Previous IAU Circulars 
(All information courtesy of the instrument teams.)
Previous IAU Circulars
Results of Observations
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:28:01 UT
NOTICE_TYPE: Swift-BAT GRB Position
TRIGGER_NUM: 824451, Seg_Num: 0
GRB_RA: 356.829d {+23h 47m 19s} (J2000),
357.051d {+23h 48m 12s} (current),
356.228d {+23h 44m 55s} (1950)
GRB_DEC: +66.791d {+66d 47' 26"} (J2000),
+66.892d {+66d 53' 32"} (current),
+66.513d {+66d 30' 46"} (1950)
GRB_ERROR: 3.00 [arcmin radius, statistical only]
GRB_INTEN: 5755 [cnts] Image_Peak=545 [image_cnts]
TRIGGER_DUR: 1.024 [sec]
TRIGGER_INDEX: 146 E_range: 25-100 keV
BKG_INTEN: 25318 [cnts]
BKG_TIME: 44851.23 SOD {12:27:31.23} UT
BKG_DUR: 8 [sec]
GRB_DATE: 18219 TJD; 101 DOY; 18/04/11
GRB_TIME: 44863.71 SOD {12:27:43.71} UT
GRB_PHI: 17.91 [deg]
GRB_THETA: 19.48 [deg]
SOLN_STATUS: 0x20002003
RATE_SIGNIF: 41.30 [sigma]
IMAGE_SIGNIF: 18.13 [sigma]
MERIT_PARAMS: +1 +0 +0 +0 +2 +5 +0 +1 -49 +0
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 34"}
SUN_DIST: 60.52 [deg] Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN: 329.39d {+21h 57m 33s} -13.72d {-13d 43' 07"}
MOON_DIST: 83.13 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 116.66, 4.70 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 41.29, 58.42 [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: There is a bright star (mag=5.95) 4.20 arcmin from this position.
COMMENTS: This is a GRB.
COMMENTS: This trigger occurred at longitude,latitude = 316.10,14.88 [deg].
COMMENTS:
COMMENTS: NOTE: This BAT event is temporally(3.0<100sec) coincident with the FERMI_GBM event (trignum=545142465).
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:28:08 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 44
TRIGGER_NUM: 545142465
GRB_RA: 351.133d {+23h 24m 32s} (J2000),
351.337d {+23h 25m 21s} (current),
350.578d {+23h 22m 19s} (1950)
GRB_DEC: +62.717d {+62d 43' 00"} (J2000),
+62.817d {+62d 49' 02"} (current),
+62.442d {+62d 26' 31"} (1950)
GRB_ERROR: 11.05 [deg radius, statistical plus systematic]
GRB_INTEN: 219 [cnts/sec]
DATA_SIGNIF: 6.10 [sigma]
INTEG_TIME: 2.048 [sec]
GRB_DATE: 18219 TJD; 101 DOY; 18/04/11
GRB_TIME: 44860.97 SOD {12:27:40.97} UT
GRB_PHI: 228.00 [deg]
GRB_THETA: 155.00 [deg]
DATA_TIME_SCALE: 2.0480 [sec]
HARD_RATIO: 0.69
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 93% GRB
2nd_MOST_LIKELY: 3% Cyg X-1
DETECTORS: 0,0,0, 0,0,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 34"}
SUN_DIST: 58.21 [deg] Sun_angle= 1.9 [hr] (West of Sun)
MOON_POSTN: 329.39d {+21h 57m 33s} -13.72d {-13d 43' 06"}
MOON_DIST: 78.42 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 113.16, 1.51 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 32.51, 57.51 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn180411519/quicklook/glg_lc_medres34_bn180411519.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 120.67,6.83 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
COMMENTS:
COMMENTS: NOTE: This GBM event is temporally(3.0<100sec) coincident with the SWIFT_BAT event (trignum=824451).
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:28:14 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 58
TRIGGER_NUM: 545142465
GRB_RA: 325.533d {+21h 42m 08s} (J2000),
325.684d {+21h 42m 44s} (current),
325.121d {+21h 40m 29s} (1950)
GRB_DEC: +55.383d {+55d 22' 60"} (J2000),
+55.467d {+55d 28' 02"} (current),
+55.154d {+55d 09' 16"} (1950)
GRB_ERROR: 8.02 [deg radius, statistical plus systematic]
GRB_INTEN: 278 [cnts/sec]
DATA_SIGNIF: 9.70 [sigma]
INTEG_TIME: 4.096 [sec]
GRB_DATE: 18219 TJD; 101 DOY; 18/04/11
GRB_TIME: 44860.97 SOD {12:27:40.97} UT
GRB_PHI: 192.00 [deg]
GRB_THETA: 155.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO: 0.00
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 100% Below horizon
2nd_MOST_LIKELY: 0% n/a
DETECTORS: 0,0,0, 0,0,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 34"}
SUN_DIST: 63.38 [deg] Sun_angle= 3.6 [hr] (West of Sun)
MOON_POSTN: 329.39d {+21h 57m 33s} -13.72d {-13d 43' 05"}
MOON_DIST: 69.26 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 98.23, 1.87 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 3.96, 62.00 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn180411519/quicklook/glg_lc_medres34_bn180411519.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 120.67,6.83 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
COMMENTS:
COMMENTS: NOTE: This GBM event is temporally(3.0<100sec) coincident with the SWIFT_BAT event (trignum=824451).
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:29:07 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 87
TRIGGER_NUM: 545142465
GRB_RA: 329.233d {+21h 56m 56s} (J2000),
329.393d {+21h 57m 34s} (current),
328.797d {+21h 55m 11s} (1950)
GRB_DEC: +55.050d {+55d 02' 60"} (J2000),
+55.137d {+55d 08' 15"} (current),
+54.811d {+54d 48' 41"} (1950)
GRB_ERROR: 5.72 [deg radius, statistical plus systematic]
GRB_INTEN: 499 [cnts/sec]
DATA_SIGNIF: 17.20 [sigma]
INTEG_TIME: 4.096 [sec]
GRB_DATE: 18219 TJD; 101 DOY; 18/04/11
GRB_TIME: 44860.97 SOD {12:27:40.97} UT
GRB_PHI: 192.00 [deg]
GRB_THETA: 155.00 [deg]
DATA_TIME_SCALE: 4.0960 [sec]
HARD_RATIO: 0.00
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 100% Below horizon
2nd_MOST_LIKELY: 0% n/a
DETECTORS: 0,0,0, 0,0,0, 0,0,1, 0,0,1, 0,0,
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 35"}
SUN_DIST: 61.36 [deg] Sun_angle= 3.4 [hr] (West of Sun)
MOON_POSTN: 329.40d {+21h 57m 35s} -13.72d {-13d 42' 58"}
MOON_DIST: 68.85 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 99.65, 0.27 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 6.63, 60.29 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2018/bn180411519/quicklook/glg_lc_medres34_bn180411519.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 120.67,6.83 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
COMMENTS:
COMMENTS: NOTE: This GBM event is temporally(46.0<100sec) coincident with the CALET_GBM event (trignum=1207484873).
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:29:16 UT
NOTICE_TYPE: Swift-XRT Position
TRIGGER_NUM: 824451, Seg_Num: 0
GRB_RA: 356.8546d {+23h 47m 25.10s} (J2000),
357.0762d {+23h 48m 18.28s} (current),
356.2528d {+23h 45m 00.68s} (1950)
GRB_DEC: +66.7784d {+66d 46' 42.2"} (J2000),
+66.8800d {+66d 52' 48.0"} (current),
+66.5005d {+66d 30' 01.7"} (1950)
GRB_ERROR: 4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN: 1.35e-08 [erg/cm2/sec]
GRB_SIGNIF: 17.11 [sigma]
IMG_START_DATE: 18219 TJD; 101 DOY; 18/04/11
IMG_START_TIME: 44930.40 SOD {12:28:50.40} UT, 66.7 [sec] since BAT Trigger Time
TAM[0-3]: 327.67 237.20 261.52 243.64
AMPLIFIER: 2
WAVEFORM: 134
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 35"}
SUN_DIST: 60.50 [deg] Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN: 329.40d {+21h 57m 35s} -13.72d {-13d 42' 57"}
MOON_DIST: 83.12 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 116.67, 4.69 [deg] galactic lon,lat of the burst
ECL_COORDS: 41.29, 58.40 [deg] ecliptic lon,lat of the burst
COMMENTS: SWIFT-XRT Coordinates.
COMMENTS: The XRT position is 0.95 arcmin from the BAT position.
COMMENTS: There is a bright star (mag=5.95) 4.78 arcmin from the XRT position.
COMMENTS: The object found at this position is either a very bright burst or a cosmic ray hit.
COMMENTS: Examine the XRT Image to differentiate (CRs are much more compact); see examples at:
COMMENTS: http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:29:27 UT
NOTICE_TYPE: Swift-XRT Image
TRIGGER_NUM: 824451, Seg_Num: 0
GRB_RA: 356.8546d {+23h 47m 25.1s} (J2000),
357.0762d {+23h 48m 18.2s} (current),
356.2528d {+23h 45m 00.6s} (1950)
GRB_DEC: +66.7784d {+66d 46' 42.2"} (J2000),
+66.8800d {+66d 52' 48.0"} (current),
+66.5005d {+66d 30' 01.7"} (1950)
GRB_ERROR: 4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN: 293 [cnts]
IMG_START_DATE: 18219 TJD; 101 DOY; 18/04/11
IMG_START_TIME: 44930.40 SOD {12:28:50.40} UT, 66.7 [sec] since BAT Trigger Time
CENTROID_X: 306.55, raw= 307 [pixels]
CENTROID_Y: 301.10, raw= 301 [pixels]
ROLL: 153.50 [deg]
GAIN: 4
MODE: 3, Long Image mode
WAVEFORM: 134
EXPO_TIME: 2.50 [sec]
GRB_POS_XRT_Y: 6.37
GRB_POS_XRT_Z: 0.36
IMAGE_URL: sw00824451000msxps_rw.img
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 35"}
SUN_DIST: 60.50 [deg] Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN: 329.40d {+21h 57m 36s} -13.72d {-13d 42' 55"}
MOON_DIST: 83.12 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 116.67, 4.69 [deg] galactic lon,lat of the burst
ECL_COORDS: 41.29, 58.40 [deg] ecliptic lon,lat of the burst
COMMENTS: SWIFT-XRT Image.
COMMENTS: The object found at this position is either a very bright burst or a cosmic ray hit.
COMMENTS: Examine the XRT Image to differentiate (CRs are much more compact); see examples at:
COMMENTS: http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .
COMMENTS: There is a bright star (mag=5.95) 4.20 arcmin from the BAT position.
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:29:34 UT
NOTICE_TYPE: Swift-XRT Processed Image
TRIGGER_NUM: 824451, Seg_Num: 0
GRB_RA: 356.8546d {+23h 47m 25.1s} (J2000),
357.0762d {+23h 48m 18.2s} (current),
356.2528d {+23h 45m 00.6s} (1950)
GRB_DEC: +66.7784d {+66d 46' 42.2"} (J2000),
+66.8800d {+66d 52' 48.0"} (current),
+66.5005d {+66d 30' 01.7"} (1950)
GRB_ERROR: 4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN: 293 [cnts]
IMG_START_DATE: 18219 TJD; 101 DOY; 18/04/11
IMG_START_TIME: 44930.40 SOD {12:28:50.40} UT, 66.7 [sec] since BAT Trigger Time
CENTROID_X: 306.55, raw= 307 [pixels]
CENTROID_Y: 301.10, raw= 301 [pixels]
ROLL: 153.50 [deg]
GAIN: 4
MODE: 3, Long Image mode
WAVEFORM: 134
EXPO_TIME: 2.50 [sec]
GRB_POS_XRT_Y: 6.37
GRB_POS_XRT_Z: 0.36
IMAGE_URL: sw00824451000msxps_rw.img
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 36"}
SUN_DIST: 60.50 [deg] Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN: 329.40d {+21h 57m 36s} -13.72d {-13d 42' 55"}
MOON_DIST: 83.12 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 116.67, 4.69 [deg] galactic lon,lat of the burst
ECL_COORDS: 41.29, 58.40 [deg] ecliptic lon,lat of the burst
COMMENTS: SWIFT-XRT Processed Image.
COMMENTS: The object found at this position is either a very bright burst or a cosmic ray hit.
COMMENTS: Examine the XRT Image to differentiate (CRs are much more compact); see examples at:
COMMENTS: http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .
COMMENTS: There is a bright star (mag=5.95) 4.20 arcmin from the BAT position.
TITLE: GCN/SWIFT NOTICE
NOTICE_DATE: Wed 11 Apr 18 12:31:28 UT
NOTICE_TYPE: Swift-BAT GRB Lightcurve
TRIGGER_NUM: 824451, Seg_Num: 0
GRB_RA: 356.829d {+23h 47m 19s} (J2000),
357.051d {+23h 48m 12s} (current),
356.228d {+23h 44m 55s} (1950)
GRB_DEC: +66.791d {+66d 47' 26"} (J2000),
+66.892d {+66d 53' 32"} (current),
+66.513d {+66d 30' 46"} (1950)
GRB_DATE: 18219 TJD; 101 DOY; 18/04/11
GRB_TIME: 44863.71 SOD {12:27:43.71} UT
TRIGGER_INDEX: 146
GRB_PHI: 17.91 [deg]
GRB_THETA: 19.48 [deg]
DELTA_TIME: 32.00 [sec]
TRIGGER_DUR: 1.024 [sec]
SOLN_STATUS: 0x2003
RATE_SIGNIF: 41.30 [sigma]
IMAGE_SIGNIF: 18.13 [sigma]
LC_URL: sw00824451000msb.lc
SUN_POSTN: 19.94d {+01h 19m 46s} +8.41d {+08d 24' 37"}
SUN_DIST: 60.52 [deg] Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN: 329.42d {+21h 57m 40s} -13.71d {-13d 42' 39"}
MOON_DIST: 83.12 [deg]
MOON_ILLUM: 21 [%]
GAL_COORDS: 116.66, 4.70 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 41.29, 58.42 [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: There is a bright star (mag=5.95) 4.20 arcmin from this position.
COMMENTS: This is a GRB.
COMMENTS: This trigger occurred at longitude,latitude = 316.10,14.88 [deg].
RA(J2000) = 23h 47m 19s Dec(J2000) = +66d 47' 26"with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 100 sec. The peak count rate was ~8000 counts/sec (15-350 keV), at ~53 sec after the trigger.
RA(J2000) = 23h 47m 25.09s Dec(J2000) = +66d 46' 41.9"with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 58 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.
RA (J2000): 23 47 24.97 Dec(J2000): +66 46 42.5with an uncertainty of 3.5 arcsec (radius, 90% confidence).
Total column: 1.91 (+0.25, -0.23) x 10^22 cm^-2 Galactic foreground: 8.3 x 10^21 cm^-2 Excess significance: 7.7 sigma Photon index: 2.01 (+/-0.16)If the light curve continues to decay with a power-law decay index of 1.09, the count rate at T+24 hours will be 0.032 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.9 x 10^-12 (4.1 x 10^-12) erg cm^-2 s^-1.
RA(J2000) = 23h 47m 21.6s Dec(J2000) = +66d 47' 25.2"with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 97%.