equivalent to:
```
RA(J2000) =A0=3D+04h 21m 49.0s
Dec(J2000) =3D-51d 10' 59.1"
```
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This loc= ation is 80 arcseconds from the BAT onboard position, within the BAT erro= r circle. This position may be improved as more data are received.
GCN Circular #16102
Klotz A., Turpin D. (IRAP-CNRS-OMP), Boer M., Gendre B., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 140413A detected by SWIFT (trigger 595616) with the TAROT robotic telescope (D=25cm) located at the European Southern Observatory, La Silla observatory, Chile.
The observations started 92.3s after the GRB trigger (16.4s after the notice) probably during the end of the prompt gamma emission regarding the BAT light curve. The elevation of the field decreased from 36 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 do not detect the GROND OT candidate (Varela et al. GCNC 16099) with a limiting magnitude of: t0+92.3s to t0+152.3s : Rlim = 17.0
The second image is 30.0s exposure in tracking mode: t0+165.6s to t0+195.6s : Rlim = 17.6
We co-added series of exposures:
```
t0+165.6s to t0+457.5s : Rlim = 19.3
t0+468.3s to t0+ 1362s : Rlim = 19.3
```
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
GCN Circular #16105
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), 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 140413A (trigger #595616) (D'Elia, et al., GCN Circ. 16098). The BAT ground-calculated position is RA, Dec = 65.439, -51.188 deg, which is
```
   RA(J2000)  =  04h 21m 45.4s 
   Dec(J2000) = -51d 11' 15.1" 
```
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 12%.
The mask-weighted light curve shows a slow rise starting at ~T-65 sec, peaking at ~T+80 sec, and a faster decay out to ~T+115 sec. T90 (15-350 keV) is 139.6 +- 12.6 sec (estimated error including systematics).
The time-averaged spectrum from T-52.0 to T+120.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.49 +- 0.08. The fluence in the 15-150 keV band is 9.4 +- 0.5 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+77.05 sec in the 15-150 keV band is 2.3 +- 0.5 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/595616/BA/
GCN Circular #16106
L. Izzo (URoma/ICRA) and V. D'Elia (ASDC) report on behalf of the Swift-XRT team:
We have analysed 13 ks of XRT data for GRB 140413A, from 2.2 ks to 83.3 ks after the BAT trigger. The data comprise 2.1 ks in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. Using 3951 s of PC mode data and 4 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 65.45475, -51.18310 which is equivalent to:
```
RA (J2000): 04h 21m 49.14s
Dec(J2000): -51d 10' 59.2"
```
with an uncertainty of 1.6 arcsec (radius, 90% confidence).
The late-time light curve (from T0+38.1 ks) can be modelled with a power-law decay with a decay index of alpha=1.7 (+/-0.4).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.989 (+0.025, -0.024). The best-fitting absorption column is 4.04 (+/-0.13) x 10^21 cm^-2, in excess of the Galactic value of 1.4 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (6.0 x 10^-11) erg cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
```
Total column:	     4.04 (+/-0.13) x 10^21 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: 49.9 sigma
Photon index:	     1.989 (+0.025, -0.024)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00595616.
This circular is an official product of the Swift-XRT team.
GCN Circular #16107
S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline on behalf of the Konus-Wind team, report:
The long GRB 140413A (Swift-BAT trigger #595616: D'Elia et al., GCN 16098; T0(BAT)=3D00:09:40 UT) was detected by Konus-Wind in the waiting mode.
The light curve shows a broad emission pulse which started ~65 s before the BAT trigger, peaked at ~T0(BAT)+80 s, and lasted till ~T0(BAT)+120 s.
A possible soft precursor is seen at ~T0(BAT)-950 s in the softest KW energy band, however its association with GRB 140413A is not confirmed yet.
The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB140413A/
As observed by Konus-Wind, the burst had a fluence of (2.9 =B1 0.3)x10^-5 erg/cm2 and a 2.944-s peak energy flux, measured from ~T0(BAT)+80 s, of (5.2 =B1 0.5)x10^-7 erg/cm2 (both in the 20 - 10000 keV energy range).
Modeling the KW 3-channel time-integrated spectrum (from T0(BAT)-60 s to T0(BAT)+121 s) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha =3D -1.37 =B1 0.11, and Ep =3D 228 =B1 42 keV.
All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.
GCN Circular #16109
S. T. Holland (STScI) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140413A 2221 s after the BAT trigger (D'Elia et al., 2014, GCNC 16098). The preliminary UVOT position is
```
     RA (J2000)  04:21:49.23  =   65.45512 (deg)
    Dec (J2000) -51:10:58.0   =  -51.18278 (deg)
```
with an estimated uncertainty of 1.79 arcsec (radius, 90% confidence, statistical + systematic). We detect the optical afterglow at the position reported by Varela et al. (2014, GCNC 16099). Preliminary UVOT photometry and 3-sigma upper limits are presented below.
```
----------------------------------------------------------------
Filter        TSTART     TSTOP   Exposure       Mag   Err  Sigma
----------------------------------------------------------------
v               2377      4303        375     >19.7
b               2476      3747        235     >21.0
u               2451      3542        236     >19.9
uvw1            2427      3336        236     >19.8
uvm2            2931      3131        197     >19.5
uvw2            3957      4157        197     >20.1
white           2221      2370        147     >20.3
                3752      3951        197      21.10 0.29    3.8
----------------------------------------------------------------
```
The quoted magnitudes and upper limits have not been corrected for the Galactic extinction along the line of sight to this burst of E_{B-V} = 0.01 mag (Schlafly et al. 2011, ApJS, 737, 103). The photometry is in the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373).
GCN Circular #16172
C. Delvaux (MPE Garching), D. A. Kann, S. Schmidl (both TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team:
We re-observed the field of GRB 140413A (Swift trigger 595616; D'Elia et al., GCN # 16098) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory (Chile).
Further epochs were obtained at 1, 2, 3 and 5 days after the trigger. The source detected in the XRT error circle in early observations (Varela et al., GCN # 16099) has faded by about 3 magnitudes in the r' band, confirming that it is the afterglow of GRB 140413A. In the later epochs we obtain detections in g'r'i'z'J at a constant level, possibly the host galaxy of the GRB. If it is the host galaxy, this may be indicative of a relatively low redshift.

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Jochen Greiner, last update: 25-Apr-2014 [Disclaimer]