Gamma-ray Burst 160411A

(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:     Mon 11 Apr 16 01:29:23 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     682339,   Seg_Num: 0
GRB_RA:          349.362d {+23h 17m 27s} (J2000),
                 349.584d {+23h 18m 20s} (current),
                 348.676d {+23h 14m 42s} (1950)
GRB_DEC:         -40.271d {-40d 16' 14"} (J2000),
                 -40.182d {-40d 10' 53"} (current),
                 -40.544d {-40d 32' 38"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1988 [cnts]    Image_Peak=105 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   181     E_range: 25-100 keV
BKG_INTEN:       22213 [cnts]
BKG_TIME:        5319.89 SOD {01:28:39.89} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17489 TJD;   102 DOY;   16/04/11
GRB_TIME:        5331.92 SOD {01:28:51.92} UT
GRB_PHI:         -133.50 [deg]
GRB_THETA:        41.94 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     15.90 [sigma]
IMAGE_SIGNIF:    7.44 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2  -2  +0  +0 -55  +0 
SUN_POSTN:        19.97d {+01h 19m 52s}   +8.42d {+08d 25' 10"}
SUN_DIST:         56.12 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.16d {+04h 44m 38s}  +17.15d {+17d 09' 06"}
MOON_DIST:        94.78 [deg]
MOON_ILLUM:      18 [%]
GAL_COORDS:      352.83,-66.56 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      332.74,-32.48 [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 = 212.42,7.15 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=482030936).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 11 Apr 16 01:29:17 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     482030936
GRB_RA:          326.883d {+21h 47m 32s} (J2000),
                 327.123d {+21h 48m 30s} (current),
                 326.144d {+21h 44m 35s} (1950)
GRB_DEC:         -32.600d {-32d 36' 00"} (J2000),
                 -32.524d {-32d 31' 25"} (current),
                 -32.832d {-32d 49' 55"} (1950)
GRB_ERROR:       22.78 [deg radius, statistical plus systematic]
GRB_INTEN:       173 [cnts/sec]
DATA_SIGNIF:     5.00 [sigma]
INTEG_TIME:      0.512 [sec]
GRB_DATE:        17489 TJD;   102 DOY;   16/04/11
GRB_TIME:        5332.52 SOD {01:28:52.52} UT
GRB_PHI:         295.00 [deg]
GRB_THETA:        90.00 [deg]
DATA_TIME_SCALE: 0.5120 [sec]
HARD_RATIO:      0.78
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      96%  GRB
2nd_MOST_LIKELY:   2%  Generic Transient
DETECTORS:       0,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:        19.97d {+01h 19m 52s}   +8.42d {+08d 25' 10"}
SUN_DIST:         64.84 [deg]   Sun_angle= 3.5 [hr] (West of Sun)
MOON_POSTN:       71.16d {+04h 44m 38s}  +17.15d {+17d 09' 06"}
MOON_DIST:       110.73 [deg]
MOON_ILLUM:      18 [%]
GAL_COORDS:       13.60,-50.06 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      317.94,-18.13 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160411062/quicklook/glg_lc_medres34_bn160411062.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 23.90,-1.05 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Mon 11 Apr 16 01:29:35 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     482030936
GRB_RA:          338.460d {+22h 33m 50s} (J2000),
                 338.694d {+22h 34m 47s} (current),
                 337.739d {+22h 30m 57s} (1950)
GRB_DEC:         -37.770d {-37d 46' 11"} (J2000),
                 -37.686d {-37d 41' 07"} (current),
                 -38.028d {-38d 01' 41"} (1950)
GRB_ERROR:       15.18 [deg radius, statistical only]
DATA_SIGNIF:     6.30 [sigma]
DATA_INTERVAL:   0.512 [sec]
GRB_DATE:        17489 TJD;   102 DOY;   16/04/11
GRB_TIME:        5332.52 SOD {01:28:52.52} UT
GRB_PHI:         299.00 [deg]
GRB_THETA:       100.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4153 (Gnd S/W Version number)
SUN_POSTN:        19.97d {+01h 19m 52s}   +8.42d {+08d 25' 10"}
SUN_DIST:         60.07 [deg]   Sun_angle= 2.8 [hr] (West of Sun)
MOON_POSTN:       71.16d {+04h 44m 38s}  +17.15d {+17d 09' 07"}
MOON_DIST:       102.29 [deg]
MOON_ILLUM:      18 [%]
GAL_COORDS:        3.92,-59.29 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      325.26,-26.52 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2016/bn160411062/quicklook/glg_lc_medres34_bn160411062.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_482030936.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
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=682339).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 16 01:33:27 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     682339,   Seg_Num: 0
GRB_RA:          349.362d {+23h 17m 27s} (J2000),
                 349.584d {+23h 18m 20s} (current),
                 348.676d {+23h 14m 42s} (1950)
GRB_DEC:         -40.271d {-40d 16' 14"} (J2000),
                 -40.182d {-40d 10' 53"} (current),
                 -40.544d {-40d 32' 38"} (1950)
GRB_DATE:        17489 TJD;   102 DOY;   16/04/11
GRB_TIME:        5331.92 SOD {01:28:51.92} UT
TRIGGER_INDEX:   181
GRB_PHI:         -133.50 [deg]
GRB_THETA:        41.94 [deg]
DELTA_TIME:      76.00 [sec]
TRIGGER_DUR:     0.512 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.90 [sigma]
IMAGE_SIGNIF:    7.44 [sigma]
LC_URL:          sw00682339000msb.lc
SUN_POSTN:        19.97d {+01h 19m 52s}   +8.42d {+08d 25' 14"}
SUN_DIST:         56.12 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.20d {+04h 44m 48s}  +17.16d {+17d 09' 23"}
MOON_DIST:        94.81 [deg]
MOON_ILLUM:      18 [%]
GAL_COORDS:      352.83,-66.56 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      332.74,-32.48 [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 = 212.42,7.15 [deg].

GCN Circular #19279
K. L. Page (U Leicester), J. A. Kennea (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 01:28:51 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 160411A (trigger=682339). Swift could not immediately slew to the burst due to an observing constraint. The BAT on-board calculated location is RA, Dec 349.362, -40.271 which is
```
   RA(J2000) = 23h 17m 27s
   Dec(J2000) = -40d 16' 14"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 0.5 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0.2 sec after the trigger.
Due to an observing constraint, Swift will not slew until T0+50.4 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is K. L. Page (klp5 AT leicester.ac.uk). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 16 02:30:55 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     682339,   Seg_Num: 0
POINT_RA:        349.391d {+23h 17m 34s} (J2000)
POINT_DEC:       -40.246d {-40d 14' 45"} (J2000)
IMG_START_DATE:  17489 TJD;   102 DOY;   16/04/11
IMG_START_TIME:  8464.20 SOD {02:21:04.20} UT,   3132.3 [sec] since BAT Trigger Time
COUNTS:          34    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:     Mon 11 Apr 16 02:31:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     682339,   Seg_Num: 0
POINT_RA:        349.391d {+23h 17m 34s} (J2000)
POINT_DEC:       -40.246d {-40d 14' 45"} (J2000)
POINT_ROLL:      37.264d
IMG_START_DATE:  17489 TJD;   102 DOY;   16/04/11
IMG_START_TIME:  8470.89 SOD {02:21:10.89} UT,   3139.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.781
N_STARS:         17
X_OFFSET:        271 [pixels]
Y_OFFSET:        663 [pixels]
X_MAX:           1230 [pixels]
Y_MAX:           1622 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00682339000msufc3138.fits
SUN_POSTN:        20.01d {+01h 20m 01s}   +8.44d {+08d 26' 07"}
SUN_DIST:         56.12 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.81d {+04h 47m 14s}  +17.22d {+17d 13' 12"}
MOON_DIST:        95.26 [deg]
MOON_ILLUM:      19 [%]
GAL_COORDS:      352.86,-66.59 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      332.78,-32.47 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 16 02:32:02 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     682339,   Seg_Num: 0
POINT_RA:        349.391d {+23h 17m 34s} (J2000)
POINT_DEC:       -40.246d {-40d 14' 45"} (J2000)
POINT_ROLL:      37.264d
IMG_START_DATE:  17489 TJD;   102 DOY;   16/04/11
IMG_START_TIME:  8470.89 SOD {02:21:10.89} UT,   3139.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.781
N_STARS:         17
X_OFFSET:        271 [pixels]
Y_OFFSET:        663 [pixels]
X_MAX:           1230 [pixels]
Y_MAX:           1622 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw00682339000msufc3138.fits
SUN_POSTN:        20.01d {+01h 20m 01s}   +8.44d {+08d 26' 07"}
SUN_DIST:         56.12 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.81d {+04h 47m 14s}  +17.22d {+17d 13' 13"}
MOON_DIST:        95.27 [deg]
MOON_ILLUM:      19 [%]
GAL_COORDS:      352.86,-66.59 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      332.78,-32.47 [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:     Mon 11 Apr 16 02:33:18 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     682339,   Seg_Num: 0
POINT_RA:        349.391d {+23h 17m 34s} (J2000)
POINT_DEC:       -40.246d {-40d 14' 45"} (J2000)
ROLL:            37.264d
IMG_START_DATE:  17489 TJD;   102 DOY;   16/04/11
IMG_START_TIME:  8470.89 SOD {02:21:10.89} UT,   3139.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482034087
X_OFFSET:        590 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       750
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00682339000msuni3155.fits
SUN_POSTN:        20.01d {+01h 20m 02s}   +8.44d {+08d 26' 08"}
SUN_DIST:         56.12 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.82d {+04h 47m 17s}  +17.22d {+17d 13' 18"}
MOON_DIST:        95.28 [deg]
MOON_ILLUM:      19 [%]
GAL_COORDS:      352.86,-66.59 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      332.78,-32.47 [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:     Mon 11 Apr 16 02:33:27 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     682339,   Seg_Num: 0
POINT_RA:        349.391d {+23h 17m 34s} (J2000)
POINT_DEC:       -40.246d {-40d 14' 45"} (J2000)
ROLL:            37.264d
IMG_START_DATE:  17489 TJD;   102 DOY;   16/04/11
IMG_START_TIME:  8470.89 SOD {02:21:10.89} UT,   3139.0 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     482034087
X_OFFSET:        590 [pixels]
Y_OFFSET:        982 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       750
Y_GRB_POS:       1142
BINNING_INDEX:   1
IM_URL:          sw00682339000msuni3155.fits
SUN_POSTN:        20.01d {+01h 20m 02s}   +8.44d {+08d 26' 09"}
SUN_DIST:         56.12 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.82d {+04h 47m 18s}  +17.22d {+17d 13' 18"}
MOON_DIST:        95.28 [deg]
MOON_ILLUM:      19 [%]
GAL_COORDS:      352.86,-66.59 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      332.78,-32.47 [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:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Mon 11 Apr 16 02:35:12 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     682339,   Seg_Num: 0
GRB_RA:          349.3550d {+23h 17m 25.20s} (J2000),
                 349.5775d {+23h 18m 18.60s} (current),
                 348.6694d {+23h 14m 40.64s} (1950)
GRB_DEC:         -40.2422d {-40d 14' 31.9"} (J2000),
                 -40.1531d {-40d 09' 11.2"} (current),
                 -40.5155d {-40d 30' 55.8"} (1950)
GRB_ERROR:       4.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  17489 TJD;   102 DOY;   16/04/11
IMG_START_TIME:  8487.00 SOD {02:21:27.00} UT,   3155.1 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:        20.01d {+01h 20m 02s}   +8.44d {+08d 26' 10"}
SUN_DIST:         56.13 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:       71.84d {+04h 47m 22s}  +17.22d {+17d 13' 25"}
MOON_DIST:        95.32 [deg]
MOON_ILLUM:      19 [%]
GAL_COORDS:      352.90,-66.57 [deg] galactic lon,lat of the burst
ECL_COORDS:      332.75,-32.45 [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 #19281
M. Perri (ASDC), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU) and G. Cusumano (INAF-IASF PA) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 160411A at 02:21:04.2 UT, 3132.3 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 349.35590, -40.24247 which is equivalent to:
```
   RA(J2000)  = 23h 17m 25.42s
   Dec(J2000) = -40d 14' 32.9"
```
with an uncertainty of 4.0 arcseconds (radius, 90% containment). This location is 103 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 1.61 x 10^20 cm^-2 (Willingale et al. 2013).
GCN Circular #19283
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 1177 s of XRT Photon Counting mode data and 3 UVOT images for GRB 160411A, 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 = 349.35691, -40.24227 which is equivalent to:
```
RA (J2000): 23h 17m 25.66s
Dec (J2000): -40d 14' 32.2"
```
with an uncertainty of 2.4 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 #19284
V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, P.Balanutsa, A.Kuznetsov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute
D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk
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)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was pointed to the GRB160411A 34 sec after notice time and 64 sec after trigger time at 2016-04-11 01:30:00 UT. On our first (10s exposure) set we haven`t found optical transient within SWIFT error-box (Page et al GCN 19279, Evans et al GCN 19283). The 5-sigma upper limit has been about 16.0 mag on single (10 sec exposure) and 18.5 on coadd (170 sec exposure) image. The observations made on high zenit distance (z=80 deg). The message may be cited.
GCN Circular #19286
C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU) and K.L. Page report on behalf of the Swift-XRT team:
We have analysed 6.7 ks of XRT data for GRB 160411A (Page et al. GCN Circ. 19279), from 3.1 ks to 22.5 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. 19283).
The light curve can be modelled with a power-law decay with a decay index of alpha=1.5 (+3.3, -0.9).
If the light curve continues to decay with a power-law decay index of 1.5, the count rate at T+24 hours will be 2.0 x 10^-4 count s^-1
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00682339.
This circular is an official product of the Swift-XRT team.
GCN Circular #19289
O.J. Roberts (UCD), C.M. Hui (NASA/MSFC) report on behalf of the Fermi GBM Team:
"At 01:28:52.52 UT on the 11th of April 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160411A (trigger 482030936 / 160411062), which was also detected by Swift (Page et al. 2016, GCN 19279). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time using the Swift XRT position is about 108 degrees.
The GBM light curve consists of a weak, short burst with a duration (T90) of about 0.2 s (50-300 keV). The time-averaged spectrum from T0-0.51 s to T0-0.35 s is best fit by a power law function with an exponential high-energy cutoff function, with Epeak = 161 +/- 37 keV and alpha = 0.26 +/- 0.67.
The event fluence (10-1000 keV) in this time interval is (1.38 +/- 0.30)E-07 erg/cm^2. The 64ms peak photon flux measured starting from T0-0.51 s in the 10-1000 keV band is 6.4 +/- 1.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN Circular #19291
M. H. Siegel (PSU) and K. L. Page (U Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 160411A 3139 s after the BAT trigger (Page et al., GCN Circ. 19279). No optical afterglow consistent with the XRT position (Perri et al. GCN Circ. 19281) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC          3139         3289          147         >20.5
white             3139         4521          344         >21.0
v                 3295         4931          393         >19.4
b                 4116         4316          197         >19.9
u                 3910         5546          393         >20.0
w1                3705         5342          393         >20.2
m2                3500         5136          393         >20.1
w2                4527         4726          197         >20.0
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #19292
R Yates, T-W Chen, and J Greiner (all MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 160411A (Swift trigger 682339; Page et al., GCN #19279) 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 09:14 UT on 11-04-2016, 7 hr 45 min after the GRB trigger. They were performed at an average seeing of 1.9" in the r'-band and at an average airmass of 1.8.
Based on the first 49 min of total exposures, we do not detect a source within the 4.0" Swift-XRT error circle reported by Perri et al. (GCN #19281) down to (all in the AB system):
```
g' > 23.7 mag,
r' > 23.9 mag,
i' > 23.1 mag,
z' > 22.9 mag,
J  > 21.3 mag,
H  > 20.8 mag, and
K  > 19.9 mag.
```
The given limits are derived based on calibrating the images against GROND zeropoints and 2MASS field stars and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlafly & Finkbeiner 2011).
GCN Circular #19293
A.J.Levan (U. Warwick), W. Fong (Arizona) report on behalf of a larger collaboration:
=E2=80=9CWe observed the location of GRB 160411A (Page et al. GCN 19279, Evans et al. GCN 19283) with Gemini-S and GMOS starting at 09:35 UT on 20 16 April 11. Observations were taken in the i-band and began 9 hours after the BAT trigger. They were taken at the start of morning twilight as the source was rising, because of this the seeing is poor (1.4=E2=80=9D) and depth relatively shallow.
The region around the enhanced XRT position is relatively complex, with multiple sources in the surrounding area. Two obvious sources are located just outside the Eastern and Western edge of the XRT circle at locations of
```
Source A:=20
RA(J2000) 23:17:25.99
DEC(J2000) -40:14:32.0

Source B:=20
RA(J2000) 23:17:25.37
DEC(J2000) -40:14:30.5
```
The sources have comparable magnitude and appear to be marginally extended, although the poor seeing and signal to noise complicates such analyses.
With thank the Gemini staff, in particular Bryan Miller, for their assistance with these observations=E2=80=9D=20
GCN Circular #19302
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlinks, we report further analysis of BAT short GRB 160411A (trigger #682339) (Page, et al., GCN Circ. 19279). The BAT ground-calculated position is RA, Dec = 349.370, -40.258 deg, which is
```
   RA(J2000)  =  23h 17m 28.8s 
   Dec(J2000) = -40d 15' 30.3" 
```
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 27%.
The mask-weighted light curve shows two overlapping peaks starting at ~T+0.0 and ending at ~T+0.5 sec. T90 (15-350 keV) is 0.36 +- 0.08 sec (estimated error including systematics).
The time-averaged spectrum from T+0.06 to T+0.46 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.43 +- 0.28. The fluence in the 15-150 keV band is 8.0 +- 1.8 x 10^-8 erg/cm2. The 1-sec peak photon flux measured from T-0.24 sec in the 15-150 keV band is 1.5 +- 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/682339/BA/
GCN Circular #19313
A.J. Levan (U. Warwick), W. Fong (Arizona) and N.R. Tanvir (Leicester) re= port on behalf of a larger collaboration:
=E2=80=9CWe obtained a second epoch of i-band observations of the short-G= RB 160411A (Page et al. GCN 19279) on 2016 April 13, 10:01 UT. Photometry= suggests that our previously identified source B (Levan & Fong GCN 19293= ) has faded by approximately 0.9 magnitudes between the two epochs obtain= ed 48 hours apart, although a source close to this location is still fain= tly detected in our imaging. We therefore suggest this source may be the = optical afterglow of GRB 160411A.
We thank the Gemini staff, in particular Bryan Miller and Rodolfo Angelon= i for assistance with these observations.=E2=80=9D
photometric redshift z = 0.81 +0.65 -0.43
of host-galaxy: A. E. Nugent et al. 2022, ApJ, 940, 57

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