Gamma-ray Burst 110411A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:34:32 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     451165,   Seg_Num: 0
GRB_RA:          291.437d {+19h 25m 45s} (J2000),
                 291.439d {+19h 25m 45s} (current),
                 291.428d {+19h 25m 43s} (1950)
GRB_DEC:         +67.732d {+67d 43' 55"} (J2000),
                 +67.755d {+67d 45' 18"} (current),
                 +67.630d {+67d 37' 49"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4341 [cnts]    Image_Peak=169 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   137     E_range: 15-50 keV
BKG_INTEN:       27929 [cnts]
BKG_TIME:        70433.15 SOD {19:33:53.15} UT
BKG_DUR:         8 [sec]
GRB_DATE:        15662 TJD;   101 DOY;   11/04/11
GRB_TIME:        70451.84 SOD {19:34:11.84} UT
GRB_PHI:         -88.35 [deg]
GRB_THETA:        20.56 [deg]
SOLN_STATUS:     0x83
RATE_SIGNIF:     12.00 [sigma]
IMAGE_SIGNIF:    6.94 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +1  -3  +0  +0 -14  +0 
SUN_POSTN:        19.93d {+01h 19m 44s}   +8.41d {+08d 24' 23"}
SUN_DIST:         81.65 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.89d {+07h 47m 32s}  +18.45d {+18d 26' 56"}
MOON_DIST:        93.70 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.13, 21.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       17.81, 81.64 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 130.79,-17.27 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:36:56 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     451165,   Seg_Num: 0
GRB_RA:          291.4363d {+19h 25m 44.71s} (J2000),
                 291.4381d {+19h 25m 45.15s} (current),
                 291.4264d {+19h 25m 42.33s} (1950)
GRB_DEC:         +67.7103d {+67d 42' 37.0"} (J2000),
                 +67.7332d {+67d 43' 59.6"} (current),
                 +67.6086d {+67d 36' 30.8"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.26e-09 [erg/cm2/sec]
GRB_SIGNIF:      6.32 [sigma]
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70578.24 SOD {19:36:18.24} UT,   126.4 [sec] since BAT Trigger Time
TAM[0-3]:        327.65 237.21 261.56 243.34
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        19.93d {+01h 19m 44s}   +8.41d {+08d 24' 25"}
SUN_DIST:         81.65 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.91d {+07h 47m 38s}  +18.44d {+18d 26' 36"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.11, 21.81 [deg] galactic lon,lat of the burst
ECL_COORDS:       17.66, 81.64 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.30 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:37:07 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     451165,   Seg_Num: 0
GRB_RA:          291.4363d {+19h 25m 44.7s} (J2000),
                 291.4381d {+19h 25m 45.1s} (current),
                 291.4264d {+19h 25m 42.3s} (1950)
GRB_DEC:         +67.7103d {+67d 42' 37.0"} (J2000),
                 +67.7332d {+67d 43' 59.6"} (current),
                 +67.6086d {+67d 36' 30.8"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       40 [cnts]
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70578.24 SOD {19:36:18.24} UT,   126.4 [sec] since BAT Trigger Time
CENTROID_X:      271.56,  raw= 272  [pixels]
CENTROID_Y:      263.39,  raw= 263  [pixels]
ROLL:            88.12 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -81.56
GRB_POS_XRT_Z:   -72.46
IMAGE_URL:       sw00451165000msxps_rw.img
SUN_POSTN:        19.93d {+01h 19m 44s}   +8.41d {+08d 24' 26"}
SUN_DIST:         81.65 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.91d {+07h 47m 38s}  +18.44d {+18d 26' 34"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.11, 21.81 [deg] galactic lon,lat of the burst
ECL_COORDS:       17.66, 81.64 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:37:15 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     451165,   Seg_Num: 0
GRB_RA:          291.4363d {+19h 25m 44.7s} (J2000),
                 291.4381d {+19h 25m 45.1s} (current),
                 291.4264d {+19h 25m 42.3s} (1950)
GRB_DEC:         +67.7103d {+67d 42' 37.0"} (J2000),
                 +67.7332d {+67d 43' 59.6"} (current),
                 +67.6086d {+67d 36' 30.8"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       40 [cnts]
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70578.24 SOD {19:36:18.24} UT,   126.4 [sec] since BAT Trigger Time
CENTROID_X:      271.56,  raw= 272  [pixels]
CENTROID_Y:      263.39,  raw= 263  [pixels]
ROLL:            88.12 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -81.56
GRB_POS_XRT_Z:   -72.46
IMAGE_URL:       sw00451165000msxps_rw.img
SUN_POSTN:        19.93d {+01h 19m 44s}   +8.41d {+08d 24' 26"}
SUN_DIST:         81.65 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.91d {+07h 47m 39s}  +18.44d {+18d 26' 33"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.11, 21.81 [deg] galactic lon,lat of the burst
ECL_COORDS:       17.66, 81.64 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:38:13 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     451165,   Seg_Num: 0
GRB_RA:          291.437d {+19h 25m 45s} (J2000),
                 291.439d {+19h 25m 45s} (current),
                 291.428d {+19h 25m 43s} (1950)
GRB_DEC:         +67.732d {+67d 43' 55"} (J2000),
                 +67.755d {+67d 45' 18"} (current),
                 +67.630d {+67d 37' 49"} (1950)
GRB_DATE:        15662 TJD;   101 DOY;   11/04/11
GRB_TIME:        70451.84 SOD {19:34:11.84} UT
TRIGGER_INDEX:   137
GRB_PHI:         -88.35 [deg]
GRB_THETA:        20.56 [deg]
DELTA_TIME:      52.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x83
RATE_SIGNIF:     12.00 [sigma]
IMAGE_SIGNIF:    6.94 [sigma]
LC_URL:          sw00451165000msb.lc
SUN_POSTN:        19.93d {+01h 19m 44s}   +8.41d {+08d 24' 27"}
SUN_DIST:         81.65 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.92d {+07h 47m 41s}  +18.44d {+18d 26' 24"}
MOON_DIST:        93.71 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.13, 21.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       17.81, 81.64 [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:        Since the IMAGE_SIGNIF is less than 7 sigma, this is a questionable detection.  
COMMENTS:        This trigger occurred at longitude,latitude = 130.79,-17.27 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:39:27 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.384d {+19h 25m 32s} (J2000)
POINT_DEC:       +67.733d {+67d 43' 57"} (J2000)
POINT_ROLL:      88.117d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70587.00 SOD {19:36:27.00} UT,   135.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.857
N_STARS:         177
X_OFFSET:        632 [pixels]
Y_OFFSET:        480 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1439 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    6
SL_URL:          sw00451165000msufc0135.fits
SUN_POSTN:        19.94d {+01h 19m 45s}   +8.41d {+08d 24' 28"}
SUN_DIST:         81.67 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.93d {+07h 47m 44s}  +18.44d {+18d 26' 14"}
MOON_DIST:        93.71 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.81, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:39:57 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.384d {+19h 25m 32s} (J2000)
POINT_DEC:       +67.733d {+67d 43' 57"} (J2000)
POINT_ROLL:      88.117d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70587.00 SOD {19:36:27.00} UT,   135.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.857
N_STARS:         177
X_OFFSET:        632 [pixels]
Y_OFFSET:        480 [pixels]
X_MAX:           1591 [pixels]
Y_MAX:           1439 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    6
SL_URL:          sw00451165000msufc0135.fits
SUN_POSTN:        19.94d {+01h 19m 45s}   +8.41d {+08d 24' 28"}
SUN_DIST:         81.67 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.94d {+07h 47m 45s}  +18.44d {+18d 26' 09"}
MOON_DIST:        93.71 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.81, 81.66 [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:     Mon 11 Apr 11 19:40:53 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.384d {+19h 25m 32s} (J2000)
POINT_DEC:       +67.733d {+67d 43' 57"} (J2000)
ROLL:            88.117d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70587.00 SOD {19:36:27.00} UT,   135.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     324243393
X_OFFSET:        1015 [pixels]
Y_OFFSET:        939 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1175
Y_GRB_POS:       1099
BINNING_INDEX:   1
IM_URL:          sw00451165000msuni0142.fits
SUN_POSTN:        19.94d {+01h 19m 45s}   +8.41d {+08d 24' 29"}
SUN_DIST:         81.67 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.95d {+07h 47m 47s}  +18.43d {+18d 26' 01"}
MOON_DIST:        93.71 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.81, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:41:11 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.384d {+19h 25m 32s} (J2000)
POINT_DEC:       +67.733d {+67d 43' 57"} (J2000)
ROLL:            88.117d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70587.00 SOD {19:36:27.00} UT,   135.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     324243393
X_OFFSET:        1015 [pixels]
Y_OFFSET:        939 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1175
Y_GRB_POS:       1099
BINNING_INDEX:   1
IM_URL:          sw00451165000msuni0142.fits
SUN_POSTN:        19.94d {+01h 19m 45s}   +8.41d {+08d 24' 29"}
SUN_DIST:         81.67 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      116.95d {+07h 47m 48s}  +18.43d {+18d 25' 59"}
MOON_DIST:        93.71 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.81, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #11918
D. Grupe (PSU), S. Campana (INAF-OAB), J. R. Cummings (NASA/UMBC), J. M. Gelbord (PSU), J. A. Kennea (PSU), C. B. Markwardt (NASA/GSFC), B. Sbarufatti (INAF-OAB/IASFPA), M. H. Siegel (PSU), E. Sonbas (GSFC/USRA/Adiyaman Univ.), R. L. C. Starling (U Leicester), C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift Team:
At 19:34:11 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 110411A (trigger=451165). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 291.437, +67.732 which is
```
   RA(J2000) = 19h 25m 45s
   Dec(J2000) = +67d 43' 55"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 120 sec. The peak count rate was ~2000 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 19:36:18.2 UT, 126.4 seconds after the BAT trigger. Using promptly downlinked data we find a bright, fading, uncatalogued X-ray source located at RA, Dec 291.43966, 67.71117 which is equivalent to:
```
   RA(J2000)  = 19h 25m 45.52s
   Dec(J2000) = +67d 42' 40.2"
```
with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 75 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.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (6.92 x 10^20 cm^-2, Kalberla et al. 2005), with an excess column of 5.4 (+3.77/-2.83) x 10^21 cm^-2 (90% confidence).
The initial flux in the 2.5 s image was 1.26e-09 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 135 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.10.
Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). 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:     Mon 11 Apr 11 19:47:57 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
POINT_ROLL:      88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70799.15 SOD {19:39:59.15} UT,   347.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.837
N_STARS:         89
X_OFFSET:        695 [pixels]
Y_OFFSET:        619 [pixels]
X_MAX:           1654 [pixels]
Y_MAX:           1578 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00451165000msufc0347.fits
SUN_POSTN:        19.94d {+01h 19m 46s}   +8.41d {+08d 24' 36"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.01d {+07h 48m 03s}  +18.42d {+18d 24' 60"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:48:13 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
POINT_ROLL:      88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70799.15 SOD {19:39:59.15} UT,   347.3 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.837
N_STARS:         89
X_OFFSET:        695 [pixels]
Y_OFFSET:        619 [pixels]
X_MAX:           1654 [pixels]
Y_MAX:           1578 [pixels]
DET_THRESH:      8
PHOTO_THRESH:    4
SL_URL:          sw00451165000msufc0347.fits
SUN_POSTN:        19.94d {+01h 19m 46s}   +8.41d {+08d 24' 36"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.02d {+07h 48m 04s}  +18.42d {+18d 24' 58"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [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:     Mon 11 Apr 11 19:48:30 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     451165,   Seg_Num: 0
GRB_RA:          291.4420d {+19h 25m 46.08s} (J2000),
                 291.4438d {+19h 25m 46.52s} (current),
                 291.4321d {+19h 25m 43.70s} (1950)
GRB_DEC:         +67.7115d {+67d 42' 41.4"} (J2000),
                 +67.7344d {+67d 44' 04.0"} (current),
                 +67.6097d {+67d 36' 35.0"} (1950)
GRB_ERROR:       2.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70629.00 SOD {19:37:09.00} UT,   177.2 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        19.94d {+01h 19m 46s}   +8.41d {+08d 24' 36"}
SUN_DIST:         81.65 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.02d {+07h 48m 05s}  +18.42d {+18d 24' 55"}
MOON_DIST:        93.75 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.11, 21.81 [deg] galactic lon,lat of the burst
ECL_COORDS:       17.67, 81.63 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
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:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:49:05 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
ROLL:            88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70799.15 SOD {19:39:59.15} UT,   347.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     324243606
X_OFFSET:        1015 [pixels]
Y_OFFSET:        939 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1175
Y_GRB_POS:       1099
BINNING_INDEX:   1
IM_URL:          sw00451165000msuni0354.fits
SUN_POSTN:        19.94d {+01h 19m 46s}   +8.41d {+08d 24' 37"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.03d {+07h 48m 06s}  +18.41d {+18d 24' 50"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:49:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
ROLL:            88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  70799.15 SOD {19:39:59.15} UT,   347.3 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     324243606
X_OFFSET:        1015 [pixels]
Y_OFFSET:        939 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1175
Y_GRB_POS:       1099
BINNING_INDEX:   1
IM_URL:          sw00451165000msuni0354.fits
SUN_POSTN:        19.94d {+01h 19m 46s}   +8.41d {+08d 24' 37"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.03d {+07h 48m 07s}  +18.41d {+18d 24' 47"}
MOON_DIST:        93.73 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:55:09 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
POINT_ROLL:      88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  71331.07 SOD {19:48:51.07} UT,   879.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.292
N_STARS:         190
X_OFFSET:        455 [pixels]
Y_OFFSET:        379 [pixels]
X_MAX:           1894 [pixels]
Y_MAX:           1818 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00451165000msufc0879.fits
SUN_POSTN:        19.95d {+01h 19m 47s}   +8.41d {+08d 24' 42"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.08d {+07h 48m 20s}  +18.40d {+18d 23' 57"}
MOON_DIST:        93.74 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 11 19:55:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
POINT_ROLL:      88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  71331.07 SOD {19:48:51.07} UT,   879.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.292
N_STARS:         190
X_OFFSET:        455 [pixels]
Y_OFFSET:        379 [pixels]
X_MAX:           1894 [pixels]
Y_MAX:           1818 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00451165000msufc0879.fits
SUN_POSTN:        19.95d {+01h 19m 47s}   +8.41d {+08d 24' 42"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.09d {+07h 48m 21s}  +18.40d {+18d 23' 55"}
MOON_DIST:        93.74 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [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:     Mon 11 Apr 11 19:56:36 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
ROLL:            88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  71331.07 SOD {19:48:51.07} UT,   879.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     324244137
X_OFFSET:        1014 [pixels]
Y_OFFSET:        938 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1174
Y_GRB_POS:       1098
BINNING_INDEX:   1
IM_URL:          sw00451165000msuni0886.fits
SUN_POSTN:        19.95d {+01h 19m 47s}   +8.41d {+08d 24' 44"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.10d {+07h 48m 23s}  +18.40d {+18d 23' 45"}
MOON_DIST:        93.75 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [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:     Mon 11 Apr 11 19:56:56 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     451165,   Seg_Num: 0
POINT_RA:        291.375d {+19h 25m 30s} (J2000)
POINT_DEC:       +67.732d {+67d 43' 55"} (J2000)
ROLL:            88.110d
IMG_START_DATE:  15662 TJD;   101 DOY;   11/04/11
IMG_START_TIME:  71331.07 SOD {19:48:51.07} UT,   879.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     324244137
X_OFFSET:        1014 [pixels]
Y_OFFSET:        938 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1174
Y_GRB_POS:       1098
BINNING_INDEX:   1
IM_URL:          sw00451165000msuni0886.fits
SUN_POSTN:        19.95d {+01h 19m 47s}   +8.41d {+08d 24' 44"}
SUN_DIST:         81.68 [deg]   Sun_angle= 5.9 [hr] (West of Sun)
MOON_POSTN:      117.10d {+07h 48m 24s}  +18.39d {+18d 23' 42"}
MOON_DIST:        93.75 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:       99.12, 21.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       17.80, 81.66 [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 #11919
O. Gres, K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Chuvalaev Irkutsk State University
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov Ural State University, Kourovka
V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka(Siberia) was pointed to the GRB110411A 19 sec s after notice time and 44 sec after GRB time at 2011-04-11 19:34:55.3 UT in two polarizations. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=19 25 45 dec=+67 43 48 r=0.050000). The 5-sigma upper limit has been about 17.5 mag Observations and data reduction is continued. The message may be cited.
GCN Circular #11920
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 2358 s of XRT Photon Counting mode data and 2 UVOT images for GRB 110411A, 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 = 291.44219, +67.71167 which is equivalent to:
```
RA (J2000): 19h 25m 46.13s
Dec (J2000): +67d 42' 42.0"
```
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 #11921
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), 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-61 to T+242 sec from the recent telemetry downlink, we report further analysis of BAT GRB 110411A (trigger #451165) (Grupe, et al., GCN Circ. 11918). The BAT ground-calculated position is RA, Dec = 291.427, 67.706 deg which is
```
     RA(J2000)  =  19h 25m 42.5s
     Dec(J2000) = +67d 42' 21.0"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%.
The burst had multiple peaks with gradual rise and fall. The two largest peaks were centered around T+5 sec and T+60 sec. T90 (15-350 keV) is 80.3 +- 5.2 sec (estimated error including systematics).
The time-averaged spectrum from T-11.9 to T+86.3 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.51 +- 0.31, and Epeak of 41.0 +- 8.1 keV (chi squared 49.70 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 3.3 +- 0.2 x 10^-06 erg/cm2 and the 1-sec peak flux measured from T+4.73 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 2.05 +- 0.07 (chi squared 59.73 for 57 d.o.f.). 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/451165/BA/
GCN Circular #11923
L.P. Xin, Z. X. Ling, Y.L. Qiu, J.Y. Wei, J. Wang, J.S. Deng, C. Wu, X. H. Han on behalf of EAFON report:
We began to observe GRB110411A ( Grope et al., GCN 11918) with Xinglong TNT telescope at 19:35:32 (UT), 81 sec after the burst. A series of White and R-band images were obtained. With the combination of all R-band images of 37*60 sec exposure time, we detected an new source nearby the errorbox of X-ray counterpart ( Goad et al., GCN 11920 ).
The coordinates of new source are:
```
Ra:    19:25:45.65 
Dec:   67:42:39.1
Epoch: J2000
```
The uncertainty of the coordinates is about 1 arc.
The brightness of this source is estimated to be about 21 +/- 0.2 mag in the R band, at the mean time of 38 min after the burst, comparing to an USNO B1.0 R2 reference star, of which the coordinates are 19:25:52.432 +67:43:44.07 J2000 R2=16.18mag.
We proposed that the new source be the optical counterpart of GRB 110411A.
This message may be cited.

GCN Circular #11924
O. Gres, K.Ivanov, V.A.Poleshchuk, S.Yazev, N.M.Budnev, O.Chuvalaev Irkutsk State University
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, N.Shatskiy, P.Balanutsa, V.V.Chazov, P.V.Kortunov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Kuznetsov, D.Zimnukhov, M. Kornilov, A.Sankovich Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalozhnich, T.Kopytova, A. Popov Ural State University, Kourovka
V.Yurkov, Yu.Sergienko, D.Varda, I.Kudelina Blagoveschensk Educational State University, Blagoveschensk
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka(Siberia) was pointed to the GRB110411A (Grupe et al., GCN 11918) 19 sec s after notice time and 44 sec after GRB time at 2011-04-11 19:34:55.3 UT in two polarizations. A series of Polarization, White and R-band images were obtained. We have not found OT at Xinglong TNT OT candidate position (Xin et al., GCN Circ 11923). The results from two tubes are: (GRB Time = 2011-04-11 19:34:11 UT)

Date time 	    Exp.time    Limit	Filt.(W-white)
    UT                   (s)   (5-sigma)
2011-04-11 19:34:55	10	17.4	W
2011-04-11 19:34:55	10	18.0	W
2011-04-11 19:35:23	10	14.8	P/
2011-04-11 19:35:23	10	15.4	P\
2011-04-11 19:35:50	20	15.5	P/
2011-04-11 19:35:51	20	16.0	P\
2011-04-11 19:36:29	30	16.0	P/
2011-04-11 19:36:29	30	16.5	P\
2011-04-11 19:37:17	40	16.0	P/
2011-04-11 19:37:18	40	16.7	P/
2011-04-11 19:38:14	50	16.3	P\
2011-04-11 19:38:14	50	16.9	P/
2011-04-11 19:39:22	60	16.5	P\
2011-04-11 19:39:22	60	17.0	P/
2011-04-11 19:40:39	80	16.6	P\
2011-04-11 19:40:39	80	17.2	P/
2011-04-11 19:42:14	3790	19.4	P\
2011-04-11 19:42:14	100	17.0	P/
2011-04-11 19:42:15	3970	18.9	P\
2011-04-11 19:42:15	100	17.7	P/
2011-04-11 19:44:10	120	17.4	P\
2011-04-11 19:44:11	120	17.4	P/
2011-04-11 19:46:26	150	17.8	P\
2011-04-11 19:46:26	150	17.7	P/
2011-04-11 19:49:11	180	18.1	P\
2011-04-11 19:49:12	180	17.9	P/
2011-04-11 19:52:30	180	18.0	P\
2011-04-11 19:52:30	180	17.9	P/
2011-04-11 19:55:46	180	18.1	P\
2011-04-11 19:55:46	180	18.0	P/
2011-04-11 19:59:02	180	18.1	P\
2011-04-11 19:59:02	180	18.1	P/
2011-04-11 20:02:17	180	18.1	P\
2011-04-11 20:02:18	180	18.1	P/
2011-04-11 20:05:33	180	18.1	P\
2011-04-11 20:05:34	180	18.1	P/
2011-04-11 20:08:49	180	18.0	P\
2011-04-11 20:08:49	180	18.0	P/
2011-04-11 20:12:06	180	18.0	P\
2011-04-11 20:12:06	180	18.0	P/
2011-04-11 20:15:23	180	18.1	P\
2011-04-11 20:15:24	180	18.0	P/
2011-04-11 20:18:40	180	18.1	P\
2011-04-11 20:18:41	180	18.0	P/
2011-04-11 20:21:57	180	18.1	P\
2011-04-11 20:21:58	180	18.0	P/
2011-04-11 20:25:14	180	18.0	P\
2011-04-11 20:25:14	180	18.0	P/
2011-04-11 20:28:38	180	18.1	P\
2011-04-11 20:28:40	180	18.0	P/
2011-04-11 20:31:56	180	18.1	P\
2011-04-11 20:31:57	180	18.0	P/
2011-04-11 20:35:13	180	18.0	P\
2011-04-11 20:35:13	180	17.9	P/
2011-04-11 20:38:32	180	18.1	P\
2011-04-11 20:38:32	180	17.9	P/
2011-04-11 20:41:48	180	17.8	P\
2011-04-11 20:41:48	180	17.9	P/
2011-04-11 20:45:04	180	17.8	P\
2011-04-11 20:45:04	180	17.9	P/
2011-04-11 20:48:20	180	17.8	P\
2011-04-11 20:48:20	180	17.7	P/
2011-04-11 20:51:45	180	17.7	P\
2011-04-11 20:51:46	180	17.7	P/
2011-04-11 20:59:09	180	19.0	W
2011-04-11 20:59:09	900	19.4	W
2011-04-11 20:59:09	180	18.8	R
2011-04-11 20:59:09	900	19.2	R
2011-04-11 21:02:42	180	18.7	W
2011-04-11 21:02:43	180	18.8	R
2011-04-11 21:06:52	180	18.5	W
2011-04-11 21:06:52	180	18.5	R
2011-04-11 21:10:28	180	18.2	W
2011-04-11 21:10:28	180	18.3	R
2011-04-11 21:14:04	180	18.0	W
2011-04-11 21:14:04	180	18.0	R

The message may be cited.

GCN Circular #11925
N.P.M. Kuin (MSSL/UCL) and D. Grupe (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 110411A 135 s after the BAT trigger (Grupe et al., GCN Circ. 11918). No optical afterglow consistent with the XRT (Goad et al., GCN Circ. 11920) or the Xinglong (Xin et al., GCN Circ. 11923) positions is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           135          285          147         >21.3
u_FC               347          597          246         >20.4
white              135         7753          883         >22.2
v                  677         8164          607         >19.9
b                  603         7548          586         >21.1
u                  347         7343          637         >20.4
w1                 726         7139          391         >20.2
m2                 701         8326          508         >20.1
w2                 653         7959          607         >20.9
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.10 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #11927
D. Grupe (PSU) reports on behalf of the Swift-XRT team:
We have analyzed 11 ks of XRT data for GRB 110411A (Grupe et al. GCN Circ. 11918), from 117 s to 37.2 ks after the BAT trigger. The data comprise 64 s in Windowed Timing (WT) mode (the first 8 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 11920).
The light curve can be modeled with a series of power-law decays. The initial decay index is alpha=6.0 (+/-0.6). At T+230 s the decay flattens to an alpha of 0.58 (+0.11, -0.12) before breaking again at T+4446 s to a final decay with index alpha=1.39 (+0.27, -0.24).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.93 (+0.23, -0.21). The best-fitting absorption column is 1.02 (+0.14, -0.12) x 10^22 cm^-2, in excess of the Galactic value of 6.9 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (2.3 x 10^-10) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.02 (+0.14, -0.12) x 10^22 cm^-2
Galactic foreground: 6.9 x 10^20 cm^-2
Excess significance: 13.5 sigma
Photon index:	     2.93 (+0.23, -0.21)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00451165.
With an excess absorption column density of 9.5 x 10^21 cm^-2 following the relation in Grupe et al. (2007, AJ, 133, 2216) the estimated maximum redshift of the afterglow is z < 1.0.
This circular is an official product of the Swift-XRT team.
GCN Circular #11928
A. Sota, J. Gorosabel and M. Jelinek (IAA-CSIC), report on behalf of a larger collaboration.
"We have observed the XRT error circle (Goad et al. GCNC 11920) of GRB 110411A (Grupe et al. GCNC 11918) with the 1.5m telescope of Observatorio de Sierra Nevada, Granada, Spain. The observations were carried out on April 12.06606-12.12741 UT (6.01-7.49 hours post trigger) in the R and I bands with an exposure time of 8x300s in each band. No object is detected within the XRT error circle down to R < 23.5 and I < 22.4, calibrated against USNO B1.0".
GCN Circular #11930
A. N. Morgan, A. Cucchiara, and J. S. Bloom (UC Berkeley) report:
We observed the field of GRB 110411A (Grupe et al., GCN 11918) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2011-04-12 09:53:13 UT, ~14.3 hours after the Swift Trigger. In mosaics (effective exposure time of 1.22 hours) taken simultaneously in the J, H, and Ks filters, we do not detect any source at the optical afterglow candidate location (Xin et al., GCN 11923).
The preliminary photometry yields:
```
post burst
t_mid (hr) exp.(hr) filt  U. Limit (3 sig)
15.37      1.22     J     > 18.7
15.37      1.22     H     > 18.0
15.37      1.22     H     > 16.6
```
All magnitudes are given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values.
GCN Report 330.1
GCN_Report 330.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_330_1.pdf by D. Grupe at PSU titled: "Final Report on Swift GRB 110411A"

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Jochen Greiner, last update: 13-Apr-2011 [Disclaimer]