Gamma-ray Burst 140628A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:35:52 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     602803,   Seg_Num: 0
GRB_RA:           40.661d {+02h 42m 39s} (J2000),
                  40.846d {+02h 43m 23s} (current),
                  40.022d {+02h 40m 05s} (1950)
GRB_DEC:          -0.366d {-00d 21' 58"} (J2000),
                  -0.305d {-00d 18' 18"} (current),
                  -0.579d {-00d 34' 42"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3111 [cnts]    Image_Peak=183 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   124     E_range: 25-100 keV
BKG_INTEN:       35476 [cnts]
BKG_TIME:        48923.80 SOD {13:35:23.80} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16836 TJD;   179 DOY;   14/06/28
GRB_TIME:        48937.37 SOD {13:35:37.37} UT
GRB_PHI:         170.35 [deg]
GRB_THETA:        30.11 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.08 [sigma]
IMAGE_SIGNIF:    9.01 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2  -1  +0  +0 -50  +0 
SUN_POSTN:        97.39d {+06h 29m 34s}  +23.26d {+23d 15' 47"}
SUN_DIST:         59.71 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.28d {+07h 25m 07s}  +16.97d {+16d 58' 04"}
MOON_DIST:        71.41 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      172.48,-52.20 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       38.12,-15.37 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is a rate 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 = 345.13,-11.34 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:37:11 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.647d {+02h 42m 35s} (J2000)
POINT_DEC:        -0.376d {-00d 22' 32"} (J2000)
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  49020.31 SOD {13:37:00.31} UT,   82.9 [sec] since BAT Trigger Time
COUNTS:          10    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:39:33 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     602803,   Seg_Num: 0
GRB_RA:           40.661d {+02h 42m 39s} (J2000),
                  40.846d {+02h 43m 23s} (current),
                  40.022d {+02h 40m 05s} (1950)
GRB_DEC:          -0.366d {-00d 21' 58"} (J2000),
                  -0.305d {-00d 18' 18"} (current),
                  -0.579d {-00d 34' 42"} (1950)
GRB_DATE:        16836 TJD;   179 DOY;   14/06/28
GRB_TIME:        48937.37 SOD {13:35:37.37} UT
TRIGGER_INDEX:   124
GRB_PHI:         170.35 [deg]
GRB_THETA:        30.11 [deg]
DELTA_TIME:      -76.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     17.08 [sigma]
IMAGE_SIGNIF:    9.01 [sigma]
LC_URL:          sw00602803000msb.lc
SUN_POSTN:        97.39d {+06h 29m 34s}  +23.26d {+23d 15' 46"}
SUN_DIST:         59.71 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.31d {+07h 25m 15s}  +16.96d {+16d 57' 48"}
MOON_DIST:        71.44 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      172.48,-52.20 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       38.12,-15.37 [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 a rate 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 = 345.13,-11.34 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:45:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.648d {+02h 42m 36s} (J2000)
POINT_DEC:        -0.377d {-00d 22' 36"} (J2000)
POINT_ROLL:      62.606d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  49215.74 SOD {13:40:15.74} UT,   278.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.041
N_STARS:         15
X_OFFSET:        565 [pixels]
Y_OFFSET:        477 [pixels]
X_MAX:           1524 [pixels]
Y_MAX:           1436 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00602803000msufc0278.fits
SUN_POSTN:        97.40d {+06h 29m 35s}  +23.26d {+23d 15' 45"}
SUN_DIST:         59.73 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.36d {+07h 25m 26s}  +16.96d {+16d 57' 23"}
MOON_DIST:        71.50 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      172.48,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.11,-15.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:45:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.648d {+02h 42m 36s} (J2000)
POINT_DEC:        -0.377d {-00d 22' 36"} (J2000)
POINT_ROLL:      62.606d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  49215.74 SOD {13:40:15.74} UT,   278.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.041
N_STARS:         15
X_OFFSET:        565 [pixels]
Y_OFFSET:        477 [pixels]
X_MAX:           1524 [pixels]
Y_MAX:           1436 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    8
SL_URL:          sw00602803000msufc0278.fits
SUN_POSTN:        97.40d {+06h 29m 35s}  +23.26d {+23d 15' 45"}
SUN_DIST:         59.73 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.36d {+07h 25m 27s}  +16.96d {+16d 57' 21"}
MOON_DIST:        71.50 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      172.48,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.11,-15.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:46:27 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.648d {+02h 42m 36s} (J2000)
POINT_DEC:        -0.377d {-00d 22' 36"} (J2000)
ROLL:            62.606d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  49215.74 SOD {13:40:15.74} UT,   278.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     425655627
X_OFFSET:        884 [pixels]
Y_OFFSET:        796 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1044
Y_GRB_POS:       956
BINNING_INDEX:   1
IM_URL:          sw00602803000msuni0291.fits
SUN_POSTN:        97.40d {+06h 29m 35s}  +23.26d {+23d 15' 45"}
SUN_DIST:         59.73 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.37d {+07h 25m 29s}  +16.95d {+16d 57' 16"}
MOON_DIST:        71.51 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      172.48,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.11,-15.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 13:46:43 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.648d {+02h 42m 36s} (J2000)
POINT_DEC:        -0.377d {-00d 22' 36"} (J2000)
ROLL:            62.606d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  49215.74 SOD {13:40:15.74} UT,   278.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     425655627
X_OFFSET:        884 [pixels]
Y_OFFSET:        796 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1044
Y_GRB_POS:       956
BINNING_INDEX:   1
IM_URL:          sw00602803000msuni0291.fits
SUN_POSTN:        97.40d {+06h 29m 35s}  +23.26d {+23d 15' 45"}
SUN_DIST:         59.73 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.37d {+07h 25m 30s}  +16.95d {+16d 57' 15"}
MOON_DIST:        71.51 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      172.48,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.11,-15.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #16467
E. Sonbas (NASA/GSFC/Adiyaman Univ.), M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB), H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL), A. Y. Lien (NASA/GSFC/ORAU), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 13:35:37 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140628A (trigger=602803). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 40.661, -0.366 which is
```
   RA(J2000) = 02h 42m 39s
   Dec(J2000) = -00d 21' 58"
```
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 10 sec. The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field after coming out of SAA mode at 13:39:40.3 UT, 243 seconds after the BAT trigger. No source was detected in 20 s of promptly downlinked data. We are waiting for the full dataset to detect and localize the XRT counterpart.
UVOT took a finding chart exposure of 48 seconds with the White filter starting 278 seconds after the BAT trigger. No credible afterglow candidate has been found in a partial 2.7'x2.7' sub-image. Results from the list of sources generated on-board are not available at this time.
Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 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:     Sat 28 Jun 14 14:38:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.632d {+02h 42m 32s} (J2000)
POINT_DEC:        -0.364d {-00d 21' 49"} (J2000)
POINT_ROLL:      62.597d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  52530.35 SOD {14:35:30.35} UT,   3593.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.454
N_STARS:         29
X_OFFSET:        705 [pixels]
Y_OFFSET:        568 [pixels]
X_MAX:           1664 [pixels]
Y_MAX:           1527 [pixels]
DET_THRESH:      18
PHOTO_THRESH:    10
SL_URL:          sw00602803000msufc3592.fits
SUN_POSTN:        97.44d {+06h 29m 44s}  +23.26d {+23d 15' 39"}
SUN_DIST:         59.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.82d {+07h 27m 17s}  +16.89d {+16d 53' 16"}
MOON_DIST:        71.95 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      172.44,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.09,-15.36 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 14:39:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.632d {+02h 42m 32s} (J2000)
POINT_DEC:        -0.364d {-00d 21' 49"} (J2000)
POINT_ROLL:      62.597d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  52530.35 SOD {14:35:30.35} UT,   3593.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.454
N_STARS:         29
X_OFFSET:        705 [pixels]
Y_OFFSET:        568 [pixels]
X_MAX:           1664 [pixels]
Y_MAX:           1527 [pixels]
DET_THRESH:      18
PHOTO_THRESH:    10
SL_URL:          sw00602803000msufc3592.fits
SUN_POSTN:        97.44d {+06h 29m 45s}  +23.26d {+23d 15' 39"}
SUN_DIST:         59.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.83d {+07h 27m 18s}  +16.89d {+16d 53' 14"}
MOON_DIST:        71.95 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      172.44,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.09,-15.36 [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:     Sat 28 Jun 14 14:40:09 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.632d {+02h 42m 32s} (J2000)
POINT_DEC:        -0.364d {-00d 21' 49"} (J2000)
ROLL:            62.597d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  52530.35 SOD {14:35:30.35} UT,   3593.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     425658942
X_OFFSET:        1024 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1184
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00602803000msuni3605.fits
SUN_POSTN:        97.44d {+06h 29m 45s}  +23.26d {+23d 15' 39"}
SUN_DIST:         59.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.83d {+07h 27m 20s}  +16.89d {+16d 53' 09"}
MOON_DIST:        71.96 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      172.44,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.09,-15.36 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 28 Jun 14 14:40:30 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     602803,   Seg_Num: 0
POINT_RA:         40.632d {+02h 42m 32s} (J2000)
POINT_DEC:        -0.364d {-00d 21' 49"} (J2000)
ROLL:            62.597d
IMG_START_DATE:  16836 TJD;   179 DOY;   14/06/28
IMG_START_TIME:  52530.35 SOD {14:35:30.35} UT,   3593.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     425658942
X_OFFSET:        1024 [pixels]
Y_OFFSET:        887 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1184
Y_GRB_POS:       1047
BINNING_INDEX:   1
IM_URL:          sw00602803000msuni3605.fits
SUN_POSTN:        97.44d {+06h 29m 45s}  +23.26d {+23d 15' 39"}
SUN_DIST:         59.78 [deg]   Sun_angle= 3.8 [hr] (West of Sun)
MOON_POSTN:      111.84d {+07h 27m 21s}  +16.89d {+16d 53' 08"}
MOON_DIST:        71.96 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      172.44,-52.22 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       38.09,-15.36 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #16470
P. D'Avanzo, M.G. Bernardini, A. Melandri (INAF/OAB), P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:
Using promptly downlinked data we find an uncatalogued and fading X-ray source. Using 40 s of XRT Photon Counting mode data and 1 UVOT image, 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 =40.66674, -0.38488 which is equivalent to:
```
RA (J2000):  02 42 40.02
Dec (J2000): -00 23 05.6
```
with an uncertainty of 2.5 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 is an official product of the Swift-XRT team.
GCN Circular #16471
M. H. Siegel (PSU), N. P. M. Kuin (UCL-MSSL) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140628A 278 s after the BAT trigger (Sonbas et al., GCN Circ. 16467). A source consistent with the XRT position (D'Avanzo et al. GCN Circ. 16470) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
   RA  (J2000) =  02:42:39.88 =  40.66617 (deg.)
   Dec (J2000) = -00:23:05.7  =  -0.38491 (deg.)
```
with an estimated uncertainty of 0.46 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:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              278          327           48         17.70 +/- 0.08
v                 3749         3949          197         19.08 +/- 0.28
b                 4569         4769          197        >20.2
u                 4364         4564          197        >19.5
w1                4159         4359          197        >19.8
m2                3954         4154          197        >21.2
w2                9366        10266          886        >21.1
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #16472
N. P. M. Kuin (UCL-MSSL) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140628A 278 s after the BAT trigger (Sonbas et al., GCN Circ. 16467). A source consistent with the XRT position (D'Avanzo et al. GCN Circ. 16470) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
    RA  (J2000) =  02:42:39.88 =  40.66617 (deg.)
    Dec (J2000) = -00:23:05.7  =  -0.38491 (deg.)
```
with an estimated uncertainty of 0.46 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:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              278          327           48         17.43 +/- 0.08
white             3593         4974          300        >21.0
v                 3749         3949          197         19.08 +/- 0.28
b                 4569         4769          197        >20.2
u                 4364         4564          197        >19.5
w1                4159         4359          197        >19.8
m2                3954         4154          197        >21.2
w2                9366        10266          886        >21.1
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #16473
W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), E. Sonbas (NASA/GSFC/Adiyaman Univ.), 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 recent telemetry downlinks, we report further analysis of BAT GRB 140628A (trigger #602803) (Sonbas, et al., GCN Circ. 16467). The BAT ground-calculated position is RA, Dec = 40.672, -0.378 deg which is
```
   RA(J2000)  =  02h 42m 41.2s 
   Dec(J2000) = -00d 22' 39.8" 
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 73%.
The mask-weighted light curve ~3 overlapping peaks starting at ~T-15 sec, peaking at ~T+2 sec, and ending at ~T+30 sec. T90 (15-350 keV) is 10.5 +- 0.9 sec (estimated error including systematics).
The time-averaged spectrum from T-1.24 to T+11.12 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.56 +- 0.09. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.94 sec in the 15-150 keV band is 2.8 +- 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/602803/BA/
GCN Circular #16474
A. Klotz, D. Turpin (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. Coward (UWA), M. Boer, B. Gendre, K. Siellez, H. Dereli, O. Bardho (UNS-CNRS-OCA), A. Williams (PO-UWA), R. Martin (PO-UWA) report:
We imaged the field of GRB 140628A detected by SWIFT (trigger 602803) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia.
The observations started 6.72h after the GRB trigger. The elevation of the field increased from 22 degrees above horizon and weather conditions were poor.
We co-added a series of exposures. We do not see any optical counterpart at the UVOT position mentioned by Kuin et al. (GCNC 16472):
t0+6.72h to t0+7.27h : Rlim = 19.9
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
GCN Circular #16475
P. D'Avanzo, M.G. Bernardini, A. Melandri (INAF/OAB), P.A. Evans (U. Leicester) and E. Sonbas (NASA/GSFC/Adiyaman Univ.) report on behalf of the Swift-XRT team:
We have analysed 8.2 ks of XRT data for GRB 140628A (Sonbas et al. GCN Circ. 16467), from 231 s to 23.2 ks after the BAT trigger. The data comprise 47 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. Using 5310 s of PC mode data and 10 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 = 40.66617, -0.38489 which is equivalent to:
```
RA (J2000): 02h 42m 39.88s
Dec(J2000): -00d 23' 05.6"
```
with an uncertainty of 1.5 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.21 (+0.03, -0.04).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.88 (+0.19, -0.18). The best-fitting absorption column is 8.9 (+5.3, -4.7) x 10^20 cm^-2, in excess of the Galactic value of 3.2 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 3.5 x 10^-11 (4.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     8.9 (+5.3, -4.7) x 10^20 cm^-2
Galactic foreground: 3.2 x 10^20 cm^-2
Excess significance: 2.0 sigma
Photon index:	     1.88 (+0.19, -0.18)
```
If the light curve continues to decay with a power-law decay index of 1.21, the count rate at T+24 hours will be 4.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.6 x 10^-13 (1.9 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/00602803.
This circular is an official product of the Swift-XRT team.
GCN Circular #16476
C. Delvaux (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 140628A (Swift trigger 602803; Sonbas et al., GCN 16467) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 08:39 UT on June 29, 2014, 19.1 hrs after the GRB trigger. They were performed at an average seeing of 1.6" and at an average airmass of 1.6.
We detect a source consistent with the Swift/UVOT position, reported by Siegel et al. (GCN 16471).
Based on a total exposure of 50 min in g'r'i' and 40 min in JHK, at a mid-time of 20.2 hrs after the burst, we measure the following preliminary magnitudes (in AB):
```
g' = 23.6 +/- 0.2 mag
r' = 23.1 +/- 0.1 mag
i' = 22.9 +/- 0.2 mag
J  > 21.2 mag,
H  > 20.1 mag, and
K  > 19.1 mag.
```
In addition we measure z' = 22.1 +/- 0.2 (in AB magnitude system), based on a total exposure of 25 min, at a midtime of 20.5 hrs after burst.
Given magnitudes are calibrated against SDSS (g'r'i'z') as well as 2MASS (JHK) field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V) = 0.03 mag in the direction of the burst (Schlegel et al. 1998).

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Jochen Greiner, last update: 29-Jun-2014 [Disclaimer]