Gamma-ray Burst 151215A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 15 Dec 15 03:01:45 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     667392,   Seg_Num: 0
GRB_RA:           93.595d {+06h 14m 23s} (J2000),
                  93.862d {+06h 15m 27s} (current),
                  92.756d {+06h 11m 01s} (1950)
GRB_DEC:         +35.509d {+35d 30' 34"} (J2000),
                 +35.504d {+35d 30' 13"} (current),
                 +35.525d {+35d 31' 29"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1722 [cnts]    Image_Peak=115 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   40     E_range: 25-100 keV
BKG_INTEN:       19950 [cnts]
BKG_TIME:        10872.44 SOD {03:01:12.44} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17371 TJD;   349 DOY;   15/12/15
GRB_TIME:        10888.95 SOD {03:01:28.95} UT
GRB_PHI:          47.72 [deg]
GRB_THETA:        28.64 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.41 [sigma]
IMAGE_SIGNIF:    8.38 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2  -1  +0  +1 +96  +0 
SUN_POSTN:       262.16d {+17h 28m 39s}  -23.24d {-23d 14' 26"}
SUN_DIST:        164.08 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.32d {+20h 37m 17s}  -14.59d {-14d 35' 39"}
MOON_DIST:       142.00 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.26,  8.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       92.99, 12.11 [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 = 237.15,-4.30 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE 
NOTICE_DATE:     Tue 15 Dec 15 03:08:38 UT 
NOTICE_TYPE:     Swift-BAT GRB Lightcurve 
TRIGGER_NUM:     6553465,   Seg_Num: 41 
GRB_RA:           93.595d {+06h 14m 23s} (J2000), 
                  93.862d {+06h 15m 27s} (current), 
                  92.756d {+06h 11m 01s} (1950) 
GRB_DEC:         +35.509d {+35d 30' 34"} (J2000), 
                 +35.504d {+35d 30' 13"} (current), 
                 +35.525d {+35d 31' 29"} (1950) 
GRB_DATE:        17371 TJD;   349 DOY;   15/12/15 
GRB_TIME:        10888.95 SOD {03:01:28.95} UT 
TRIGGER_INDEX:   40 
GRB_PHI:          47.72 [deg] 
GRB_THETA:        28.64 [deg] 
DELTA_TIME:      9.00 [sec] 
TRIGGER_DUR:     0.512 [sec]  
SOLN_STATUS:     0x3 
RATE_SIGNIF:     0.00 [sigma] 
IMAGE_SIGNIF:    0.00 [sigma] 
LC_URL:          sw00667392000msb.lc 
SUN_POSTN:       262.17d {+17h 28m 40s}  -23.24d {-23d 14' 27"} 
SUN_DIST:        164.08 [deg]   Sun_angle= 11.2 [hr] (West of Sun) 
MOON_POSTN:      309.39d {+20h 37m 33s}  -14.58d {-14d 34' 53"} 
MOON_DIST:       141.95 [deg] 
MOON_ILLUM:      15 [%] 
GAL_COORDS:      177.26,  8.52 [deg] galactic lon,lat of the burst (or transient) 
ECL_COORDS:       92.99, 12.11 [deg] ecliptic lon,lat of the burst (or transient) 
COMMENTS:        SWIFT-BAT GRB Lightcurve.
COMMENTS:            
COMMENTS:        WARNING: No BAT_Position TDRSS message was received for this trigger_number!   
COMMENTS:            
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 = 237.15,-4.30 [deg].   
COMMENTS:        The 3rd packet (of 3) was missing in the lightcurve data stream.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 15 Dec 15 03:04:26 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.579d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.495d {+35d 29' 43"} (J2000)
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11058.12 SOD {03:04:18.12} UT,   169.2 [sec] since BAT Trigger Time
COUNTS:          3    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:     Tue 15 Dec 15 03:07:15 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.579d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.495d {+35d 29' 43"} (J2000)
POINT_ROLL:      42.056d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11062.47 SOD {03:04:22.47} UT,   173.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.170
N_STARS:         140
X_OFFSET:        601 [pixels]
Y_OFFSET:        498 [pixels]
X_MAX:           1560 [pixels]
Y_MAX:           1457 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00667392000msufc0173.fits
SUN_POSTN:       262.17d {+17h 28m 40s}  -23.24d {-23d 14' 27"}
SUN_DIST:        164.10 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.37d {+20h 37m 29s}  -14.58d {-14d 35' 02"}
MOON_DIST:       141.95 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 15 Dec 15 03:07:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.579d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.495d {+35d 29' 43"} (J2000)
POINT_ROLL:      42.056d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11062.47 SOD {03:04:22.47} UT,   173.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.170
N_STARS:         140
X_OFFSET:        601 [pixels]
Y_OFFSET:        498 [pixels]
X_MAX:           1560 [pixels]
Y_MAX:           1457 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00667392000msufc0173.fits
SUN_POSTN:       262.17d {+17h 28m 40s}  -23.24d {-23d 14' 27"}
SUN_DIST:        164.10 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.38d {+20h 37m 31s}  -14.58d {-14d 34' 59"}
MOON_DIST:       141.95 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [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:     Tue 15 Dec 15 03:09:02 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.579d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.495d {+35d 29' 43"} (J2000)
ROLL:            42.056d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11062.47 SOD {03:04:22.47} UT,   173.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     471841478
X_OFFSET:        920 [pixels]
Y_OFFSET:        817 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1080
Y_GRB_POS:       977
BINNING_INDEX:   1
IM_URL:          sw00667392000msuni0189.fits
SUN_POSTN:       262.17d {+17h 28m 40s}  -23.24d {-23d 14' 27"}
SUN_DIST:        164.10 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.39d {+20h 37m 33s}  -14.58d {-14d 34' 50"}
MOON_DIST:       141.94 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [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:     Tue 15 Dec 15 03:09:22 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.579d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.495d {+35d 29' 43"} (J2000)
ROLL:            42.056d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11062.47 SOD {03:04:22.47} UT,   173.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     471841478
X_OFFSET:        920 [pixels]
Y_OFFSET:        817 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1080
Y_GRB_POS:       977
BINNING_INDEX:   1
IM_URL:          sw00667392000msuni0189.fits
SUN_POSTN:       262.17d {+17h 28m 40s}  -23.24d {-23d 14' 27"}
SUN_DIST:        164.10 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.39d {+20h 37m 34s}  -14.58d {-14d 34' 48"}
MOON_DIST:       141.93 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [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:     Tue 15 Dec 15 03:09:27 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     667392,   Seg_Num: 0
GRB_RA:           93.5819d {+06h 14m 19.65s} (J2000),
                  93.8495d {+06h 15m 23.89s} (current),
                  92.7429d {+06h 10m 58.30s} (1950)
GRB_DEC:         +35.5150d {+35d 30' 54.0"} (J2000),
                 +35.5092d {+35d 30' 33.2"} (current),
                 +35.5304d {+35d 31' 49.2"} (1950)
GRB_ERROR:       5.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11161.00 SOD {03:06:01.00} UT,   272.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       262.17d {+17h 28m 40s}  -23.24d {-23d 14' 27"}
SUN_DIST:        164.08 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.39d {+20h 37m 34s}  -14.58d {-14d 34' 47"}
MOON_DIST:       141.93 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.25,  8.52 [deg] galactic lon,lat of the burst
ECL_COORDS:       92.98, 12.11 [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 0.11% < P(seren) < 0.58%.

GCN Circular #18691
S. L. Gibson (U Leicester), J. A. Kennea (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 03:01:28 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 151215A (trigger=667392). Swift slewed to the burst after a short delay due to observing constraints. The BAT on-board calculated location is RA, Dec 93.595, +35.509 which is
```
   RA(J2000) = 06h 14m 23s
   Dec(J2000) = +35d 30' 34"
```
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 5 sec. The peak count rate was ~1300 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 03:04:18.1 UT, 169.1 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 93.58198, 35.51503 which is equivalent to:
```
   RA(J2000)  = 06h 14m 19.68s
   Dec(J2000) = +35d 30' 54.1"
```
with an uncertainty of 5.1 arcseconds (radius, 90% containment). This location is 43 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 4.02 x 10^21 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 173 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 0.40.
Burst Advocate for this burst is S. L. Gibson (slg44 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:     Tue 15 Dec 15 03:20:28 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.578d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.496d {+35d 29' 46"} (J2000)
POINT_ROLL:      42.054d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11764.76 SOD {03:16:04.76} UT,   875.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.146
N_STARS:         190
X_OFFSET:        361 [pixels]
Y_OFFSET:        258 [pixels]
X_MAX:           1800 [pixels]
Y_MAX:           1697 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00667392000msufc0875.fits
SUN_POSTN:       262.18d {+17h 28m 42s}  -23.24d {-23d 14' 29"}
SUN_DIST:        164.11 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.50d {+20h 38m 00s}  -14.56d {-14d 33' 34"}
MOON_DIST:       141.84 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 15 Dec 15 03:20:51 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.578d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.496d {+35d 29' 46"} (J2000)
POINT_ROLL:      42.054d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11764.76 SOD {03:16:04.76} UT,   875.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.146
N_STARS:         190
X_OFFSET:        361 [pixels]
Y_OFFSET:        258 [pixels]
X_MAX:           1800 [pixels]
Y_MAX:           1697 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00667392000msufc0875.fits
SUN_POSTN:       262.18d {+17h 28m 42s}  -23.24d {-23d 14' 29"}
SUN_DIST:        164.11 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.50d {+20h 38m 01s}  -14.56d {-14d 33' 31"}
MOON_DIST:       141.84 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [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:     Tue 15 Dec 15 03:20:58 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     667392,   Seg_Num: 0
GRB_RA:           93.5840d {+06h 14m 20.16s} (J2000),
                  93.8516d {+06h 15m 24.39s} (current),
                  92.7450d {+06h 10m 58.80s} (1950)
GRB_DEC:         +35.5159d {+35d 30' 57.2"} (J2000),
                 +35.5101d {+35d 30' 36.5"} (current),
                 +35.5313d {+35d 31' 52.5"} (1950)
GRB_ERROR:       2.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11161.00 SOD {03:06:01.00} UT,   272.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       262.18d {+17h 28m 42s}  -23.24d {-23d 14' 29"}
SUN_DIST:        164.09 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.50d {+20h 38m 01s}  -14.56d {-14d 33' 31"}
MOON_DIST:       141.83 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.25,  8.52 [deg] galactic lon,lat of the burst
ECL_COORDS:       92.98, 12.11 [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 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 15 Dec 15 03:21:56 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.578d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.496d {+35d 29' 46"} (J2000)
ROLL:            42.054d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11764.76 SOD {03:16:04.76} UT,   875.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     471842180
X_OFFSET:        920 [pixels]
Y_OFFSET:        817 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1080
Y_GRB_POS:       977
BINNING_INDEX:   1
IM_URL:          sw00667392000msuni0891.fits
SUN_POSTN:       262.18d {+17h 28m 42s}  -23.24d {-23d 14' 29"}
SUN_DIST:        164.11 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.51d {+20h 38m 03s}  -14.56d {-14d 33' 24"}
MOON_DIST:       141.83 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [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:     Tue 15 Dec 15 03:22:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     667392,   Seg_Num: 0
POINT_RA:         93.578d {+06h 14m 19s} (J2000)
POINT_DEC:       +35.496d {+35d 29' 46"} (J2000)
ROLL:            42.054d
IMG_START_DATE:  17371 TJD;   349 DOY;   15/12/15
IMG_START_TIME:  11764.76 SOD {03:16:04.76} UT,   875.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     471842180
X_OFFSET:        920 [pixels]
Y_OFFSET:        817 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1080
Y_GRB_POS:       977
BINNING_INDEX:   1
IM_URL:          sw00667392000msuni0891.fits
SUN_POSTN:       262.18d {+17h 28m 42s}  -23.24d {-23d 14' 29"}
SUN_DIST:        164.11 [deg]   Sun_angle= 11.2 [hr] (West of Sun)
MOON_POSTN:      309.52d {+20h 38m 04s}  -14.56d {-14d 33' 21"}
MOON_DIST:       141.83 [deg]
MOON_ILLUM:      15 [%]
GAL_COORDS:      177.27,  8.51 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       92.98, 12.09 [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 #18692
S. B. Cenko (NASA/GSFC) reports on behalf of a larger collaboration:
We have imaged the location of GRB151215A (Gibson et al., GCN 18691) with the robotic Palomar 60 inch telescope. Observations began at 3:07 UT (~ 6 minutes after the BAT trigger) and were obtained in the r', i', and z' filters.
Just outside the XRT error circle, we find a fading source at (J2000.0) coordinates:
```
   RA: 06:14:20.22
   Dec: +35:30:57.2
```
Using calibration from nearby point sources, we find the object fades from i' = 17.47 +/- 0.05 mag at 3:07 UT to 18.58 +/- 0.15 mag at 3:24 UT. Thus, we believe this quite likely to be the optical afterglow of GRB151215A.
Further observations are planned.
GCN Circular #18693
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 151215A, we find an enhanced XRT position of the afterglow: RA, Dec: 93.5840, 35.5162 which is equivalent to:
```
   RA (J2000)  = 06 14 20.17
   Dec (J2000) = +35 30 58.3
```
with an uncertainty of 2.2 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/667392.
Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular #18694
P. Wiseman (MPE Garching), D. A. Kann (TLS Tautenburg), T. Schweyer, and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 151215A (Swift trigger 667392; Gibson et al., GCN #18691) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 04:04 UT on 15/12/2015, 63 minutes after the GRB trigger, and are continuing. They were performed at an average seeing of 1.40" and at an average airmass of 2.5.
We found a single point source within the 2.2" Swift-XRT error circle reported by Evans et al. (GCN #18693) and consistent with that of Cenko GCN #18692), at:
```
RA (J2000.0) = 93.58416 = 06:14:20.2
Dec. (J2000.0) = +35.51596 = +35:30:57.5
```
with an uncertainty of 0.3" in each coordinate.
Based on the first 3.3 min of total exposures in g'r'i'z' and 3.0 min in JHK, we estimate preliminary magnitudes (AB system) of
```
g' = 21.81 +/- 0.09 mag,
r' = 20.80 +/- 0.05 mag,
i' = 20.44 +/- 0.05 mag,
z' = 20.36 +/- 0.07 mag,
J = 19.6 +/- 0.2 mag,
H = 19.8 +/- 0.5 mag, and
K = 18.4 +/- 0.4 mag.
```
Given magnitudes are calibrated against SDSS as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.34 mag in the direction of the burst (Schlafly & Finkbeiner et al. 2011).
GCN Circular #18695
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 2236 s of XRT Photon Counting mode data and 2 UVOT images for GRB 151215A, 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 = 93.58409, +35.51608 which is equivalent to:
```
RA (J2000): 06h 14m 20.18s
Dec (J2000): +35d 30' 57.9"
```
with an uncertainty of 1.9 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 #18696
D. Xu (NAOC/CAS), N. R. Tanvir (Univ. Leicester), D. Malesani (DARK/NBI), J. P. U. Fynbo (DARK/NBI), P. Jakobsson (Univ. Iceland), J. Saario (NOT and Univ. Turku) report on behalf of a larger collaboration:
We observed the optical afterglow (Cenko, GCN 18692; Wiseman et al., GCN 18694) of GRB 151215A (Gibson et al., GCN 18691) using the Nordic Optical Telescope (NOT) equipped with the AlFOSC camera and spectrograph.
The optical afterglow is clearly visible in our images, and we measure its brightness on Dec 15.160 UT (0.81 hr after the GRB) to be R = 20.07 +- 0.02 (Vega, assuming R = 16.31 for the USNO star at RA = 06:14:19.93, Dec = +35:31:06.0).
A sequence of three spectra of 1200 s each was carried out starting on Dec 15.176 UT (1.2 hr after the trigger), covering the wavelength range 3200-9000 AA.
A wide trough is visible superimposed on the afterglow continuum, indicating Lyalpha absorption from neutral hydrogen. We also detect several narrow absorption features, which we interpret as due to, e.g., Si II, O I, Al II, all at a common redshift of z = 2.59. A preliminary fit to the Lyalpha profile yields an HI column density of 3x10^21 cm^-2, though establishing the system as a DLA.
GCN Circular #18697
R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
E. Gorbovskoy, V. Lipunov, N.Tyurina, D. Vlasenko, V.Kornilov, P.Balanutsa, A.Kuznetsov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institute
O. Gress, K. Ivanov, N.M. Budnev, V.A. Poleshchuk, S.A. Yazev Irkutsk State University
V.Yurkov, Yu.Sergienko, A.Gabovich, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk
report on behalf of the MASTER Team:
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 34917111) located in IAC was pointed to the GRB151215A (Gibson et al. GCN 18691) 18 sec after notice time and 33 sec after trigger time at 2015-12-15 03:02:05 UT with 10s exposition in two perpendicular polarization planes. We detect OT (Cenko et al GCN 18691, Wiseman et al. GCN 18694) in first image with magnitude 17.8 +- 0.5 at a growing stage (midle time 38 sec after trigger). We definetely see OT on all images till 1500-th second.
The GRB optical light curve have a maximum at third image (110 s after triger time) with 17.0 +- 0.1 mag. The automatic light curve in one polarization available here http://master.sai.msu.ru/static/GRB151215A_v1.png All magnitudes are unfiltered (0.2B+0.8R) with respect to number USNO B1.0 stars.
This is preliminary results. The message may be cited.
GCN Circular #18698
M. De Pasquale (UCL-MSSL) and S. L. Gibson (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 151215A 174 s after the BAT trigger (Gibson et al., GCN Circ. 18691). We detect the optical afterglow of GRB151215A within the XRT error circle (Evans et al. GCN Circ. 18695), in the initial UVOT exposures.
The preliminary UVOT position is:
```
     RA  (J2000) =3D  06:14:20.25 =3D  93.58438 (deg.)
     Dec (J2000) =3D +35:30:57.4  =3D  35.51595 (deg.)
```
with an estimated uncertainty of 0.46 arc sec. (radius, 90% confidence).
The position of this source is consistent with those given by Cenko et al. (GCN Circ. 18692) and GROND (Wiseman et al. GCN Circ. 18694).
There is no detection in UVOT uv filters, which is congruous with the redshift z=3D2.6 of the event (Xu et al., GCN circ. 18696).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter                     T_start(s)   T_stop(s) Exp(s)           Mag

white (Finding Chart)         174          323          147 19.05 =B1 0.14
white                         531         2586          362 20.59 =B1 0.19
v                             408         2636          253 19.67 =B1 0.35
b                             507         2561          233 20.85 =B1 0.42
u                             482         2536          233 >20.3
w1                            458         2512          233 >19.9
m2                            433         2651          225 >19.6
w2                            384         2612          253 >19.9
```
The magnitudes in the table are not corrected for the substantial Galactic extinction due to the reddening of E(B-V) =3D 0.39 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #18699
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), N. Gehrels (GSFC), S. L. Gibson (U Leicester) H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 151215A (trigger #667392) (Gibson, et al., GCN Circ. 18691). The BAT ground-calculated position is RA, Dec = 93.622, 35.529 deg which is
```
   RA(J2000)  =  06h 14m 29.3s
   Dec(J2000) = +35d 31' 45.0"
```
with an uncertainty of 2.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 51%.
The mask-weighted light curve shows a multi-peak episode starting ~T-15 sec, highest peak at ~T+0 sec, and the episode ends around ~T+5 sec. T90 (15-350 keV) is 17.8 +- 1.0 sec (estimated error including systematics).
The time-averaged spectrum from T-15.46 to T+3.13 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.99 +- 0.33. The fluence in the 15-150 keV band is 3.1 +- 0.7 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T-0.16 sec in the 15-150 keV band is 1.6 +- 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/667392/BA/
GCN Circular #18700
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU) and S.L. Gibson report on behalf of the Swift-XRT team:
We have analysed 7.4 ks of XRT data for GRB 151215A (Gibson et al. GCN Circ. 18691), from 180 s to 35.7 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 18693).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.88 (+0.07, -0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.21 (+0.18, -0.17). The best-fitting absorption column is consistent with the Galactic value of 4.0 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.5 x 10^-11 (6.2 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Galactic foreground: 4.0 x 10^21 cm^-2
Intrinsic column:    4 (+/-12) x 10^21 cm^-2 at z=2.59
Photon index:	     2.21 (+0.18, -0.17)
```
If the light curve continues to decay with a power-law decay index of 0.88, the count rate at T+24 hours will be 3.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-13 (2.2 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00667392.
This circular is an official product of the Swift-XRT team.
GCN Circular #18702
Y.Muraki, T.Fujiwara, T. Yoshii, Y. Saito, Y. Tachibana, Y.Yano, S.Harita, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We searched for the optical counterpart of GRB 151215A (S. L. Gibson et al., GCN Circular #18691) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2015-12-15 16:23:38 UT (~13.4 h after the burst). We did not find any new point source within Swift/XRT circle in all three bands.
We obtained following limits for the magnitudes.
```
T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
-------------------------------------------------------------
48230  17:48:09  5070  > 20.9  > 20.6  > 19.6
-------------------------------------------------------------
T0+ : Elapsed time after the burst 
T-EXP: Total Exposure time 
```
We used GSC2.3 catalog for flux calibration.
GCN Circular #18703
L. K. Hardy (Sheffield), S. P. Littlefair (Sheffield), V. S. Dhillon (Sheffield, IAC), T. Butterley (Durham) and R. W. Wilson (Durham) report:
The automated robotic telescope 'pt5m' (Hardy et al. 2015, MNRAS 454, 4316) on La Palma observed the field of GRB 151215A (Gibson et al., GCN 18691) starting at 03:02:42 UT on Dec 15, 53 seconds after the alert notice release and 74 seconds after the GRB detection.
Observations comprised of 59 x 60-second exposures in the Johnson/Cousins R-band with approximately 6-seconds dead time between images. The final image was taken 65 minutes after the first.
We detect the optical counterpart to the GRB and observe a rapidly declining light curve. Photometry is performed using historical instrumental zeropoints. We measure an initial magnitude of R = 17.13 +/- 0.04 (2 minutes after the GRB) and a final magnitude of R = 20.8 +/- 0.7 (67 minutes after the GRB).
The light curve is available at: http://slittlefair.staff.shef.ac.uk/images/grb151215.png
GCN Circular #18707
S. B. Cenko (NASA/GSFC) and D. A. Perley (DARK/NBI) report on behalf of a larger collaboration:
We imaged the field of the optical afterglow (Cenko et al., GCN 18692) of GRB151215A (Gibson et al., GCN 18691) with the robotic Palomar 60 inch telescope. Observations were obtained in the r', i', and z' filters beginning at 3:41 UT on 16 December 2015 (1.0 d after the Swift trigger). We do not detect any emission at the location of the afterglow in any filter. Using nearby point sources from SDSS for calibration, we calculate an upper limit of i' > 21.7 mag at a mean epoch of 1.04 d after the burst.
GCN Circular #18708
E. Mazaeva (IKI), I. Reva (Fesenkov Astrophysical Institute), A. Kusakin=20 (Fesenkov Astrophysical Institute), A. Volnova (IKI), A. Pozanenko (IKI)=20 report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 151215A (Gibson et al., GCN 18691) with=20 Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory=20 starting on Dec. 15 (UT) 16:47:23. We obtained several images in R=20 filter. The afterglow (Cenko, GCN 18692) is detected in a combined=20 image. Preliminary photometry of the afterglow is following
```
Date       UT start    t-T0     Filter  Exp.    OT     Err
                        (mid, days)      (s)

2015-12-15 16:47:23    0.61190  R       21*300  22.1   0.3
```
The photometry is based on nearby SDSS stars.
```
GRB 151215A
observatory TSHAO
date 2015-12-15
UT start 16:47:23.69
t-T0 0.61190 d
exptime 21*300 s
filter R
OT 22.07 +/- 0.38 (=D0=B2=D1=8B=D1=87=D0=B8=D1=82=D0=B0=D0=BD=D0=B8=D0=B5=
=D0=BC =D0=BF=D0=BE=D1=82=D0=BE=D0=BA=D0=BE=D0=B2)
uplim 22.4
fwhm 2.4 "
```
GCN Circular #19001
Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report:
We imaged the field of GRB 151215A detected by SWIFT (trigger 667392) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
The observations started 31.6s after the GRB trigger (17.7s after the notice). The elevation of the field decreased from 56 degrees above horizon and weather conditions were good but images were slightly unfocused.
The first image is trailed with a duration of 60.0s (see the description in Klotz et al., 2006, A&A 451, L39). Due to the unfocused condition, we took time to reprocess the image to extract the magnitude of the optical transient discovered by Cenko et al. (GCNC 18692):
```
t1(s) t2(s)  Rmag   d_Rmag
31.6  44.5  17.3    0.5
44.5  91.6  16.7    0.3
```
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.

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Jochen Greiner, last update: 07-Feb-2016 [Disclaimer]