Gamma-ray Burst 201209A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:45:06 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1011980,   Seg_Num: 0
GRB_RA:           23.106d {+01h 32m 25s} (J2000),
                  23.373d {+01h 33m 29s} (current),
                  22.469d {+01h 29m 52s} (1950)
GRB_DEC:          -1.763d {-01d 45' 47"} (J2000),
                  -1.656d {-01d 39' 21"} (current),
                  -2.020d {-02d 01' 11"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5077 [cnts]    Image_Peak=195 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   155     E_range: 50-350 keV
BKG_INTEN:       20977 [cnts]
BKG_TIME:        20677.87 SOD {05:44:37.87} UT
BKG_DUR:         8 [sec]
GRB_DATE:        19192 TJD;   344 DOY;   20/12/09
GRB_TIME:        20692.53 SOD {05:44:52.53} UT
GRB_PHI:         169.30 [deg]
GRB_THETA:        50.83 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     43.24 [sigma]
IMAGE_SIGNIF:    10.19 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +3  +0  +0  +0 +53  +0 
SUN_POSTN:       256.54d {+17h 06m 10s}  -22.86d {-22d 51' 32"}
SUN_DIST:        122.75 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.21d {+12h 20m 51s}   +3.32d {+03d 19' 13"}
MOON_DIST:       161.78 [deg]
MOON_ILLUM:      37 [%]
GAL_COORDS:      145.82,-62.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       20.71,-10.62 [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 = 178.88,19.98 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Wed 09 Dec 20 05:45:38 UT
NOTICE_TYPE:    INTEGRAL SPI ACS Trigger
TRIGGER_NUM:    8887,   Sub_Num: 0
GRB_INTEN:      10.07 [sigma]  
GRB_TIME:       20692.75 SOD {05:44:52.75} UT
GRB_DATE:       19192 TJD;   344 DOY;   20/12/09
COMMENTS:       INTEGRAL SPI_ACS GRB Trigger.
COMMENTS:       Time_Scale=0.2000 and Time_Error=0.1000.
COMMENTS:
COMMENTS:       NOTE: This SPIACS event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=1011980).
COMMENTS:
COMMENTS:       The SPIACS lightcurve can be found at:
COMMENTS:       ftp://isdcarc.unige.ch/arc/FTP/ibas/spiacs/2020-12/2020-12-09T05-44-52.6091-17836-02960-0.lc

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:47:23 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
GRB_RA:           23.0916d {+01h 32m 21.9s} (J2000),
                  23.3585d {+01h 33m 26.0s} (current),
                  22.4546d {+01h 29m 49.1s} (1950)
GRB_DEC:          -1.7523d {-01d 45' 08.2"} (J2000),
                  -1.6452d {-01d 38' 42.6"} (current),
                  -2.0090d {-02d 00' 32.4"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       30 [cnts]
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20804.16 SOD {05:46:44.16} UT,   111.6 [sec] since BAT Trigger Time
CENTROID_X:      322.87,  raw= 323  [pixels]
CENTROID_Y:      315.01,  raw= 315  [pixels]
ROLL:            241.29 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   39.86
GRB_POS_XRT_Z:   36.48
IMAGE_URL:       sw01011980000msxps_rw.img
SUN_POSTN:       256.54d {+17h 06m 10s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.74 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.23d {+12h 20m 56s}   +3.31d {+03d 18' 39"}
MOON_DIST:       161.82 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.78,-62.79 [deg] galactic lon,lat of the burst
ECL_COORDS:       20.70,-10.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:47:26 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
GRB_RA:           23.0916d {+01h 32m 21.9s} (J2000),
                  23.3585d {+01h 33m 26.0s} (current),
                  22.4546d {+01h 29m 49.1s} (1950)
GRB_DEC:          -1.7523d {-01d 45' 08.2"} (J2000),
                  -1.6452d {-01d 38' 42.6"} (current),
                  -2.0090d {-02d 00' 32.4"} (1950)
GRB_ERROR:       5.8 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       30 [cnts]
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20804.16 SOD {05:46:44.16} UT,   111.6 [sec] since BAT Trigger Time
CENTROID_X:      322.87,  raw= 323  [pixels]
CENTROID_Y:      315.01,  raw= 315  [pixels]
ROLL:            241.29 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   39.86
GRB_POS_XRT_Z:   36.48
IMAGE_URL:       sw01011980000msxps_rw.img
SUN_POSTN:       256.54d {+17h 06m 10s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.74 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.23d {+12h 20m 56s}   +3.31d {+03d 18' 38"}
MOON_DIST:       161.82 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.78,-62.79 [deg] galactic lon,lat of the burst
ECL_COORDS:       20.70,-10.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:47:12 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1011980,   Seg_Num: 0
GRB_RA:           23.0916d {+01h 32m 21.98s} (J2000),
                  23.3585d {+01h 33m 26.04s} (current),
                  22.4546d {+01h 29m 49.10s} (1950)
GRB_DEC:          -1.7523d {-01d 45' 08.2"} (J2000),
                  -1.6452d {-01d 38' 42.6"} (current),
                  -2.0090d {-02d 00' 32.4"} (1950)
GRB_ERROR:       6.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       6.48e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.47 [sigma]
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20804.16 SOD {05:46:44.16} UT,   111.6 [sec] since BAT Trigger Time
TAM[0-3]:        327.63 237.20 261.65 243.35
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       256.54d {+17h 06m 10s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.74 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.23d {+12h 20m 56s}   +3.31d {+03d 18' 41"}
MOON_DIST:       161.81 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.78,-62.79 [deg] galactic lon,lat of the burst
ECL_COORDS:       20.70,-10.60 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.07 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:49:07 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1011980,   Seg_Num: 0
GRB_RA:           23.106d {+01h 32m 25s} (J2000),
                  23.373d {+01h 33m 29s} (current),
                  22.469d {+01h 29m 52s} (1950)
GRB_DEC:          -1.763d {-01d 45' 47"} (J2000),
                  -1.656d {-01d 39' 21"} (current),
                  -2.020d {-02d 01' 11"} (1950)
GRB_DATE:        19192 TJD;   344 DOY;   20/12/09
GRB_TIME:        20692.53 SOD {05:44:52.53} UT
TRIGGER_INDEX:   155
GRB_PHI:         169.30 [deg]
GRB_THETA:        50.83 [deg]
DELTA_TIME:      -24.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     43.24 [sigma]
IMAGE_SIGNIF:    10.19 [sigma]
LC_URL:          sw01011980000msb.lc
SUN_POSTN:       256.54d {+17h 06m 11s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.74 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.25d {+12h 21m 00s}   +3.30d {+03d 18' 13"}
MOON_DIST:       161.82 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.82,-62.80 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       20.71,-10.62 [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 = 178.88,19.98 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:49:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.076d {+01h 32m 18s} (J2000)
POINT_DEC:        -1.748d {-01d 44' 51"} (J2000)
POINT_ROLL:      241.286d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20813.69 SOD {05:46:53.69} UT,   121.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.306
N_STARS:         14
X_OFFSET:        280 [pixels]
Y_OFFSET:        440 [pixels]
X_MAX:           1239 [pixels]
Y_MAX:           1399 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    6
SL_URL:          sw01011980000msufc0121.fits
SUN_POSTN:       256.55d {+17h 06m 11s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.26d {+12h 21m 01s}   +3.30d {+03d 18' 03"}
MOON_DIST:       161.85 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:50:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.076d {+01h 32m 18s} (J2000)
POINT_DEC:        -1.748d {-01d 44' 51"} (J2000)
POINT_ROLL:      241.286d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20813.69 SOD {05:46:53.69} UT,   121.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.306
N_STARS:         14
X_OFFSET:        280 [pixels]
Y_OFFSET:        440 [pixels]
X_MAX:           1239 [pixels]
Y_MAX:           1399 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    6
SL_URL:          sw01011980000msufc0121.fits
SUN_POSTN:       256.55d {+17h 06m 11s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.26d {+12h 21m 02s}   +3.30d {+03d 17' 60"}
MOON_DIST:       161.86 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 09 Dec 20 05:51:11 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.076d {+01h 32m 18s} (J2000)
POINT_DEC:        -1.748d {-01d 44' 51"} (J2000)
ROLL:            241.286d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20813.69 SOD {05:46:53.69} UT,   121.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     629185639
X_OFFSET:        699 [pixels]
Y_OFFSET:        832 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       992
BINNING_INDEX:   1
IM_URL:          sw01011980000msuni0148.fits
SUN_POSTN:       256.55d {+17h 06m 11s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.27d {+12h 21m 04s}   +3.29d {+03d 17' 42"}
MOON_DIST:       161.87 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 09 Dec 20 05:51:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.076d {+01h 32m 18s} (J2000)
POINT_DEC:        -1.748d {-01d 44' 51"} (J2000)
ROLL:            241.286d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20813.69 SOD {05:46:53.69} UT,   121.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     629185639
X_OFFSET:        699 [pixels]
Y_OFFSET:        832 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       992
BINNING_INDEX:   1
IM_URL:          sw01011980000msuni0148.fits
SUN_POSTN:       256.55d {+17h 06m 11s}  -22.86d {-22d 51' 33"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.27d {+12h 21m 04s}   +3.29d {+03d 17' 40"}
MOON_DIST:       161.87 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 #29004
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, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
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-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB201209.24 (trigger No 1011980,01h 32m 25.44s , -01d 45m 46.8s, R=0.05) errorbox 29 sec after notice time and 51 sec after trigger time at 2020-12-09 05:45:44 UT, with upper limit up to 16.8 mag. The observations began at zenith distance = 75 deg. The sun altitude is -33.0 deg.
The galactic latitude b = -62 deg., longitude l = 147 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1499038
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

      57 |         MASTER-OAFA |   C |    10 | 16.8 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 05:58:17 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
POINT_ROLL:      241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21026.73 SOD {05:50:26.73} UT,   334.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.627
N_STARS:         11
X_OFFSET:        379 [pixels]
Y_OFFSET:        512 [pixels]
X_MAX:           1338 [pixels]
Y_MAX:           1471 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw01011980000msufc0334.fits
SUN_POSTN:       256.55d {+17h 06m 12s}  -22.86d {-22d 51' 35"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.33d {+12h 21m 19s}   +3.27d {+03d 15' 56"}
MOON_DIST:       161.93 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN Circular #29005
J.D. Gropp (PSU), H. A. Krimm (NSF), F. E. Marshall (NASA/GSFC), M. J. Moss (GWU), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (PSU), M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
At 05:44:52 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201209A (trigger=1011980). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 23.106, -1.763 which is
```
   RA(J2000) = 01h 32m 25s
   Dec(J2000) = -01d 45' 47"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 30 sec. The peak count rate was ~8000 counts/sec (15-350 keV), at ~7 sec after the trigger.
The XRT began observing the field at 05:46:44.1 UT, 111.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 23.09079, -1.75347 which is equivalent to:
```
   RA(J2000)  = 01h 32m 21.79s
   Dec(J2000) = -01d 45' 12.5"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 64 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 https://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 3.60 x 10^20 cm^-2 (Willingale et al. 2013).
The initial flux in the 2.5 s image was 6.48e-10 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 121 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 100% 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 0.04.
Burst Advocate for this burst is J.D. Gropp (jdg44 AT psu.edu). 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 09 Dec 20 05:58:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
POINT_ROLL:      241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21026.73 SOD {05:50:26.73} UT,   334.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.627
N_STARS:         11
X_OFFSET:        379 [pixels]
Y_OFFSET:        512 [pixels]
X_MAX:           1338 [pixels]
Y_MAX:           1471 [pixels]
DET_THRESH:      7
PHOTO_THRESH:    3
SL_URL:          sw01011980000msufc0334.fits
SUN_POSTN:       256.55d {+17h 06m 12s}  -22.86d {-22d 51' 35"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.33d {+12h 21m 20s}   +3.26d {+03d 15' 54"}
MOON_DIST:       161.93 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 09 Dec 20 05:59:39 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
ROLL:            241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21026.73 SOD {05:50:26.73} UT,   334.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     629185852
X_OFFSET:        699 [pixels]
Y_OFFSET:        832 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       992
BINNING_INDEX:   1
IM_URL:          sw01011980000msuni0361.fits
SUN_POSTN:       256.55d {+17h 06m 13s}  -22.86d {-22d 51' 35"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.34d {+12h 21m 22s}   +3.26d {+03d 15' 36"}
MOON_DIST:       161.94 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 09 Dec 20 05:59:54 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
ROLL:            241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21026.73 SOD {05:50:26.73} UT,   334.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     629185852
X_OFFSET:        699 [pixels]
Y_OFFSET:        832 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       992
BINNING_INDEX:   1
IM_URL:          sw01011980000msuni0361.fits
SUN_POSTN:       256.55d {+17h 06m 13s}  -22.86d {-22d 51' 36"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.35d {+12h 21m 23s}   +3.26d {+03d 15' 32"}
MOON_DIST:       161.94 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 06:05:13 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
POINT_ROLL:      241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21555.42 SOD {05:59:15.42} UT,   862.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.430
N_STARS:         84
X_OFFSET:        139 [pixels]
Y_OFFSET:        272 [pixels]
X_MAX:           1578 [pixels]
Y_MAX:           1711 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw01011980000msufc0862.fits
SUN_POSTN:       256.56d {+17h 06m 14s}  -22.86d {-22d 51' 37"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.39d {+12h 21m 34s}   +3.24d {+03d 14' 13"}
MOON_DIST:       161.99 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 09 Dec 20 06:06:25 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
ROLL:            241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21555.42 SOD {05:59:15.42} UT,   862.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     629186381
X_OFFSET:        698 [pixels]
Y_OFFSET:        831 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       858
Y_GRB_POS:       991
BINNING_INDEX:   1
IM_URL:          sw01011980000msuni0889.fits
SUN_POSTN:       256.56d {+17h 06m 14s}  -22.86d {-22d 51' 37"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.40d {+12h 21m 37s}   +3.23d {+03d 13' 55"}
MOON_DIST:       162.01 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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:     Wed 09 Dec 20 06:05:29 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
POINT_ROLL:      241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21555.42 SOD {05:59:15.42} UT,   862.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.430
N_STARS:         84
X_OFFSET:        139 [pixels]
Y_OFFSET:        272 [pixels]
X_MAX:           1578 [pixels]
Y_MAX:           1711 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw01011980000msufc0862.fits
SUN_POSTN:       256.56d {+17h 06m 14s}  -22.86d {-22d 51' 37"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.40d {+12h 21m 35s}   +3.24d {+03d 14' 09"}
MOON_DIST:       162.00 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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 09 Dec 20 06:06:38 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1011980,   Seg_Num: 0
POINT_RA:         23.078d {+01h 32m 19s} (J2000)
POINT_DEC:        -1.746d {-01d 44' 46"} (J2000)
ROLL:            241.288d
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  21555.42 SOD {05:59:15.42} UT,   862.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     629186381
X_OFFSET:        698 [pixels]
Y_OFFSET:        831 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       858
Y_GRB_POS:       991
BINNING_INDEX:   1
IM_URL:          sw01011980000msuni0889.fits
SUN_POSTN:       256.56d {+17h 06m 14s}  -22.86d {-22d 51' 37"}
SUN_DIST:        122.72 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.41d {+12h 21m 37s}   +3.23d {+03d 13' 52"}
MOON_DIST:       162.01 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.75,-62.79 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       20.69,-10.59 [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:     Wed 09 Dec 20 06:27:09 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1011980,   Seg_Num: 0
GRB_RA:           23.0910d {+01h 32m 21.84s} (J2000),
                  23.3579d {+01h 33m 25.90s} (current),
                  22.4540d {+01h 29m 48.96s} (1950)
GRB_DEC:          -1.7536d {-01d 45' 12.9"} (J2000),
                  -1.6465d {-01d 38' 47.3"} (current),
                  -2.0103d {-02d 00' 37.0"} (1950)
GRB_ERROR:       3.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19192 TJD;   344 DOY;   20/12/09
IMG_START_TIME:  20855.00 SOD {05:47:35.00} UT,   162.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       256.57d {+17h 06m 18s}  -22.86d {-22d 51' 42"}
SUN_DIST:        122.71 [deg]   Sun_angle= -8.5 [hr] (East of Sun)
MOON_POSTN:      185.59d {+12h 22m 21s}   +3.15d {+03d 08' 46"}
MOON_DIST:       162.18 [deg]
MOON_ILLUM:      36 [%]
GAL_COORDS:      145.78,-62.80 [deg] galactic lon,lat of the burst
ECL_COORDS:       20.70,-10.60 [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:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #29006
Martin Jelinek, Jan Strobl (ASU CAS Ondrejov, CZ), Martin Masek, Petr Janecek, Sergey Karpov, Jakub Jurysek, Jan Ebr, Ronan Cunniffe, Petr Travnicek and Michael Prouza (Institute of Physics, Prague, CZ)
report:
The 30cm robotic telescope FRAM-Auger in Malargue (Argentina) reacted robotically to the Swift/BAT alert of GRB201209A (Gropp et al., GCNC 29005), starting with a series of 20 s R-band images at 05:45:40 UT, i.e. 48 s post trigger.
We do not detect any new or strongly variable source at or around the reported X-ray error box in single frames nor in a combined 20 x 20 s image spanning the period from 0.8 min to 11.9 min after the initial trigger. The combined exposure has a 3-sigma limiting magnitude R(Vega) ~ 17.4.
GCN Circular #29007
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 201209A (Gropp et al., GCN 29005) starting at 05:48:09 UT, 197 s after the burst under cloudy condition. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. We do not detect any optical afterglow candidate within the XRT position error circle (Gropp et al., GCN 29005), neither in single image, nor in the co-add images. The typical limiting magnitude of our single clear image is about 15.0 mag calibrated to the USNOB1.0 catalog.
GCN Circular #29009
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1536 s of XRT Photon Counting mode data and 2 UVOT images for GRB 201209A, 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 = 23.09069, -1.75468 which is equivalent to:
```
RA (J2000): 01h 32m 21.77s
Dec (J2000): -01d 45' 16.8"
```
with an uncertainty of 1.7 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 #29011
D. Nadella (NITK), G. Waratkar (IITB), A. Vibhute (IUCAA), S. Gupta (IUCAA), P. Sawant (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al, 2020, arxiv:2011.07067) showed detection of a long GRB 201209A, which was also detected by Swift-BAT (GCN #29005).
The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-12-09 05:44:56.500 UT. The measured peak count rate associated with the burst is 456 (+51, -54) cts/s above the background in the combined data of four quadrants, with a total of 3215 (+719, -885) cts. The local mean background count rate was 557 (+4, -3) cts/s. Using cumulative rates, we measure a T90 of 23 (+14, -12) s.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-12-09 05:44:56.336 UT. The measured peak count rate is 697 (+81, -89) cts/s above the background in the combined Veto data of four quadrants, with a total of 4866 (+1506, -1667) cts. The local mean background count rate was 1856 (+6, -7) cts/s. We measure a T90 of 25 (+26, -15) s from the cumulative Veto light curve.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular #29013
Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu, D. Xu (NAOC) report on behalf of a larger collaboration:
We observed the field of GRB 201209A (Gropp et al., GCN 29005) using the 2.16-m optical telescope located at Xinglong, Hebei, China, equipped with the BFOSC camera. Observations started at 13:05:43 UT on 2020-12-09, and 2x360 s, 3x600 s R-band frames were obtained.
An uncatalogued source is detected in our stacked image at coordinates
```
R.A. (J2000) = 1:32:21.76
Dec. (J2000) = -1:45:17.13
```
with an uncertainty of ~0.5 arcsec, being fully consistent with the Enhanced XRT position (Goad et al., GCN 29009). Calibrated with nearby PS1 stars, the source has m(R) = 22.05 +/- 0.16 mag at a median time of 0.321 days post-burst, whereas PS1 is deeper but no object is present at the position. We thus conclude that the source is likely the optical afterglow of the burst.
We acknowledge excellent support from the Xinglong-2.16m observing staff, in particular Aiying Zhou and Jie Zheng.
GCN Circular #29014
J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and J.D. Gropp report on behalf of the Swift-XRT team:
We have analysed 6.2 ks of XRT data for GRB 201209A (Gropp et al. GCN Circ. 29005), from 117 s to 29.1 ks after the BAT trigger. The data comprise 43 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 29009).A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.98 (+/-0.08). The best-fitting absorption column is 1.54 (+0.26, -0.25) x 10^21 cm^-2, in excess of the Galactic value of 3.6 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 3.5 x 10^-11 (4.3 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.54 (+0.26, -0.25) x 10^21 cm^-2
Galactic foreground: 3.6 x 10^20 cm^-2
Excess significance: 7.9 sigma
Photon index:	     1.98 (+/-0.08)
```
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01011980.
This circular is an official product of the Swift-XRT team.
GCN Circular #29021
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201209A (trigger #1011980) (Gropp, et al., GCN Circ. 29005). The BAT ground-calculated position is RA, Dec = 23.096, -1.762 deg which is
```
  RA(J2000)  =  01h 32m 23.0s 
  Dec(J2000) = -01d 45' 43.8" 
```
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%.
The mask-weighted light curve shows some early emission starting at ~T-20 sec, and two bright, symmetrical peaks centered at T+0 and T+7 sec. The burst has faded to background by T+30 sec. T90 (15-350 keV) is 48.0 +- 16.0 sec (estimated error including systematics).
The time-averaged spectrum from T-31.66 to T+32.34 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.56 +- 0.06. The fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+7.84 sec in the 15-150 keV band is 12.2 +- 1.1 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/1011980/BA/
GCN Circular #29026
GRB 201209A: Swift/UVOT Upper Limits
K. K. Simpson (PSU) and J. D. Gropp (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 201209A 121 s after the BAT trigger (Gropp et al., GCN Circ. 29005). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 29009) 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           121          271          147         >20.1
u_FC               334          584          246         >20.3
white              121         1706          412         >20.9
v                  663         1583          117         >19.2
b                  590         1682          117         >19.5
u                  334         1657          343         >20.7
w1                 712         1632           97         >19.8
m2                 688         1260           39         >19.2
w2                1018         1211           39         >19.4
```
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).
GCN Circular #29050
Y. Q. Zhang, C. Cai, J. C. Liu, Q. Luo, S. Xiao, W. C. Xue, Q. B. Yi, C. Zheng，Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, X. Y. Song, S. L. Xiong, C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, M. Wu, Y. P. Xu, S. N. Zhang (IHEP), report on behalf of the Insight-HXMT team:
At 2020-12-09T05:44:52.53 (T0), Insight-HXMT/HE detected GRB 201209A (trigger ID: HEB201209239) in a routine search of the data, which also triggered Swift/BAT (Gropp J. et al., GCN #29005) and AstroSat/CZTI ( Nadella D. et al., GCN #29011)..
The Insight-HXMT/HE light curve mainly consists of multiple pulses with a duration (T90) of 9.99 s measured from T0-1.09 s. The 1-ms peak rate, measured from T0+7.16 s, is 778 cnts/sec. The total counts from this burst is 2926 counts. URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB201209239_lc.jpg
All measurements above are made with the CsI detectors operating in the regular mode with the energy range of about 80-800 keV (deposited energy). Only gamma-rays with energy greater than about 200 keV can penetrate the spacecraft and leave signals in the CsI detectors installed inside of the telescope.
Insight-HXMT is the first Chinese space X-ray telescope, which was funded jointly by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). More information about it could be found at: http://www.hxmt.org.
GCN Circular #29094
N. Pankov (HSE), A. Pozanenko (IKI), A. Volnova (IKI), S. Belkin (IKI), E. Klunko (ISTP) report on behalf of IKI GRB FuN:
We observed the field of GRB 201209A (Gropp et al., GCN 29005) with AZT-33IK telescope of Sayan observatory (Mondy) starting on Dec. 09 (UT) 11:41:13 (i.e. 0.28 days) and next epochs later. We detected a weak source within enhanced XRT position (Goad et al., GCN 29005) at ~1.4 days after GRB 201209A trigger and not detected in other epochs. Thus we confirm the optical afterglow detection on 0.321 days at R = 22.05 +/- 0.16 (Zhu et al. GCN 29013).
Preliminary photometry of the field and afterglow is following
```
Date       UT start   t-T0       Filter Exp.    OT    Err.  UL(3sigma)
                       (mid, days)        (s)

2020-12-09  11:41:13  42*120  R        0.27873   n/d    n/d  21.7
2020-12-10  14:26:13  45*120  R        1.39332   23.4   0.3  23.5
2020-12-12  11:14:21  39*120  R        3.25868   n/d    n/d  22.2
2020-12-13  12:03:41  38*120  R        4.26307   n/d    n/d  22.9
```
The photometry is based on nearby USNO-B1.0 stars.

Back to JG's homepage

Jochen Greiner, last update: 20-Dec-2020 [Disclaimer]