Gamma-ray Burst 140311B

(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 11 Mar 14 21:15:44 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     591392,   Seg_Num: 0
GRB_RA:          252.291d {+16h 49m 10s} (J2000),
                 252.374d {+16h 49m 30s} (current),
                 252.000d {+16h 48m 00s} (1950)
GRB_DEC:         +52.747d {+52d 44' 50"} (J2000),
                 +52.723d {+52d 43' 23"} (current),
                 +52.832d {+52d 49' 57"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4652 [cnts]    Image_Peak=194 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   150     E_range: 25-100 keV
BKG_INTEN:       30697 [cnts]
BKG_TIME:        76452.25 SOD {21:14:12.25} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16727 TJD;    70 DOY;   14/03/11
GRB_TIME:        76469.72 SOD {21:14:29.72} UT
GRB_PHI:         -146.42 [deg]
GRB_THETA:        23.61 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     8.83 [sigma]
IMAGE_SIGNIF:    7.34 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -3  +0  +0 +15  +0 
SUN_POSTN:       351.93d {+23h 27m 44s}   -3.48d {-03d 28' 51"}
SUN_DIST:         98.55 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      118.54d {+07h 54m 10s}  +15.60d {+15d 35' 59"}
MOON_DIST:       100.95 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.39, 39.56 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      229.08, 73.67 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
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 = 198.00,9.16 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(6.0<100sec) coincident with the FERMI_GBM event (trignum=416265278).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 11 Mar 14 21:14:42 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     416265278
GRB_RA:          247.383d {+16h 29m 32s} (J2000),
                 247.460d {+16h 29m 50s} (current),
                 247.115d {+16h 28m 28s} (1950)
GRB_DEC:         +55.367d {+55d 22' 00"} (J2000),
                 +55.336d {+55d 20' 11"} (current),
                 +55.474d {+55d 28' 28"} (1950)
GRB_ERROR:       26.38 [deg radius, statistical plus systematic]
GRB_INTEN:       77 [cnts/sec]
DATA_SIGNIF:     5.70 [sigma]
INTEG_TIME:      4.096 [sec]
GRB_DATE:        16727 TJD;    70 DOY;   14/03/11
GRB_TIME:        76475.65 SOD {21:14:35.65} UT
GRB_PHI:         260.98 [deg]
GRB_THETA:       105.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO:      0.95
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   2%  Cyg X-1
DETECTORS:       0,0,0, 0,1,0, 0,0,1, 0,0,0, 0,0,
SUN_POSTN:       351.93d {+23h 27m 44s}   -3.48d {-03d 28' 52"}
SUN_DIST:        101.06 [deg]   Sun_angle= 7.0 [hr] (West of Sun)
MOON_POSTN:      118.53d {+07h 54m 07s}  +15.60d {+15d 36' 05"}
MOON_DIST:        97.07 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       84.43, 41.97 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      215.18, 74.49 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 195.20,19.75 [deg].

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Tue 11 Mar 14 21:14:49 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     416265278
GRB_RA:          279.610d {+18h 38m 26s} (J2000),
                 279.686d {+18h 38m 45s} (current),
                 279.342d {+18h 37m 22s} (1950)
GRB_DEC:         +53.630d {+53d 37' 48"} (J2000),
                 +53.643d {+53d 38' 36"} (current),
                 +53.584d {+53d 35' 03"} (1950)
GRB_ERROR:       14.45 [deg radius, statistical only]
DATA_SIGNIF:     8.70 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        16727 TJD;    70 DOY;   14/03/11
GRB_TIME:        76475.65 SOD {21:14:35.65} UT
GRB_PHI:         280.00 [deg]
GRB_THETA:       103.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4143 (Gnd S/W Version number)
SUN_POSTN:       351.93d {+23h 27m 44s}   -3.48d {-03d 28' 52"}
SUN_DIST:         82.44 [deg]   Sun_angle= 4.8 [hr] (West of Sun)
MOON_POSTN:      118.53d {+07h 54m 08s}  +15.60d {+15d 36' 04"}
MOON_DIST:       108.89 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       82.76, 23.40 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      294.61, 76.25 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN Circular #15945
J. L. Racusin (NASA/GSFC), W. H. Baumgartner (GSFC/UMBC), N. Gehrels (NASA/GSFC), L. Izzo (URoma/ICRA), J. A. Kennea (PSU), D. Malesani (DARK/NBI), F. E. Marshall (NASA/GSFC), B. Sbarufatti (INAF-OAB/PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift Team:
At 21:14:29 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 140311B (trigger=591392). Swift could not immediately slew to the burst due to the Earth limb constraint. The BAT on-board calculated location is RA, Dec 252.291, +52.747 which is
```
   RA(J2000) = 16h 49m 10s
   Dec(J2000) = +52d 44' 50"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). We are awaiting information on the BAT light curve.
Due to an observing constraint, Swift will not slew until T0+55 minutes. There will be no XRT or UVOT data until this time.
The observation of this burst will delay the observation of GRB 140311A.
Burst Advocate for this burst is J. L. Racusin (judith.racusin AT nasa.gov). 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 Circular #15948
E. Gorbovskoy, V. Lipunov, M. Pruzhinskaya, D.Denisenko, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
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 Tunka was pointed to the GRB140311B 29 sec after notice time and 107 sec after trigger time at 2014-03-11 21:16:16 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box (Racusin et. al. GCN 15945). The 5-sigma upper limit has been about 17.0 mag. The observations is proceed.
MASTER II robotic telescope located in Blagoveschensk was pointed to the GRB140311B 9 sec after notice time and 85 sec after trigger time at 2014-03-11 21:15:54 UT in two polarizations. On our first (20s exposure) set we haven`t found optical transient within SWIFT error-box. The 5-sigma upper limit has been about 14.0 mag. The observations on this place made on the bright morning sky.
The message may be cited.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 11 Mar 14 22:21:02 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     591392,   Seg_Num: 0
POINT_RA:        252.265d {+16h 49m 04s} (J2000)
POINT_DEC:       +52.753d {+52d 45' 12"} (J2000)
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79864.37 SOD {22:11:04.37} UT,   3394.6 [sec] since BAT Trigger Time
COUNTS:          37    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        4    Max_iter_allowed= 4
ERROR_CODE:      2
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        Algorithm did not converge; too many iterations.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 11 Mar 14 22:22:22 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     591392,   Seg_Num: 0
POINT_RA:        252.265d {+16h 49m 04s} (J2000)
POINT_DEC:       +52.753d {+52d 45' 12"} (J2000)
POINT_ROLL:      84.347d
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79867.77 SOD {22:11:07.77} UT,   3398.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.384
N_STARS:         47
X_OFFSET:        616 [pixels]
Y_OFFSET:        531 [pixels]
X_MAX:           1575 [pixels]
Y_MAX:           1490 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00591392000msufc3398.fits
SUN_POSTN:       351.97d {+23h 27m 54s}   -3.46d {-03d 27' 45"}
SUN_DIST:         98.58 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      119.10d {+07h 56m 23s}  +15.49d {+15d 29' 36"}
MOON_DIST:       100.79 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.40, 39.58 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      229.02, 73.67 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 11 Mar 14 22:22:44 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     591392,   Seg_Num: 0
POINT_RA:        252.265d {+16h 49m 04s} (J2000)
POINT_DEC:       +52.753d {+52d 45' 12"} (J2000)
POINT_ROLL:      84.347d
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79867.77 SOD {22:11:07.77} UT,   3398.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.384
N_STARS:         47
X_OFFSET:        616 [pixels]
Y_OFFSET:        531 [pixels]
X_MAX:           1575 [pixels]
Y_MAX:           1490 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00591392000msufc3398.fits
SUN_POSTN:       351.97d {+23h 27m 54s}   -3.46d {-03d 27' 45"}
SUN_DIST:         98.58 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      119.10d {+07h 56m 24s}  +15.49d {+15d 29' 34"}
MOON_DIST:       100.79 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.40, 39.58 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      229.02, 73.67 [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 11 Mar 14 22:24:02 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     591392,   Seg_Num: 0
POINT_RA:        252.265d {+16h 49m 04s} (J2000)
POINT_DEC:       +52.753d {+52d 45' 12"} (J2000)
ROLL:            84.347d
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79867.77 SOD {22:11:07.77} UT,   3398.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     416268679
X_OFFSET:        935 [pixels]
Y_OFFSET:        850 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1095
Y_GRB_POS:       1010
BINNING_INDEX:   1
IM_URL:          sw00591392000msuni3410.fits
SUN_POSTN:       351.98d {+23h 27m 54s}   -3.46d {-03d 27' 44"}
SUN_DIST:         98.58 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      119.11d {+07h 56m 27s}  +15.49d {+15d 29' 27"}
MOON_DIST:       100.79 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.40, 39.58 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      229.02, 73.67 [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 11 Mar 14 22:24:28 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     591392,   Seg_Num: 0
POINT_RA:        252.265d {+16h 49m 04s} (J2000)
POINT_DEC:       +52.753d {+52d 45' 12"} (J2000)
ROLL:            84.347d
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79867.77 SOD {22:11:07.77} UT,   3398.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     416268679
X_OFFSET:        935 [pixels]
Y_OFFSET:        850 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1095
Y_GRB_POS:       1010
BINNING_INDEX:   1
IM_URL:          sw00591392000msuni3410.fits
SUN_POSTN:       351.98d {+23h 27m 54s}   -3.46d {-03d 27' 43"}
SUN_DIST:         98.58 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      119.11d {+07h 56m 27s}  +15.49d {+15d 29' 24"}
MOON_DIST:       100.79 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.40, 39.58 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      229.02, 73.67 [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 11 Mar 14 22:25:40 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     591392,   Seg_Num: 0
GRB_RA:          252.3253d {+16h 49m 18.07s} (J2000),
                 252.4082d {+16h 49m 37.97s} (current),
                 252.0335d {+16h 48m 08.05s} (1950)
GRB_DEC:         +52.7245d {+52d 43' 28.1"} (J2000),
                 +52.7006d {+52d 42' 02.0"} (current),
                 +52.8097d {+52d 48' 34.9"} (1950)
GRB_ERROR:       4.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79880.00 SOD {22:11:20.00} UT,   3410.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       351.98d {+23h 27m 54s}   -3.46d {-03d 27' 42"}
SUN_DIST:         98.54 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      119.12d {+07h 56m 30s}  +15.49d {+15d 29' 17"}
MOON_DIST:       100.83 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.36, 39.55 [deg] galactic lon,lat of the burst
ECL_COORDS:      229.19, 73.66 [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 Circular #15949
D. Xu (DARK/NBI), C.-H. Bai, X. Zhang, A. Esamdin, L. Ma (XAO) report:
We observed the field of GRB 140311B (Racusin et al., GCN 15945) using the 1m telescope located in Nanshan, Xinjiang, China. Observations started at 21:41:05 UT on 2014-03-11 and some 300s/600s R-band frames were obtained.
The afterglow is detected in each image within the XRT error circle (http://www.swift.ac.uk/sper/) at coordinates
```
R.A. (J2000) = 16:49:17.97
Dec. (J2000) = +52:43:26.41
```
Uncertainty radius: ~1.5 aecsec
The first 300s image reveals that the afterglow has m(R)=20.6 at 29.1 min post-burst, calibrated with nearby two SDSS stars.
Observations are ongoing.
GCN Circular #15950
J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), G. Tagliaferri (INAF-OAB), S. Campana (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 140311B at 22:11:04.3 UT, 3394.7 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 252.32458, 52.72393 which is equivalent to:
```
   RA(J2000)  = 16h 49m 17.90s
   Dec(J2000) = +52d 43' 26.1"
```
with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 110 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 consistent with the Galactic value of 3.03 x 10^20 cm^-2 (Kalberla et al. 2005).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 11 Mar 14 23:07:55 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     591392,   Seg_Num: 0
GRB_RA:          252.3241d {+16h 49m 17.78s} (J2000),
                 252.4071d {+16h 49m 37.69s} (current),
                 252.0323d {+16h 48m 07.76s} (1950)
GRB_DEC:         +52.7239d {+52d 43' 26.0"} (J2000),
                 +52.7000d {+52d 41' 59.8"} (current),
                 +52.8091d {+52d 48' 32.7"} (1950)
GRB_ERROR:       3.6 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16727 TJD;    70 DOY;   14/03/11
IMG_START_TIME:  79880.00 SOD {22:11:20.00} UT,   3410.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       352.00d {+23h 28m 01s}   -3.45d {-03d 27' 01"}
SUN_DIST:         98.55 [deg]   Sun_angle= 6.6 [hr] (West of Sun)
MOON_POSTN:      119.48d {+07h 57m 54s}  +15.42d {+15d 25' 11"}
MOON_DIST:       100.74 [deg]
MOON_ILLUM:      80 [%]
GAL_COORDS:       80.36, 39.55 [deg] galactic lon,lat of the burst
ECL_COORDS:      229.18, 73.66 [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:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #15951
V. D'Elia (ASDC), L. Izzo (URoma/ICRA) and J. Racusin (NASA/GSFC) report:
XRT began observing GRB140311B (Racusin et al. GCN 15945) 55 minutes =20 after the trigger.
Using promptly downlinked data we find a bright uncatalogued X ray =20 source located at RA,Dec =3D 252.3242, 52.7240 which is equivalent to:
```
RA  (J2000.0) =3D=A0 16 49 17.81
DEC (J2000.0) =3D=A0 +52 43 26.4
```
with an uncertainty of 3.6 arcsec (radius, 90% containment). This =20 location is 109.6 arcsec from the BAT position, inside the BAT error =20 circle.
This is an official product of the Swift/XRT team.
GCN Circular #15955
Klotz A., Turpin D. (IRAP-CNRS-OMP), Gendre B., Boer M., Siellez K., Dereli H., Bardho O. (UNS-CNRS-OCA), Atteia J.L. (IRAP-CNRS-OMP) report:
We imaged the field of GRB 140311B detected by SWIFT (trigger 513505) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
The observations started 5 minutes after the GRB trigger The elevation of the field increased from 20 degrees above horizon and weather conditions were good.
The first image is 60.0s exposure in tracking mode. We do not detect the OT discovered by Xu et al. (GCNC 15949) with a limiting magnitude of: t0+246s to t0+306s : Rlim = 17.3
We co-added a series of exposures: We do not detect the OT with limiting magnitudes of:
```
t0+246s to t0+511s : Rlim = 17.8
t0+541s to t0+1568s : Rlim = 18.4
```
Magnitudes were estimated with the nearby NOMAD1 stars and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 80.3934 lat=+39.5637 and the galactic extinction in R band is about 0.2 magnitude estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
GCN Circular #15958
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 2577 s of XRT Photon Counting mode data and 6 UVOT images for GRB 140311B, 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 = 252.32518, +52.72426 which is equivalent to:
```
RA (J2000): 16h 49m 18.04s
Dec (J2000): +52d 43' 27.3"
```
with an uncertainty of 1.7 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 #15960
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
E. Gorbovskoy, V. Lipunov, M. Pruzhinskaya, D.Denisenko, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
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 Tunka was pointed to the GRB140311B (Racusin et al., GCN 15945) 29 sec after notice time and 107 sec after trigger time (Gorbovskoy et. al GCN 15948 ) and made observations during ~ 1.5 h before sunrise. We see OT (Xu et. al. GCN 15949) only on several coadditional images. On all of them the object is close to limit and has s/n from 3 to 6. Our preliminary ligth curve available in table below and on image here http://master.sai.msu.ru/static/GRB/grb140311B.png.
```
T_start       T_t-T_m  Exptime   Mag.   Coadd
                 [s]     [s]      [m]
21:17:12        326      220     19.4     4
21:18:18        432      300     19.0     4
21:16:16        557      650     19.4     8
21:19:44        557      380     18.7     4
21:19:44        661      550     18.9     5
21:21:19        708      490     18.9     4
21:18:18        834      960     19.4     8
21:25:40       1485     1380     19.8     8
21:25:40       1702     1740     20.0    10
```
T_t is GRB trigger time, T_m is middle time of our exposure. Our unfiltered magnitude is well described by a parity 0.8R + 0.2B (USNO B1)
The power low index alpha from 380 to 1740 seconds after the trigger is 1.07+-0.10 (F ~ t-apha).
We also apologize for an error in the title of our previous telegram (GCN 15948) if it misled somebody.
The message may be cited.
GCN Circular #15963
V. D'Elia (ASDC), L. Izzo (URoma/ICRA) and J. L. Racusin (NASA/GSFC) report on behalf of the Swift-XRT team:
We have analysed 7.8 ks of XRT data for GRB 140311B (Racusin et al. GCN Circ. 15945), from 3.4 ks to 46.3 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. 15958).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.66 (+0.18, -0.15).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.68 (+0.25, -0.23). The best-fitting absorption column is 1.6 (+0.9, -0.8) x 10^21 cm^-2, in excess of the Galactic value of 3.6 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.1 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.6 (+0.9, -0.8) x 10^21 cm^-2
Galactic foreground: 3.6 x 10^20 cm^-2
Excess significance: 2.7 sigma
Photon index:	     1.68 (+0.25, -0.23)
```
If the light curve continues to decay with a power-law decay index of 1.66, the count rate at T+24 hours will be 9.6 x 10^-4 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.0 x 10^-14 (4.8 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00591392.
This circular is an official product of the Swift-XRT team.
GCN Circular #15970
Owen Littlejohns (ASU), Antonino Cucchiara (ORAU/GSFC), 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), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos=E9 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=FAs Gonz=E1lez (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
We observed the field of GRB 140311B (Racusin, et al., GCN 15945) with the Reionization and Transients Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at the Observatorio Astron=F3mico Nacional on Sierra San Pedro M=E1rtir from 2014/03 12.37 to 2014/03 12.52 UTC (11.52 to 15.25 hours after the BAT trigger), obtaining a total of 2.84 hours exposure in the r and i bands and 1.19 hours exposure in the Z and Y bands.
For a source within the Swift-XRT error circle, in comparison with the SDSS DR9 and 2MASS, we obtain the following upper limits (3-sigma):
```
  r     > 23.99
  i     > 23.82
  Z     > 22.85
  Y     > 22.26
```
These magnitudes are in the AB system and are not corrected for Galactic extinction in the direction of the GRB. In comparison to the earlier detection of the optical afterglow (Xu, et al., GCN 15949) the GRB has faded. A power-law temporal decay with an index of alpha =3D -0.94 or steeper is required for our r-band upper limit to be consistent with the earlier detection.
We thank the staff of the Observatorio Astron=F3mico Nacional in San Pedro M=E1rtir.
GCN Circular #15972
S. T. Holland (STScI) and J. L. Racusin (NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 140311B 3398 s after the BAT trigger (Racusin et al. 2014, GCNC 15945). We do not detect any new source consistent with the Nansan afterglow position (Xu et al. 2014, GCNC 15949) in any of the UVOT exposures. Preliminary 3-sigma upper limits, using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373), for the finding chart and summed exposures are presented below.
```
---------------------------------------------------
Filter        TSTART     TSTOP   Exposure       Mag
---------------------------------------------------
white (FC)      3398      3548        147     >21.2
---------------------------------------------------
v               3555      5191        393     >20.0
b               4375      5990        372     >20.4
u               4170      5806        393     >20.2
uvw1            3965      5601        393     >20.3
uvm2            3760      5396        393     >20.2
uvw2            4787      4986        197     >20.1
white           4580      4780        197     >21.4
---------------------------------------------------
```
The quoted upper limits have not been corrected for the expected extinction due to the Galactic reddening along the line of sight to this burst of E(B-V) = 0.05 mag (Schlafly et al. 2011, ApJS, 737, 103).
GCN Circular #15975
M. Stanbro (UAH) reports on behalf of the Fermi GBM Team:
"At 21:14:35.65 UT on 11 March 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140311B (trigger 416265278/140311885), which was also detected by Swift (J. L. Racusin et al. 2014, GCN 15945). The GBM on-ground location, using the Fermi GBM trigger data, is consistent with the Swift/BAT location.The angle to the Fermi LAT boresight is 110 deg. from Swift location.
The GBM light curve consists of several overlapping peaks with a combined duration (T90) of 72 s (50-300 keV). The time-averaged spectrum from T0-3 s to T0+69 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -0.5 +/- 0.1 and the high energy cutoff, parameterized as Epeak, is 117 +/- 8 keV.
The event fluence (10-1000 keV) in this time interval is (7.9 +/- 0.4)E-06 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+0.6 s in the 10-1000 keV band is 3.2 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #15979
A. Y. Lien (NASA/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (looking), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-0 to T+3 sec from the recent telemetry downlink, we report further analysis of BAT GRB 140311B (trigger #591392) (Racusin, et al., GCN Circ. 15945). The BAT ground-calculated position is RA, Dec = 252.333, +52.733 deg which is
```
    RA(J2000)  =  16h 49m 20.0s
    Dec(J2000) = +52d 44' 00"
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 89%.
This trigger followed that of GRB 140311A by only about 9 minutes, which led to a complication in recording the photon-event data. Only 3 seconds of photon-event data was recorded, so no mask-weighted lightcurve is available. T90 (15-350 keV) is estimated to be 70 +- 10 sec. The burst had multiple peaks. Peak emission occurred about 15 seconds after the trigger time.
The time-averaged spectrum for the limited range of data available (about 5% of T90) from T+0 to T+3 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.12 +- 0.15 (90% confidence). Because of the lack of event data, the fluence is not available. Based on an eye-ball estimate comparing the non-maskweighted lightcurve to those of other bursts with a similar partial coding, the fluence in the 15-150 keV band was on the order of several times 10^-6 ergs/cm^2
GCN Circular #15995
A.Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 140311B (Racusin et al., GCN 15945) with AZT-33IK telescope of Mondy observatory starting on Mar. 12 (UT) 20:21:16. Within enhanced Swift-XRT eror circle (Evans et al., GCN 15958) we do not detect the optical afterglow (Xu et al., GCN 15949). Details of the photometry is following:
```
date       UT start   t-T0      Exp.    Filter  UpperLimit (3sigma)
                     (mid, days) (s)
2014-03-12 20:21:16  0.98389    30x120  R       20.2
```
The photometry is based on reference star SDSS-DR9, (R mag, transformation by Lupton 2005):
```
N  SDSS_id          R(Lupton)   err
J164910.91+524333.6 17.449    0.009
```

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Jochen Greiner, last update: 18-Mar-2014 [Disclaimer]