Gamma-ray Burst 120817A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 17 Aug 12 06:50:05 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     531267,   Seg_Num: 0
GRB_RA:          250.706d {+16h 42m 49s} (J2000),
                 250.920d {+16h 43m 41s} (current),
                 249.858d {+16h 39m 26s} (1950)
GRB_DEC:         -38.340d {-38d 20' 25"} (J2000),
                 -38.364d {-38d 21' 48"} (current),
                 -38.247d {-38d 14' 47"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4993 [cnts]    Image_Peak=218 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       30741 [cnts]
BKG_TIME:        24566.45 SOD {06:49:26.45} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16156 TJD;   230 DOY;   12/08/17
GRB_TIME:        24582.83 SOD {06:49:42.83} UT
GRB_PHI:         -131.57 [deg]
GRB_THETA:        19.58 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.84 [sigma]
IMAGE_SIGNIF:    7.78 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -2  +0  +1 +31  +0 
SUN_POSTN:       147.06d {+09h 48m 14s}  +13.26d {+13d 15' 52"}
SUN_DIST:        108.98 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      140.95d {+09h 23m 49s}  +10.15d {+10d 08' 53"}
MOON_DIST:       111.90 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.74,  5.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      254.36,-15.94 [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 = 273.00,0.13 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 17 Aug 12 06:53:14 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     531267,   Seg_Num: 0
GRB_RA:          250.706d {+16h 42m 49s} (J2000),
                 250.920d {+16h 43m 41s} (current),
                 249.858d {+16h 39m 26s} (1950)
GRB_DEC:         -38.340d {-38d 20' 25"} (J2000),
                 -38.364d {-38d 21' 48"} (current),
                 -38.247d {-38d 14' 47"} (1950)
GRB_DATE:        16156 TJD;   230 DOY;   12/08/17
GRB_TIME:        24582.83 SOD {06:49:42.83} UT
TRIGGER_INDEX:   146
GRB_PHI:         -131.57 [deg]
GRB_THETA:        19.58 [deg]
DELTA_TIME:      -37.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.84 [sigma]
IMAGE_SIGNIF:    7.78 [sigma]
LC_URL:          sw00531267000msb.lc
SUN_POSTN:       147.06d {+09h 48m 15s}  +13.26d {+13d 15' 49"}
SUN_DIST:        108.98 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      140.98d {+09h 23m 55s}  +10.14d {+10d 08' 19"}
MOON_DIST:       111.87 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.74,  5.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      254.36,-15.94 [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 = 273.00,0.13 [deg].

GCN Circular #13661
B.P. Gompertz (U Leicester), P. A. Evans (U Leicester), C. Guidorzi (U Ferrara), K. L. Page (U Leicester), D. M. Palmer (LANL) and R. L. C. Starling (U Leicester) report on behalf of the Swift Team:
At 06:49:42 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 120817A (trigger=531267). Swift could not immediately slew due to an Earth limb pointing constraint. The BAT on-board calculated location is RA, Dec 250.706, -38.340 which is
```
   RA(J2000) = 16h 42m 49s
   Dec(J2000) = -38d 20' 25"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multiple-peaked structure with a duration of about 25 sec. The peak count rate was ~1700 counts/sec (15-350 keV), at ~0 sec after the trigger.
Due to an observing constraint, Swift will not slew until T0+50.1 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is B.P. Gompertz (bpg6 AT le.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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 17 Aug 12 07:41:57 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     531267,   Seg_Num: 0
POINT_RA:        250.679d {+16h 42m 43s} (J2000)
POINT_DEC:       -38.353d {-38d 21' 09"} (J2000)
IMG_START_DATE:  16156 TJD;   230 DOY;   12/08/17
IMG_START_TIME:  27693.57 SOD {07:41:33.57} UT,   3110.7 [sec] since BAT Trigger Time
COUNTS:          5    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        3    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:     Fri 17 Aug 12 07:46:24 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     531267,   Seg_Num: 0
POINT_RA:        250.677d {+16h 42m 42s} (J2000)
POINT_DEC:       -38.354d {-38d 21' 14"} (J2000)
POINT_ROLL:      272.332d
IMG_START_DATE:  16156 TJD;   230 DOY;   12/08/17
IMG_START_TIME:  27697.85 SOD {07:41:37.85} UT,   3115.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        0.553
N_STARS:         190
X_OFFSET:        384 [pixels]
Y_OFFSET:        729 [pixels]
X_MAX:           1343 [pixels]
Y_MAX:           1688 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00531267000msufc3115.fits
SUN_POSTN:       147.10d {+09h 48m 23s}  +13.25d {+13d 15' 06"}
SUN_DIST:        108.92 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      141.45d {+09h 25m 48s}   +9.98d {+09d 58' 37"}
MOON_DIST:       111.38 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.72,  5.09 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      254.34,-15.96 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 17 Aug 12 07:46:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     531267,   Seg_Num: 0
POINT_RA:        250.677d {+16h 42m 42s} (J2000)
POINT_DEC:       -38.354d {-38d 21' 14"} (J2000)
POINT_ROLL:      272.332d
IMG_START_DATE:  16156 TJD;   230 DOY;   12/08/17
IMG_START_TIME:  27697.85 SOD {07:41:37.85} UT,   3115.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        0.553
N_STARS:         190
X_OFFSET:        384 [pixels]
Y_OFFSET:        729 [pixels]
X_MAX:           1343 [pixels]
Y_MAX:           1688 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw00531267000msufc3115.fits
SUN_POSTN:       147.10d {+09h 48m 23s}  +13.25d {+13d 15' 06"}
SUN_DIST:        108.92 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      141.46d {+09h 25m 50s}   +9.98d {+09d 58' 31"}
MOON_DIST:       111.37 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.72,  5.09 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      254.34,-15.96 [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:     Fri 17 Aug 12 07:48:03 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     531267,   Seg_Num: 0
POINT_RA:        250.677d {+16h 42m 42s} (J2000)
POINT_DEC:       -38.354d {-38d 21' 14"} (J2000)
ROLL:            272.332d
IMG_START_DATE:  16156 TJD;   230 DOY;   12/08/17
IMG_START_TIME:  27697.85 SOD {07:41:37.85} UT,   3115.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     366882107
X_OFFSET:        703 [pixels]
Y_OFFSET:        1048 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       863
Y_GRB_POS:       1208
BINNING_INDEX:   1
IM_URL:          sw00531267000msuni3125.fits
SUN_POSTN:       147.10d {+09h 48m 23s}  +13.25d {+13d 15' 05"}
SUN_DIST:        108.92 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      141.47d {+09h 25m 52s}   +9.97d {+09d 58' 19"}
MOON_DIST:       111.36 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.72,  5.09 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      254.34,-15.96 [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:     Fri 17 Aug 12 07:48:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     531267,   Seg_Num: 0
POINT_RA:        250.677d {+16h 42m 42s} (J2000)
POINT_DEC:       -38.354d {-38d 21' 14"} (J2000)
ROLL:            272.332d
IMG_START_DATE:  16156 TJD;   230 DOY;   12/08/17
IMG_START_TIME:  27697.85 SOD {07:41:37.85} UT,   3115.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     366882107
X_OFFSET:        703 [pixels]
Y_OFFSET:        1048 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       863
Y_GRB_POS:       1208
BINNING_INDEX:   1
IM_URL:          sw00531267000msuni3125.fits
SUN_POSTN:       147.10d {+09h 48m 23s}  +13.25d {+13d 15' 05"}
SUN_DIST:        108.92 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      141.47d {+09h 25m 52s}   +9.97d {+09d 58' 17"}
MOON_DIST:       111.36 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.72,  5.09 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      254.34,-15.96 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 17 Aug 12 08:03:13 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     531267,   Seg_Num: 0
GRB_RA:          250.6909d {+16h 42m 45.81s} (J2000),
                 250.9052d {+16h 43m 37.25s} (current),
                 249.8434d {+16h 39m 22.40s} (1950)
GRB_DEC:         -38.3540d {-38d 21' 14.3"} (J2000),
                 -38.3771d {-38d 22' 37.6"} (current),
                 -38.2600d {-38d 15' 35.9"} (1950)
GRB_ERROR:       4.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16156 TJD;   230 DOY;   12/08/17
IMG_START_TIME:  27788.00 SOD {07:43:08.00} UT,   3205.2 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       147.11d {+09h 48m 26s}  +13.25d {+13d 14' 53"}
SUN_DIST:        108.92 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      141.60d {+09h 26m 24s}   +9.93d {+09d 55' 32"}
MOON_DIST:       111.24 [deg]
MOON_ILLUM:      0 [%]
GAL_COORDS:      344.72,  5.09 [deg] galactic lon,lat of the burst
ECL_COORDS:      254.35,-15.96 [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.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 6.6% < P(seren) < 10%.

GCN Circular #13662
M. Perri (ASDC), G. Tagliaferri (INAF-OAB), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU) and J.A. Kennea (PSU) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 120817A at 07:41:33.5 UT, 3110.8 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 250.69098, -38.35404 which is equivalent to:
```
   RA(J2000)  = 16h 42m 45.84s
   Dec(J2000) = -38d 21' 14.5"
```
with an uncertainty of 4.2 arcseconds (radius, 90% containment). This location is 65 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 2.88 x 10^21 cm^-2 (Kalberla et al. 2005).
GCN Circular #13664
C. Guidorzi (U. Ferrara), C.G. Mundell, C.J. Mottram, F. Virgili (LJMU), A. Gomboc (U. Ljubljana) report on behalf of a larger collaboration:
The 2-m Faulkes Telescope North (FTN) automatically began observing GRB 120817A (Gompertz et al. GCN Circ. 13661) on August 17 2012, 06:53:57 UT corresponding to 4.2 minutes post burst trigger with BVRi' filters. Within the XRT error circle (Perri et al. GCN Circ. 13662), close to a USNOB1 object we detect a faint, uncatalogued, possibly fading source at the following position
```
R.A. = 16:42:45.92
Dec = -38:21:12.4   (J2000)
```
with an uncertainty of about 1". The detection is marginal, with an estimated magnitude of 19.3 +/- 0.4 in the R band at a mean time of 17.4 minutes (60 s exposure) calibrated against nearby USNOB-1 stars.
The 2-m Faulkes Telescope South (FTS) began observing at 77 min post burst. In a stacked R-band frame we find marginal evidence for fading, with R=19.8 +- 0.3 mag at a mean time of 105 min (total exposure of 360 s). The nearby USNOB1 object is compatible with being constant between the two observations.
The comparison between the FTN and FTS R-band images is available at http://www.fe.infn.it/u/guidorzi/GRB120817A_XRT_FT_candidate.jpg
GCN Circular #13667
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 2321 s of XRT Photon Counting mode data and 5 UVOT images for GRB 120817A, 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 = 250.68918, -38.35451 which is equivalent to:
```
RA (J2000): 16h 42m 45.40s
Dec (J2000): -38d 21' 16.2"
```
with an uncertainty of 1.8 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #13669
D. M. Palmer (LANL), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), B.P. Gompertz (U Leicester), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):

Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 120817A (trigger #531267) (Gompertz, et al., GCN Circ. 13661). The BAT ground-calculated position is RA, Dec = 250.692, -38.377 deg, which is
```
   RA(J2000)  =  16h 42m 46.2s 
   Dec(J2000) = -38d 22' 36.8" 
```
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 85%.
The mask-weighted light curve shows two slighly overlapping peaks starting at ~T-2 sec, peaking at ~T+0.0 and ~T+11 sec, with a tail ending at ~T+65 sec. T90 (15-350 keV) is 28.2 +- 6.8 sec (estimated error including systematics).
The time-averaged spectrum from T-2.24 to T+30.77 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.97 +- 0.16. The fluence in the 15-150 keV band is 6.9 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.12 sec in the 15-150 keV band is 0.8 +- 0.1 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/531267/BA/
GCN Circular #13673
B.P. Gompertz (U Leicester) reports on behalf of the Swift-XRT team:
We have analysed 9.7 ks of XRT data for GRB 120817A (Gompertz et al. GCN Circ. 13661), from 3.1 ks to 22.9 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN. Circ 13667).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.70 (+/-0.18).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.0 (+0.4, -0.3). The best-fitting absorption column is 5.9 (+2.6, -1.9) x 10^21 cm^-2, in excess of the Galactic value of 2.9 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.8 x 10^-11 (8.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     5.9 (+2.6, -1.9) x 10^21 cm^-2
Galactic foreground: 2.9 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index:	     2.0 (+0.4, -0.3)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00531267.
This circular is an official product of the Swift-XRT team.
GCN Circular #13694
J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis, of Los Alamos National Laboratory report:
A RAPTOR wide-field monitor located in Maui observed the location of Swift trigger 531267 (Gompertz et al., GCN 13661) during the period that the Swift BAT was observing gamma-ray emission. The 10 s exposure began at 06:49:38.0 UTC -- 4 s before the Swift trigger. We detect no new object at the location of the refined Swift XRT location (Gompertz et al., GCN 13673) to a 3-sigma limiting magnitude of 10.3. Our unfiltered images are calibrated to the Tycho-2 V-band.
GCN Circular #13701
S. Immler (NASA/CRESST/GSFC) and B. P. Gompertz (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 120817A 3115 s after the BAT trigger (Gompertz et al., GCN Circ. 13661). No optical afterglow consistent with the XRT (Beardmore et al., GCN 13667) or the FTN positions (Guidorzi et al., GCN 13664) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC          3115         3265          147         >19.4
white             3115         4496          344         >20.4
v                 3272        10816         1278         >20.2
b                 4092        17166          945         >21.1
u                 3887        22943         1904         >21.1
w1                3682        22294         2164         >20.3
m2                3476        21386         1838         >20.2
w2                4503         9902         1082         >20.0
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.84 in the direction of the burst (Schlegel et al. 1998).
GCN Report 385.1
GCN_Report 385.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_385_1.pdf by B.P. Gompertz at U.Leicester titled: "Swift Observations of GRB 120817A"

Back to JG's homepage

Jochen Greiner, last update: 28-Aug-2012 [Disclaimer]