Gamma-ray Burst 190515B

(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:     Wed 15 May 19 16:04:50 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     903845,   Seg_Num: 0
GRB_RA:           98.840d {+06h 35m 22s} (J2000),
                  99.226d {+06h 36m 54s} (current),
                  97.843d {+06h 31m 22s} (1950)
GRB_DEC:         +52.295d {+52d 17' 41"} (J2000),
                 +52.278d {+52d 16' 40"} (current),
                 +52.335d {+52d 20' 06"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3799 [cnts]    Image_Peak=212 [image_cnts]
TRIGGER_DUR:     2.048 [sec] 
TRIGGER_INDEX:   264     E_range: 25-100 keV
BKG_INTEN:       36583 [cnts]
BKG_TIME:        57825.09 SOD {16:03:45.09} UT
BKG_DUR:         24 [sec]
GRB_DATE:        18618 TJD;   135 DOY;   19/05/15
GRB_TIME:        57861.31 SOD {16:04:21.31} UT
GRB_PHI:         -87.68 [deg]
GRB_THETA:        25.55 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.41 [sigma]
IMAGE_SIGNIF:    9.98 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +2  +0  +0  +0 -65  +0 
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.90d {+18d 54' 16"}
SUN_DIST:         49.40 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.61d {+12h 54m 27s}   -0.33d {-00d 19' 35"}
MOON_DIST:        92.94 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.06, 18.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       96.17, 29.04 [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 = 0.68,0.36 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:06:28 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     903845,   Seg_Num: 0
GRB_RA:           98.8511d {+06h 35m 24.2s} (J2000),
                  99.2371d {+06h 36m 56.9s} (current),
                  97.8537d {+06h 31m 24.8s} (1950)
GRB_DEC:         +52.3184d {+52d 19' 06.2"} (J2000),
                 +52.3014d {+52d 18' 05.2"} (current),
                 +52.3588d {+52d 21' 31.8"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       43 [cnts]
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57943.74 SOD {16:05:43.74} UT,   82.4 [sec] since BAT Trigger Time
CENTROID_X:      296.59,  raw= 297  [pixels]
CENTROID_Y:      262.04,  raw= 262  [pixels]
ROLL:            245.39 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -85.68
GRB_POS_XRT_Z:   -23.11
IMAGE_URL:       sw00903845000msxps_rw.img
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.90d {+18d 54' 17"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.63d {+12h 54m 30s}   -0.33d {-00d 19' 57"}
MOON_DIST:        92.95 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.04, 18.84 [deg] galactic lon,lat of the burst
ECL_COORDS:       96.18, 29.07 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:06:27 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     903845,   Seg_Num: 0
GRB_RA:           98.8511d {+06h 35m 24.2s} (J2000),
                  99.2371d {+06h 36m 56.9s} (current),
                  97.8537d {+06h 31m 24.8s} (1950)
GRB_DEC:         +52.3184d {+52d 19' 06.2"} (J2000),
                 +52.3014d {+52d 18' 05.2"} (current),
                 +52.3588d {+52d 21' 31.8"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       43 [cnts]
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57943.74 SOD {16:05:43.74} UT,   82.4 [sec] since BAT Trigger Time
CENTROID_X:      296.59,  raw= 297  [pixels]
CENTROID_Y:      262.04,  raw= 262  [pixels]
ROLL:            245.39 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -85.68
GRB_POS_XRT_Z:   -23.11
IMAGE_URL:       sw00903845000msxps_rw.img
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.90d {+18d 54' 17"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.63d {+12h 54m 30s}   -0.33d {-00d 19' 57"}
MOON_DIST:        92.95 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.04, 18.84 [deg] galactic lon,lat of the burst
ECL_COORDS:       96.18, 29.07 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:06:12 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     903845,   Seg_Num: 0
GRB_RA:           98.8511d {+06h 35m 24.26s} (J2000),
                  99.2371d {+06h 36m 56.90s} (current),
                  97.8537d {+06h 31m 24.88s} (1950)
GRB_DEC:         +52.3184d {+52d 19' 06.2"} (J2000),
                 +52.3014d {+52d 18' 05.2"} (current),
                 +52.3588d {+52d 21' 31.8"} (1950)
GRB_ERROR:       5.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       7.78e-10 [erg/cm2/sec]
GRB_SIGNIF:      6.55 [sigma]
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57943.74 SOD {16:05:43.74} UT,   82.4 [sec] since BAT Trigger Time
TAM[0-3]:        327.65 237.18 261.64 243.35
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.90d {+18d 54' 16"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.62d {+12h 54m 30s}   -0.33d {-00d 19' 53"}
MOON_DIST:        92.94 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.04, 18.84 [deg] galactic lon,lat of the burst
ECL_COORDS:       96.18, 29.07 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.48 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:07:48 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     903845,   Seg_Num: 0
GRB_RA:           98.840d {+06h 35m 22s} (J2000),
                  99.226d {+06h 36m 54s} (current),
                  97.843d {+06h 31m 22s} (1950)
GRB_DEC:         +52.295d {+52d 17' 41"} (J2000),
                 +52.278d {+52d 16' 40"} (current),
                 +52.335d {+52d 20' 06"} (1950)
GRB_DATE:        18618 TJD;   135 DOY;   19/05/15
GRB_TIME:        57861.31 SOD {16:04:21.31} UT
TRIGGER_INDEX:   264
GRB_PHI:         -87.68 [deg]
GRB_THETA:        25.55 [deg]
DELTA_TIME:      57.00 [sec]
TRIGGER_DUR:     2.048 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.41 [sigma]
IMAGE_SIGNIF:    9.98 [sigma]
LC_URL:          sw00903845000msb.lc
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.90d {+18d 54' 17"}
SUN_DIST:         49.40 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.64d {+12h 54m 33s}   -0.34d {-00d 20' 15"}
MOON_DIST:        92.97 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.06, 18.82 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       96.17, 29.04 [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 = 0.68,0.36 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:09:36 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.876d {+06h 35m 30s} (J2000)
POINT_DEC:       +52.299d {+52d 17' 56"} (J2000)
POINT_ROLL:      245.386d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57953.71 SOD {16:05:53.71} UT,   92.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.171
N_STARS:         76
X_OFFSET:        612 [pixels]
Y_OFFSET:        671 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1630 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00903845000msufc0092.fits
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.91d {+18d 54' 18"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.65d {+12h 54m 37s}   -0.34d {-00d 20' 39"}
MOON_DIST:        92.96 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:09:55 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.876d {+06h 35m 30s} (J2000)
POINT_DEC:       +52.299d {+52d 17' 56"} (J2000)
POINT_ROLL:      245.386d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57953.71 SOD {16:05:53.71} UT,   92.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.171
N_STARS:         76
X_OFFSET:        612 [pixels]
Y_OFFSET:        671 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1630 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00903845000msufc0092.fits
SUN_POSTN:        52.19d {+03h 28m 45s}  +18.91d {+18d 54' 19"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.66d {+12h 54m 38s}   -0.35d {-00d 20' 43"}
MOON_DIST:        92.96 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [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:     Wed 15 May 19 16:11:19 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.876d {+06h 35m 30s} (J2000)
POINT_DEC:       +52.299d {+52d 17' 56"} (J2000)
ROLL:            245.386d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57953.71 SOD {16:05:53.71} UT,   92.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     579629176
X_OFFSET:        932 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1092
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw00903845000msuni0115.fits
SUN_POSTN:        52.19d {+03h 28m 46s}  +18.91d {+18d 54' 19"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.67d {+12h 54m 41s}   -0.35d {-00d 21' 02"}
MOON_DIST:        92.97 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:11:35 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.876d {+06h 35m 30s} (J2000)
POINT_DEC:       +52.299d {+52d 17' 56"} (J2000)
ROLL:            245.386d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  57953.71 SOD {16:05:53.71} UT,   92.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     579629176
X_OFFSET:        932 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1092
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw00903845000msuni0115.fits
SUN_POSTN:        52.19d {+03h 28m 46s}  +18.91d {+18d 54' 20"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.67d {+12h 54m 41s}   -0.35d {-00d 21' 06"}
MOON_DIST:        92.98 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.84 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #24553
M. J. Moss (George Washington University), C. Gronwall (PSU), J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), M. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 16:04:21 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 190515B (trigger=903845). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 98.840, +52.295 which is
```
   RA(J2000) = 06h 35m 22s
   Dec(J2000) = +52d 17' 41"
```
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 20 sec. The peak count rate was ~800 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 16:05:43.7 UT, 82.4 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 98.84892, 52.31725 which is equivalent to:
```
   RA(J2000)  = 06h 35m 23.74s
   Dec(J2000) = +52d 19' 02.1"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 82 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 1.27 x 10^21 cm^-2 (Willingale et al. 2013).
The initial flux in the 2.5 s image was 7.78e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 92 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 84% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.09.
Burst Advocate for this burst is M. J. Moss (mikejmoss3 AT gmail.com). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:18:25 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.880d {+06h 35m 31s} (J2000)
POINT_DEC:       +52.301d {+52d 18' 04"} (J2000)
POINT_ROLL:      245.391d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  58166.39 SOD {16:09:26.39} UT,   305.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.285
N_STARS:         45
X_OFFSET:        612 [pixels]
Y_OFFSET:        671 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1630 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00903845000msufc0305.fits
SUN_POSTN:        52.20d {+03h 28m 47s}  +18.91d {+18d 54' 24"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.74d {+12h 54m 56s}   -0.38d {-00d 22' 38"}
MOON_DIST:        93.03 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:18:43 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.880d {+06h 35m 31s} (J2000)
POINT_DEC:       +52.301d {+52d 18' 04"} (J2000)
POINT_ROLL:      245.391d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  58166.39 SOD {16:09:26.39} UT,   305.1 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.285
N_STARS:         45
X_OFFSET:        612 [pixels]
Y_OFFSET:        671 [pixels]
X_MAX:           1571 [pixels]
Y_MAX:           1630 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00903845000msufc0305.fits
SUN_POSTN:        52.20d {+03h 28m 47s}  +18.91d {+18d 54' 24"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.74d {+12h 54m 57s}   -0.38d {-00d 22' 42"}
MOON_DIST:        93.03 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [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:     Wed 15 May 19 16:19:49 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.880d {+06h 35m 31s} (J2000)
POINT_DEC:       +52.301d {+52d 18' 04"} (J2000)
ROLL:            245.391d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  58166.39 SOD {16:09:26.39} UT,   305.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     579629389
X_OFFSET:        932 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1092
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw00903845000msuni0328.fits
SUN_POSTN:        52.20d {+03h 28m 47s}  +18.91d {+18d 54' 24"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.75d {+12h 54m 59s}   -0.38d {-00d 22' 57"}
MOON_DIST:        93.04 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 15 May 19 16:20:04 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     903845,   Seg_Num: 0
POINT_RA:         98.880d {+06h 35m 31s} (J2000)
POINT_DEC:       +52.301d {+52d 18' 04"} (J2000)
ROLL:            245.391d
IMG_START_DATE:  18618 TJD;   135 DOY;   19/05/15
IMG_START_TIME:  58166.39 SOD {16:09:26.39} UT,   305.1 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     579629389
X_OFFSET:        932 [pixels]
Y_OFFSET:        991 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1092
Y_GRB_POS:       1151
BINNING_INDEX:   1
IM_URL:          sw00903845000msuni0328.fits
SUN_POSTN:        52.20d {+03h 28m 47s}  +18.91d {+18d 54' 25"}
SUN_DIST:         49.42 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      193.75d {+12h 55m 00s}   -0.38d {-00d 23' 01"}
MOON_DIST:        93.05 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:      163.07, 18.85 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       96.20, 29.05 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN Circular #24554
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 190515B, we find an enhanced XRT position of the afterglow: RA, Dec: 98.8489, 52.3168 which is equivalent to:
```
   RA (J2000)  = 06 35 23.73
   Dec (J2000) = +52 19 00.4
```
with an uncertainty of 2.2 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/903845.
Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular #24555
M. J. Moss (GWU) reports on behalf of the Swift team:
The GRB name reported in M. J. Moss et al. GCN Circ. #24553 (Swift trigger number: 903845) should be GRB 190515B.
We apologize for any confusion caused.
GCN Circular #24556
S. Belkin (IKI), A. Novichonok (KIAM), A. Pozanenko (IKI), E. Mazaeva (IKI), A. Volnova (IKI), I. Molotov (KIAM) report on behalf of larger IKI GRB FuN collaboration:
We observed the field of the Swift GRB 190515B (Moss et al., GCN 24553) with RC-36 0.36-m telescope of Kitab Observatory starting on May 15 (UT) 16:13:02 in Clear filter. We do not find any optical source neither in the first image, nor in a stacked image within prompt enhanced Swift-XRT position (Evans et al., GCN 24554). Preliminary photometry of the field is following.
```
Date       UT start   t-T0       Filter Exp.   OT  Err.   UL(3sigma)
                       (mid, days)        (s)

2019-05-15 16:13:02   0.00655    CR     1*90   n/d  n/d       18.6
2019-05-15 16:13:02   0.02686    CR    40*90   n/d  n/d       20.3
```
The photometry is based on the nearby USNO-B1 (R2) star:
```
USNO-B1.0_id R2
1422-0205150 15.02
```
The closest object which is not presented in any catalogs marginally detected in our stacked image has coordinates (J2000) 06:35:24.07 +52:19:12.4 with uncertainty of 1 arcsec in both coordinates and brightness of 20.4m (S/N =2). The position of the object is 12 arcsec apart from the the center of prompt enhanced Swift-XRT position (Evans et al., GCN 24554). At this time we cannot say about variability of the object.
GCN Circular #24557
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 611 s of XRT Photon Counting mode data and 1 UVOT images for GRB 190515B, 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 = 98.84772, +52.31665 which is equivalent to:
```
RA (J2000): 06h 35m 23.45s
Dec (J2000): +52d 18' 59.9"
```
with an uncertainty of 2.3 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 #24557
A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), M. Blazek, L. Izzo, C.C. Thoene, D.A. Kann, K. Bensch (all HETH/IAA-CSIC), A. Sota (IAA-CSIC) report:
We observed the field of GRB 190515B (Moss et al. GCN 24553) with the 1.5m OSN telescope, at Sierra Nevada Observatory (Granada, Spain). The observation started at 21:13 UT (5.15 hr after the burst) when clouds over the observatory allowed, at an airmass of 2, and consisted of 3x300s exposures in I-band.
No new object is detected within the refined XRT error circle (Osborne et al. GCN 24557) down to a 3-sigma limit of I(AB) = 20.5 mag, as compared to stars of the PanSTARRS catalogue.
GCN Circular #24560
D. Kocevski (NASA/MSFC), M. Axelsson (KTH and Stockholm Univ.), L. Scotton (INFN Torino), E. Burns (NASA/GSFC), and M. Arimoto (Kanazawa Univ.) report on behalf of the Fermi-LAT team:
At 04:33:03 on 2019-05-15, Fermi-LAT triggered on high-energy emission from short GRB 190515B, which was also detected by Fermi-GBM (trigger 579587588/190515190).
The best LAT on-ground location is found to be
RA, Dec = 137.687 , 29.276 (J2000)
with an error radius of 0.907 deg (90% containment, statistical error only). This was 44 deg from the LAT boresight at the time of the trigger and 10 deg from the center of the GBM localization (GCN 24550).
The data from the Fermi-LAT show a significant increase in the event rate that is temporally correlated with the GBM emission with high significance. The highest-energy photon is a 874 MeV event which is observed 3 seconds after the GBM trigger.
The photon flux above 100 MeV in the time interval 0-300s after the GBM trigger is 6.5e-06 ph/cm2/s +/- 2.4e-06. The estimated photon index above 100 MeV is -2.6 +/- 0.5.
The Fermi-LAT point of contact for this burst is Magnus Axelsson (magnusa@fysik.su.se).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #24561
A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A. Tohuvavohu (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester) and report on behalf of the Swift-XRT team: report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 190515B, from 88 s to 27.5 ks after the BAT trigger. The data comprise 66 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 24557).
The light curve can be modelled with an initial power-law decay with an index of alpha=3.85 (+0.26, -0.23), followed by a break at T+296 s to an alpha of 0.38 (+0.11, -0.12).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.26 (+0.33, -0.30). The best-fitting absorption column is 2.1 (+0.6, -0.5) x 10^21 cm^-2, in excess of the Galactic value of 1.3 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.06 (+0.24, -0.15) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.3 x 10^-11 (4.3 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:        1.3 (+0.6, -0.0) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:        2.06 (+0.24, -0.15)
```
If the light curve continues to decay with a power-law decay index of 0.38, the count rate at T+24 hours will be 0.027 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.0 x 10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00903845.
This circular is an official product of the Swift-XRT team.
GCN Circular #24564
H. A. Krimm (NSF), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), M. J. Moss (GWU), 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-239 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 190515B (trigger #903845) (Moss et al., GCN Circ. 24553). The BAT ground-calculated position is RA, Dec = 98.826, 52.322 deg which is
```
   RA(J2000)  =  06h 35m 18.3s
   Dec(J2000) = +52d 19' 17.6"
```
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 67%.
The mask-weighted light curve shows a single-pulse structure that starts at ~T-30 s, peaks at ~T0, and ends at ~T+30 s. T90 (15-350 keV) is 46.4 +- 12.3 sec (estimated error including systematics).
The time-averaged spectrum from T-30.84 to T+31.02 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.74 +- 0.15. The fluence in the 15-150 keV band is 1.6 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T-0.39 sec in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/903845/BA/
GCN Circular #24567
Y.-D. Hu, X.-Y. Li, E. Fernandez-Garcia, A. Ayala, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), S. Guziy (Univ. of Nikolaev), D. Xiong, Y. Fan, X. Zhao, J. Bai, C. Wang, Y. Xin, J. Mao (Yunnan Nacional Astronomical Observatory), A. Fernandez and I. Hermelo (CAHA), on behalf of a larger collaboration, report:
Following the detection of GRB 190515B by Swift (Moss et al. GCNC 24553), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) automatically responded gathering 9 frames (g’ filter, 30s exposures) starting at 16:10:44UT (0.11 hr after trigger). In addition, 23 frames at the 2.2m Calar Alto telescope equipped with CAFOS (I-band, 120s exposures) were taken starting at 20:45:41 UT (4.69 h post burst). On the co-added images, no optical afterglow is found down to 18.9 mag (g-band) or 22.1 (I-band) respectively at the enhaced XRT position (Evans et al. GCNC 24554), in agreement with Belkin et al. (GCNC 24556) and de Ugarte Postigo et al. (GCNC 24558). Particularly the Calar Alto co-add I-band frame does not detect the marginal object reported in GCNC 24556.
We thank the CAHA staff for excellent support.
GCN Circular #24568
M. H. Siegel (PSU) and M. J. Moss (George Washington University) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 190515B 93 s after the BAT trigger (Moss et al., GCN Circ. 24553). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 24557) 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            93          242          147         >19.9
u_FC               305          555          246         >19.4
white               93          605          167         >20.0
v                  636         4442          216         >18.9
b                  561          754           39         >18.7
u                  305          730          265         >19.5
w1                 685         4722           88         >18.9
m2                 661         4647          216         >19.6
w2                 612         4237          216         >19.0
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.09 in the direction of the burst (Schlegel et al. 1998).

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Jochen Greiner, last update: 17-May-2019 [Disclaimer]