Gamma-ray Burst 201223A

(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 23 Dec 20 17:58:41 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1014316,   Seg_Num: 0
GRB_RA:          132.849d {+08h 51m 24s} (J2000),
                 133.367d {+08h 53m 28s} (current),
                 131.600d {+08h 46m 24s} (1950)
GRB_DEC:         +71.174d {+71d 10' 26"} (J2000),
                 +71.094d {+71d 05' 38"} (current),
                 +71.361d {+71d 21' 39"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       2902 [cnts]    Image_Peak=162 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       16813 [cnts]
BKG_TIME:        64693.79 SOD {17:58:13.79} UT
BKG_DUR:         8 [sec]
GRB_DATE:        19206 TJD;   358 DOY;   20/12/23
GRB_TIME:        64706.97 SOD {17:58:26.97} UT
GRB_PHI:          91.75 [deg]
GRB_THETA:        25.08 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.19 [sigma]
IMAGE_SIGNIF:    8.13 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -2  +0  +0 +60  +0 
SUN_POSTN:       272.59d {+18h 10m 22s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.95 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.77d {+01h 27m 05s}   +4.26d {+04d 15' 22"}
MOON_DIST:        92.79 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.91, 35.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      110.29, 50.74 [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 = 182.20,15.00 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 17:59:46 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.904d {+08h 51m 37s} (J2000)
POINT_DEC:       +71.196d {+71d 11' 47"} (J2000)
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64780.71 SOD {17:59:40.71} UT,   73.7 [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:     Wed 23 Dec 20 18:02:04 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1014316,   Seg_Num: 0
GRB_RA:          132.849d {+08h 51m 24s} (J2000),
                 133.367d {+08h 53m 28s} (current),
                 131.600d {+08h 46m 24s} (1950)
GRB_DEC:         +71.174d {+71d 10' 26"} (J2000),
                 +71.094d {+71d 05' 38"} (current),
                 +71.361d {+71d 21' 39"} (1950)
GRB_DATE:        19206 TJD;   358 DOY;   20/12/23
GRB_TIME:        64706.97 SOD {17:58:26.97} UT
TRIGGER_INDEX:   146
GRB_PHI:          91.75 [deg]
GRB_THETA:        25.08 [deg]
DELTA_TIME:      -38.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     15.19 [sigma]
IMAGE_SIGNIF:    8.13 [sigma]
LC_URL:          sw01014316000msb.lc
SUN_POSTN:       272.59d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.95 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.79d {+01h 27m 11s}   +4.27d {+04d 16' 04"}
MOON_DIST:        92.77 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.91, 35.11 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      110.29, 50.74 [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 = 182.20,15.00 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 18:02:49 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.905d {+08h 51m 37s} (J2000)
POINT_DEC:       +71.197d {+71d 11' 47"} (J2000)
POINT_ROLL:      48.015d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64785.48 SOD {17:59:45.48} UT,   78.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.854
N_STARS:         92
X_OFFSET:        297 [pixels]
Y_OFFSET:        691 [pixels]
X_MAX:           1256 [pixels]
Y_MAX:           1650 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    6
SL_URL:          sw01014316000msufc0078.fits
SUN_POSTN:       272.59d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.80d {+01h 27m 12s}   +4.27d {+04d 16' 13"}
MOON_DIST:        92.78 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.88, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 18:03:06 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.905d {+08h 51m 37s} (J2000)
POINT_DEC:       +71.197d {+71d 11' 47"} (J2000)
POINT_ROLL:      48.015d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64785.48 SOD {17:59:45.48} UT,   78.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.854
N_STARS:         92
X_OFFSET:        297 [pixels]
Y_OFFSET:        691 [pixels]
X_MAX:           1256 [pixels]
Y_MAX:           1650 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    6
SL_URL:          sw01014316000msufc0078.fits
SUN_POSTN:       272.59d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.80d {+01h 27m 12s}   +4.27d {+04d 16' 16"}
MOON_DIST:        92.78 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.88, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [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 23 Dec 20 18:04:16 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.905d {+08h 51m 37s} (J2000)
POINT_DEC:       +71.197d {+71d 11' 47"} (J2000)
ROLL:            48.015d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64785.48 SOD {17:59:45.48} UT,   78.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     630439211
X_OFFSET:        616 [pixels]
Y_OFFSET:        1010 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       776
Y_GRB_POS:       1170
BINNING_INDEX:   1
IM_URL:          sw01014316000msuni0105.fits
SUN_POSTN:       272.60d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.81d {+01h 27m 15s}   +4.28d {+04d 16' 31"}
MOON_DIST:        92.77 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.88, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [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 23 Dec 20 18:03:37 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1014316,   Seg_Num: 0
GRB_RA:          132.7866d {+08h 51m 08.78s} (J2000),
                 133.3052d {+08h 53m 13.25s} (current),
                 131.5374d {+08h 46m 08.97s} (1950)
GRB_DEC:         +71.1793d {+71d 10' 45.4"} (J2000),
                 +71.0996d {+71d 05' 58.4"} (current),
                 +71.3662d {+71d 21' 58.2"} (1950)
GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64788.00 SOD {17:59:48.00} UT,   81.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       272.60d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.96 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.81d {+01h 27m 13s}   +4.27d {+04d 16' 23"}
MOON_DIST:        92.75 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.91, 35.09 [deg] galactic lon,lat of the burst
ECL_COORDS:      110.26, 50.74 [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:     Wed 23 Dec 20 18:04:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.905d {+08h 51m 37s} (J2000)
POINT_DEC:       +71.197d {+71d 11' 47"} (J2000)
ROLL:            48.015d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64785.48 SOD {17:59:45.48} UT,   78.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     630439211
X_OFFSET:        616 [pixels]
Y_OFFSET:        1010 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       776
Y_GRB_POS:       1170
BINNING_INDEX:   1
IM_URL:          sw01014316000msuni0105.fits
SUN_POSTN:       272.60d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.81d {+01h 27m 15s}   +4.28d {+04d 16' 32"}
MOON_DIST:        92.77 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.88, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [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.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 18:06:00 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     1014316,   Seg_Num: 0
GRB_RA:          132.7896d {+08h 51m 09.50s} (J2000),
                 133.3082d {+08h 53m 13.97s} (current),
                 131.5404d {+08h 46m 09.69s} (1950)
GRB_DEC:         +71.1798d {+71d 10' 47.2"} (J2000),
                 +71.1001d {+71d 06' 00.2"} (current),
                 +71.3667d {+71d 22' 00.1"} (1950)
GRB_ERROR:       0.6 [arcsec radius, statistical only]
GRB_MAG:         16.15 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64782.00 SOD {17:59:42.00} UT,   75.0 [sec] since BAT Trigger Time
SUN_POSTN:       272.60d {+18h 10m 23s}  -23.41d {-23d 24' 51"}
SUN_DIST:        126.96 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.82d {+01h 27m 18s}   +4.28d {+04d 16' 52"}
MOON_DIST:        92.73 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.91, 35.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      110.26, 50.74 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN Circular #29156
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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB201223.75 (trigger No 1014316,08h 51m 23.76s , +71d 10m 26.4s, R=0.05) errorbox 33 sec after notice time and 51 sec after trigger time at 2020-12-23 17:59:18 UT, with upper limit up to 18.6 mag. The observations began at zenith distance = 51 deg. The sun altitude is -40.4 deg.
The galactic latitude b = 36 deg., longitude l = 143 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1510350
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     141 |      MASTER-Tavrida |   C |   180 | 18.6 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #29157
V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University
V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk
R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA)
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
D. Buckley, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory
MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the GRB201223.75 35 sec after notice time and 51 sec after trigger time at 2020-12-23 17:59:18 UT. On our first (180s exposure) set we found 1 optical transient within Swift error-box (ra=132.846 dec=71.1739 r=0.05) brighter than 18.1.
```
 T-Tmid      Date      Time       Expt.        Ra                Dec           Mag
---------|---------------------|-------|-----------------|-----------------|-------
     141   2020-12-23 17:59:18     180   (  8h 51m 09.2s , +71d 10m 47.8s)     15.2
```
The 5-sigma upper limit has been about 18.1mag The message may be cited.
GCN Circular #29158
J.D. Gropp (PSU), S. D. Barthelmy (GSFC), J. A. Kennea (PSU), N. J. Klingler (PSU), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), B. Sbarufatti (PSU) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 17:58:26 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 201223A (trigger=1014316). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 132.849, +71.174 which is
```
   RA(J2000) = 08h 51m 24s
   Dec(J2000) = +71d 10' 26"
```
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 50 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 17:59:40.7 UT, 73.7 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 132.78615, 71.17926 which is equivalent to:
```
   RA(J2000)  = 08h 51m 08.68s
   Dec(J2000) = +71d 10' 45.3"
```
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 75 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.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 3.13 x 10^20 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 78 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	08:51:09.51 = 132.78963
  DEC(J2000) = +71:10:47.4  =  71.17982
```
with a 90%-confidence error radius of about 0.61 arc sec. This position is 3.8 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.16 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.05.
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 23 Dec 20 18:21:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.910d {+08h 51m 38s} (J2000)
POINT_DEC:       +71.198d {+71d 11' 53"} (J2000)
POINT_ROLL:      48.019d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64997.71 SOD {18:03:17.71} UT,   290.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.306
N_STARS:         78
X_OFFSET:        57 [pixels]
Y_OFFSET:        451 [pixels]
X_MAX:           1496 [pixels]
Y_MAX:           1890 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01014316000msufc0290.fits
SUN_POSTN:       272.61d {+18h 10m 26s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.94d {+01h 27m 46s}   +4.33d {+04d 20' 05"}
MOON_DIST:        92.68 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.87, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 18:22:58 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.910d {+08h 51m 38s} (J2000)
POINT_DEC:       +71.198d {+71d 11' 53"} (J2000)
ROLL:            48.019d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64997.71 SOD {18:03:17.71} UT,   290.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     630439423
X_OFFSET:        616 [pixels]
Y_OFFSET:        1010 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       776
Y_GRB_POS:       1170
BINNING_INDEX:   1
IM_URL:          sw01014316000msuni0317.fits
SUN_POSTN:       272.61d {+18h 10m 26s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.95d {+01h 27m 48s}   +4.34d {+04d 20' 19"}
MOON_DIST:        92.67 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.87, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [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 23 Dec 20 18:22:01 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.910d {+08h 51m 38s} (J2000)
POINT_DEC:       +71.198d {+71d 11' 53"} (J2000)
POINT_ROLL:      48.019d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64997.71 SOD {18:03:17.71} UT,   290.7 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.306
N_STARS:         78
X_OFFSET:        57 [pixels]
Y_OFFSET:        451 [pixels]
X_MAX:           1496 [pixels]
Y_MAX:           1890 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01014316000msufc0290.fits
SUN_POSTN:       272.61d {+18h 10m 26s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.94d {+01h 27m 46s}   +4.34d {+04d 20' 08"}
MOON_DIST:        92.67 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.87, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [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 23 Dec 20 18:22:22 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1014316,   Seg_Num: 0
GRB_RA:          132.7894d {+08h 51m 09.45s} (J2000),
                 133.3080d {+08h 53m 13.92s} (current),
                 131.5402d {+08h 46m 09.65s} (1950)
GRB_DEC:         +71.1795d {+71d 10' 46.2"} (J2000),
                 +71.0998d {+71d 05' 59.1"} (current),
                 +71.3664d {+71d 21' 59.0"} (1950)
GRB_ERROR:       2.2 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64788.00 SOD {17:59:48.00} UT,   81.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       272.61d {+18h 10m 26s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.96 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.95d {+01h 27m 47s}   +4.34d {+04d 20' 12"}
MOON_DIST:        92.64 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.91, 35.09 [deg] galactic lon,lat of the burst
ECL_COORDS:      110.26, 50.74 [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:     Wed 23 Dec 20 18:23:06 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.910d {+08h 51m 38s} (J2000)
POINT_DEC:       +71.198d {+71d 11' 53"} (J2000)
ROLL:            48.019d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  64997.71 SOD {18:03:17.71} UT,   290.7 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     630439423
X_OFFSET:        616 [pixels]
Y_OFFSET:        1010 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       776
Y_GRB_POS:       1170
BINNING_INDEX:   1
IM_URL:          sw01014316000msuni0317.fits
SUN_POSTN:       272.61d {+18h 10m 26s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.95d {+01h 27m 48s}   +4.34d {+04d 20' 21"}
MOON_DIST:        92.67 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.87, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [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.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 18:26:58 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.909d {+08h 51m 38s} (J2000)
POINT_DEC:       +71.198d {+71d 11' 52"} (J2000)
POINT_ROLL:      48.020d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  65575.99 SOD {18:12:55.99} UT,   869.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.324
N_STARS:         111
X_OFFSET:        57 [pixels]
Y_OFFSET:        451 [pixels]
X_MAX:           1496 [pixels]
Y_MAX:           1890 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw01014316000msufc0869.fits
SUN_POSTN:       272.61d {+18h 10m 27s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.98d {+01h 27m 55s}   +4.35d {+04d 21' 08"}
MOON_DIST:        92.65 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.87, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 23 Dec 20 18:27:11 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1014316,   Seg_Num: 0
POINT_RA:        132.909d {+08h 51m 38s} (J2000)
POINT_DEC:       +71.198d {+71d 11' 52"} (J2000)
POINT_ROLL:      48.020d
IMG_START_DATE:  19206 TJD;   358 DOY;   20/12/23
IMG_START_TIME:  65575.99 SOD {18:12:55.99} UT,   869.0 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.324
N_STARS:         111
X_OFFSET:        57 [pixels]
Y_OFFSET:        451 [pixels]
X_MAX:           1496 [pixels]
Y_MAX:           1890 [pixels]
DET_THRESH:      23
PHOTO_THRESH:    14
SL_URL:          sw01014316000msufc0869.fits
SUN_POSTN:       272.61d {+18h 10m 27s}  -23.41d {-23d 24' 50"}
SUN_DIST:        126.92 [deg]   Sun_angle= 9.3 [hr] (West of Sun)
MOON_POSTN:       21.98d {+01h 27m 56s}   +4.35d {+04d 21' 11"}
MOON_DIST:        92.65 [deg]
MOON_ILLUM:      67 [%]
GAL_COORDS:      142.87, 35.12 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      110.30, 50.77 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN Circular #29159
Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 201223A (Gropp et al., GCN 29158) using the NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China. Observations automatically started at 18:01:14 UT on 2020-12-23, i.e., 168 s after the BAT trigger. We obtained a series of 2x40s, 4x60s and 12x90s frames in the Sloan r-filter, and observations are ongoing.
An uncatalogued decaying optical transient is detected at the Swift/UVOT position (Gropp et al., GCN 29158), which is thus concluded to be the optical afterglow of burst. The afterglow has r = 15.67 +/- 0.01 mag in our first image, calibrated with nearby PS1 stars.
GCN Circular #29160
Y.-D. Hu, E. Fernandez-Garcia, M. A. Castro, A. J. Castro-Tirado (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), S. Guziy (Univ. of Nikolaev) and D. Xiong, Y. Fan, X. Zhao, J. Bai, C. Wang, Y. Xin (Yunnan Nacional Astronomical Observatory) on behalf of a larger collaboration, report:
Following the detection of GRB 201223A by Swift (Gropp et al. GCNC 29158), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical Observatory (China) started to gather images in clear filter starting at 18:01:22 UT (~176 s after trigger). The optical afterglow reported by Swift/UVOT (Gropp et al. GCNC 29158), MASTER (Lipunov et al. GCNC 29157) and Nanshan/NEXT (Zhu et al. GCNC 29159) is detected with a magnitude of 15.7+-0.15. Additional observations are ongoing.
We thank the staff at Lijiang observatory for their excellent support.
GCN Circular #29161
J. Wood (NASA/MSFC) reports on behalf of the Fermi GBM Team:
"At 17:58:25.69 UT on 23 December 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201223A (trigger 630439110 / 201223749) which was also detected by the Swift/BAT and Swift/XRT (Gropp et al. 2020, GCN 29158). The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 63 degrees.
The GBM light curve shows multiple peaks with a duration (T90) of about 33 s (50-300 keV). The time-averaged spectrum from T0-17 s to T0+13 s is best fit by a Band function with Epeak = 86 +/- 12 keV, alpha = 0.14 +/- 0.38 and beta = -2.6 +/- 0.4. A power law function with an exponential high-energy cutoff fits the spectrum equally well. The power law index is -0.14 +/- 0.24 and the cutoff energy, parameterized as Epeak, is 99 +/- 8 keV.
The event fluence (10-1000 keV) in this time interval is (2.1 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.1 s in the 10-1000 keV band is 2.4 +/- 0.2 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular #29163
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J.D. Gropp (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), 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+882 sec from the recent telemetry downlink, we report further analysis of BAT GRB 201223A (trigger #1014316) (Gropp et al., GCN Circ. 29158). The BAT ground-calculated position is RA, Dec = 132.735, 71.176 deg which is
```
   RA(J2000)  =  08h 50m 56.3s
   Dec(J2000) = +71d 10' 34.9"
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 53%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~T-25 s and ends at ~T+8 s. The main peak occurs at ~T0. T90 (15-350 keV) is 29.0 +- 6.7 sec (estimated error including systematics).
The time-averaged spectrum from T-25.18 to T+7.82 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.35 +- 0.13. The fluence in the 15-150 keV band is 1.3 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T-0.18 sec in the 15-150 keV band is 1.5 +- 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/1014316/BA/
GCN Circular #29164
R. Hosokawa, K. L. Murata, R. Adachi, M. Niwano, F. Ogawa, N. Nakamura, N. Ito, S. Ogata, H. Takamatsu, H. Hara, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 201223A (J.D. Gropp et al., GCN #29158, J. Wood et al., GCN #29161) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan. The observation started at 2020-12-23 17:59:18 UT (52s after Swift BAT trigger). We detected the point source at the position consistent with the afterglow detected previously (Lipunov et al. GCN #29157, Gropp et al., GCN #29158, Z.P. Zhu et al. GCN #29159, Y.-D. Hu et al. GCN #29160). We measured the magnitudes as follows.
```
T0+[sec] MID-UT T-EXP[sec] measured magnitudes
------------------------------------------------------------------------------------------------
52 17:59:48 60 g'=15.45+/-0.05, Rc=15.04+/-0.03, Ic=14.77+/-0.04
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used PS1 catalog for flux calibration. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al., https://doi.org/10.1093/pasj/psaa091, https://arxiv.org/abs/2008.11486; https://github.com/MNiwano/Eclaire).
GCN Circular #29165
```
TITLE:   GCN CIRCULAR
NUMBER:  29165 
SUBJECT: GRB 201223A: iTelescope optical afterglow observations
DATE:    20/12/24 02:49:44 GMT 
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer  
```
I observed the field of GRB 201223A (Gropp et al., GCN Circ. 29158) with remote telescope T18 (0.32-m f/8.0 reflector + CCD) of iTelescope.Net in observatory AstroCamp at Nerpio (Spain) on 2020-12-23 since 19:49:22 UT (1 hour 50 minutes 56 seconds after the trigger). 5 images (with exposures 300, 120 and 180 seconds) were obtained with Astrodon luminance filter and 4 images (exposures: 300 and 60 seconds) with photometric Johnson V filter. I detected the optical afterglow in images with position: RA 08:51:09.46 Dec +71:10:47.00. It is not present in the Pan-STARRS images.
The following magnitudes were measured from comparison to r magnitudes of nearby stars from Pan-STARRS DR1 catalogue (Chambers et al., 2016):
```
Time of start (UT)  Exp.time (s.)  Bin.  Mag. r   Mag. error    Filter
---------------------------------------------------------------------------
19:49:22            300            1     19.2     0.2           Luminance
19:56:25            300            1     19.3     0.4           V
20:26:25            300            2     19.9     0.4           V
20:33:07            300            2     20.1     0.3           Luminance
---------------------------------------------------------------------------
```
Magnitudes were not corrected for Galactic extinction.
Stacked image (4x300 + 2x120 + 180 sec.) available here: https://www.flickr.com/photos/filipp-romanov/50753199496
GCN Circular #29166
L. P. Xin(NAOC), L. H. Li(NAOC), X. H. Han(NAOC), J. Y. Wei(NAOC), J. Wang(GXU), C. Wu(NAOC), X. G. Wang(GXU), E. W. Liang (GXU), Y. L. Qiu(NAOC), and J. S. Deng(NAOC) report:
We began to observe GRB 201223A (Gropp et al., GCN #29158, Wood et al., GCN #29161) with Xinglong GWAC-F60A telescope, China, at 17:59:10.1 (UT), 23th. Dec. 2020, about 44 sec after the burst.
A series of R, I, and B band images were obtained. The optical afterglow reported by (Lipunov et al., GCN #29157; Gropp et al., GCN #29158; Zhu et al., GCN #29159; Hu et al.，GCN #29160; Hosokawa et al., GCN #29164; Filipp Dmitrievich Romanov GCN #29165) was clear detected in our images.
The brightness is fading from 15.0 mag to 18.8 mag in R band during about 100 sec to 10000 sec after the burst.
The R-band brightness is calibrated to the USNO B1.0 catalog, (RA=08:50:21.447, DEC=+71:12:12.80, J2000, R2=9.92)
More analysis are still continuing.
The message may be cited.
GCN Circular #29167
S. Belkin (IKI), A. Pozanenko (IKI), N. Pankov (HSE), E. Klunko (ISTP), A. Novichonok (Petrozavodsk State University, KIAM), Sh. Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN:
We observed the field of GRB 201223A (Gropp et al., GCN 29158) with AZT-33IK telescope of Sayan observatory (Mondy) starting on Dec. 23 (UT) 18:29:01 and Kitab-ISON RC-36 telescope starting (UT) 19:25:57. The optical transient (Lipunov et al. GCN 29157; Gropp et al., GCN 29158; Zhu et al. GCN 29159; Hu et al. GCN 29160; Hosokawa et al. GCN 29164; Romanov et al. GCN 29165; Xin et al. GCN 29166) is detected in our stacked images in R-filter.
Preliminary photometry of the optical transient in a combined images is following
```
Date       UT start   t-T0    Filter Exp.    OT    Err.  UL(3sigma)
                       (mid, days)     (s)

2020-12-23 18:29:01   0.05943 R      10*120  18.95 0.23  19.5 AZT-33IK
2020-12-23 18:29:01   0.05943 R      55*120  19.38 0.09  22.1 AZT-33IK
2020-12-23 19:25:57   0.08161 R      60*60   19.40 0.20  19.6 RC-36
```
The photometry is based on the nearby USNO-B1.0 stars
```
USNO-B1.0_id R2
1611-0080890 18.64
1612-0081305 18.44
```
GCN Circular #29168
H. Kumar (IITB), U. Stanzin (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA), report on behalf of the GROWTH-India collaboration:
We observed GRB 201223A detected by Swift-BAT (J.D. Gropp et al., GCN #29158); optical counterpart first reported by V. Lipunov et al., (GCN #29157) with 0.7m GROWTH-India Telescope, starting at 2020-12-23T18:30:33.51 UT. We obtained multiple images of 300 sec each in the r' filter. We clearly detected the afterglow at a position consistent with Swift-UVOT (GCN #29158) and MASTER-Net OT (GCN #29157) positions.
We obtained the following photometric results:
```
------------------------------------------------------------------

 JD (start) | T_start-T0 (hrs) | Filter | Mag (AB)|

------------------------------------------------------------------

2459207.27122 | 0.5 | r' | 18.52 +/- 0.03

2459207.28623 | 0.9 | r' | 19.12 +/- 0.04

2459207.32568 | 1.8 | r' | 19.98 +/- 0.09

2459207.34029 | 2.2 | r' | 20.15 +/- 0.09

------------------------------------------------------------------
```
Combining our photometric results with r band measurements of Z.P. Zhu et. al., (GCN #29159), we conclude that the source is fading with a power-law index of 1.04 +/- 0.01. The magnitudes are calibrated against PanSTARRs PS1 data release, (Flewelling et al., 2018) and not corrected for galactic extinction. Processing of more data is underway.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
GCN Circular #29169
D. Xu (NAOC), D. B. Malesani (DTU Space), P. Galindo (NOT), Z.P. Zhu (NAOC, HUST), D. A. Kann (HETH/IAA-CSIC), report on behalf of a larger collaboration:
We observed the field of GRB 201223A (Gropp et al., GCN 29158) using the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. We obtained 2x120s Sloan r-band frames starting at 02:21:52 UT on 2020-12-24, i.e., 8.4 hr after the BAT trigger.
The previously reported optical afterglow (Lipunov et al. GCN 29157; Gropp et al., GCN 29158; Zhu et al. GCN 29159; Hu et al. GCN 29160; Hosokawa et al. GCN 29164; Romanov et al. GCN 29165; Xin et al. GCN 29166; Belkin et al., GCN 29167; Kumar et al., GCN 29168) is not detected in the stacked image, down to a limiting magnitude of r > 22.0 mag.
Further analysis of our previous NEXT observations (Zhu et al. GCN 29159) shows that the afterglow is decaying as F_rband ~ t^(-\alpha), where \alpha = 1.1 since the very beginning. The afterglow would be slightly fainter than 22.0 mag if this powerlaw decay is extrapolated until the NOT observational time, being consistent with the observed NOT upper limit. So the afterglow could be decaying in a single powerlaw until the NOT observation or have broken to a steeper decay before the NOT observation.
GCN Circular #29170
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team.
Using 1078 s of XRT Photon Counting mode data and 2 UVOT images for GRB 201223A, 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 = 132.79017, +71.17923 which is equivalent to:
```
RA (J2000): 08h 51m 9.64s
Dec (J2000): +71d 10' 45.2"
```
with an uncertainty of 1.8 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 #29171
M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and J.D. Gropp report on behalf of the Swift-XRT team:
We have analysed 8.0 ks of XRT data for GRB 201223A (Gropp et al. GCN Circ. 29158), from 81 s to 18.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Goad et al. (GCN Circ. 29170).
The light curve can be modelled with a power-law decay with a decay index of alpha=0.82 (+/-0.04).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.87 (+0.18, -0.13). The best-fitting absorption column is 4.1 (+4.0, -0.9) x 10^20 cm^-2, consistent with the Galactic value of 3.1 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 (2.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     4.1 (+4.0, -0.9) x 10^20 cm^-2
Galactic foreground: 3.1 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.87 (+0.18, -0.13)
```
If the light curve continues to decay with a power-law decay index of 0.82, the count rate at T+24 hours will be 5.7 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x 10^-13 (1.6 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01014316.
This circular is an official product of the Swift-XRT team.
GCN Circular #29173
Rahul Gupta (ARIES), Dimple (ARIES), Amit Kumar (ARIES), Vineet Ojha (ARIES), Ankur Ghosh (ARIES), Amar Aryan (ARIES), Shashi B. Pandey (ARIES), and Kuntal Misra (ARIES) report:
We observed the optical afterglow ( Lipunov et al., GCN 29157; Gropp et al., GCN 29158; Zhu et al., GCN 29159; Hu et al., GCN 29160; Hosokawa et al., GCN 29164; Romanov et al., GCN 29165; Xin et al., GCN 29166; Belkin et al., GCN 29167; and Kumar et al., GCN 29168) of Swift and Fermi detected GRB 201223A (Gropp et al., GCN 29158; and Wood et al., GCN 29161) using the 1.3m Devasthal Fast Optical Telescope (DFOT) and 1.04m Sampurnanand Telescope (ST) of Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations were started on 2020-12-23 at 19:01:46 UT. Multiple frames having an exposure time of 300 s were taken in the I filter using DFOT and in BVRI filters using ST. We clearly detected the optical counterpart at the position reported by Gropp et al., GCN 29158.
The preliminary photometric estimate of the afterglow using I band data of DFOT is the following :
```
Date Start_UT           T_start-T0 (hrs)      Filter      Exp time (s)  Magnitude    Mag_err
------------------------------ ------------------------------------------------------------ -------

2020-12-23   19:07:55      1.158              I              300*1          18.71           0.04

------------------------------ ------------------------------------------------------------ -------
```
The magnitude is not corrected for the Galactic and Host extinction in the direction of the burst. Photometric calibration is performed using the standard stars from the USNO-B1.0 catalogue. Further processing of data is going on.
This circular may be cited.
GCN Circular #29174
N. Pankov (HSE, IKI), A. Pozanenko (IKI), S. Belkin (IKI), R. Ya. Inasaridze (AbAO), V. R. Ayvazian (AbAO), G. V. Kapanadze (AbAO), A. Volnova (IKI) report on behalf of IKI-GRB-FuN:
We observed the field of GRB 201223A (Gropp et al., GCN 29158; Wood et al., GCN 29161) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter. The optical afterglow (Lipunov et al., GCN 29157; Gropp et al., GCN 29158; Zhu et al., GCN 29159; Hu et al., GCN 29160; Hosokawa et al., GCN 29164; Romanov et al., GCN 29165; Xin et al., GCN 29166; Belkin et al., GCN 29167; Kumar et al., GCN 29168; Xu et al., GCN 29169; Gupta et al., GCN 29173) is detected in stacked images.
```
Date       UT start   t-T0    Filter Exp.    OT    Err.  UL(3sigma)
                        (mid, days)     (s)

2020-12-23 19:39:59   0.0733  R      8*60   19.38  0.17  19.8
2020-12-23 21:19:22   0.1517  R     35*60   20.28  0.13  20.9
```
The photometry is based on nearby USNO-B1.0 stars.
GCN Circular #29176
H. Kumar(IITB), D. K. Sahu (IIA), V. Bhalerao(IITB), G. C. Anupama(IIA), S. Barway(IIA) report on behalf of the HCT team:
We observed GRB 201223A detected by Swift-BAT (J.D. Gropp et al., GCN #29158); optical counterpart first reported by V. Lipunov et al., (GCN #29157) with 2.0m Himalayan Chandra Telescope (HCT). We obtained a series of 180-sec exposures in the Bessell R filter and did not detect the afterglow in our stacked image. We obtained the following upper limit:
-------------------------------------------------------------------
JD (mid) | T_mid-T0(hrs) | Exposure | Filter | Lim_mag (5-sigma) |
-------------------------------------------------------------------
2459208.4569 | 28.99 | 180*10 (stacked) | Bessell R | > 22.49 |
-------------------------------------------------------------------
Our upper limit is consistent with power-law decay extrapolation suggested by D. Xu et al., (GCN #29169), Kumar et al., (GCN #29168).
These observations were carried out under the ToO program "HCT-2020-C3-P6". We thank HCT staff for undertaking the observations.
GCN Circular #29177
A. Belles (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 201223A 79 s after the BAT trigger (Gropp et al., GCN Circ. 29158).
A source consistent with the XRT position (Goad et al., GCN Circ. 29170) is detected in the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 08:51:09.51 = 132.78961 (deg.)
Dec (J2000) = +71:10:47.4 = 71.17984 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).
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
white_FC 79 229 147 16.06+/-0.03
white 571 1019 186 18.04+/-0.08
white 5921 6121 196 >20.17
white 12121 12630 497 20.09+/-0.30
v 621 1069 58 >17.44
b 547 1167 58 17.97+/-0.25
b 11208 12115 885 >20.38
u_FC 292 541 246 16.75 +/- 0.04
u 694 1142 38 >17.58
w1 670 1118 58 >17.65
m2 645 1093 58 >17.87
w2 596 1045 58 >17.81
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 #29180
M. Nakamura, K. Hasuda, T. Sakamoto (AGU)
We observed the field of GRB 201223A detected by Swift (Gropp et al., GCN Circ. 29158) with the 14-inch AGU Robotic Optical Monitor for Astrophysical object - Narrow (AROMA-N) located at the Sagamihara campus of Aoyama Gakuin University. 58 images of 60 sec exposures were taken in the R filter starting from December 23 18:04:02 (UT) about 5.6 minutes after the trigger and stopped on December 23 19:16:09 (UT). We do not detect the optical afterglow both in the individual images and the stacked image. The estimated five sigma upper limit of the combined image (total exposure of 3480 sec) is ~17.3 mag using the USNO-B1 catalog.
GCN Circular #29201
L. P. Xin(NAOC), X. H. Han(NAOC), J. Y. Wei(NAOC), L. H. Li(NAOC), J. Wang(GXU), D. Turpin(CEA), H. B. Cai(NAOC), X. Y. Wang(NJU), C. Wu(NAOC), X. G. Wang(GXU), Z. G. Dai (NJU), G. W. Li(NAOC), E. W. Liang (GXU), S.S.Sun(GXU), L. Huang(NAOC), X. M. Lu(NAOC), Y. G. Yang(HNU), C. Gao(GXU), Y. L. Qiu(NAOC), and J. S. Deng(NAOC) report:
The optical counterpart of GRB 201223A (Gropp et al., GCN #29158, Wood et al., GCN #29161) reported by (Lipunov et al., GCN #29157; Gropp et al., GCN #29158; Zhu et al., GCN #29159; Hu et al., GCN #29160; Hosokawa et al., GCN #29164; Filipp Dmitrievich Romanov GCN #29165; Xin et al., GCN #29166; Belkin et al., GCN #29167; Kumar et al., GCN #29168; Xu et al., GCN #29169; Gupta te al., GCN #29173; Pankov et al., GCN #29174; Kumar et al., GCN #29176; Belles et al., GCN #29177 ) was detected by Ground Wide Angle Camera (GWAC) in white band at Xinglong observatory, China, during the Swift prompt emission phase. The exposure time for each GWAC image is 10 seconds.
Preliminary process showed that the brightness was about R~15.5 mag at ~2 sec after the burst, and then brighten to the peak of R~14.8 mag at about 80 sec post the trigger time.
All these magnitudes were calibrated to USNO B1.0 R2 mag catalog.
More analyses are still continuing.

Back to JG's homepage

Jochen Greiner, last update: 30-Dec-2020 [Disclaimer]