Gamma-ray Burst 121017A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Oct 12 19:24:01 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     536172,   Seg_Num: 0
GRB_RA:          288.816d {+19h 15m 16s} (J2000),
                 288.982d {+19h 15m 56s} (current),
                 288.168d {+19h 12m 40s} (1950)
GRB_DEC:          -1.595d {-01d 35' 43"} (J2000),
                  -1.572d {-01d 34' 20"} (current),
                  -1.684d {-01d 41' 01"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4616 [cnts]    Image_Peak=161 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   172     E_range: 15-50 keV
BKG_INTEN:       59236 [cnts]
BKG_TIME:        69798.22 SOD {19:23:18.22} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16217 TJD;   291 DOY;   12/10/17
GRB_TIME:        69808.08 SOD {19:23:28.08} UT
GRB_PHI:          37.09 [deg]
GRB_THETA:        35.95 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.88 [sigma]
IMAGE_SIGNIF:    7.89 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +1  -2  +0  +1  -7  +0 
SUN_POSTN:       203.00d {+13h 31m 59s}   -9.61d {-09d 36' 44"}
SUN_DIST:         85.78 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.30d {+15h 37m 11s}  -19.50d {-19d 30' 00"}
MOON_DIST:        56.37 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.23, -6.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      290.14, 20.54 [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 = 322.99,-1.12 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Oct 12 19:26:07 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     536172,   Seg_Num: 0
POINT_RA:        288.789d {+19h 15m 09s} (J2000)
POINT_DEC:        -1.599d {-01d 35' 54"} (J2000)
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  69903.33 SOD {19:25:03.33} UT,   95.2 [sec] since BAT Trigger Time
COUNTS:          4    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:     Wed 17 Oct 12 19:27:52 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     536172,   Seg_Num: 0
GRB_RA:          288.816d {+19h 15m 16s} (J2000),
                 288.982d {+19h 15m 56s} (current),
                 288.168d {+19h 12m 40s} (1950)
GRB_DEC:          -1.595d {-01d 35' 43"} (J2000),
                  -1.572d {-01d 34' 20"} (current),
                  -1.684d {-01d 41' 01"} (1950)
GRB_DATE:        16217 TJD;   291 DOY;   12/10/17
GRB_TIME:        69808.08 SOD {19:23:28.08} UT
TRIGGER_INDEX:   172
GRB_PHI:          37.09 [deg]
GRB_THETA:        35.95 [deg]
DELTA_TIME:      -24.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     12.88 [sigma]
IMAGE_SIGNIF:    7.89 [sigma]
LC_URL:          sw00536172000msb.lc
SUN_POSTN:       203.00d {+13h 32m 00s}   -9.61d {-09d 36' 47"}
SUN_DIST:         85.78 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.34d {+15h 37m 21s}  -19.51d {-19d 30' 20"}
MOON_DIST:        56.33 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.23, -6.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      290.14, 20.54 [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 = 322.99,-1.12 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Oct 12 19:45:39 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     536172,   Seg_Num: 0
GRB_RA:          288.8310d {+19h 15m 19.44s} (J2000),
                 288.9968d {+19h 15m 59.23s} (current),
                 288.1829d {+19h 12m 43.89s} (1950)
GRB_DEC:          -1.6037d {-01d 36' 13.3"} (J2000),
                  -1.5806d {-01d 34' 50.1"} (current),
                  -1.6921d {-01d 41' 31.4"} (1950)
GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  70911.00 SOD {19:41:51.00} UT,   1102.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       203.01d {+13h 32m 03s}   -9.62d {-09d 37' 03"}
SUN_DIST:         85.78 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.53d {+15h 38m 08s}  -19.53d {-19d 31' 56"}
MOON_DIST:        56.17 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.23, -6.05 [deg] galactic lon,lat of the burst
ECL_COORDS:      290.15, 20.53 [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 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Oct 12 19:46:14 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     536172,   Seg_Num: 0
POINT_RA:        288.788d {+19h 15m 09s} (J2000)
POINT_DEC:        -1.601d {-01d 36' 01"} (J2000)
POINT_ROLL:      260.492d
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  70949.77 SOD {19:42:29.77} UT,   1141.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.101
N_STARS:         190
X_OFFSET:        296 [pixels]
Y_OFFSET:        658 [pixels]
X_MAX:           1255 [pixels]
Y_MAX:           1617 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00536172000msufc1141.fits
SUN_POSTN:       203.01d {+13h 32m 03s}   -9.62d {-09d 37' 04"}
SUN_DIST:         85.74 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.54d {+15h 38m 09s}  -19.53d {-19d 32' 00"}
MOON_DIST:        56.12 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.21, -6.01 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      290.11, 20.54 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 17 Oct 12 19:46:41 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     536172,   Seg_Num: 0
POINT_RA:        288.788d {+19h 15m 09s} (J2000)
POINT_DEC:        -1.601d {-01d 36' 01"} (J2000)
POINT_ROLL:      260.492d
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  70949.77 SOD {19:42:29.77} UT,   1141.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.101
N_STARS:         190
X_OFFSET:        296 [pixels]
Y_OFFSET:        658 [pixels]
X_MAX:           1255 [pixels]
Y_MAX:           1617 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00536172000msufc1141.fits
SUN_POSTN:       203.01d {+13h 32m 03s}   -9.62d {-09d 37' 04"}
SUN_DIST:         85.74 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.54d {+15h 38m 10s}  -19.53d {-19d 32' 01"}
MOON_DIST:        56.12 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.21, -6.01 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      290.11, 20.54 [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:     Wed 17 Oct 12 19:46:43 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     536172,   Seg_Num: 0
GRB_RA:          288.8297d {+19h 15m 19.12s} (J2000),
                 288.9955d {+19h 15m 58.92s} (current),
                 288.1816d {+19h 12m 43.57s} (1950)
GRB_DEC:          -1.6041d {-01d 36' 14.7"} (J2000),
                  -1.5810d {-01d 34' 51.6"} (current),
                  -1.6925d {-01d 41' 32.8"} (1950)
GRB_ERROR:       2.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  70911.00 SOD {19:41:51.00} UT,   1102.9 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       203.01d {+13h 32m 03s}   -9.62d {-09d 37' 04"}
SUN_DIST:         85.78 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.54d {+15h 38m 10s}  -19.53d {-19d 32' 02"}
MOON_DIST:        56.16 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.23, -6.04 [deg] galactic lon,lat of the burst
ECL_COORDS:      290.15, 20.53 [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:     Wed 17 Oct 12 19:47:53 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     536172,   Seg_Num: 0
POINT_RA:        288.788d {+19h 15m 09s} (J2000)
POINT_DEC:        -1.601d {-01d 36' 01"} (J2000)
ROLL:            260.492d
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  70949.77 SOD {19:42:29.77} UT,   1141.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     372195759
X_OFFSET:        615 [pixels]
Y_OFFSET:        977 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       775
Y_GRB_POS:       1137
BINNING_INDEX:   1
IM_URL:          sw00536172000msuni1151.fits
SUN_POSTN:       203.01d {+13h 32m 03s}   -9.62d {-09d 37' 05"}
SUN_DIST:         85.74 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.56d {+15h 38m 13s}  -19.54d {-19d 32' 08"}
MOON_DIST:        56.11 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.21, -6.01 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      290.11, 20.54 [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 Circular #13875
D. Grupe (PSU), B. N. Barlow (PSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), E. A. Helder (PSU), S. T. Holland (STScI), J. A. Kennea (PSU), H. A. Krimm (CRESST/GSFC/USRA), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), C. J. Mountford (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and C. A. Swenson (PSU) report on behalf of the Swift Team:
At 19:23:28 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 121017A (trigger=536172). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 288.816, -1.595 which is
```
   RA(J2000)  =  19h 15m 16s
   Dec(J2000) = -01d 35' 43"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows at least two peaks with a duration of about 10 sec (possibly longer). The peak count rate was ~2500 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 19:25:03.3 UT, 95.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 288.8302, -1.6042 which is equivalent to:
```
   RA(J2000)  = 19h 15m 19.25s
   Dec(J2000) = -01d 36' 15.1"
```
with an uncertainty of 2.2 arcseconds (radius, 90% containment). This location is 60 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 (2.22 x 10^21 cm^-2, Kalberla et al. 2005), with an excess column of 3 (+2.89/-2.40) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 1141 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. There is no new source down to a limit of about 19th mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the region. No correction has been made for the expected extinction corresponding to E(B-V) of 0.44.
XRT and UVOT detections were delayed due to entry into the SAA shortly after the initial trigger.
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:     Wed 17 Oct 12 19:48:19 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     536172,   Seg_Num: 0
POINT_RA:        288.788d {+19h 15m 09s} (J2000)
POINT_DEC:        -1.601d {-01d 36' 01"} (J2000)
ROLL:            260.492d
IMG_START_DATE:  16217 TJD;   291 DOY;   12/10/17
IMG_START_TIME:  70949.77 SOD {19:42:29.77} UT,   1141.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     372195759
X_OFFSET:        615 [pixels]
Y_OFFSET:        977 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       775
Y_GRB_POS:       1137
BINNING_INDEX:   1
IM_URL:          sw00536172000msuni1151.fits
SUN_POSTN:       203.01d {+13h 32m 03s}   -9.62d {-09d 37' 06"}
SUN_DIST:         85.74 [deg]   Sun_angle= -5.7 [hr] (East of Sun)
MOON_POSTN:      234.56d {+15h 38m 15s}  -19.54d {-19d 32' 10"}
MOON_DIST:        56.10 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       34.21, -6.01 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      290.11, 20.54 [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 #13876
GRB 121017A: BOOTES-2/TELMA observations
M. Jel=EDnek, A. J. Castro-Tirado, J. Gorosabel (IAA-CSIC Granada), S. Guziy (Nikolaev Univ.), on behalf of a larger collaboration, report:
Following the detection of GRB 121017A by Swift (Grupe et al. GCN Circ. 13875) the 0.6m TELMA robotic telescope (+ COLORES) in M=E1laga (Spain) started to take images (unfiltered) about 3 min postburst (19:26:10 UT), following the initial BAT position. There is no optical counterpart within the Swift/X-ray error box down to R =3D 18.5 for a 153s combined exposure (5 min post burst). Further exposures in i=92-band (22:05 UT, 1200s on the aggregate) set a limit of 19.5 (35 min post burst). We note the considerable extinction (A_v =3D 1.4) towards this direction 6 deg below the Galactic Plane. Observations are ongoing.
GCN Circular #13877
A. A. Volnova (SAI MSU, IKI RAS), A. S. Moskvitin (SAO RAS) on behalf of larger collaboration, reports
We observed the field of GRB 121017A (Grupe et al., GCN Circ. 13875) with the 1-m Zeiss-1000 telescope of SAO RAS in Rc band. The weather conditions were good, airmass =3D 5 - 6, seeing =3D 2.6". Observations were started since 9.5 minutes after the BAT trigger, middle time t-t0 =3D 0.01407 days.
We do not detect any object in the XRT error circle down to a limiting magnitude 18.8 as well as Jel=EDnek et al. (GCN Circ. 13876).
GCN Circular #13878
J. Gorosabel (IAA-CSIC, Granada), S. Mottola (DLR, Berlin), report on behalf of a larger collaboration:
"We imaged the field of the Swift GRB 121017A (Grupe et al., GCN Circ. 13875) with the 1.23m Calar Alto telescope. The observations were carried out in the R-band on Oct. 17.85440--17.86153 UT (1.11--1.29 hours post burst) with a total exposure time of 2x300s. No optical source brighter than R~20 was found within the XRT error circle."
GCN Circular #13879
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 388 s of XRT Photon Counting mode data and 1 UVOT images for GRB 121017A, 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 = 288.83026, -1.60418 which is equivalent to:
```
RA (J2000): 19h 15m 19.26s
Dec (J2000): -01d 36' 15.0"
```
with an uncertainty of 2.0 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 #13880
T. N. Ukwatta (MSU), 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 (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC) (i.e. the Swift-BAT team):
Using the data set from T-61 to T+242 sec from recent telemetry downlinks, we report further analysis of BAT GRB 121017A (trigger #536172) (Grupe, et al., GCN Circ. 13875). The BAT ground-calculated position is RA, Dec = 288.820, -1.602 deg, which is
```
   RA(J2000)  =  19h 15m 16.8s 
   Dec(J2000) = -01d 36' 07.3" 
```
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 35%.
The mask-weighted light curve a single peak starting at ~T-3 sec, peaking at ~T+1 sec, and ending at ~T+5 sec. T90 (15-350 keV) is 4.2 +- 0.5 sec (estimated error including systematics).
The time-averaged spectrum from T-2.72 to T+2.53 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.74 +- 0.17. The fluence in the 15-150 keV band is 6.6 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.31 sec in the 15-150 keV band is 3.3 +- 0.4 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/536172/BA/
GCN Circular #13881
D. A. Kann (MPE/Universe Cluster), M. Nardini (Milano-Bicocca), and J. Greiner (MPE) report on behalf of the GROND team:
We observed the field of GRB 121017A (Swift trigger 536172, Grupe et al., GCN # 13875) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile).
Observations started on October 17, 2012, at 23:50 UT, 4.45 hr after the GRB trigger. They were performed at an average seeing of 1" (in r') and at an average airmass of 1.3.
We do not detect any sources in the enhanced XRT error circle (Goad et al., GCN # 13879), in agreement with earlier reports of optical observations (Jel=EDnek et al., GCN # 13876, Volnova et al., GCN # 13877, Gorosabel & Mottola, GCN # 13878). There is a star at the eastern edge of the error circle but this affects only a small part of it.
Based on 284 s of total exposures in g'r'i'z' (mean time 0.18978 days after the trigger) and 480 s in JHK (mean time 0.19003 days after the trigger) we estimate preliminary AB magnitudes (upper limits are 3 sigma) of
g' > 23.2,
r' > 23.2,
i' > 22.4,
z' > 22.2,
J > 19.8,
H > 19.4 and
K > 19.3.
Given magnitudes are calibrated against GROND zeropoints in the optical as well as 2MASS field stars in the NIR and are not corrected for the high Galactic foreground reddening of E_(B-V) =3D 0.44 mag (Schlegel et al. 1998).
GCN Circular #13882
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), V. D'Elia (ASDC), A. Maselli (INAF-IASFPA), V. Mangano (INAF-IASFPA), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU) and D. Grupe report on behalf of the Swift-XRT team:
We have analysed 8.0 ks of XRT data for GRB 121017A (Grupe et al. GCN Circ. 13875), from 1.1 ks to 30.0 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN. Circ 13879).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.93 (+/-0.07).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.10 (+0.28, -0.27). The best-fitting absorption column is 6.0 (+1.7, -1.4) x 10^21 cm^-2, in excess of the Galactic value of 2.2 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 4.6 x 10^-11 (9.1 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     6.0 (+1.7, -1.4) x 10^21 cm^-2
Galactic foreground: 2.2 x 10^21 cm^-2
Excess significance: 4.4 sigma
Photon index:	     2.10 (+0.28, -0.27)
```
If the light curve continues to decay with a power-law decay index of 0.93, the count rate at T+24 hours will be 9.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.4 x 10^-13 (8.7 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/00536172.
This circular is an official product of the Swift-XRT team.
GCN Circular #13883
A. A. Breeveld (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 121017A 1142 s after the BAT trigger (Grupe et al., GCN Circ. 13875). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 13879) 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          1142         1291          147         >21.1
white             1142         1442          167         >21.2
v                 1298         1492           39         >18.5
b                 1397         1417           19         >19.1
u                 1373         1392           19         >18.6
w1                1347         1367           19         >18.1
w2                1448         1468           19         >18.1
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.44 in the direction of the burst (Schlegel et al. 1998).
GCN Report 398.1
GCN_Report 398.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_398_1.pdf by D. Grupe at PSU titled: "Swift Observations of GRB 121017A"

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Jochen Greiner, last update: 18-Oct-2012 [Disclaimer]