Gamma-ray Burst 160220A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Feb 16 01:26:14 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     674670,   Seg_Num: 0
GRB_RA:          236.925d {+15h 47m 42s} (J2000),
                 237.157d {+15h 48m 38s} (current),
                 236.207d {+15h 44m 50s} (1950)
GRB_DEC:         -18.555d {-18d 33' 17"} (J2000),
                 -18.604d {-18d 36' 13"} (current),
                 -18.402d {-18d 24' 05"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       12543 [cnts]    Image_Peak=238 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   299     E_range: 25-100 keV
BKG_INTEN:       112216 [cnts]
BKG_TIME:        5072.13 SOD {01:24:32.13} UT
BKG_DUR:         40 [sec]
GRB_DATE:        17438 TJD;    51 DOY;   16/02/20
GRB_TIME:        5125.70 SOD {01:25:25.70} UT
GRB_PHI:          99.16 [deg]
GRB_THETA:        28.79 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     11.31 [sigma]
IMAGE_SIGNIF:    7.35 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +2  -3  +0  +0  +3  +0 
SUN_POSTN:       332.89d {+22h 11m 33s}  -11.18d {-11d 10' 33"}
SUN_DIST:         91.77 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      120.71d {+08h 02m 50s}  +16.23d {+16d 13' 35"}
MOON_DIST:       119.63 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.92, 27.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      238.83,  1.38 [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 = 141.78,14.14 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=477624330).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 20 Feb 16 01:25:51 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      47
TRIGGER_NUM:     477624330
GRB_RA:          243.233d {+16h 12m 56s} (J2000),
                 243.466d {+16h 13m 52s} (current),
                 242.514d {+16h 10m 03s} (1950)
GRB_DEC:         -17.783d {-17d 46' 59"} (J2000),
                 -17.824d {-17d 49' 24"} (current),
                 -17.656d {-17d 39' 22"} (1950)
GRB_ERROR:       21.67 [deg radius, statistical plus systematic]
GRB_INTEN:       74 [cnts/sec]
DATA_SIGNIF:     5.50 [sigma]
INTEG_TIME:      2.048 [sec]
GRB_DATE:        17438 TJD;    51 DOY;   16/02/20
GRB_TIME:        5126.97 SOD {01:25:26.97} UT
GRB_PHI:          57.98 [deg]
GRB_THETA:        45.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO:      0.45
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      94%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       1,1,0, 0,0,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       332.89d {+22h 11m 32s}  -11.18d {-11d 10' 34"}
SUN_DIST:         86.06 [deg]   Sun_angle= 6.0 [hr] (West of Sun)
MOON_POSTN:      120.71d {+08h 02m 49s}  +16.23d {+16d 13' 37"}
MOON_DIST:       125.46 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      356.13, 23.65 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      244.56,  3.32 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160220059/quicklook/glg_lc_medres34_bn160220059.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 52.72,3.35 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 20 Feb 16 01:26:05 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      56
TRIGGER_NUM:     477624330
GRB_RA:          246.160d {+16h 24m 38s} (J2000),
                 246.404d {+16h 25m 37s} (current),
                 245.404d {+16h 21m 37s} (1950)
GRB_DEC:         -24.510d {-24d 30' 35"} (J2000),
                 -24.546d {-24d 32' 45"} (current),
                 -24.396d {-24d 23' 44"} (1950)
GRB_ERROR:       10.95 [deg radius, statistical only]
DATA_SIGNIF:     7.90 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        17438 TJD;    51 DOY;   16/02/20
GRB_TIME:        5126.97 SOD {01:25:26.97} UT
GRB_PHI:          48.00 [deg]
GRB_THETA:        43.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:       332.89d {+22h 11m 33s}  -11.18d {-11d 10' 34"}
SUN_DIST:         82.22 [deg]   Sun_angle= 5.8 [hr] (West of Sun)
MOON_POSTN:      120.71d {+08h 02m 50s}  +16.23d {+16d 13' 35"}
MOON_DIST:       128.73 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      352.70, 17.14 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      248.39, -2.84 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160220059/quicklook/glg_lc_medres34_bn160220059.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_477624330.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~4 min after the notice.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Sat 20 Feb 16 01:27:12 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      0
TRIGGER_NUM:     477624330
GRB_RA:          235.660d {+15h 42m 38s} (J2000),
                 235.904d {+15h 43m 37s} (current),
                 234.905d {+15h 39m 37s} (1950)
GRB_DEC:         -26.560d {-26d 33' 35"} (J2000),
                 -26.611d {-26d 36' 37"} (current),
                 -26.401d {-26d 24' 04"} (1950)
GRB_ERROR:       8.81 [deg radius, statistical only]
DATA_SIGNIF:     8.10 [sigma]
DATA_INTERVAL:   12.288 [sec]
GRB_DATE:        17438 TJD;    51 DOY;   16/02/20
GRB_TIME:        5126.97 SOD {01:25:26.97} UT
GRB_PHI:          54.00 [deg]
GRB_THETA:        34.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41531 (Gnd S/W Version number)
SUN_POSTN:       332.89d {+22h 11m 33s}  -11.18d {-11d 10' 33"}
SUN_DIST:         91.13 [deg]   Sun_angle= 6.5 [hr] (West of Sun)
MOON_POSTN:      120.72d {+08h 02m 52s}  +16.23d {+16d 13' 30"}
MOON_DIST:       119.37 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      344.01, 22.35 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      239.47, -6.69 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160220059/quicklook/glg_lc_medres34_bn160220059.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_477624330.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~4 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=674670).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Feb 16 01:29:21 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     674670,   Seg_Num: 0
GRB_RA:          236.925d {+15h 47m 42s} (J2000),
                 237.157d {+15h 48m 38s} (current),
                 236.207d {+15h 44m 50s} (1950)
GRB_DEC:         -18.555d {-18d 33' 17"} (J2000),
                 -18.604d {-18d 36' 13"} (current),
                 -18.402d {-18d 24' 05"} (1950)
GRB_DATE:        17438 TJD;    51 DOY;   16/02/20
GRB_TIME:        5125.70 SOD {01:25:25.70} UT
TRIGGER_INDEX:   299
GRB_PHI:          99.16 [deg]
GRB_THETA:        28.79 [deg]
DELTA_TIME:      -76.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.31 [sigma]
IMAGE_SIGNIF:    7.35 [sigma]
LC_URL:          sw00674670000msb.lc
SUN_POSTN:       332.89d {+22h 11m 33s}  -11.18d {-11d 10' 31"}
SUN_DIST:         91.78 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      120.74d {+08h 02m 57s}  +16.22d {+16d 13' 20"}
MOON_DIST:       119.61 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.92, 27.46 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      238.83,  1.38 [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 = 141.78,14.14 [deg].

GCN Circular #19023
A. Y. Lien (GSFC/UMBC), P.A. Evans (U Leicester), J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 01:25:25 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160220A (trigger=674670). Swift could not immediately slew to the burst. The BAT on-board calculated location is RA, Dec 236.925, -18.555 which is
```
   RA(J2000) = 15h 47m 42s
   Dec(J2000) = -18d 33' 17"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 15 sec. The peak count rate was ~500 counts/sec (15-350 keV), at ~5 sec after the trigger.
Due to an observing constraint, Swift will not slew until T0+50.1 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is A. Y. Lien (amy.y.lien 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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Feb 16 02:21:46 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     674670,   Seg_Num: 0
POINT_RA:        236.910d {+15h 47m 38s} (J2000)
POINT_DEC:       -18.541d {-18d 32' 26"} (J2000)
IMG_START_DATE:  17438 TJD;    51 DOY;   16/02/20
IMG_START_TIME:  8363.83 SOD {02:19:23.83} UT,   3238.1 [sec] since BAT Trigger Time
COUNTS:          3    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Feb 16 02:47:28 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     674670,   Seg_Num: 0
POINT_RA:        236.909d {+15h 47m 38s} (J2000)
POINT_DEC:       -18.544d {-18d 32' 37"} (J2000)
POINT_ROLL:      102.506d
IMG_START_DATE:  17438 TJD;    51 DOY;   16/02/20
IMG_START_TIME:  9235.94 SOD {02:33:55.94} UT,   4110.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.038
N_STARS:         128
X_OFFSET:        612 [pixels]
Y_OFFSET:        544 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1503 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00674670000msufc4110.fits
SUN_POSTN:       332.94d {+22h 11m 46s}  -11.16d {-11d 09' 21"}
SUN_DIST:         91.85 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      121.45d {+08h 05m 49s}  +16.12d {+16d 07' 10"}
MOON_DIST:       118.89 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.92, 27.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      238.82,  1.38 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 20 Feb 16 02:49:05 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     674670,   Seg_Num: 0
POINT_RA:        236.909d {+15h 47m 38s} (J2000)
POINT_DEC:       -18.544d {-18d 32' 37"} (J2000)
POINT_ROLL:      102.506d
IMG_START_DATE:  17438 TJD;    51 DOY;   16/02/20
IMG_START_TIME:  9235.94 SOD {02:33:55.94} UT,   4110.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.038
N_STARS:         128
X_OFFSET:        612 [pixels]
Y_OFFSET:        544 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1503 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00674670000msufc4110.fits
SUN_POSTN:       332.94d {+22h 11m 46s}  -11.16d {-11d 09' 19"}
SUN_DIST:         91.85 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      121.47d {+08h 05m 53s}  +16.12d {+16d 07' 02"}
MOON_DIST:       118.88 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.92, 27.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      238.82,  1.38 [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:     Sat 20 Feb 16 02:49:18 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     674670,   Seg_Num: 0
POINT_RA:        236.909d {+15h 47m 38s} (J2000)
POINT_DEC:       -18.544d {-18d 32' 37"} (J2000)
ROLL:            102.506d
IMG_START_DATE:  17438 TJD;    51 DOY;   16/02/20
IMG_START_TIME:  9235.94 SOD {02:33:55.94} UT,   4110.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     477628451
X_OFFSET:        931 [pixels]
Y_OFFSET:        863 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1091
Y_GRB_POS:       1023
BINNING_INDEX:   1
IM_URL:          sw00674670000msuni4126.fits
SUN_POSTN:       332.94d {+22h 11m 46s}  -11.16d {-11d 09' 19"}
SUN_DIST:         91.85 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      121.47d {+08h 05m 53s}  +16.12d {+16d 07' 01"}
MOON_DIST:       118.88 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.92, 27.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      238.82,  1.38 [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:     Sat 20 Feb 16 02:49:43 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     674670,   Seg_Num: 0
POINT_RA:        236.909d {+15h 47m 38s} (J2000)
POINT_DEC:       -18.544d {-18d 32' 37"} (J2000)
ROLL:            102.506d
IMG_START_DATE:  17438 TJD;    51 DOY;   16/02/20
IMG_START_TIME:  9235.94 SOD {02:33:55.94} UT,   4110.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     477628451
X_OFFSET:        931 [pixels]
Y_OFFSET:        863 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1091
Y_GRB_POS:       1023
BINNING_INDEX:   1
IM_URL:          sw00674670000msuni4126.fits
SUN_POSTN:       332.94d {+22h 11m 46s}  -11.16d {-11d 09' 19"}
SUN_DIST:         91.85 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      121.47d {+08h 05m 54s}  +16.12d {+16d 06' 59"}
MOON_DIST:       118.87 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.92, 27.48 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      238.82,  1.38 [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:     Sat 20 Feb 16 02:51:27 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     674670,   Seg_Num: 0
GRB_RA:          236.9516d {+15h 47m 48.38s} (J2000),
                 237.1837d {+15h 48m 44.08s} (current),
                 236.2334d {+15h 44m 56.00s} (1950)
GRB_DEC:         -18.5650d {-18d 33' 54.0"} (J2000),
                 -18.6138d {-18d 36' 49.8"} (current),
                 -18.4117d {-18d 24' 42.1"} (1950)
GRB_ERROR:       3.9 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17438 TJD;    51 DOY;   16/02/20
IMG_START_TIME:  9239.00 SOD {02:33:59.00} UT,   4113.3 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       332.94d {+22h 11m 46s}  -11.16d {-11d 09' 17"}
SUN_DIST:         91.81 [deg]   Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN:      121.49d {+08h 05m 58s}  +16.11d {+16d 06' 51"}
MOON_DIST:       118.90 [deg]
MOON_ILLUM:      93 [%]
GAL_COORDS:      350.94, 27.44 [deg] galactic lon,lat of the burst
ECL_COORDS:      238.86,  1.37 [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 2.8% < P(seren) < 6.6%.

GCN Circular #19024
S. Campana (INAF-OAB), G. Cusumano (INAF-IASF PA), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU) and J.A. Kennea (PSU) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 160220A at 02:19:23.8 UT, 3238.1 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 236.95167, -18.56501 which is equivalent to:
```
   RA(J2000)  = 15h 47m 48.40s
   Dec(J2000) = -18d 33' 54.0"
```
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 97 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.09 x 10^21 cm^-2 (Willingale et al. 2013).
GCN Circular #19025
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1730 s of XRT Photon Counting mode data and 5 UVOT images for GRB 160220A, 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 = 236.95288, -18.56605 which is equivalent to:
```
RA (J2000): 15h 47m 48.69s
Dec (J2000): -18d 33' 57.8"
```
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 #19026
C. M. Hui (NASA/MSFC) and E. Burns (UAH) report on behalf of the Fermi GBM Team:
"At 01:25:26.968 UT on 20 February 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160220A (trigger 477624330 / 160220059), which was also detected by the Swift/BAT (Lien et al. 2016, GCN 19023). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 46 degrees.
The GBM light curve shows a single peak with a duration (T90) of about 9 s (50-300 keV). The time-averaged spectrum from T0-3.072 s to T0+9.216 s is best fit by a simple power law function with index -1.5 +/- 0.1.
The event fluence (10-1000 keV) in this time interval is (1.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.43 s in the 10-1000 keV band is 1.7 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #19027
P. Wiseman, F. Knust, J. Greiner (all MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 160220A (Swift trigger 674670; Lien et al., GCN #19023) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla Observatory (Chile).
Observations started at 05:46 UT on 2016-02-20, 4.5 hrs after the GRB trigger. They were performed at an average seeing of 1.5" and at an average airmass of 1.6.
We do not find any single point source within the 1.9" Enhanced Swift-XRT error circle reported by Evans et al. (GCN #19025). Based on 36.00 min of total exposures in g'r'i'z' and 30.00 min in JHK, at a mid-time of 06:49 UT, we estimate preliminary upper limiting magnitudes (AB system) of
```
g' > 23.4 mag,
r' > 23.9 mag,
i' > 23.6 mag,
z' > 23.3 mag,
J  > 21.6 mag,
H  > 20.9 mag, and
K  > 18.0 mag.
```
Given limits are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.12 mag in the direction of the burst (Schlafly & Finkbeiner 2011).

GCN Circular #19028
D.Buckley, S. Potter, M.Kotze South African Astronomical Observatory
A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda Blagoveschensk Educational State University, Blagoveschensk
E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk Irkutsk State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian The Instituto de Astrofisica de Canarias
MASTER-SAAO robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was pointed to the GRB160220A (Lien et al., GCN #19023) 22 sec after notice time and 65 sec after trigger time at 2016-02-20 01:26:34 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (ra=15 47 41 dec=-18 33 16 r=0.050000). The 5-sigma upper limit has been about 15.5mag The automatically generated table image limits you can see below:

Pro.ID Pro.type      time      Exp.	Limit	Filt.   Tube
                        UT        s       mag  polaroid

162238	Alert 	    01:26:34	10	15.5	P/	EAST
162239	Alert       01:26:34	10      15.5	P\	WEST
162240	Alert 	    01:26:56	20	14.8	P/	EAST
162241  Alert       01:26:56    20      14.8    P\      WEST
162241  Alert       01:26:56    20      14.8    P\      WEST
162242  Alert       01:27:29    20      16.7    P/      EAST
162243  Alert       01:27:29    20      16.6    P\      WEST
162244  Alert       01:28:02    30      17.9    P/      EAST
162245  Alert       01:28:02    30      17.9    P\      WEST
162246  Alert       01:28:44    40      16.5    P/      EAST
162247 	Alert 	    01:28:44 	40 	16.4 	P\ 	WEST
162264 SumAlert     01:26:56    70      17.7    P/      EAST
162265 SumAlert     01:26:56    70      17.8    P\      WEST
162266 SumAlert     01:28:44   150      18.2    P/      EAST
162267 SumAlert     01:28:44   150      18.3    P\      WEST
162323 SumAlert     01:26:56   670	19.3	P/	EAST
162321 SumAlert     01:26:56   670	19.1	P\	WEST
........
162338 SumAlert     01:40:23  1800	19.4	P/	EAST
162337 SumAlert     01:40:23  1800 	19.2 	P\ 	WEST

GCN Circular #19030
Klotz A., Turpin D., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Laugier, R. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report:
We imaged the field of GRB 160220A detected by SWIFT (trigger 674670) with the TAROT robotic telescopes (D=25cm) located at the Calern observatory, France and at the European Southern Observatory, La Silla observatory, Chile.
The observations started 1.64h after the GRB trigger at Calern and 4.00h after the GRB trigger at la Silla (the field was not visible at the date of the trigger). The elevation of the field increased from 20 degrees above horizon and weather conditions were good.
We co-added a series of exposures. We do not detected the X-ray couterpart mentioned by Campana et al. (GCNC 19024):
```
t1(h) t2(h)  Rmag_lim  Site
1.64 3.30    17.5      TAROT Calern
4.00 4.69    19.0      TAROT La Silla
```
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
GCN Circular #19032
M. De Pasquale (MSSL-UCL) and A. Lien (GSFC/UMBC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160220A 4.11 ks after the BAT trigger (Lien et al., GCN Circ. 19023). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 19025) is detected in the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the summed UVOT exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white             4110         5493          344         >20.6
v                 4268        34517          903         >19.4
b                 5088         5288          197         >19.7
u                 4882        17290          424         >19.5

w1                4678        17052         1175         >20.3
m2                4472        11445         1271         >20.3
w2                5499        32840         1177         >20.5
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.13 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #19038
H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 160220A (trigger #674670) (Lien, et al., GCN Circ. 19023). The BAT ground-calculated position is RA, Dec = 236.942, -18.539 deg which is
```
    RA(J2000)  =  15h 47m 46.2s
    Dec(J2000) = -18d 32' 20.6"
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 26%.
The mask-weighted light curve shows a single peak of about 20 seconds total duration starting at ~0 sec. The spacecraft slewed away from the burst location at ~T+220 sec due to a pre-planned maneuver. T90 (15-350 keV) is 8.3 +- 1.2 sec (estimated error including systematics).
The time-averaged spectrum from T-0.02 to T+8.99 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.55 +- 0.24. The fluence in the 15-150 keV band is 5.2 +- 0.7 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+0.33 sec in the 15-150 keV band is 1.0 +- 0.3 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/674670/BA/
GCN Circular #19039
A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), S.L. Gibson (U. Leicester), P. D'Avanzo (INAF-OAB) and A.Y. Lien report on behalf of the Swift-XRT team:
We have analysed 7.7 ks of XRT data for GRB 160220A (Lien et al. GCN Circ. 19023), from 4.1 ks to 63.2 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. 19025).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.94 (+0.20, -0.18).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.67 (+0.37, -0.18). The best-fitting absorption column is consistent with the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.0 x 10^-11 (4.6 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.1 (+/-1.1) x 10^21 cm^-2
Galactic foreground: 1.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.67 (+0.37, -0.18)
```
If the light curve continues to decay with a power-law decay index of 0.94, the count rate at T+24 hours will be 3.9 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.5 x 10^-13 (1.8 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/00674670.
This circular is an official product of the Swift-XRT team.
GCN Circular #19040
R. Starling, N. Tanvir, K. Wiersema (U. Leicester) and J. Bailey (UNSW) report on behalf of a larger collaboration:
We observed the field of GRB 160220A (Swift trigger 674670, Lien et al. GCN Circ. 19023; Fermi trigger 477624330/16022005, Hui & Burns GCN Circ. 19026) with the 4m Anglo Australian Telescope, AAT, at Siding Spring, Australia on 2016 February 20th, 14 hours after burst.
We obtained near-IR photometry with the Infrared Imager and Spectrograph, IRIS2, in the Ks band beginning at 15:35 UT and in the J band beginning 16:09 UT, and totalling 27 minutes exposure in each filter. No source was detected within the Swift XRT error circle (Evans et al. GCN Circ. 19025). We find the following approximate limiting magnitudes (at 5-sigma in the Vega system):
```
J > 21 
Ks > 18
```
We acknowledge excellent support from the Australian Astronomical Observatory staff.

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Jochen Greiner, last update: 22-Feb-2016 [Disclaimer]