Gamma-ray Burst 191019A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 15:12:47 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     930285,   Seg_Num: 0
GRB_RA:          340.038d {+22h 40m 09s} (J2000),
                 340.304d {+22h 41m 13s} (current),
                 339.367d {+22h 37m 28s} (1950)
GRB_DEC:         -17.333d {-17d 19' 59"} (J2000),
                 -17.230d {-17d 13' 45"} (current),
                 -17.594d {-17d 35' 39"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       1303 [cnts]    Image_Peak=142 [image_cnts]
TRIGGER_DUR:     0.256 [sec] 
TRIGGER_INDEX:   39     E_range: 25-100 keV
BKG_INTEN:       21338 [cnts]
BKG_TIME:        54744.22 SOD {15:12:24.22} UT
BKG_DUR:         8 [sec]
GRB_DATE:        18775 TJD;   292 DOY;   19/10/19
GRB_TIME:        54753.63 SOD {15:12:33.63} UT
GRB_PHI:         -170.50 [deg]
GRB_THETA:        44.49 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     24.18 [sigma]
IMAGE_SIGNIF:    10.94 [sigma]
MERIT_PARAMS:     +1  +0  +0  -2  +2  +0  +0  +0 +62  +0 
SUN_POSTN:       204.06d {+13h 36m 14s}  -10.02d {-10d 01' 14"}
SUN_DIST:        128.89 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       92.69d {+06h 10m 46s}  +22.68d {+22d 40' 33"}
MOON_DIST:       116.73 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.94,-58.19 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      335.05, -8.26 [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 = 163.79,12.83 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 15:16:37 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     930285,   Seg_Num: 0
GRB_RA:          340.038d {+22h 40m 09s} (J2000),
                 340.304d {+22h 41m 13s} (current),
                 339.367d {+22h 37m 28s} (1950)
GRB_DEC:         -17.333d {-17d 19' 59"} (J2000),
                 -17.230d {-17d 13' 45"} (current),
                 -17.594d {-17d 35' 39"} (1950)
GRB_DATE:        18775 TJD;   292 DOY;   19/10/19
GRB_TIME:        54753.63 SOD {15:12:33.63} UT
TRIGGER_INDEX:   39
GRB_PHI:         -170.50 [deg]
GRB_THETA:        44.49 [deg]
DELTA_TIME:      19.00 [sec]
TRIGGER_DUR:     0.256 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     24.18 [sigma]
IMAGE_SIGNIF:    10.94 [sigma]
LC_URL:          sw00930285000msb.lc
SUN_POSTN:       204.06d {+13h 36m 14s}  -10.02d {-10d 01' 18"}
SUN_DIST:        128.89 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       92.73d {+06h 10m 55s}  +22.68d {+22d 40' 42"}
MOON_DIST:       116.77 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.94,-58.19 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      335.05, -8.26 [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 = 163.79,12.83 [deg].

GCN Circular #26031
K. K. Simpson (PSU), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), A. Y. Lien (GSFC/UMBC), K. L. Page (U Leicester), D. M. Palmer (LANL) and A. Tohuvavohu (Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
At 15:12:33 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 191019A (trigger=930285). Swift did not slew due to an observing constraint. The BAT on-board calculated location is RA, Dec 340.038, -17.333, which is
```
   RA(J2000)  =  22h 40m 09s
   Dec(J2000) = -17d 19' 59"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows multiple peaks in a FRED envelope with a total duration of about 80 sec. The peak count rate was ~4500 counts/sec (15-350 keV), at ~4 sec after the trigger.
Due to an observing constraint, Swift will not slew until T0+51.6 minutes. There will be no XRT or UVOT data until this time.
Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 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 Circular #26032
V. Lipunov, N.Tiurina, E. Gorbovskoy, V.Kornilov, F.Balakin,P.Balanutsa,A.Kuznetsov, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov,V.Senik, T.Pogrosheva, K.Pozdnyakov,A.Chasovnikov, V.Topolev, D.Kuvshinov(Lomonosov Moscow State University, SAI,Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico FelixAguilar OAFA), H.Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), D. Buckley(South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova(Irkutsk State University, API), A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk Educational StateUniversity)
MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, v.2010, 30L) started Swift GRB191019A (Simpson et al. GCN26031 , BAT, RA,Dec= RA(J2000) = 22h 40m 09s, -17d 19' 59") observations at 2019-10-19 15:13:14Ut with exp. 10s, but sun altitude=-10. The first image with mlim=15.0 made at 2019-10-19 15:23:59UT.
Real time updated cover map and possibly OT, that can be discovered, will be available here: https://master.sai.msu.ru/site/master2/event.php?id=1171578
The observation and reduction will be continued. The message may be cited.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 16:06:17 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     930285,   Seg_Num: 0
POINT_RA:        339.998d {+22h 39m 59s} (J2000)
POINT_DEC:       -17.355d {-17d 21' 18"} (J2000)
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  57964.53 SOD {16:06:04.53} UT,   3210.9 [sec] since BAT Trigger Time
COUNTS:          2    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 19 Oct 19 16:11:20 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     930285,   Seg_Num: 0
POINT_RA:        339.997d {+22h 39m 59s} (J2000)
POINT_DEC:       -17.358d {-17d 21' 29"} (J2000)
POINT_ROLL:      241.165d
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  58048.03 SOD {16:07:28.03} UT,   3294.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.415
N_STARS:         25
X_OFFSET:        191 [pixels]
Y_OFFSET:        733 [pixels]
X_MAX:           1150 [pixels]
Y_MAX:           1692 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    11
SL_URL:          sw00930285000msufc3294.fits
SUN_POSTN:       204.10d {+13h 36m 23s}  -10.04d {-10d 02' 07"}
SUN_DIST:        128.80 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       93.27d {+06h 13m 05s}  +22.71d {+22d 42' 47"}
MOON_DIST:       117.31 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.87,-58.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.00, -8.27 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 16:10:17 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     930285,   Seg_Num: 0
GRB_RA:          340.0248d {+22h 40m 05.95s} (J2000),
                 340.2901d {+22h 41m 09.62s} (current),
                 339.3539d {+22h 37m 24.93s} (1950)
GRB_DEC:         -17.3284d {-17d 19' 42.2"} (J2000),
                 -17.2247d {-17d 13' 29.0"} (current),
                 -17.5895d {-17d 35' 22.1"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  58009.00 SOD {16:06:49.00} UT,   3255.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       204.09d {+13h 36m 23s}  -10.04d {-10d 02' 06"}
SUN_DIST:        128.84 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       93.26d {+06h 13m 02s}  +22.71d {+22d 42' 45"}
MOON_DIST:       117.27 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.94,-58.18 [deg] galactic lon,lat of the burst
ECL_COORDS:      335.04, -8.25 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 16:11:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     930285,   Seg_Num: 0
POINT_RA:        339.997d {+22h 39m 59s} (J2000)
POINT_DEC:       -17.358d {-17d 21' 29"} (J2000)
POINT_ROLL:      241.165d
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  58048.03 SOD {16:07:28.03} UT,   3294.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.415
N_STARS:         25
X_OFFSET:        191 [pixels]
Y_OFFSET:        733 [pixels]
X_MAX:           1150 [pixels]
Y_MAX:           1692 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    11
SL_URL:          sw00930285000msufc3294.fits
SUN_POSTN:       204.10d {+13h 36m 23s}  -10.04d {-10d 02' 07"}
SUN_DIST:        128.80 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       93.27d {+06h 13m 06s}  +22.71d {+22d 42' 48"}
MOON_DIST:       117.32 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.87,-58.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.00, -8.27 [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 19 Oct 19 16:11:50 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     930285,   Seg_Num: 0
GRB_RA:          340.0242d {+22h 40m 05.80s} (J2000),
                 340.2895d {+22h 41m 09.48s} (current),
                 339.3533d {+22h 37m 24.78s} (1950)
GRB_DEC:         -17.3292d {-17d 19' 45.1"} (J2000),
                 -17.2255d {-17d 13' 31.8"} (current),
                 -17.5903d {-17d 35' 25.0"} (1950)
GRB_ERROR:       3.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  58009.00 SOD {16:06:49.00} UT,   3255.4 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       204.10d {+13h 36m 23s}  -10.04d {-10d 02' 08"}
SUN_DIST:        128.84 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       93.28d {+06h 13m 06s}  +22.71d {+22d 42' 49"}
MOON_DIST:       117.28 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.94,-58.18 [deg] galactic lon,lat of the burst
ECL_COORDS:      335.04, -8.25 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 16:13:59 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     930285,   Seg_Num: 0
POINT_RA:        339.997d {+22h 39m 59s} (J2000)
POINT_DEC:       -17.358d {-17d 21' 29"} (J2000)
ROLL:            241.165d
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  58048.03 SOD {16:07:28.03} UT,   3294.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     593194071
X_OFFSET:        510 [pixels]
Y_OFFSET:        1052 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       670
Y_GRB_POS:       1212
BINNING_INDEX:   1
IM_URL:          sw00930285000msuni3318.fits
SUN_POSTN:       204.10d {+13h 36m 23s}  -10.04d {-10d 02' 10"}
SUN_DIST:        128.80 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       93.30d {+06h 13m 11s}  +22.71d {+22d 42' 53"}
MOON_DIST:       117.34 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.87,-58.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.00, -8.27 [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).  
COMMENTS:        This notice was forced out after watchdog timer expiring -- most likely due to missing packet(s);  
COMMENTS:        as a consequence some of the fields may be incoorect (eg TRIGGER_NUM,RA,DEC).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 19 Oct 19 16:14:15 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     930285,   Seg_Num: 0
POINT_RA:        339.997d {+22h 39m 59s} (J2000)
POINT_DEC:       -17.358d {-17d 21' 29"} (J2000)
ROLL:            241.165d
IMG_START_DATE:  18775 TJD;   292 DOY;   19/10/19
IMG_START_TIME:  58048.03 SOD {16:07:28.03} UT,   3294.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     593194071
X_OFFSET:        510 [pixels]
Y_OFFSET:        1052 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       670
Y_GRB_POS:       1212
BINNING_INDEX:   1
IM_URL:          sw00930285000msuni3318.fits
SUN_POSTN:       204.10d {+13h 36m 23s}  -10.04d {-10d 02' 10"}
SUN_DIST:        128.80 [deg]   Sun_angle= -9.1 [hr] (East of Sun)
MOON_POSTN:       93.30d {+06h 13m 12s}  +22.71d {+22d 42' 54"}
MOON_DIST:       117.34 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:       43.87,-58.16 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      335.00, -8.27 [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.  
COMMENTS:        This notice was forced out after watchdog timer expiring -- most likely due to missing packet(s);  
COMMENTS:        as a consequence some of the fields may be incoorect (eg TRIGGER_NUM,RA,DEC).

GCN Circular #26033
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University)
MASTER-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB191019.63 (trigger No 930285,22h 40m 09.120s , -17d 19m 58.80s, R=0.05) errorbox 610 sec after notice time and 685 sec after trigger time at 2019-10-19 15:23:59 UT, with upper limit up to 18.2 mag. Observations started at twilight. The observations began at zenit distance = 70 deg. The sun altitude is -11.9 deg.
The galactic latitude b = -60 deg., longitude l = 98 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1171584
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     756 |   MASTER-Kislovodsk |  P| |   140 | 14.9 |        
     921 |   MASTER-Kislovodsk |  P| |   170 | 17.3 |        
    1107 |   MASTER-Kislovodsk |  P- |   180 | 17.4 |        
    1107 |   MASTER-Kislovodsk |  P| |   180 | 17.8 |        
    1311 |   MASTER-Kislovodsk |  P- |   180 | 17.7 |        
    1311 |   MASTER-Kislovodsk |  P| |   180 | 18.0 |        
    1515 |   MASTER-Kislovodsk |  P- |   180 | 17.8 |        
    1515 |   MASTER-Kislovodsk |  P| |   180 | 18.1 |        
    1720 |   MASTER-Kislovodsk |  P- |   180 | 17.7 |        
    1720 |   MASTER-Kislovodsk |  P| |   180 | 18.0 |        
    1924 |   MASTER-Kislovodsk |  P- |   180 | 17.9 |        
    1924 |   MASTER-Kislovodsk |  P| |   180 | 18.1 |        
    2135 |   MASTER-Kislovodsk |  P- |   180 | 18.0 |        
    2135 |   MASTER-Kislovodsk |  P| |   180 | 18.2 |        
    2348 |   MASTER-Kislovodsk |  P| |   180 | 18.2 |        
    2348 |   MASTER-Kislovodsk |  P- |   180 | 18.0 |        
    2553 |   MASTER-Kislovodsk |  P- |   180 | 17.9 |        
    2553 |   MASTER-Kislovodsk |  P| |   180 | 18.1 |        
```
The observation and reduction will continue. The message may be cited.
GCN Circular #26034
P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), S. Campana (INAF-OAB) and G. Cusumano (INAF-IASF PA) report on behalf of the Swift-XRT team:
The XRT began observing the field of GRB 191019A at 16:06:04.5 UT, 3210.9 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source with an enhanced position: RA, Dec 340.0244, -17.3286 which is equivalent to:
```
   RA(J2000)  = 22h 40m 05.86s
   Dec(J2000) = -17d 19' 42.9"
```
with an uncertainty of 3.1 arcseconds (radius, 90% containment). This location is 49 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 in excess of the Galactic value (3.28 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.5 (+2.44/-3.29) x 10^22 cm^-2 (90% confidence).
GCN Circular #26036
I. Reva (FAPHI), A. Pozanenko (IKI), M. Krugov (FAPHI), S. Belkin (IKI), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of IKI-GRB-FuN:
We observed the field of GRB 191019A (Simpson et al. GCN 26031) with Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on Oct. 19 (UT) 15:26:32, i.e. 14 minutes after GRB trigger. Within XRT error circle (Evans et al., GCN 26034) we found only one source which is presented in catalogs. Preliminary photometry of the source is following.
```
Date       UT start t-T0    Filter  Exp. OT    Err.
                     (mid, days)     (s)

2019-10-19 15:26:32 0.013877  R     720 18.37  0.03
```
The photometry is based nearby USNO-B1.0 stars.
The brightness of the catalogued source is R2(USNO-B1.0 340.024514480) = 19.36 and r'(Pan-STARRS 0726-1153339) = 19.30. The source is probably a host galaxy of GRB 191019A and we suggest the afterglow of the source on a top of the host galaxy.
GCN Circular #26039
D. A. Perley (LJMU), D. B. Malesani (DTU Space), A. de Ugarte Postigo (HETH, IAA/CSIC; DARK/NBI), D. Xu (NAO/CAS), J. P. U. Fynbo (DAWN/NBI), K. E. Heintz (Univ. Iceland), and N. E. Jannsen (NOT) report on behalf of a larger collaboration:
We observed the field of GRB 191019A (Simpson et al., GCN 26031) with the Nordic Optical Telescope (NOT) equipped with the ALFOSC imaging camera. Observations started on 2019 Oct 19.822 UT (4.52 hr after the trigger).
In a single 120 s image taken in the SDSS i band, we detect the object mentioned by Reva et al. (GCN 26036), which is also visible in the Pan-STARRS archival images and is consistent with the X-ray position (Evans et al., GCN 26034). The target is clearly extended (FWHM 1.4" with a seeing of 1.1").
The object centroid has coordinates (J2000, calibrated against the Gaia catalog):
```
RA  =  22:40:05.89
Dec = -17:19:42.7
```
Measuring its magnitude over an aperture of 1.7" radius, we obtain i = 18.66 +/- 0.01 AB (statistical error), compared to i = 18.71 +/- 0.01 from the Pan-STARRS catalog (Chambers et al. 2015, arXiv:1612.05560), confirmed by our own measurement on the i-band Pan-STARRS image. The small flux difference may be due to calibration, color effects, or variable aperture correction, so we do not claim any afterglow detection. A conservative limit on the afterglow magnitude at the time of our observation would be i > 21.
We note the elevated column density measured in a preliminary analysis of the X-ray spectra (Evans et al., GCN 26034). This may suggest a dust-obscured event.
GCN Circular #26041
J. P. U. Fynbo (DAWN/NBI), D. A. Perley (LJMU), A. de Ugarte Postigo (HETH/IAA-CSIC; DARK/NBI), D. B. Malesani (DTU Space), N. E. Jannsen (NOT), report on behalf of a larger collaboration:
Spectroscopy was secured of the optical counterpart (Reva et al., GCN 26036; Perley et al., GCN 26039) of GRB 191019A (Simpson et al., GCN 26031), using the ALFOSC instrument mounted on the Nordic Optical Telescope (NOT). Observations started on 2019 Oct 19.873 UT (5.74 hr after the GRB), for a total of 2x1800 s exposure.
Our spectrum, secured with grism #4, covers the approximate wavelength range 3500-9400 AA. The continuum is well detected. No prominent emission lines are visible. However, several absorption features can be identified, including Ca H & K, Na I D, Hdelta, Hgamma, Hbeta, G band, all at a common redshift z = 0.248. The 4000 AA break is also present.
The spectrum is typical of an old stellar population, and is unlike that of long-duration GRB host galaxies. The association of this object with GRB 191019A is therefore unclear.
Using the formula by Bloom et al. (2002, AJ, 123, 1111), the chance association probability for a source with magnitude r = 19.14 AB (from the Pan-STARRS catalog) and an error circle radius of 3.1" (Evans et al., GCN 26034) is approximately 3*10^-3.
GCN Circular #26042
A. Nicuesa Guelbenzu (TLS Tautenburg) reports:
GROND (Greiner et al. 2008, PASP 120, 405) performed a first visit of the field of GRB 191019A (Swift trigger 930285; Simpson et al., GCN 26031) at 01:35 UT on 2019-10-20, about 10.3 hours after the burst. Observations were performed at an airmass of 1.02 and a seeing of 2.0 arcsec. Second-epoch observations started at 05:10 UT on the same night (airmass 1.75, seeing 1.7 arcsec).
The potential afterglow plus host-galaxy complex is clearly detected. Between the 1st and the 2nd-epoch observations there is no evidence for fading in any band (g'r'i'z' as well as in JHKs). The GROND r'(AB = 19.14 +/- 0.01) and i' (AB = 18.73 +/- 0.01) magnitudes are in agreement with the NOT observations and the Pan-STARRS catalog (Perley et al., GCN 26039; Fynbo et al., GCN 26041).
I acknowledge the excellent support from Sam Kim on La Silla in acquiring these observations
GCN Circular #26043
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 616 s of XRT Photon Counting mode data and 2 UVOT images for GRB 191019A, 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 = 340.02470, -17.32803 which is equivalent to:
```
RA (J2000): 22h 40m 5.93s
Dec (J2000): -17d 19' 40.9"
```
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 #26045
A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), J. D. Gropp (PSU), A. Tohuvavohu (U. Toronto), J.A. Kennea (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and K.K. Simpson report on behalf of the Swift-XRT team:
We have analysed 3.9 ks of XRT data for GRB 191019A (Simpson et al. GCN Circ. 26031), from 3.3 ks to 17.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 26043). The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00930285.
This circular is an official product of the Swift-XRT team.
GCN Circular #26046
H. A. Krimm (NSF), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), K. K. Simpson (PSU), 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 191019A (trigger #930285) (Simpson et al., GCN Circ. 26031). The BAT ground-calculated position is RA, Dec = 340.035, -17.340 deg which is
```
   RA(J2000)  =  22h 40m 08.3s
   Dec(J2000) = -17d 20' 23.9"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%.
The mask-weighted light curve shows a complex structure with many overlapping pulses that starts at ~T0 and ends at ~T+90 s. The burst went out of the BAT FOV at ~T+400 s. T90 (15-350 keV) is 64.35 +- 4.45 sec (estimated error including systematics).
The time-averaged spectrum from T-0.83 to T+84.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.25 +- 0.05. The fluence in the 15-150 keV band is 1.0 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T-0.14 sec in the 15-150 keV band is 5.7 +- 0.4 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/930285/BA/
GCN Circular #26048
B. Sbarufatti (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester) and K.K. Simpson (PSU) report on behalf of the Swift-XRT team:
We have analyzed 8.5 ks of XRT data for GRB 191019a (Simpson et al. GCN Circ. 26031), from 3.3 ks to 32.4 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN Circ. 26043).
The light curve can be modeled with a power-law decay with a decay index of alpha=1.0 (+/-0.2).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.0 (+/- 0.40). The best-fitting absorption column is consistent with the Galactic value of 3.3 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total intrinsic column:	    < 2.23 x 10^21 cm^-2
Galactic foreground: 3.3 x 10^20 cm^-2
Photon index:	    2.0 (+/- 0.4)
```
If the light curve continues to decay with a power-law decay index of 1.0, the count rate at T+48 hours will be 1.2 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.1 x 10^-14 (4.9 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00930285/.
This circular is an official product of the Swift-XRT team.
GCN Circular #26053
GRB 191019A: Swift/UVOT Detection
S. J. LaPorte (PSU) and K. K. Simpson (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 191019A 3294 s after the BAT trigger (Simpson et al., GCN Circ. 26031). A fading source consistent with the XRT position (Evans et al. GCN Circ. 26034) is detected in the initial UVOT exposures.
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

b               4541          4741             196           19.55+-0.30
uvm2        5361          5561             196              >19.20
u               4336          4536             196              >19.43
v               5156          5356              196             >18.75
uvw1        4131          4331              196              >19.13
uvw2        4952          5151              196              >19.28
white        4746          4946              196                19.66+-0.20

white      27982        28668              668                20.27+-0.18
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998). Additionally, these magnitudes likely include a contribution from the probable host-galaxy, as reported by TSHAO (Reva et al., GCN Circ. 26036), NOT (Fynbo et al., GCN Circ. 26041), and GROND (Guelbenzu et al. GCN Circ. 26042).
GCN Circular #26059
Z.P. Zhu, B.Y. Yu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School) report:
We observed the field of GRB 191019A (Simpson et al., GCN 26031) using the 0.6m NEXT telescope located at Nanshan, Xinjiang, China. Observations started at 15:34:01 UT (i.e., 21.5 min after the BAT trigger) and ended at 18:22:51 UT on 2019-10-19, and a series of 60 s, 200 s, 300 s Sloan r-band frames were obtain in a high airmass.
A source is detected in our images at the XRT position (Osborne et al., GCN 26043), which is already present in Pan-STARRS with m(r) = 19.12 +/- 0.01. The source had m(r) = 18.96 +/- 0.10 at the beginning and decayed to m(r) = 19.19 +/- 0.10 in about an hour. Because the flux difference is small and observations were carried out in high airmass, it's not clear if there is a GRB afterglow contribution. Our measurements are in agreement with that by NOT (Perley et al., GCN 26039; Fynbo et al., GCN 26041) and GROND (Guelbenzu et al., GCN 26042).
GCN Circular #26062
D. A. Perley (LJMU), D. B. Malesani (DTU Space), A. J. Levan (Radboud Univ.), J. P. U. Fynbo (DAWN/NBI), and A. A. Djupvik (NOT) report on behalf of a larger collaboration:
We obtained additional observations of the optical counterpart (Reva et al., GCN 26036; LaPorte & Simpson, GCN 26053; Zhu et al., GCN 26059) of GRB 191019A (Simpson et al., GCN 26031), using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. A total of 25 minutes exposure was secured with mid time Oct 22.875 UT (77.8 hr after the GRB).
The archival object consistent with the XRT error circle is well detected, with a magnitude of i = 18.71 +/- 0.02 AB, consistent with the Pan-STARRS tabulated value of i = 18.71 +/- 0.01 and slightly fainter than our earlier observation (Perley et al., GCN 26039), for which the mid time was 4.60 hr after the GRB.
Digital image subtraction was carried out with ISIS (Alard 2000, A&AS, 144, 363) between the two epochs. A clear point-like residual is detected, for which we measure a magnitude i = 21.78 +/- 0.05 AB (assuming no residual flux in our second epoch). Its position calibrated against the Gaia catalog is:
```
RA(J2000) = 22:40:05.89
Dec(J2000) = -17:19:42.6
```
(+/- 0.3")
An image showing the subtraction result is available here: http://outer.space.dtu.dk/~dmales/GRB/191019A/subtraction.jpg
The transient location is 0.07" east of the galaxy nucleus, strengthening the case for a physical association between the two objects. The offset is within the margin of error, although the NOT spectroscopy (Fynbo et al., GCN 26041) does not suggest that the source is an AGN.
Our observations thus confirm the presence of a transient optical source at a position consistent with the X-ray afterglow, located to within the errors on top of the nucleus of the candidate host. The lack of any non-obscured star formation makes this system unique among long-duration GRBs.
We encourage observations of this puzzling source at all wavelengths.
GCN Circular #26098
B. Gendre (OzGrav-UWA), H. Crisp (OzGrav-UWA), D. Coward (OzGrav-UWA), J. Zadko (Claire Energy), J. A. Moore (OzGrav-UWA), A. Burrell (OzGrav-UWA), A. Klotz (IRAP-OMP-UPS), P. Thierry (Auragne Observatory), E.J. Howell (OzGrav-UWA), A. Verveer (ASA), J. Kennewell (UWA, ASA)
report:
We observed GRB 191019A (Simpson et al., GCN 26031) with the Zadko Telescope (Coward et al. 2017), starting at 2019 October the 19th at 15:20:23 UT (7 minutes 50 seconds after the trigger) under fair conditions.
The object reported by Reva et al. (GCN 26036) is clearly visible in our images. However, we measure an R magnitude of 18.92 at the time reported by the GCN. Observations stopped one hour twenty three minutes after the burst, and during that time we do not see any variation on the light curve, similar to other teams (Perley et al., GCN 26039; Fynbo et al., GCN 26041; and Zhu et al., GCN 26059). At that position, the USNO catalog reports a source of magnitude R = 19.0, consistent with our findings. We conclude that this object is not the afterglow of GRB 191019A, but the host galaxy, as reported by Perley et al. (GCN 26062).
The Zadko Telescope has been under refurbishment during the last year, and is still in recommissioning mode. This message can be cited.

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Jochen Greiner, last update: 30-Oct-2019 [Disclaimer]