Gamma-ray Burst 171209A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 09 Dec 17 14:46:55 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     796100,   Seg_Num: 0
GRB_RA:          139.382d {+09h 17m 32s} (J2000),
                 139.573d {+09h 18m 18s} (current),
                 138.848d {+09h 15m 24s} (1950)
GRB_DEC:         -30.528d {-30d 31' 38"} (J2000),
                 -30.604d {-30d 36' 12"} (current),
                 -30.317d {-30d 19' 01"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       9775 [cnts]    Image_Peak=263 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   307     E_range: 50-350 keV
BKG_INTEN:       79131 [cnts]
BKG_TIME:        53115.87 SOD {14:45:15.87} UT
BKG_DUR:         40 [sec]
GRB_DATE:        18096 TJD;   343 DOY;   17/12/09
GRB_TIME:        53176.22 SOD {14:46:16.22} UT
GRB_PHI:          25.83 [deg]
GRB_THETA:        31.48 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.00 [sigma]
IMAGE_SIGNIF:    7.97 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +3  -2  +0  +0 +16  +0 
SUN_POSTN:       256.66d {+17h 06m 37s}  -22.87d {-22d 52' 09"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.09d {+10h 44m 22s}   +9.93d {+09d 55' 45"}
MOON_DIST:        45.50 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.67, 12.98 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      154.46,-43.56 [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 = 248.52,-7.48 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 09 Dec 17 14:48:24 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     796100,   Seg_Num: 0
GRB_RA:            0.0000d {+00h 00m 00.0s} (J2000),
                   0.2298d {+00h 00m 55.1s} (current),
                 359.3595d {+23h 57m 26.2s} (1950)
GRB_DEC:          +0.0000d {+00d 00' 00.0"} (J2000),
                  +0.0999d {+00d 05' 59.5"} (current),
                  -0.2784d {-00d 16' 42.2"} (1950)
GRB_ERROR:       -773094113.3 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       0 [cnts]
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53275.37 SOD {14:47:55.37} UT,   99.2 [sec] since BAT Trigger Time
CENTROID_X:      0.00,  raw= 0  [pixels]
CENTROID_Y:      0.00,  raw= 0  [pixels]
ROLL:            0.00 [deg]
GAIN:            0
MODE:            0, illegal mode
WAVEFORM:        0
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   42.11
GRB_POS_XRT_Z:   13.27
IMAGE_URL:       sw00796100000msxps_rw.img
SUN_POSTN:       256.66d {+17h 06m 38s}  -22.87d {-22d 52' 09"}
SUN_DIST:        102.53 [deg]   Sun_angle= -6.9 [hr] (East of Sun)
MOON_POSTN:      161.11d {+10h 44m 25s}   +9.93d {+09d 55' 30"}
MOON_DIST:       158.49 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:       96.34,-60.19 [deg] galactic lon,lat of the burst
ECL_COORDS:        0.00,  0.00 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        WARNING: This Notice was received with 1 (or more) critical values out of range.  
COMMENTS:        WARNING: The centroided position is more than 100 rows or columns from the center of the FOV.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 09 Dec 17 14:49:42 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     796100,   Seg_Num: 0
GRB_RA:          139.382d {+09h 17m 32s} (J2000),
                 139.573d {+09h 18m 18s} (current),
                 138.848d {+09h 15m 24s} (1950)
GRB_DEC:         -30.528d {-30d 31' 38"} (J2000),
                 -30.604d {-30d 36' 12"} (current),
                 -30.317d {-30d 19' 01"} (1950)
GRB_DATE:        18096 TJD;   343 DOY;   17/12/09
GRB_TIME:        53176.22 SOD {14:46:16.22} UT
TRIGGER_INDEX:   307
GRB_PHI:          25.83 [deg]
GRB_THETA:        31.48 [deg]
DELTA_TIME:      44.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     9.00 [sigma]
IMAGE_SIGNIF:    7.97 [sigma]
LC_URL:          sw00796100000msb.lc
SUN_POSTN:       256.66d {+17h 06m 38s}  -22.87d {-22d 52' 09"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.12d {+10h 44m 28s}   +9.92d {+09d 55' 17"}
MOON_DIST:        45.50 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.67, 12.98 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      154.46,-43.56 [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 = 248.52,-7.48 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 09 Dec 17 15:07:55 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     796100,   Seg_Num: 0
POINT_RA:        139.397d {+09h 17m 35s} (J2000)
POINT_DEC:       -30.531d {-30d 31' 51"} (J2000)
ROLL:            123.882d
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53283.51 SOD {14:48:03.51} UT,   107.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     534523703
X_OFFSET:        734 [pixels]
Y_OFFSET:        828 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       894
Y_GRB_POS:       988
BINNING_INDEX:   1
IM_URL:          sw00796100000msuni0128.fits
SUN_POSTN:       256.67d {+17h 06m 41s}  -22.87d {-22d 52' 14"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.28d {+10h 45m 08s}   +9.87d {+09d 52' 13"}
MOON_DIST:        45.53 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.68, 12.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.48,-43.56 [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:     Sat 09 Dec 17 15:08:10 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     796100,   Seg_Num: 0
POINT_RA:        139.397d {+09h 17m 35s} (J2000)
POINT_DEC:       -30.531d {-30d 31' 51"} (J2000)
ROLL:            123.882d
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53283.51 SOD {14:48:03.51} UT,   107.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     534523703
X_OFFSET:        734 [pixels]
Y_OFFSET:        828 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       894
Y_GRB_POS:       988
BINNING_INDEX:   1
IM_URL:          sw00796100000msuni0128.fits
SUN_POSTN:       256.67d {+17h 06m 41s}  -22.87d {-22d 52' 14"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.29d {+10h 45m 09s}   +9.87d {+09d 52' 11"}
MOON_DIST:        45.53 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.68, 12.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.48,-43.56 [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:     Sat 09 Dec 17 15:11:46 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     796100,   Seg_Num: 0
POINT_RA:        139.399d {+09h 17m 36s} (J2000)
POINT_DEC:       -30.529d {-30d 31' 44"} (J2000)
POINT_ROLL:      123.881d
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53441.45 SOD {14:50:41.45} UT,   265.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.764
N_STARS:         53
X_OFFSET:        414 [pixels]
Y_OFFSET:        508 [pixels]
X_MAX:           1373 [pixels]
Y_MAX:           1467 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00796100000msufc0265.fits
SUN_POSTN:       256.68d {+17h 06m 42s}  -22.87d {-22d 52' 15"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.32d {+10h 45m 17s}   +9.86d {+09d 51' 34"}
MOON_DIST:        45.53 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.68, 12.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.48,-43.55 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 09 Dec 17 15:12:01 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     796100,   Seg_Num: 0
POINT_RA:        139.399d {+09h 17m 36s} (J2000)
POINT_DEC:       -30.529d {-30d 31' 44"} (J2000)
POINT_ROLL:      123.881d
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53441.45 SOD {14:50:41.45} UT,   265.2 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.764
N_STARS:         53
X_OFFSET:        414 [pixels]
Y_OFFSET:        508 [pixels]
X_MAX:           1373 [pixels]
Y_MAX:           1467 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00796100000msufc0265.fits
SUN_POSTN:       256.68d {+17h 06m 42s}  -22.87d {-22d 52' 15"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.32d {+10h 45m 17s}   +9.86d {+09d 51' 32"}
MOON_DIST:        45.53 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.68, 12.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.48,-43.55 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 09 Dec 17 15:13:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     796100,   Seg_Num: 0
POINT_RA:        139.399d {+09h 17m 36s} (J2000)
POINT_DEC:       -30.529d {-30d 31' 44"} (J2000)
ROLL:            123.881d
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53441.45 SOD {14:50:41.45} UT,   265.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     534523861
X_OFFSET:        734 [pixels]
Y_OFFSET:        828 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       894
Y_GRB_POS:       988
BINNING_INDEX:   1
IM_URL:          sw00796100000msuni0286.fits
SUN_POSTN:       256.68d {+17h 06m 42s}  -22.87d {-22d 52' 15"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.33d {+10h 45m 20s}   +9.86d {+09d 51' 21"}
MOON_DIST:        45.53 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.68, 12.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.48,-43.55 [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:     Sat 09 Dec 17 15:13:20 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     796100,   Seg_Num: 0
POINT_RA:        139.399d {+09h 17m 36s} (J2000)
POINT_DEC:       -30.529d {-30d 31' 44"} (J2000)
ROLL:            123.881d
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53441.45 SOD {14:50:41.45} UT,   265.2 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     534523861
X_OFFSET:        734 [pixels]
Y_OFFSET:        828 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       894
Y_GRB_POS:       988
BINNING_INDEX:   1
IM_URL:          sw00796100000msuni0286.fits
SUN_POSTN:       256.68d {+17h 06m 42s}  -22.87d {-22d 52' 15"}
SUN_DIST:         99.39 [deg]   Sun_angle= 7.8 [hr] (West of Sun)
MOON_POSTN:      161.33d {+10h 45m 20s}   +9.86d {+09d 51' 18"}
MOON_DIST:        45.53 [deg]
MOON_ILLUM:      58 [%]
GAL_COORDS:      257.68, 12.99 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      154.48,-43.55 [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 #22213
S. J. LaPorte (PSU), D. N. Burrows (PSU), P. D'Avanzo (INAF-OAB), S. W. K Emery (UCL-MSSL), J.D. Gropp (PSU), J. A. Kennea (PSU), N. P. M. Kuin (UCL-MSSL), A. Melandri (INAF-OAB) and D. M. Palmer (LANL) report on behalf of the Swift Team:
At 14:46:16 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 171209A (trigger=796100). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 139.382, -30.528 which is
```
   RA(J2000) = 09h 17m 32s
   Dec(J2000) = -30d 31' 38"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 100 sec. The peak count rate was ~1300 counts/sec (15-350 keV), at ~80 sec after the trigger.
UVOT took a finding chart exposure of 194 seconds with the U filter starting 265 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 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.2 mag. The 8'x8' region for the list of sources generated on-board covers 98% of the BAT error circle. The list of sources is typically complete to about 18.0 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.15. However, a possible candidate source of magnitude 17.3 in white is present at RA(J2000) = 09h 17m 36.70s Dec(J2000) = -30d 31m 12.0s which is very close to two other sources in the DSS survey image.
The XRT detected the afterglow from this GRB. However, due to data transmission problems, an XRT position will not be available until more data is transmitted to the ground.
Burst Advocate for this burst is S. J. LaPorte (extragsam AT gmail.com). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN Circular #22214
C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU), C.G. Mundell (U. Bath),=20 A. Gomboc (U. Nova Gorica), I.A. Steele (LJMU) on behalf of a large=20 collaboration report:
We observed Swift GRB171209A (LaPorte et al. GCN 22213) on December 9,=20 16:25 UT (1.65 hours post burst) with one of the 1-m LCO telescopes in=20 Siding Springs in the SDSS ri filters. We detect the UVOT candidate,=20 which is not visible in archival Pan-STARRS images, with the following=20 magnitudes:
```
Mid Time=A0=A0=A0=A0 Exposure=A0=A0=A0=A0=A0=A0=A0 Filter=A0=A0=A0=A0 Mag=
nitude (AB)
(hr)=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 (s)
------------------------------------------------------
1.69=A0=A0=A0=A0=A0=A0=A0=A0=A0 2x120=A0=A0=A0=A0=A0=A0=A0=A0=A0 SDSS-R=A0=
=A0=A0=A0=A0=A0 18.2 +- 0.3
1.78=A0=A0=A0=A0=A0=A0=A0=A0=A0 2x120=A0=A0=A0=A0=A0=A0=A0=A0=A0 SDSS-I=A0=
=A0=A0=A0=A0=A0 17.8 +- 0.3
------------------------------------------------------
```
as calibrated against nearby Pan-STARRS objects. Due to the vicinity of=20 (~4") of a bright object, our estimated magnitudes are to be taken=20 cautiously.
GCN Circular #22218
P. D=E2=80=99Avanzo, A. Melandri (INAF-OAB), J. A. Kennea (PSU), P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team:
Using 2454 s of XRT Photon Counting mode data and 6 UVOT images, 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 =3D 139.40280, -30.52016 which is equivalent to:
```
RA (J2000):  09 17 36.67
Dec (J2000): -30 31 12.6
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
This position is consistent with the one reported for the Swift/UVOT candidate (LaPorte et al., GCN 22213).=20
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 is an official product of the Swift-XRT team.
GCN Circular #22219
B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (PSU) and S.J. LaPorte report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 171209A (LaPorte et al. GCN Circ. 22213), from 92 s to 17.9 ks after the BAT trigger. The data comprise 349 s in Windowed Timing (WT) mode (the first 5 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. Using 2454 s of PC mode data and 6 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 139.40280, -30.52016 which is equivalent to:
```
RA (J2000): 09h 17m 36.67s
Dec(J2000): -30d 31' 12.6"
```
with an uncertainty of 1.7 arcsec (radius, 90% confidence).
The light curve can be modelled with a series of power-law decays. The initial decay index is alpha=1.87 (+/-0.08). At T+231 s the decay steepens to an alpha of 3.42 (+0.26, -0.22) before breaking again at T+629 s to a final decay with index alpha=0.74 (+0.12, -0.11).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.37 (+/-0.04). The best-fitting absorption column is 2.54 (+0.27, -0.25) x 10^21 cm^-2, in excess of the Galactic value of 2.1 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 2.06 (+0.08, -0.07) and a best-fitting absorption column consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.5 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.11 (+0.10, -0.00) x 10^21 cm^-2
Galactic foreground: 2.1 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.06 (+0.08, -0.07)
```
If the light curve continues to decay with a power-law decay index of 0.74, the count rate at T+24 hours will be 0.036 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-12 (1.6 x 10^-12) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00796100.
This circular is an official product of the Swift-XRT team.
GCN Circular #22221
N. P. M. Kuin (UCL-MSSL) and and S. J. LaPorte (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 171209A 107 s after the BAT trigger (LaPorte et al., GCN Circ. 22213). The proposed possible transient position was confirmed by independent observations of the LCO telescopes in Siding Springs in the SDSS r and i filters (Guidorzi et al, GCN Corc. 22214) and by the XRT (d'Avanzo et al. GCN Circ. 22218).
Due to the nearby star (at 3.7"), the count rates were determined using a smaller than normal aperture of 2.5 arcsec, and for the reported magnitudes no aperture correction has been applied. The brightness is seen to rise to 16th magnitude around 400s past the trigger at which time there is a break in the UVOT observations until 4000s past the trigger at which time the source is seen to be decaying. After binning the white filter data in 10s bins, half a magnitude large variability is seen up to 175s after the trigger. There is no measurable flux in the uvw1,uvm2, and uvw1 filters which were observed after the gap, which suggests a redshifted source with a redshift in the range z = 1.8 - 2.8.
Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white              175          185          541         17.4
v                 4630         6265          393         17.3
b                 4014         5649          393         18.2
u                  320          350           30         16.5
w1                5039         6480          201         >19.6
m2                4834         6470          393         >20.2
w2                4425         6060          393         >20.1
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.15 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #22229
J. R. Cummings (CPI), S. D. Barthelmy (GSFC), H. A. Krimm (NSF/USRA), S. J. LaPorte (PSU), 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+400 sec from the recent telemetry downlink, we report further analysis of BAT GRB 171209A (trigger #796100) (LaPorte et al., GCN Circ. 22213). The BAT ground-calculated position is RA, Dec = 139.387, -30.523 deg which is
```
  RA(J2000)  =  09h 17m 32.8s
  Dec(J2000) = -30d 31' 22.4"
```
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 61%.
The mask-weighted light curve shows a multi-peaked structure that starts at ~ T-70 s and ends at ~ T+230 s. T90 (15-350 keV) is 161.7 +- 30.8 sec (estimated error including systematics).
The time-averaged spectrum from T-70.76 to T+228.44 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.58 +- 0.07. The fluence in the 15-150 keV band is 7.5 +- 0.3 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+79.52 sec in the 15-150 keV band is 1.6 +- 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/796100/BA/
GCN Circular #22230
GRB 171209A: Lulin 1m telescope observations
A.K.H. Kong (NTHU, Taiwan) reports
We observed the field of GRB 171209A (LaPorte et al. GCN 22213) with the 1m telescope at the Lulin Observatory in Taiwan. The observations were done with the SDSS r and i filters and the first observation were started at 2017-12-09 20:20:16 UT (5.6 hours post burst). We detect the optical afterglow identified by the UVOT and LCO (Guidorzi et al. GCN 22214). We obtained the following magnitudes:
```
Start time     Exposure     Filter     Magnitude (AB)
20:20:16       300s         SDSS-r     19.47+/-0.11
20:25:50       300s         SDSS-i     18.97+/-0.09
```
The magnitudes were calibrated with nearby Pan-STARRS objects.
GCN Circular #22237
E. Gorbovskoy, V. Lipunov, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU
R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA), National University of San Juan, Argentina
H. Levato, C. Saffe Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina
D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory
R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias
O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, Irkutsk State University
V.Yurkov, Yu.Sergienko Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in OAFA was starting survey on the SWIFT GRB171209A error-box (LaPorte et al. GCN 22213) 44912 sec after notice time and 44965 sec after trigger time at 2017-12-10 03:15:41 UT. The 5-sigma upper limit on our single (180s exposure) set is about 19.4-m and 20.0-m on coadd (3x180 = 540s) image. We not see OT previously reported by Kuin et al. GCN 22221 , Guidorzi et al. GCN 22214 , Kong et al. GCN 22230.
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was starting survey on the SWIFT GRB171209A 114607 sec (~ 32 hours) after trigger time at 2017-12-10 03:15:41 UT. The 5-sigma upper limit on our single (180s exposure) set is about 19.4-m and 20.5-m on coadd (10 x 180 = 1800 s) image. Here we also not see any OT.
This message can be cited.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Tue 12 Dec 17 12:02:26 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     796100,   Seg_Num: 0
GRB_RA:            0.0000d {+00h 00m 00.00s} (J2000),
                   0.2298d {+00h 00m 55.16s} (current),
                 359.3595d {+23h 57m 26.27s} (1950)
GRB_DEC:          +0.0000d {+00d 00' 00.0"} (J2000),
                  +0.0999d {+00d 05' 59.5"} (current),
                  -0.2784d {-00d 16' 42.2"} (1950)
GRB_ERROR:       0.0 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       0.00e+00 [erg/cm2/sec]
GRB_SIGNIF:      0.00 [sigma]
IMG_START_DATE:  18096 TJD;   343 DOY;   17/12/09
IMG_START_TIME:  53277.89 SOD {14:47:57.89} UT,   10236.2 [sec] since BAT Trigger Time
TAM[0-3]:          0.00   0.00   0.00   0.00
AMPLIFIER:       0
WAVEFORM:        0
SUN_POSTN:       259.83d {+17h 19m 20s}  -23.11d {-23d 06' 24"}
SUN_DIST:         99.60 [deg]   Sun_angle= -6.7 [hr] (East of Sun)
MOON_POSTN:      196.90d {+13h 07m 36s}   -2.41d {-02d 24' 21"}
MOON_DIST:       163.18 [deg]
MOON_ILLUM:      28 [%]
GAL_COORDS:       96.34,-60.19 [deg] galactic lon,lat of the burst
ECL_COORDS:        0.00,  0.00 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        WARNING: This Notice was received with 1 (or more) critical values out of range.

GCN Circular #22360
A.Kozlova, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
The long GRB 171209A (Swift-BAT trigger #796100: LaPorte et al., GCN 22213; Cummings et al., GCN 22229) was detected by Konus-Wind (KW) in the waiting mode.
The burst light curve shows a multi-peaked structure with a duration of ~ 147 s.
As observed by KW, the burst had a fluence of 1.56(-0.17,+0.16)x10^-5 erg/cm2 and a 2.944-s peak flux, measured from ~T0(BAT)+22.4 s, of 3.06(-0.62,+0.61)x10^-7 erg/cm2/s (both in the 20 - 10000 keV energy range).
Modeling the KW 3-channel time-integrated spectrum (from ~T0(BAT)-1.2 s to ~T0(BAT)+146 s) by a power law with exponential cutoff model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -1.13 (-0.23,+0.40), and Ep = 279 (-86,+141) keV.
The KW light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB171209A/
All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.

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Jochen Greiner, last update: 17-Jan-2018 [Disclaimer]