Gamma-ray Burst 080703

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 03 Jul 08 19:00:34 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     315819,   Seg_Num: 0
GRB_RA:          101.867d {+06h 47m 28s} (J2000),
                 101.884d {+06h 47m 32s} (current),
                 101.765d {+06h 47m 04s} (1950)
GRB_DEC:         -63.222d {-63d 13' 19"} (J2000),
                 -63.232d {-63d 13' 54"} (current),
                 -63.165d {-63d 09' 54"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4275 [cnts]    Image_Peak=168 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       27554 [cnts]
BKG_TIME:        68397.08 SOD {18:59:57.08} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14650 TJD;   185 DOY;   08/07/03
GRB_TIME:        68413.59 SOD {19:00:13.59} UT
GRB_PHI:           1.57 [deg]
GRB_THETA:        39.00 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.78 [sigma]
IMAGE_SIGNIF:    7.30 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +2  +2  +0  +0  -6  +1 
SUN_POSTN:       103.26d {+06h 53m 02s}  +22.88d {+22d 52' 41"}
SUN_DIST:         86.12 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.01d {+07h 36m 01s}  +23.98d {+23d 58' 47"}
MOON_DIST:        87.74 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.27,-24.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      151.93,-83.97 [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 = 172.71,-16.87 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 03 Jul 08 19:01:59 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     315819,   Seg_Num: 0
POINT_RA:        101.888d {+06h 47m 33s} (J2000)
POINT_DEC:       -63.198d {-63d 11' 53"} (J2000)
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  68508.01 SOD {19:01:48.01} UT,   94.4 [sec] since BAT Trigger Time
COUNTS:          5    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:     Thu 03 Jul 08 19:04:08 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     315819,   Seg_Num: 0
POINT_RA:        101.888d {+06h 47m 33s} (J2000)
POINT_DEC:       -63.198d {-63d 11' 53"} (J2000)
POINT_ROLL:      1.283d
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  68512.56 SOD {19:01:52.56} UT,   99.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.744
N_STARS:         115
X_OFFSET:        294 [pixels]
Y_OFFSET:        594 [pixels]
X_MAX:           1253 [pixels]
Y_MAX:           1553 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00315819000msufc0098.fits
SUN_POSTN:       103.26d {+06h 53m 02s}  +22.88d {+22d 52' 41"}
SUN_DIST:         86.09 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.04d {+07h 36m 11s}  +23.97d {+23d 58' 16"}
MOON_DIST:        87.71 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.25,-24.44 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      151.81,-83.95 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 03 Jul 08 19:04:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     315819,   Seg_Num: 0
POINT_RA:        101.888d {+06h 47m 33s} (J2000)
POINT_DEC:       -63.198d {-63d 11' 53"} (J2000)
POINT_ROLL:      1.283d
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  68512.56 SOD {19:01:52.56} UT,   99.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.744
N_STARS:         115
X_OFFSET:        294 [pixels]
Y_OFFSET:        594 [pixels]
X_MAX:           1253 [pixels]
Y_MAX:           1553 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00315819000msufc0098.fits
SUN_POSTN:       103.26d {+06h 53m 02s}  +22.88d {+22d 52' 40"}
SUN_DIST:         86.09 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.05d {+07h 36m 12s}  +23.97d {+23d 58' 11"}
MOON_DIST:        87.71 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.25,-24.44 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      151.81,-83.95 [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:     Thu 03 Jul 08 19:04:30 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     315819,   Seg_Num: 0
GRB_RA:          101.867d {+06h 47m 28s} (J2000),
                 101.884d {+06h 47m 32s} (current),
                 101.765d {+06h 47m 04s} (1950)
GRB_DEC:         -63.222d {-63d 13' 19"} (J2000),
                 -63.232d {-63d 13' 54"} (current),
                 -63.165d {-63d 09' 54"} (1950)
GRB_DATE:        14650 TJD;   185 DOY;   08/07/03
GRB_TIME:        68413.59 SOD {19:00:13.59} UT
TRIGGER_INDEX:   146
GRB_PHI:           1.57 [deg]
GRB_THETA:        39.00 [deg]
DELTA_TIME:      -50.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.78 [sigma]
IMAGE_SIGNIF:    7.30 [sigma]
LC_URL:          sw00315819000msb.lc
SUN_POSTN:       103.26d {+06h 53m 02s}  +22.88d {+22d 52' 40"}
SUN_DIST:         86.12 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.05d {+07h 36m 12s}  +23.97d {+23d 58' 12"}
MOON_DIST:        87.73 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.27,-24.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      151.93,-83.97 [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 = 172.71,-16.87 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 03 Jul 08 19:06:26 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     315819,   Seg_Num: 0
POINT_RA:        101.888d {+06h 47m 33s} (J2000)
POINT_DEC:       -63.198d {-63d 11' 53"} (J2000)
ROLL:            1.283d
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  68512.56 SOD {19:01:52.56} UT,   99.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     236804515
X_OFFSET:        613 [pixels]
Y_OFFSET:        913 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       773
Y_GRB_POS:       1073
BINNING_INDEX:   1
IM_URL:          sw00315819000msuni0098.fits
SUN_POSTN:       103.26d {+06h 53m 03s}  +22.88d {+22d 52' 40"}
SUN_DIST:         86.09 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.07d {+07h 36m 17s}  +23.97d {+23d 57' 55"}
MOON_DIST:        87.70 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.25,-24.44 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      151.81,-83.95 [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:     Thu 03 Jul 08 19:06:51 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     315819,   Seg_Num: 0
POINT_RA:        101.888d {+06h 47m 33s} (J2000)
POINT_DEC:       -63.198d {-63d 11' 53"} (J2000)
ROLL:            1.283d
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  68512.56 SOD {19:01:52.56} UT,   99.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     236804515
X_OFFSET:        613 [pixels]
Y_OFFSET:        913 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       773
Y_GRB_POS:       1073
BINNING_INDEX:   1
IM_URL:          sw00315819000msuni0098.fits
SUN_POSTN:       103.26d {+06h 53m 03s}  +22.88d {+22d 52' 40"}
SUN_DIST:         86.09 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.07d {+07h 36m 18s}  +23.96d {+23d 57' 52"}
MOON_DIST:        87.70 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.25,-24.44 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      151.81,-83.95 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN Circular #7935
E.S. Rykoff (UCSB), B. E. Schaefer (Louisiana State), report on behalf of the ROTSE collaboration:
ROTSE-IIIa, located at Siding Spring Observatory, Australia, responded to GRB 080703A (Swift trigger 315819). The first image was at 19:00:45.1 UT, 31.5 s after the burst (11.1 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 14.7 magnitude, steady source with coordinates:
06:47:12.7 -63:13:08.6 (J2000), with positional
uncertainty of 1" or better
```
start UT    	mag     mlim(of image)
----------------------------------
19:00:45.1     14.7     15.9
```
This source is not visible in DSS (second epoch), 2MASS or the MPChecker database.
A jpeg image is available at http://www.rotse.net/images/gsb315819_3a00_img.jpg Note that the object marked 18 is the candidate in question.
Continuing observations are in progress.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 03 Jul 08 19:16:34 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     315819,   Seg_Num: 0
GRB_RA:          101.8027d {+06h 47m 12.64s} (J2000),
                 101.8198d {+06h 47m 16.75s} (current),
                 101.7016d {+06h 46m 48.37s} (1950)
GRB_DEC:         -63.2190d {-63d 13' 08.4"} (J2000),
                 -63.2287d {-63d 13' 43.2"} (current),
                 -63.1623d {-63d 09' 44.2"} (1950)
GRB_ERROR:       0.7 [arcsec radius, statistical only]
GRB_MAG:         17.60 +/- 1.00 [mag]
FILTER:          10, White
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  69215.39 SOD {19:13:35.39} UT,   801.8 [sec] since BAT Trigger Time
SUN_POSTN:       103.27d {+06h 53m 04s}  +22.88d {+22d 52' 38"}
SUN_DIST:         86.11 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.18d {+07h 36m 43s}  +23.94d {+23d 56' 25"}
MOON_DIST:        87.72 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.26,-24.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      151.74,-83.99 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 03 Jul 08 19:17:08 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     315819,   Seg_Num: 0
GRB_RA:          101.8052d {+06h 47m 13.2s} (J2000),
                 101.8223d {+06h 47m 17.3s} (current),
                 101.7041d {+06h 46m 48.9s} (1950)
GRB_DEC:         -63.2203d {-63d 13' 13.0"} (J2000),
                 -63.2300d {-63d 13' 47.9"} (current),
                 -63.1636d {-63d 09' 48.8"} (1950)
GRB_ERROR:       2.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  14650 TJD;   185 DOY;   08/07/03
IMG_START_TIME:  68519.00 SOD {19:01:59.00} UT,   105.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       103.27d {+06h 53m 04s}  +22.88d {+22d 52' 38"}
SUN_DIST:         86.11 [deg]   Sun_angle= 0.1 [hr] (West of Sun)
MOON_POSTN:      114.19d {+07h 36m 45s}  +23.94d {+23d 56' 20"}
MOON_DIST:        87.72 [deg]
MOON_ILLUM:      1 [%]
GAL_COORDS:      273.26,-24.48 [deg] galactic lon,lat of the burst
ECL_COORDS:      151.75,-83.99 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.

GCN Circular #7936
H. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC), M. M. Chester (PSU), J. R. Cummings (NASA/UMBC), P. A. Evans (U Leicester), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), P. T. O'Brien (U Leicester), C. Pagani (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), D. Perez (U Leicester), P. Schady (MSSL-UCL), R. L. C. Starling (U Leicester), M. C. Stroh (PSU), T. N. Ukwatta (GSFC/GWU), D. E. Vanden Berk (PSU) and P. A. Ward (MSSL-UCL) report on behalf of the Swift Team:
At 19:00:13 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080703 (trigger=315819). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 101.867, -63.222 which is
```
   RA(J2000)  =  06h 47m 28s
   Dec(J2000) = -63d 13' 19"
```
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 5 sec. The peak count rate was ~1500 counts/sec (15-350 keV), at ~0 sec after the trigger.
Using promptly downlinked data we find a bright, uncatalogued X-ray source. The position, astrometrically enhanced by aligning promptly available UVOT field source positions to the USNO-B1 catalogue, is RA,Dec = 101.80538, -63.22039 (degrees) which is equivalent to:
```
RA  (J2000.0) =  06 47 13.29
DEC (J2000.0) =  -63 13 13.4
```
with an uncertainty of 3.04 arcsec (radius, 90% containment). This position is 100.1 arcsec from the BAT position, inside the BAT error circle and 6.3 arcseconds from the UVOT position.
UVOT took a finding chart exposure of nominal 100 seconds with the White (160-650 nm) filter starting 100 seconds after the BAT trigger. There is a candidate afterglow in the list of sources generated on-board at
```
  RA(J2000)  =  06:47:12.65 = 101.8027
  DEC(J2000) = -63:13:08.8  = -63.2191
```
with a 1-sigma error radius of about 0.8 arc sec. This position is 104.9 arc sec. from the center of the BAT error circle. The estimated magnitude is 17.6 with a 1-sigma error of about 0.5 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.07.
Burst Advocate for this burst is H. Ziaeepour (hz AT mssl.ucl.ac.uk). 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 Circular #7938
T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU), H. Ziaeepour (UCL-MSSL) (i.e. the Swift-BAT team):
Using the data set from T-120 to T+183 sec from the recent telemetry downlink, we report further analysis of BAT GRB 080703 (trigger #315819) (Ziaeepour, et al., GCN Circ. 7936). The BAT ground-calculated position is RA, Dec = 101.822, -63.211 deg, which is
```
   RA(J2000)  =  06h 47m 17.2s 
   Dec(J2000) = -63d 12' 40.7" 
```
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%.
The mask-weighted light curve shows a single peak starting at ~T-5 sec, peaking at ~T+0 sec, and ending at ~T+4 sec. T90 (15-350 keV) is 3.4 +- 0.8 sec (estimated error including systematics).
The time-averaged spectrum from T-1.7 to T+2.1 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.53 +- 0.22. The fluence in the 15-150 keV band is 2.0 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.04 sec in the 15-150 keV band is 1.0 +- 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/315819/BA/
GCN Circular #7939
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 3392 s of overlapping XRT Photon Counting mode and UVOT data for GRB 080703, 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 = 101.80180, -63.21893 which is equivalent to:
```
RA (J2000): 06h 47m 12.43s
Dec (J2000): -63d 13' 08.2"
```
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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method.
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #7940
D. Malesani, P. M. Vreeswijk, J. P. U. Fynbo, J. Hjorth (DARK/NBI), P. Jakobsson (Univ. Hertfordshire), report on behalf of a larger collaboration:
We observed the field of GRB 080703 (Ziaeepour et al., GCN 7936) with the ESO VLT equipped with FORS1. Due to visibility constraints, observations could only be carried out during twilight at high airmass.
The optical afterglow first reported by Rykoff & Schaefer (GCN 7935; see also Ziaeepour et al., GCN 7936) is detected in our image (15 s exposure). On 2008 Jul 3.948 UT (3.76 hr after the GRB), the afterglow had R ~ 21.6 assuming R = 15.92 for the USNO star at (06:47:12.61, -63:12:31.7).
A finding chart is posted at
http://www.astro.ku.dk/~malesani/GRB/080703/080703_finder.png
No further observations are planned. We acknowledge excellent support from the ESO staff in executing this challenging observation, particularly Thomas Szeifert and Dominique Naef.
GCN Circular #7941
P. Ward (MSSL-UCL) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift/UVOT team:
The Swift Ultra-Violet/Optical Telescope (UVOT) started observing GRB 080703 (Rykoff et al. GCN 7935, Ziaeepour et. al, GCN 7936) ~100 seconds after the trigger.
A quickly fading candidate afterglow is found in the UVOT White and V filters. The preliminary Swift/UVOT position of the optical afterglow candidate is:
```
  RA(J2000)  = 06:47:12.639 = 101.8027
  DEC(J2000) = -63:13:08.96 = -63.2192
```
with a 1-sigma error radius of about 0.5 arcsec. The following table gives the measured magnitudes:
```
Filter T_start T_stop Exp     Mag

White  101    200    99.8     17.40 +/- 0.03
White  857    956    99.8     20.27 +/- 0.35
White  5905   6102   196.6    21.29 +/- 0.49
White  5905   19222  869.5  > 21.77 (1.9-sigma)
V      207    606    399.8    18.02 +/- 0.10
V      963    1362   399.8    19.06 +/- 0.27
V      6315   6512   196.6  > 19.65 (0.2-sigma)
V      6315   12021  1081.7 > 20.83 (0.9-sigma)
B      687    1788   78.9   > 19.48 (1.8-sigma)
B      663    1764   99.0   > 19.33 (1.5-sigma)
UVW1   638    1885   99.9   > 19.55 (0.1-sigma)
UVM2   613    1878   118.7  > 19.67 (1.7-sigma)
UVW2   718    1829   79.1   > 19.55 (0.9-sigma)
```
The values quoted above are in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627). No correction has been made for the expected extinction corresponding to E(B-V) of 0.071 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #7942
We analysed 12.1 ks of data in Photon Counting (PC) mode obtained for GRB 080703 (Ziaeepour et al., GCN Circ 7936) between 106 s and 3.1e4s after the trigger (T0). The UVOT-enhanced XRT position was given by Osborne et al. in GCN Circ. 7939.
The X-ray light-curve shows an initial rise from T0+106s to ~T0+200s and then decays with a slope of ~1.2. From ~T0+700s to ~T0+2000s, the XRT light-curve shows some flaring activities. The light-curve after ~T0+1e4s decays with a slope of 1.57 +/-0.21.
The hardness ratio does not show any significant spectral variation from T0+106s to T0+3.1e4s. The PC spectrum from T0+106s to T0+3.1e4s is well fitted by an absorbed power-law with a photon index of 1.7 +/-0.1 and an absorption column of (8.9 +3.9/-3.3)e20 cm**-2, in excess with respect to the Galactic one (5.2e20 cm**-2; Kalberla et al. 2005). The observed 0.3-10 keV flux over this time interval is (8.2 +0.8/-1.2)e-12 erg/cm**2/s.
If the light-curve continues to decay with alpha = 1.6, the count rate at 24 hours after the trigger is estimated to be 7e-3 counts/s, which corresponds to an observed flux of 6.7e-13 erg/cm**2/s.
This is an official product of the Swift-XRT team.
GCN Circular #7944
C. Clemens, S. Loew, J. Greiner, A. Yoldas, T. Kruehler (all MPE Garching), A. Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) report on behalf of the GROND team:
We observed the field of GRB 080703 (Swift trigger 315819; Ziaeepour et al., GCN #7936) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La Silla Observatory (Chile).
Observations started at 23:04 UT on July 3rd, 2008, 4.1 hrs after the GRB trigger with 4.7 min of effective exposures in g'r'i'z' and 8.0 min in JHK, and were performed at an average seeing of 1.8" during astronomical twilight.
We do not detect any object within the 0.5'' Swift-UVOT error circle reported by Ward & Ziaeepour (GCN #7941) to the following upper limits:
```
g' > 22.1 mag,
r' > 22.6 mag,
i' > 21.8 mag,
z' > 21.3 mag,
J > 19.3 mag,
H > 18.1 mag and
K > 17.0 mag.
```
These upper limits are calibrated against USNO-B1 as well as 2MASS field stars.
GCN Report 149.1
GCN_Report 149.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_149_1.pdf by H. Ziaeepour at UCL/MSSL titled: "Final Swift Observations of GRB 080703"

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Jochen Greiner, last update: 10-Jul-2008 [Disclaimer]