Gamma-ray Burst 080710

(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:     Thu 10 Jul 08 07:13:51 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     316534,   Seg_Num: 0
GRB_RA:            8.257d {+00h 33m 02s} (J2000),
                   8.369d {+00h 33m 28s} (current),
                   7.603d {+00h 30m 25s} (1950)
GRB_DEC:         +19.492d {+19d 29' 31"} (J2000),
                 +19.539d {+19d 32' 20"} (current),
                 +19.216d {+19d 12' 58"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       18615 [cnts]    Image_Peak=387 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   290     E_range: 15-50 keV
BKG_INTEN:       165590 [cnts]
BKG_TIME:        25933.07 SOD {07:12:13.07} UT
BKG_DUR:         40 [sec]
GRB_DATE:        14657 TJD;   192 DOY;   08/07/10
GRB_TIME:        25990.79 SOD {07:13:10.79} UT
GRB_PHI:          85.08 [deg]
GRB_THETA:        25.64 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.00 [sigma]
IMAGE_SIGNIF:    8.57 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +1  +1  +0  +0  +5  +1 
SUN_POSTN:       109.93d {+07h 19m 44s}  +22.17d {+22d 10' 24"}
SUN_DIST:         92.79 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      196.54d {+13h 06m 09s}  -11.97d {-11d 58' 04"}
MOON_DIST:       169.09 [deg]
MOON_ILLUM:      51 [%]
GAL_COORDS:      116.98,-43.17 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       15.40, 14.61 [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 = 68.16,20.00 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Jul 08 07:16:52 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     316534,   Seg_Num: 0
GRB_RA:            8.257d {+00h 33m 02s} (J2000),
                   8.369d {+00h 33m 28s} (current),
                   7.603d {+00h 30m 25s} (1950)
GRB_DEC:         +19.492d {+19d 29' 31"} (J2000),
                 +19.539d {+19d 32' 20"} (current),
                 +19.216d {+19d 12' 58"} (1950)
GRB_DATE:        14657 TJD;   192 DOY;   08/07/10
GRB_TIME:        25990.79 SOD {07:13:10.79} UT
TRIGGER_INDEX:   290
GRB_PHI:          85.08 [deg]
GRB_THETA:        25.64 [deg]
DELTA_TIME:      -11.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.00 [sigma]
IMAGE_SIGNIF:    8.57 [sigma]
LC_URL:          sw00316534000msb.lc
SUN_POSTN:       109.93d {+07h 19m 44s}  +22.17d {+22d 10' 23"}
SUN_DIST:         92.79 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      196.56d {+13h 06m 14s}  -11.98d {-11d 58' 43"}
MOON_DIST:       169.08 [deg]
MOON_ILLUM:      51 [%]
GAL_COORDS:      116.98,-43.17 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       15.40, 14.61 [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 = 68.16,20.00 [deg].

GCN Circular #7957
B. Sbarufatti (INAF-IASFPA), W. H. Baumgartner (GSFC/UMBC), P. A. Evans (U Leicester), C. Guidorzi (INAF-OAB), E. A. Hoversten (PSU), V. La Parola (INAF-IASFPA), V. Mangano (INAF-IASFPA), C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester), P. Romano (INAF-IASFPA) and T. N. Ukwatta (GSFC/GWU) report on behalf of the Swift Team:
At 07:13:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080710 (trigger=316534). The BAT on-board calculated location is RA, Dec 8.257, +19.492 which is
```
   RA(J2000) = 00h 33m 02s
   Dec(J2000) = +19d 29' 31"
```
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 20 sec. The peak count rate was ~1,000 counts/sec (15-350 keV), at 0 sec after the trigger.
Due to an observing constraint, Swift will not slew until T0+49.5 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is B. Sbarufatti (sbarufatti AT ifc.inaf.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:     Thu 10 Jul 08 08:05:39 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     316534,   Seg_Num: 0
POINT_RA:          8.231d {+00h 32m 56s} (J2000)
POINT_DEC:       +19.490d {+19d 29' 23"} (J2000)
IMG_START_DATE:  14657 TJD;   192 DOY;   08/07/10
IMG_START_TIME:  29122.38 SOD {08:05:22.38} UT,   3131.6 [sec] since BAT Trigger Time
COUNTS:          1    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        0    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 10 Jul 08 08:08:13 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     316534,   Seg_Num: 0
POINT_RA:          8.232d {+00h 32m 56s} (J2000)
POINT_DEC:       +19.490d {+19d 29' 23"} (J2000)
POINT_ROLL:      65.203d
IMG_START_DATE:  14657 TJD;   192 DOY;   08/07/10
IMG_START_TIME:  29126.31 SOD {08:05:26.31} UT,   3135.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.767
N_STARS:         103
X_OFFSET:        662 [pixels]
Y_OFFSET:        527 [pixels]
X_MAX:           1621 [pixels]
Y_MAX:           1486 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00316534000msufc3135.fits
SUN_POSTN:       109.97d {+07h 19m 53s}  +22.17d {+22d 10' 06"}
SUN_DIST:         92.85 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      196.96d {+13h 07m 51s}  -12.16d {-12d 09' 48"}
MOON_DIST:       168.91 [deg]
MOON_ILLUM:      52 [%]
GAL_COORDS:      116.95,-43.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       15.37, 14.62 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 10 Jul 08 08:08:41 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     316534,   Seg_Num: 0
POINT_RA:          8.232d {+00h 32m 56s} (J2000)
POINT_DEC:       +19.490d {+19d 29' 23"} (J2000)
POINT_ROLL:      65.203d
IMG_START_DATE:  14657 TJD;   192 DOY;   08/07/10
IMG_START_TIME:  29126.31 SOD {08:05:26.31} UT,   3135.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.767
N_STARS:         103
X_OFFSET:        662 [pixels]
Y_OFFSET:        527 [pixels]
X_MAX:           1621 [pixels]
Y_MAX:           1486 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00316534000msufc3135.fits
SUN_POSTN:       109.97d {+07h 19m 53s}  +22.17d {+22d 10' 06"}
SUN_DIST:         92.85 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      196.97d {+13h 07m 52s}  -12.17d {-12d 09' 54"}
MOON_DIST:       168.91 [deg]
MOON_ILLUM:      52 [%]
GAL_COORDS:      116.95,-43.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       15.37, 14.62 [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 10 Jul 08 08:08:58 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     316534,   Seg_Num: 0
POINT_RA:          8.232d {+00h 32m 56s} (J2000)
POINT_DEC:       +19.490d {+19d 29' 23"} (J2000)
ROLL:            65.203d
IMG_START_DATE:  14657 TJD;   192 DOY;   08/07/10
IMG_START_TIME:  29126.31 SOD {08:05:26.31} UT,   3135.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     237369929
X_OFFSET:        981 [pixels]
Y_OFFSET:        846 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1141
Y_GRB_POS:       1006
BINNING_INDEX:   1
IM_URL:          sw00316534000msuni3135.fits
SUN_POSTN:       109.97d {+07h 19m 53s}  +22.17d {+22d 10' 06"}
SUN_DIST:         92.85 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      196.97d {+13h 07m 53s}  -12.17d {-12d 09' 58"}
MOON_DIST:       168.91 [deg]
MOON_ILLUM:      52 [%]
GAL_COORDS:      116.95,-43.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       15.37, 14.62 [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 10 Jul 08 08:09:25 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     316534,   Seg_Num: 0
POINT_RA:          8.232d {+00h 32m 56s} (J2000)
POINT_DEC:       +19.490d {+19d 29' 23"} (J2000)
ROLL:            65.203d
IMG_START_DATE:  14657 TJD;   192 DOY;   08/07/10
IMG_START_TIME:  29126.31 SOD {08:05:26.31} UT,   3135.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     237369929
X_OFFSET:        981 [pixels]
Y_OFFSET:        846 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1141
Y_GRB_POS:       1006
BINNING_INDEX:   1
IM_URL:          sw00316534000msuni3135.fits
SUN_POSTN:       109.97d {+07h 19m 53s}  +22.17d {+22d 10' 06"}
SUN_DIST:         92.85 [deg]   Sun_angle= 6.8 [hr] (West of Sun)
MOON_POSTN:      196.97d {+13h 07m 54s}  -12.17d {-12d 10' 04"}
MOON_DIST:       168.91 [deg]
MOON_ILLUM:      52 [%]
GAL_COORDS:      116.95,-43.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       15.37, 14.62 [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 #7958
B. Sbarufatti (INAF-IASFPA), P. A. Evans (U Leicester) and V. Mangano (INAF-IASFPA) report on behalf of the Swift Team:
The XRT began observing the field at 08:05:22.4 UT, 3131.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 8.27344, 19.50157 which is equivalent to:
```
   RA(J2000)  = 00h 33m 5.63s
   Dec(J2000) = +19d 30' 05.7"
```
with an uncertainty of 3.2 arcseconds (radius, 90% containment). This location is 65 arcseconds from the BAT onboard position, within the BAT error circle.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.1e+20 cm^-2, Kalberla et al. 2005), with an excess column of 2 (+2.03/-1.73) x 1021 cm^-2 (90% confidence).
GCN Circular #7959
W. Li, R. Chornock, D. A. Perley, and A. V. Filippenko, University of California at Berkeley, on behalf of the KAIT GRB team, report:
KAIT responded to GRB 080710 (Swift trigger 316534; Sbarufatti et al., GCN 7957; Sbarufatti et al., GCN 7958) and started to take images at 09:10:20 UT, 1.953 hours after the BAT trigger. There is an optical afterglow at position
```
RA = 00:33:05.64
DEC = +19:30:05.7
```
(equinox J2000)
The measured magnitude is R = 16.8 in a 20s unfiltered image, calibrated to USNO B1. Observations are ongoing.
GCN Circular #7960
P. D'Avanzo, D. Fugazza, L.A. Antonelli, L. Calzoletti, S. Campana, G. Chincarini, S. Covino, M.L. Conciatore, S. Cutini, V. D'Elia, F. D'Alessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F. Vitali report on behalf of the REM team:
The robotic 60-cm REM telescope located at La Silla (Chile) observed automatically the field of the GRB 080710 (Sbarufattion et al. GCN 7957, 7958) on July 10 starting at 07:14:36 UT.
We can detect in optical and NIR bands the object reported by Li et al. (GCN 7959). The object is variable and we measure a brightening from H ~ 15.0 to H ~14.3 between two epochs of observations (arount 07:21 and 08:47 UT, respectively). Further analysis is ongoing.
GCN Circular #7961
P. Schady (MSSL-UCL) reports on behalf of the Swift/UVOT team:
The UVOT began observing the field of GRB 080710 3138.2s after the BAT trigger. A single white band finding chart was downlinked promptly, and a bright, uncatalogued source with magnitude wh = 16.88+/-0.02 is detected at
```
	RA  =  00:33:05.67   = 8.27363
	Dec = +19:30:04.69 = 19.50130
```
with an uncertainty of 0.5 arcseconds (90% confidence), consistent with the XRT position (Sbarufatti et al., GCN 7958) and KAIT position (Chornock et al., GCN 7959).
The value quoted above has not been corrected for the expected Galactic extinction corresponding to a reddening of E(B-V) = 0.08 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #7962
D. A. Perley, R. Chornock, and J. S. Bloom report on behalf of a larger collaboration:
Starting at 09:25 UT on 2008 July 10 we began spectroscopy of the optical counterpart (Li et al., GCN 7959) of GRB 080710 (Sbarufatti et al., GCN 7957) using Gemini-South (+GMOS). We acquired 2x1200s integrations using the B600 grism, covering a wavelength range from 3800 to 6700 Angstroms.
The spectrum shows several strong absorption features, corresponding to the Mg II (2796+2803) doublet, Fe II (2586+2600) doublet, Mg I (2853), and Fe II (2344+2374+2382) at a common redshift of z=0.845. We tentatively associate this redshift with GRB 080710. Additional analysis of the spectrum is ongoing.
We thank the Gemini staff for conducting these observations.
GCN Circular #7963
D. Bersier (Liverpool JMU) and A. Gomboc (U. Ljubljana) report on behalf of a larger collaboration:
We observed GRB 080710 (Sbarufatti et al. GCN 7957) with the 2m robotic Faulkes Telescope North. We obtained multi-colour images (BVRi) starting 4.2 hours after the burst. We confirm the presence of a fading source at the position of the afterglow (Li et al. GCN 7959; D'Avanzo et al GCN 7960). At a time of 4.4 hours after burst we measure an R-band magnitude of 17.8 (calibrated with respect to USNO R2). The decay rate is approximately -0.82.
We note that the afterglow is well detected in the B band, indicating a rather low redshift (in agreement with Perley et al. GCN 7962).
Observations are continuing.
GCN Circular #7964
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 8101 s of XRT Photon Counting mode data and 10 UVOT images for GRB 080710, 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 = 8.27364, +19.50158 which is equivalent to:
```
RA (J2000): 00h 33m 5.67s
Dec (J2000): +19d 30' 05.7"
```
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 #7965
W.B. Landsman (NASA/GSFC) and B. Sbarufatti(INAF-OAB) report on behalf of the Swift/UVOT team
The Swift/UVOT observed the field of GRB 08710 starting at 3186s after the BAT trigger ( Sbarufatti et al., GCN 7957). We detect the afterglow in all seven UVOT filters at the position
```
RA(J2000.0)  =   00:33:05.65
DEC(J2000.0) =  +19:30:05.3
```
with an estimated uncertainty of 0.5 arcsec (radius, 90% confidence). This position is consistent with the enhanced XRT position (Evans et al. GCN 7964) and the KAIT afterglow position (Li et al., GCN 7959). The detection in the UVW2 (1950 A) filter is consistent with the redshift of ~0.845 estimated from spectroscopic observations by Perley et al. (GCN 7962). The white and v exposure are consistent with a decay slope of alpha ~-0.8, as also found by Bersier and Gomboc (GCN 7963).
The magnitudes with 1 sigma errors are reported below.
```
Filter    TMid(s)    Expo(s)               Magnitude
-----------------------------------------------------
white     3185          98              16.88 +/- 0.02
white     5615         186              17.37 +/- 0.03
v         3342         197              17.06 +/- 0.06
v        10560         295              17.79 +/- 0.08
b         5416         197              17.56 +/- 0.05
u         5211         197              16.70 +/- 0.04
uvw1      5006         197              16.86 +/- 0.06
uvm2      3477          58              17.08 +/- 0.17
uvw2      9344         777              17.88 +/- 0.05
-----------------------------------------------------
```
The above magnitudes are not corrected for the Galactic extinction corresponding to a reddening of E{B-V} = 0.07 mag (Schlegel et al. 1998). The photometry is on the UVOT flight system described in Poole et al. (2008,MNRAS,383,627).
GCN Circular #7966
B. Sbarufatti, V. Mangano (INAF/IASF Pa) report on behalf of the Swift XRT team
Swift XRT began observations of GRB 080710 (Sbarufatti et al., GCN Circ. 7957) at 08:02 UT, 49 minutes after the trigger. The refined position for the afterglow, obtained using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue (see Evans et al., GCN Circ. 7964) is RA, Dec = 8.27364, 19.50158 which is equivalent to:
```
RA (J2000):  00 33 5.67
Dec (J2000): +19 30 05.7
```
with an uncertainty of 1.4 arcsec (radius, 90% confidence).
The XRT observations consist of 7.9 ks in Photon Counting mode. The light-curve can be fitted by a simple power-law model with slope (1.0 +/- 0.1), with superposed flaring activity.
The average spectrum can be modeled by a power-law with photon index 2.09 +/-0.1 and an intrinsic absorbing column of (1.6 +/-0.7) E21 cm^-2 at z=0.845 (Perley et al., GCN Circ. 7962) in excess with respect to the Galactic value (4.1E+20 cm^-2, Kalberla et al. 2005). The observed (unabsorbed) flux in the 0.3-10 keV band is 5.35 (5.84)E-12 ergs cm^-2 s^-1. The count rate to flux conversion factor is 4.1E-11.
The predicted flux for tomorrow, 07:13 UT (24 h after the trigger) is 6.9E-13 ergs cm^-2 s^-1.
This circular is an official product of the Swift XRT team.
GCN Circular #7967
E. Weaver, J. P. West, D. Reichart, M. Nysewander, A. LaCluyze, K. Ivarsen, J. A. Crain, A. Foster, T. Brennan, J. Haislip, R. Holmes, R. Rhine, M. Schubel, J. Styblova, and A. Trotter report:
Skynet observed the localization of GRB 080710 (Sbarufatti et al., GCN 7957) with three of the 16" PROMPT telescopes at CTIO beginning 64 seconds after the trigger in BVRI.
We detect the afterglow (Sbarufatti et al., GCN 7957) in BVRI. At 627 seconds after the burst we measure B ~ 17.7 mag (calibrated to 9 USNO B1 stars), at 626 seconds we measure V ~ 17.6 mag (calibrated to 12 USNO B1 stars), at 535 seconds we measure R ~ 17.6 mag (calibrated to 13 NOMAD stars), and at 444 seconds we measure I ~ 16.9 mag (calibrated to 11 USNO B1 stars).
GCN Circular #7969
J. Tueller (GSFC), 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), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), T. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 080710 (trigger #316534) (Sbarufatti, et al., GCN Circ. 7957). The BAT ground-calculated position is RA, Dec = 8.259, 19.484 deg which is
```
   RA(J2000)  =  00h 33m 02.2s 
   Dec(J2000) = +19d 29' 00.8" 
```
with an uncertainty of 2.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 48%.
The mask-weighted light curve shows a weak emission starting around T-120 sec, and then, following a FRED like spike starting from T+0 sec and ending at T+43 sec. T90 (15-350 keV) is 120 +- 17 sec (estimated error including systematics).
The time-averaged spectrum from T-96.9 to T+43.3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.47 +- 0.23. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.89 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/316534/BA/
GCN Circular #7970
D. A. Perley (UC Berkeley) and C. Melis (UCLA) report:
On the night of 2008-07-10 starting at 10:32:30 UT, we began a series of IR exposures with the Lick Shane 3 meter telescope, equipped with the GEMINI IR imager. We acquired imaging in J and K' filters simultaneously between 10:32 and 10:44. We returned to the field during morning twilight and took additional imaging between 12:19 and 12:25 in H and K' simultaneously.
Calibrating to two nearby 2MASS stars, we estimate a preliminary magnitude in the first epoch J-band imaging of:
J = 16.24 +/- 0.05
between 10:32 and 10:44 (mid-time of 206 minutes after the GRB.)
The GRB afterglow displays tentative evidence of brightening over the exposure period. Additional analysis is ongoing.
GCN Circular #7972
S. Schulze, D. A. Kann, A. Rossi, E. Gonsalves, C. Hoegner and B. Stecklum (TLS Tautenburg) report:
We observed the optical afterglow location (Li et al., GCN 7959) of Swift GRB 080710 (Sbarufatti et al., GCN 7957) with the TLS 1.34m Schmidt telescope under inclement but improving conditions. 600 second B and V observations were affected by passing clouds and yielded no detections and shallow upper limits only. We detect the afterglow clearly in a single Rc image as well as in four Ic images (600 seconds each) before dawn shut us down. We measure afterglow magnitudes against eight USNOB1.0 stars in each case:
```
time (days)	filter	magnitude	exposure

0.7275		Rc	20.05 +/- 0.12	600
0.7468		Ic	19.75 +/- 0.13	4 x 600
```
In comparison with the magnitude as well as the slope reported from the Faulkes Telescope North (Bersier et al., GCN 7963) (R = 17.8 at 4.4h, alpha = 0.82), our measurement implies a significant steepening of the decay, we find alpha = 1.5 between 4.4 and 17.5 hours after the GRB. This implies that a break must have occurred inbetween, and possibly the slope during the time of our observations is already > 2 and the break is a jet break.
Using the redshift of 0.845 (Perley et al., GCN 7962) as well as the values derived in the BAT refined analysis (Tueller et al., GCN 7969) and estimating the peak energy following equation 3 of Liang et al. (2007, ApJ, 670, 565), we derive a bolometric isotropic energy release of 6.8 +2.0 -1.9 x 10^51 erg. If there is a jet break before 17 hours, this would imply a low collimation-corrected energy release.
No further observations from TLS are possible due to an instrument change.
This message may be cited.
GCN Circular #7973
M. Yoshida, K. Yanagisawa, D. Kuroda, Y. Shimizu, S. Nagayama, H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the optical afterglow (Li et al. GCN 7959; D'Avanzo et al. GCN 7960; Schady GCN 7961) of GRB 080710 (Sbarufatti et al. GCN 7957) with the optical three color (g', Rc and Ic) imager attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory. We started the observation at 2008-07-10 15:37:23 UT. Photometric results are listed below. We used four USNO-B1.0 stars around the afterglow. The Rc band magnitude is consistent with the power-law decay with alpha = 1.5 reported by Schulze et al. (GCN 7972).
mid-UT of the observation: 2008-07-10 16:27:00 (0.384595 days after trigger)
```
T-T0(days) exp-T        g'              Rc              Ic
----------------------------------------------------------------
0.384595   86min  18.79 +/- 0.08  18.96 +/- 0.06  18.57 +/- 0.06
----------------------------------------------------------------
```

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Jochen Greiner, last update: 12-Jul-2008 [Disclaimer]