Gamma-ray Burst 141026A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:38:08 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     616502,   Seg_Num: 0
GRB_RA:           44.080d {+02h 56m 19s} (J2000),
                  44.300d {+02h 57m 12s} (current),
                  43.342d {+02h 53m 22s} (1950)
GRB_DEC:         +26.960d {+26d 57' 36"} (J2000),
                 +27.019d {+27d 01' 09"} (current),
                 +26.759d {+26d 45' 31"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=2012 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        16956 TJD;   299 DOY;   14/10/26
GRB_TIME:        9411.29 SOD {02:36:51.29} UT
GRB_PHI:         129.02 [deg]
GRB_THETA:        15.75 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    11.00 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +0  +0  +0 +94  +0 
SUN_POSTN:       210.40d {+14h 01m 37s}  -12.37d {-12d 22' 25"}
SUN_DIST:        160.40 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.50d {+15h 50m 00s}  -16.71d {-16d 42' 26"}
MOON_DIST:       164.01 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.53,-28.14 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       49.48,  9.75 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
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 = 54.12,20.32 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:40:01 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     616502,   Seg_Num: 0
GRB_RA:           44.0839d {+02h 56m 20.13s} (J2000),
                  44.3030d {+02h 57m 12.71s} (current),
                  43.3461d {+02h 53m 23.06s} (1950)
GRB_DEC:         +26.9262d {+26d 55' 34.3"} (J2000),
                 +26.9853d {+26d 59' 07.2"} (current),
                 +26.7250d {+26d 43' 29.8"} (1950)
GRB_ERROR:       6.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.58e-08 [erg/cm2/sec]
GRB_SIGNIF:      5.09 [sigma]
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9568.29 SOD {02:39:28.29} UT,   157.0 [sec] since BAT Trigger Time
TAM[0-3]:        327.67 237.21 261.58 243.45
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       210.40d {+14h 01m 37s}  -12.37d {-12d 22' 27"}
SUN_DIST:        160.42 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.52d {+15h 50m 05s}  -16.71d {-16d 42' 34"}
MOON_DIST:       164.02 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.17 [deg] galactic lon,lat of the burst
ECL_COORDS:       49.48,  9.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 2.02 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:40:09 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     616502,   Seg_Num: 0
GRB_RA:           44.0839d {+02h 56m 20.1s} (J2000),
                  44.3030d {+02h 57m 12.7s} (current),
                  43.3461d {+02h 53m 23.0s} (1950)
GRB_DEC:         +26.9262d {+26d 55' 34.3"} (J2000),
                 +26.9853d {+26d 59' 07.2"} (current),
                 +26.7250d {+26d 43' 29.8"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       26 [cnts]
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9568.29 SOD {02:39:28.29} UT,   157.0 [sec] since BAT Trigger Time
CENTROID_X:      371.45,  raw= 371  [pixels]
CENTROID_Y:      283.55,  raw= 284  [pixels]
ROLL:            44.02 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -33.59
GRB_POS_XRT_Z:   155.94
IMAGE_URL:       sw00616502000msxps_rw.img
SUN_POSTN:       210.40d {+14h 01m 37s}  -12.37d {-12d 22' 27"}
SUN_DIST:        160.42 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.52d {+15h 50m 05s}  -16.71d {-16d 42' 35"}
MOON_DIST:       164.02 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.17 [deg] galactic lon,lat of the burst
ECL_COORDS:       49.48,  9.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:40:17 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     616502,   Seg_Num: 0
GRB_RA:           44.0839d {+02h 56m 20.1s} (J2000),
                  44.3030d {+02h 57m 12.7s} (current),
                  43.3461d {+02h 53m 23.0s} (1950)
GRB_DEC:         +26.9262d {+26d 55' 34.3"} (J2000),
                 +26.9853d {+26d 59' 07.2"} (current),
                 +26.7250d {+26d 43' 29.8"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       26 [cnts]
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9568.29 SOD {02:39:28.29} UT,   157.0 [sec] since BAT Trigger Time
CENTROID_X:      371.45,  raw= 371  [pixels]
CENTROID_Y:      283.55,  raw= 284  [pixels]
ROLL:            44.02 [deg]
GAIN:            1
MODE:            2, Short Image mode
WAVEFORM:        134
EXPO_TIME:       0.10 [sec]
GRB_POS_XRT_Y:   -33.59
GRB_POS_XRT_Z:   155.94
IMAGE_URL:       sw00616502000msxps_rw.img
SUN_POSTN:       210.40d {+14h 01m 37s}  -12.37d {-12d 22' 27"}
SUN_DIST:        160.42 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.52d {+15h 50m 05s}  -16.71d {-16d 42' 36"}
MOON_DIST:       164.02 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.17 [deg] galactic lon,lat of the burst
ECL_COORDS:       49.48,  9.71 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:41:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.110d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.965d {+26d 57' 55"} (J2000)
POINT_ROLL:      44.014d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9576.88 SOD {02:39:36.88} UT,   165.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.200
N_STARS:         20
X_OFFSET:        280 [pixels]
Y_OFFSET:        528 [pixels]
X_MAX:           1239 [pixels]
Y_MAX:           1487 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00616502000msufc0165.fits
SUN_POSTN:       210.40d {+14h 01m 37s}  -12.37d {-12d 22' 28"}
SUN_DIST:        160.38 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.53d {+15h 50m 07s}  -16.71d {-16d 42' 39"}
MOON_DIST:       164.01 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.51,  9.75 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:41:21 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.110d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.965d {+26d 57' 55"} (J2000)
POINT_ROLL:      44.014d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9576.88 SOD {02:39:36.88} UT,   165.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.200
N_STARS:         20
X_OFFSET:        280 [pixels]
Y_OFFSET:        528 [pixels]
X_MAX:           1239 [pixels]
Y_MAX:           1487 [pixels]
DET_THRESH:      9
PHOTO_THRESH:    4
SL_URL:          sw00616502000msufc0165.fits
SUN_POSTN:       210.41d {+14h 01m 37s}  -12.37d {-12d 22' 28"}
SUN_DIST:        160.38 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.53d {+15h 50m 08s}  -16.71d {-16d 42' 41"}
MOON_DIST:       164.01 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.51,  9.75 [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:     Sun 26 Oct 14 02:42:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.110d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.965d {+26d 57' 55"} (J2000)
ROLL:            44.014d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9576.88 SOD {02:39:36.88} UT,   165.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     435983989
X_OFFSET:        554 [pixels]
Y_OFFSET:        1085 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       714
Y_GRB_POS:       1245
BINNING_INDEX:   1
IM_URL:          sw00616502000msuni0178.fits
SUN_POSTN:       210.41d {+14h 01m 37s}  -12.38d {-12d 22' 30"}
SUN_DIST:        160.38 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.55d {+15h 50m 11s}  -16.71d {-16d 42' 48"}
MOON_DIST:       164.00 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.51,  9.75 [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:     Sun 26 Oct 14 02:43:09 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     616502,   Seg_Num: 0
GRB_RA:           44.080d {+02h 56m 19s} (J2000),
                  44.300d {+02h 57m 12s} (current),
                  43.342d {+02h 53m 22s} (1950)
GRB_DEC:         +26.960d {+26d 57' 36"} (J2000),
                 +27.019d {+27d 01' 09"} (current),
                 +26.759d {+26d 45' 31"} (1950)
GRB_DATE:        16956 TJD;   299 DOY;   14/10/26
GRB_TIME:        9411.29 SOD {02:36:51.29} UT
TRIGGER_INDEX:   20000
GRB_PHI:         129.02 [deg]
GRB_THETA:        15.75 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    11.00 [sigma]
LC_URL:          sw00616502000msb.lc
SUN_POSTN:       210.41d {+14h 01m 38s}  -12.38d {-12d 22' 30"}
SUN_DIST:        160.40 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.55d {+15h 50m 12s}  -16.71d {-16d 42' 49"}
MOON_DIST:       163.98 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.53,-28.14 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       49.48,  9.75 [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 an image 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 = 54.12,20.32 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 02:43:34 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.110d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.965d {+26d 57' 55"} (J2000)
ROLL:            44.014d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  9576.88 SOD {02:39:36.88} UT,   165.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     435983989
X_OFFSET:        554 [pixels]
Y_OFFSET:        1085 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       714
Y_GRB_POS:       1245
BINNING_INDEX:   1
IM_URL:          sw00616502000msuni0178.fits
SUN_POSTN:       210.41d {+14h 01m 38s}  -12.38d {-12d 22' 30"}
SUN_DIST:        160.38 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      237.55d {+15h 50m 13s}  -16.71d {-16d 42' 51"}
MOON_DIST:       163.99 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.55,-28.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.51,  9.75 [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 #16950
L. M. Z. Hagen (PSU), S. D. Barthelmy (GSFC), N. Gehrels (NASA/GSFC), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 02:36:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 141026A (trigger=616502). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 44.080, +26.960 which is
```
   RA(J2000)  =  02h 56m 19s
   Dec(J2000) = +26d 57' 36"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The real-time TDRSS BAT light curve does not show anything as is typical for an image trigger.
The XRT began observing the field at 02:39:28.2 UT, 157.0 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 44.0839, 26.9262 which is equivalent to:
```
   RA(J2000)  = +02h 56m 20.14s
   Dec(J2000) = +26d 55' 34.3"
```
with an uncertainty of 6.1 arcseconds (radius, 90% containment). This location is 122 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
The initial flux in the 0.1 s image was 1.58e-08 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 43 seconds with the White filter starting 165 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 0.19.
Burst Advocate for this burst is L. M. Z. Hagen (lea.zernow.hagen AT gmail.com). 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:     Sun 26 Oct 14 03:37:29 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.107d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.912d {+26d 54' 43"} (J2000)
POINT_ROLL:      43.984d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  12873.96 SOD {03:34:33.96} UT,   3462.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.780
N_STARS:         42
X_OFFSET:        373 [pixels]
Y_OFFSET:        395 [pixels]
X_MAX:           1332 [pixels]
Y_MAX:           1354 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00616502000msufc3462.fits
SUN_POSTN:       210.44d {+14h 01m 46s}  -12.39d {-12d 23' 16"}
SUN_DIST:        160.45 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      238.07d {+15h 52m 16s}  -16.78d {-16d 47' 02"}
MOON_DIST:       163.70 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.58,-28.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.49,  9.69 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 26 Oct 14 03:37:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.107d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.912d {+26d 54' 43"} (J2000)
POINT_ROLL:      43.984d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  12873.96 SOD {03:34:33.96} UT,   3462.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.780
N_STARS:         42
X_OFFSET:        373 [pixels]
Y_OFFSET:        395 [pixels]
X_MAX:           1332 [pixels]
Y_MAX:           1354 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00616502000msufc3462.fits
SUN_POSTN:       210.44d {+14h 01m 46s}  -12.39d {-12d 23' 16"}
SUN_DIST:        160.45 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      238.07d {+15h 52m 16s}  -16.78d {-16d 47' 03"}
MOON_DIST:       163.70 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.58,-28.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.49,  9.69 [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:     Sun 26 Oct 14 03:38:59 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.107d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.912d {+26d 54' 43"} (J2000)
ROLL:            43.984d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  12873.96 SOD {03:34:33.96} UT,   3462.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     435987286
X_OFFSET:        692 [pixels]
Y_OFFSET:        714 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       874
BINNING_INDEX:   1
IM_URL:          sw00616502000msuni3475.fits
SUN_POSTN:       210.44d {+14h 01m 46s}  -12.39d {-12d 23' 18"}
SUN_DIST:        160.45 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      238.08d {+15h 52m 19s}  -16.79d {-16d 47' 09"}
MOON_DIST:       163.69 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.58,-28.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.49,  9.69 [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:     Sun 26 Oct 14 03:39:18 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     616502,   Seg_Num: 0
POINT_RA:         44.107d {+02h 56m 26s} (J2000)
POINT_DEC:       +26.912d {+26d 54' 43"} (J2000)
ROLL:            43.984d
IMG_START_DATE:  16956 TJD;   299 DOY;   14/10/26
IMG_START_TIME:  12873.96 SOD {03:34:33.96} UT,   3462.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     435987286
X_OFFSET:        692 [pixels]
Y_OFFSET:        714 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       874
BINNING_INDEX:   1
IM_URL:          sw00616502000msuni3475.fits
SUN_POSTN:       210.44d {+14h 01m 47s}  -12.39d {-12d 23' 18"}
SUN_DIST:        160.45 [deg]   Sun_angle= 11.1 [hr] (West of Sun)
MOON_POSTN:      238.08d {+15h 52m 20s}  -16.79d {-16d 47' 10"}
MOON_DIST:       163.69 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      154.58,-28.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       49.49,  9.69 [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 #16951
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
The Palomar 60-inch telescope automatically responded to the alert for GRB 141026A (Hagen et al, GCN 16950) and began imaging the field at 02:41:55.320 UT, 5.07 minutes after the Swift trigger. A sequence of 60-second r, i, and z exposures was obtained. The field was at high airmass (~3.3) at the start of the observations.
We do not detect any clear source inside the XRT error circle in the individual exposures. After stacking the first 11 frames taken in each filter, in the r-band stack only there is a marginal detection of a possible source at RA = 02:56:19.885, dec = +26:55:35.80 with R~22 mag.
Observations are continuing and additional follow-up is planned.
GCN Circular #16952
Owen Littlejohns (ASU), Nat Butler (ASU), Antonino Cucchiara (ORAU/GSFC), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos=C3=A9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=C3=BAs Gonz=C3=A1lez (UNAM), Carlos Rom=C3=A1n-Z=C3=BA=C3=B1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 141026A (Hagen, et al., GCN 16950) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=C3=B3mico Nacional on Sierra San Pedro M=C3=A1rtir from 26.13 to 26.20 UTC (0.54 to 2.20 hours after the BAT trigger), obtaining a total of 1.07 hours exposure in the r and i bands.
For a source within the Swift-XRT error circle, we obtain the following upper limits (3-sigma):
```
  r     > 23.50
  i     > 23.56
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB.
We do not detect the source observed by P60 (Perley, et al., GCN 16951). We do, however, detect a source at the edge of the Swift- XRT error circle at RA(J2000) =3D 44.084036, Dec(J2000) =3D 26.928134.
```
  r     21.67 +/- 0.08
  i     21.52 +/- 0.07
```
We cannot presently determine if this source is fading.
We thank the staff of the Observatorio Astron=C3=B3mico Nacional in San Pedro M=C3=A1rtir.
GCN Circular #16953
K. Varela (MPE Garching), D. A. Kann (TLS Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 141026A (Swift trigger 616502; Hagen et al., GCN #16950) 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 02:51 UT on October 26th, approximately 15 min after the GRB trigger. They were performed at high airmass (2.5 but rising) but decent seeing (1".2).
At the position of the P60 candidate (Perley, GCN #16951) we do not detect any source. We find a source just to the north of the 5".8 Swift-XRT error circle reported by Hagen et al. at
```
RA (J2000.0) = 02:56:20.16
DEC (J2000.0) = +26:55:41.4
```
with an error of 0".5. This source is also reported by RATIR (Littlejohns et al., GCN #16952). We do not find any variability within errors over the course of our observations. It is likely not associated with the GRB.
Based on images with an exposure time of 1500 s in the optical and 1200 s in the NIR, centered at 0.05598 days after the trigger, we estimate preliminary magnitudes and limits (all in AB system) for this source of:
```
g' = 23.2 +/- 0.1 mag
r' = 21.8 +/- 0.1 mag
i' = 21.5 +/- 0.1 mag
z' = 21.2 +/- 0.1 mag
J = 20.9 +/- 0.3 mag
H = 20.5 +/- 0.3 mag
K > 18.7 mag
```
Given magnitudes are calibrated against GROND zeropoints (g'r'i'z') and 2MASS field stars (JHK) and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.18 mag in the direction of the burst (Schlegel et al. 1998).
GCN Circular #16954
J. Gorosabel (IAA-CSIC/UPV-EHU), S. Hellmich (DLR), A. de Ugarte Postigo (IAA-CSIC/DARK), S. Mottola (DLR), report on behalf of a larger collaboration:
We observed the field of the GRB141026A (Hagen, et al., GCN 16950) with the 1.23m CAHA telescope in the I-band filter. Observations started on Oct. 26.11639 UT (10.75 min post burst). A faint object is detected at RA=02:56:20.13, DEC=26:55:41.3 (+/-0.6", J2000) with Vega magnitude I~20.6 against the USNO B1.0 catalog. The coordinates of this object are consistent with the ones reported by Littlejohns et al. (GCN 16592) and Varela et al. (GCN 16953). No object brighter than I~21.0 (Vega) is detected consistent with the optical source reported by Perley (GCN 16951).
GCN Circular #16955
D. A. Perley, M. Brown, I. Wong, and E. Bailey (Caltech) report:
We imaged the location of GRB 141026A (Hagen et al., GCN 16950) using the Large-Format Camera on the 5m Hale Telescope at Palomar Observatory. Six exposures of four minutes each were acquired using the Broad-RI (620-920 nm) filter between 03:34:50 and 04:03:51 UT (58-87 minutes after the BAT trigger).
The object north of the error circle reported by Littlejohns et al. (GCN 16592), Varela et al. (GCN 16953), and Gorosabel et. al (GCN 16954) is well-detected in the stacked image. No other object is detected in or near the XRT error circle, including at the position of the previously-reported, low-significance object from the early P60 imaging (GCN 16951), down to a limit of RI > 25.5 mag (calibrated relative to the R2 magnitude of a nearby USNO B1.0 star).
GCN Circular #16956
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team.
Using 2855 s of XRT Photon Counting mode data and 8 UVOT images for GRB 141026A, 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 = 44.08435, +26.92804 which is equivalent to:
```
RA (J2000): 02h 56m 20.24s
Dec (J2000): +26d 55' 40.9"
```
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 #16957
E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Denisenko Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A. Gabovich Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka
Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB141026A 22 sec after notice time and 99 sec after trigger time at 2014-10-26 02:38:31 UT in two polarizations. On our first single and coadd images we haven`t found optical transient within SWIFT error-box (Hagen et. al. GCN 16950). The 5-sigma upper limit has been about 16.5 on single (20s exposure) and 17.5 on coadd image (from first 3 images with total exposure 80 sec). The message may be cited.
The publication delay was due to time zone changes during this night.
This message may be cited.
GCN Circular #16958
E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Denisenko Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov, A. Gabovich Blagoveschensk Educational State University, Blagoveschensk
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka
Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA)
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the GRB141026A 22 sec after notice time and 99 sec after trigger time at 2014-10-26 02:38:31 UT in two polarizations. On our first single and coadd images we haven`t found optical transient within SWIFT error-box (Hagen et. al. GCN 16950). The 5-sigma upper limit has been about 16.5 on single (20s exposure) and 17.5 on coadd image (from first 3 images with total exposure 80 sec). The message may be cited.
This message may be cited.
[GCN OPS NOTE: The disrtibution was delayed ~8.8 hours due to a problem with the authentication process.]
GCN Circular #16960
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), L. M. Z. Hagen (PSU), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+380 sec from the recent telemetry downlink, we report further analysis of BAT GRB 141026A (trigger #616502) (Hagen, et al., GCN Circ. 16950). The BAT ground-calculated position is RA, Dec = 44.049, 26.925 deg which is
```
  RA(J2000)  =  02h 56m 11.8s 
  Dec(J2000) = +26d 55' 31.7" 
```
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment). The partial coding was 88%.
The mask-weighted light curve shows a weak episode starting at ~T+15 sec, and ending around ~T+180 sec. T90 (15-350 keV) is 146 +- 13 sec (estimated error including systematics). Note since this GRB went outside the FOV of BAT around ~T+250 sec, this duration measurement might be affected if there were significant emission from the source after ~T+250 sec.
The time-averaged spectrum from T+13.96 to T+177.75 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.34 +- 0.19. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+65.64 sec in the 15-150 keV band is 0.4 +- 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/616502/BA/
GCN Circular #16961
V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), D.N. Burrows (PSU), J.A. Kennea (PSU), V. Mangano (PSU), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester), J.P. Osborne (U. Leicester), A. Maselli (INAF-IASFPA) and L.M.Z. Hagen report on behalf of the Swift-XRT team:
We have analysed 10 ks of XRT data for GRB 141026A (Hagen et al. GCN Circ. 16950), from 160 s to 46.2 ks after the BAT trigger. The data comprise 49 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Beardmore et al. (GCN Circ. 16956).
The late-time light curve (from T0+3.5 ks) can be modelled with a power-law decay with a decay index of alpha=0.35 (+0.11, -0.12).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.07 (+0.09, -0.08). The best-fitting absorption column is 4.9 (+/-0.5) x 10^21 cm^-2, in excess of the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.92 (+0.28, -0.26) and a best-fitting absorption column of 2.8 (+1.2, -1.0) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (5.4 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.8 (+1.2, -1.0) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: 2.0 sigma
Photon index:	     1.92 (+0.28, -0.26)
```
If the light curve continues to decay with a power-law decay index of 0.35, the count rate at T+24 hours will be 0.023 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.9 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00616502.
This circular is an official product of the Swift-XRT team.
GCN Circular #16962
FROM: Nat Butler at UC berkeley
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), Willia= m H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB) , J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos=C3=A9 A. de Diego (UNAM), Leonid Georgiev (UNAM)= , Jes=C3=BAs Gonz=C3=A1lez (UNAM), Carlos Rom=C3=A1n-Z=C3=BA=C3=B1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 141026A (Hagen, et al., GCN 16950)) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=C3=B3mico Nacional on Sierra San Pedro M=C3=A1rtir from 2014/10 26.13 to 2014/10 26.26 UTC (0.5 4 to 3.58 hours after the BAT trigger), obtaining a total of 2.49 hours exposure in the r, i, and z bands.
With increased time-coverage, the source reported in Littlejohns et al. (GCN 16952; also Perley et al., GCN 16955, Varela et al., GCN 16953, Gorosabel et al., GCN 16954, ) appears to peak on a timescale of 1 hour, and then fade in the r and i bands. Given also that its position is consistent with the enhanched XRT error region (Beardmore et al., GCN 16956), this source is likely to be the afterglow to GRB 141026A. In comparison with 2MASS, we obtain the following detections and upper limit (3-sigma):
```
  r     21.74 +/- 0.07
  i     21.54 +/- 0.06
  z  >  20.5
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. Further observations are planned.
We thank the staff of the Observatorio Astron=C3=B3mico Nacional in San Pedro M=C3=A1rtir.
GCN Circular #16964
L. M. Z. Hagen (PSU) reports on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 141026A 166 s after the BAT trigger (Hagen et al., GCN Circ. 16950). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 16956) or the likely optical afterglow (Littlejohns et al. GCN Circ. 16952, Varela et al. GCN Circ. 16953, Gorosabel et al. GCN Circ. 16954, Perley et al. GCN Circ. 16955, Butler et al. GCN Circ. 16962) 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 initial exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white (fc)         165          208           83         >19.98
white             3462         5667          688         >21.45
v                  144         5962          290         >19.34
b                 3826         5463          393         >20.48
u                 3621         5258          393         >20.15
uvw1              4852         5052          196         >19.61
uvm2              4647         4847          196         >19.58
uvw2              4237         5873          393         >20.26
```
The magnitudes in the table are not corrected for the Galactic extinction due to the substantial reddening of E(B-V) = 0.19 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #16965
Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz (UCSC), Jos=C3=A9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=C3=BAs Gonz=C3=A1lez (UNAM), Carlos Rom=C3=A1n-Z=C3=BA=C3=B1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 141026A (Hagen, et al., GCN 16950)) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=C3=B3mico Nacion= al on Sierra San Pedro M=C3=A1rtir from 2014/10 27.13 to 2014/10 27.53 UTC (24.= 48 to 34.08 hours after the BAT trigger), obtaining a total of 4.64 hours exposure in the r, i, and z bands.
The optical afterlow (Littlejohns et al., GCN 16952; also Perley et al., GCN 16955, Varela et al., GCN 16953, Gorosabel et al., GCN 16954, Butler, et al., GCN 16962) continues to fade. In comparison with 2MASS, we obtain the following detections and upper limit (3-sigma):
```
  r     22.94 +/- 0.16
  i     23.16 +/- 0.22
  z  >  20.1
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. The source appears to have faded roughly as t^(-0.5) since our last epoch (GCN 16962).
We thank the staff of the Observatorio Astron=C3=B3mico Nacional in San Pedro M=C3=A1rtir. Further observations are planned.
GCN Circular #16966
A. S. Moskvitin, V. N. Komarova, T. N. Sokolova (SAO RAS) report on behalf of the GRB follow-up team:
We observed the field of GRB 141026A (Hagen et al., GCN 16950) with the SAO RAS 1-m telescope Zeiss-1000 at the October 26/27 night. The observations were started at 20:09:49 UT (in 17.55 hours after the trigger), ended at 03:32:34. We obtained 61 x 300 sec. images in the Rc filter.
The object mentioned by Littlejohns et al. (GCN 16592, GCN 16963), Varela et al. (GCN 16953), Gorosabel et al. (GCN 16954), Perley et al. (GCN 16955), Butler et al. (GCN 16962, GCN 16965) is clearly detected in the stacked image. The magnitude of OT is R = 22.1 +/- 0.1 (in Vega system, not corrected for the Milky Way extinction). The photometry is based on the nearby USNO-B1 stars.
GCN Circular #16967
A. Trotter, J. Haislip, D. Reichart, V. Hoette, K. Cudworth, D. Harper, R. Kron, T. Linder, R. Russell, E. Struble, A. Aji, R. Beauchemin, T. Berger, A. Dow, A. Foster, N. Frank, M. Hinckle, K. Ivarsen, A. LaCluyze, M. Maples, J. Moore, M. Nysewander, C. Salemi, L. Zbinden, and J. A. Crain report:
Skynet observed the Swift BAT/XRT localization of GRB 141026A (Hagen et al., GCN 16950, Swift trigger=616502) with one 24" telescope (PROMPT 8; I band) and four 16" telescopes (PROMPT 3,1,4,5; BVRI bands) of the PROMPT array at CTIO, Chile, and with the 41" telescope of Yerkes Observatory in Wisconsin, USA (g'r'i' bands). Starting at 2014-10-26 02:38:30 UT and continuing until 03:03 UT (t=1.5-26m post-trigger), Skynet took a total of 89 exposures ranging from 10s-160s each. We stacked subsets of these images to maximize the S/N ratio, and detected no optical source in any band at the OT position first reported by RATIR (Littlejohns et al., GCN 16952), and confirmed in later notices. Our 3-sigma limiting magnitudes are:
```
==================================
tmid  scope   expos  fil  limit
==================================
10m  PROMPT3  4x80s   B   >19.9
20m  PROMPT1  4x160s  V   >20.4
19m  PROMPT4  3x160s  R   >19.8
17m  PROMPT5  4x80s   I   >19.9
               4X160s
17m  PROMPT8 12x80s   I   >20.0
63m  Yerkes   1x80s   g'  >21.2
               2x160s
60m  Yerkes   2x80s   r'  >20.9
               1x160s
66m  Yerkes   1x80s   i'  >20.5
               1x160s
==================================
```
BVRI magnitudes are in the Vega System, and g'r'i' magnitudes are in the AB system, calibrated to 4 APASS stars in the field. Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.16 (Schlafly & Finkbeiner 2011).
No further Skynet observations are scheduled.
GCN Circular #16968
A. de Ugarte Postigo (IAA-CISC, DARK/NBI), C.C. Thoene (IAA-CSIC), N.R. Tanvir (U. Leicester), J. Gorosabel (UPV, IAA-CSIC), J. Fynbo (DARK/NBI), G. Lombardi (GTC), D. Reverte-Paya (GTC), and D. Perez (GTC) report:
We observed the afterglow of GRB 141026A (Hagen et al. GCN 16950, Perley GCN 16951, Littlejohns et al. GCN 16952, Varela et al. GCN 16953, Gorosabel et al. GCN 16954, Perley et al. GCN 16955, Beardmore et al. GCN 16956, Butler et al. GCN 16962,Moskvitin et al. GCN 16966) with OSIRIS at the 10.4m Gran Telescopio Canarias. Observations consisted of z-band imaging, and spectroscopy using the R1000R grism (covering from 5100 to 10000 A with a resolution of ~1000). The spectroscopic observations were delayed due to bad weather and had a mean epoch of 6:12 UT (3.59 hours after the burst), and consisted of 2x900s exposures. Conditions were not optimal, as the airmass at that time was ~1.8 and most of the observation was performed during twilight.
The spectrum shows a low S/N continuum, which is however, visible between 5100 and 9500 A. Some absorption features seem to be present, and in particular we identify a broad feature at 5300 A, with an observed equivalent width of ~30 A. This could correspond to a weak Ly-alpha (log(N_H/cm^-2) ~< 20) absorption at z=3.35. However, no other features corresponding to that same redshift are seen, which is not unexpected for a low density line of sight that would correspond to such a Ly-alpha feature and a low S/N spectrum. Further absorptions could correspond to intervening MgII absorbers.
This redshift solution is supported by the photometric drop seen by GROND in the g-band (Varela et al. GCN 16953), which would correspond to a similar photometric redshift.
GCN Circular #16970
Owen Littlejohns (ASU), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos=C3=A9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=C3=BAs Gonz=C3=A1lez (UNAM), Carlos Rom=C3=A1n-Z=C3=BA= =C3=B1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We again observed the field of GRB 141026A (Hagen, et al., GCN 16950) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.or= g) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=C3=B3mico Nacional on Sierra San Pedro M=C3=A1rtir from 2014/10 28.13 to 2014/10 28.19 UTC (48.58 to 49.84 hours after the BAT trigger), obtaining a total of 1.07 hours exposure in the r, i and z bands.
For a source within the Swift-XRT error circle, we obtain the following upper limits (3-sigma):
```
  r     > 23.54
  i     > 23.31
  z     > 19.82
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to previous epochs of RATIR observations (Butler, et al., GCN 16965; Littlejohns, et al., GCN 16962), the GRB has continued to fade. The r band upper limit indicates a power-law decay between this and the previous epoch of RATIR observations with a minimum approximate index of t^(-0.9). This is steeper than that reported in Butler, et al. (GCN 16965).
We thank the staff of the Observatorio Astron=C3=B3mico Nacional in San Pedro M=C3=A1rtir.
GCN Circular #16974
A. J. Castro-Tirado, J. C. Tello, J. Gorosabel (IAA-CSIC Granada), C. Kramer, I. Hermelo, G. Paubert, A. Sievers (IRAM Granada) and J. G. Staguhn (NASA/GSFC Greenbelt),on behalf of a larger collaboration, report:
Following the detection of GRB 141026A by Swift (Hagen et al. GCNC 16950), observations with the IRAM 30m antenna (+GISMO) at Pico Veleta (Spain) were triggered on 26-27 Oct. At the position of the optical afterglow (Littlejohns et al. GCNC 16952, Varela et al. GCNC 16953, Gorosabel et al. GCNC 16954), we detect no mm afterglow (at 2 mm) down to a preliminary flux density of 1.2 mJy (3 sigma) on Oct 26, 14:30 UT (mid time). We acknowledge excellent assistance from the IRAM observers.
GCN Circular #17019
A. Corsi (Texas Tech U.) reports on behalf of a larger collaboration:
We observed the location of GRB 141026A (Hagen et al., GCN 16950) with the Karl G. Jansky Very Large Array (VLA) in its C configuration. Observations were carried out in the frequency bands 18.7-24.9 GHz and 4.5-7.8 GHz. A provisional reduction shows marginal detections at 21.8 GHz (at about 1.1 d and 4.3 d after the burst), and a clearer detection at 6.2 GHz (at about 6 d after the burst), of a source consistent with the location of the GRB optical afterglow (Littlejohns et al. GCN 16952; Varela et al., GCN 16953; Gorosabel et al., GCN 16954; Perley et al. GCN 16955). We estimate preliminary fluxes for this source of:
```
Mean epoch |  Freq. (GHz) | Flux (uJy) | map rms (uJy)
------------------------------
6.5 hr  | 21.8 | 11 | 11
------------------------------
1.1 d | 21.8 | 43 | 11
------------------------------
4.3 d | 21.8 | 31 | 8
------------------------------
6.0 d | 6.2 | 91 | 7
------------------------------
```
GCN Circular #17031
W. Fong (U. Arizona) and D. B. Fox (PSU) report on behalf of a larger collaboration:
"We observed the location of the long-duration GRB 141026A (Hagen et al., GCN 16950) with the Gemini Multi-Object Spectrograph (GMOS) and the Near InfraRed Imager (NIRI) mounted on the Gemini-North 8-m telescope starting on 2014 Oct 26.402 UT (7.03 hr after the BAT trigger). We obtained 540-sec of z-band imaging, and a total of 1800-sec in the YJHKs-bands. We clearly detect the afterglow (Littlejohns et al., GCN 16952; Varela et al., GCN 16953; Gorosabel et al., GCN 16954; Perley et al., GCN 16955; Butler et al., GCN 16962, GCN 16970; Moskvitin et al., GCN 16966) in all bands. Using tabulated Gemini zeropoints, we measure an afterglow brightness of z(AB) = 22.0 +/- 0.1 mag and J(AB) = 21.9 +/- 0.1 mag at 7.03 hr after the burst. These magnitudes have not been corrected for Galactic extinction in the direction of the burst.
We thank the Gemini staff for their assistance with these observations."
GCN Circular #17033 (identical to 17033)
V. Rumyantsev (CrAO), E. Mazaeva (IKI), A. Volnova (IKI), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
The GCN #17032 should be read as following: (We are sorry for inconvenience)
We observed the field of the Swift GRB GRB 141026A (Hagen et al., GCN 16950) with ZTSh telescope of CrAO observatory starting on Oct. 26 (UT) 18:25:48. We took several images in R-filter of 120 s exposure under poor weather conditions and mean seeing of 5". The optical afterglow (Littlejohns et al. GCN 16592; Varela et al. GCN 16953; Gorosabel et al. GCN 16954) is clearly visible in our stacked image. Photometry of a combined image is following
```
Date       UT start,  t-t0     Filter   Exp.      OT   OT_err
                       (mid, days)        (s)

2014-10-26 18:25:48   0.7020   R        53*120    21.88 0.18
```
The photometry is based on USNO-B1.0 stars
```
RA             DEC           R
044,065509    +26,958050     18.71
044,051792    +26,894737     18.59
044,049131    +26,929059     17.48
```

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Jochen Greiner, last update: 06-Nov-2014 [Disclaimer]