Gamma-ray Burst 141212B

(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:     Fri 12 Dec 14 13:24:03 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     621234,   Seg_Num: 0
GRB_RA:          250.869d {+16h 43m 28s} (J2000),
                 251.011d {+16h 44m 03s} (current),
                 250.391d {+16h 41m 34s} (1950)
GRB_DEC:         +31.749d {+31d 44' 57"} (J2000),
                 +31.722d {+31d 43' 20"} (current),
                 +31.842d {+31d 50' 30"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3346 [cnts]    Image_Peak=157 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       21058 [cnts]
BKG_TIME:        48211.09 SOD {13:23:31.09} UT
BKG_DUR:         8 [sec]
GRB_DATE:        17003 TJD;   346 DOY;   14/12/12
GRB_TIME:        48228.24 SOD {13:23:48.24} UT
GRB_PHI:           0.57 [deg]
GRB_THETA:        30.19 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.74 [sigma]
IMAGE_SIGNIF:    7.17 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -3  +0  +0 -56  +0 
SUN_POSTN:       259.59d {+17h 18m 23s}  -23.09d {-23d 05' 30"}
SUN_DIST:         55.43 [deg]   Sun_angle= 0.6 [hr] (West of Sun)
MOON_POSTN:      149.91d {+09h 59m 38s}   +8.28d {+08d 17' 03"}
MOON_DIST:        94.95 [deg]
MOON_ILLUM:      68 [%]
GAL_COORDS:       52.96, 39.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      242.16, 53.36 [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 = 3.36,-15.36 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Dec 14 13:25:28 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     621234,   Seg_Num: 0
POINT_RA:        250.862d {+16h 43m 27s} (J2000)
POINT_DEC:       +31.733d {+31d 43' 58"} (J2000)
IMG_START_DATE:  17003 TJD;   346 DOY;   14/12/12
IMG_START_TIME:  48313.40 SOD {13:25:13.40} UT,   85.2 [sec] since BAT Trigger Time
COUNTS:          13    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        2    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:     Fri 12 Dec 14 13:27:43 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     621234,   Seg_Num: 0
GRB_RA:          250.869d {+16h 43m 28s} (J2000),
                 251.011d {+16h 44m 03s} (current),
                 250.391d {+16h 41m 34s} (1950)
GRB_DEC:         +31.749d {+31d 44' 57"} (J2000),
                 +31.722d {+31d 43' 20"} (current),
                 +31.842d {+31d 50' 30"} (1950)
GRB_DATE:        17003 TJD;   346 DOY;   14/12/12
GRB_TIME:        48228.24 SOD {13:23:48.24} UT
TRIGGER_INDEX:   146
GRB_PHI:           0.57 [deg]
GRB_THETA:        30.19 [deg]
DELTA_TIME:      44.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.74 [sigma]
IMAGE_SIGNIF:    7.17 [sigma]
LC_URL:          sw00621234000msb.lc
SUN_POSTN:       259.60d {+17h 18m 23s}  -23.09d {-23d 05' 31"}
SUN_DIST:         55.43 [deg]   Sun_angle= 0.6 [hr] (West of Sun)
MOON_POSTN:      149.94d {+09h 59m 45s}   +8.28d {+08d 16' 31"}
MOON_DIST:        94.93 [deg]
MOON_ILLUM:      68 [%]
GAL_COORDS:       52.96, 39.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      242.16, 53.36 [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 = 3.36,-15.36 [deg].

GCN Circular #17159
M. Stamatikos (OSU/NASA/GSFC), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), B.P. Gompertz (U Leicester), J. A. Kennea (PSU), K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 13:23:48 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 141212B (trigger=621234). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 250.869, +31.749 which is
```
   RA(J2000)  =  16h 43m 28s
   Dec(J2000) = +31d 44' 57"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a multiple-peak structure with a duration of about 15 sec. The peak count rate was ~7000 counts/sec (15-350 keV), at ~4 sec after the trigger.
The XRT began observing the field at 13:25:13.4 UT, 85.2 seconds after the BAT trigger. No source was detected in the 2.5-s promptly available image. We are waiting for the full dataset to detect and localise the XRT counterpart.
Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). 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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Dec 14 13:37:11 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     621234,   Seg_Num: 0
POINT_RA:        250.864d {+16h 43m 27s} (J2000)
POINT_DEC:       +31.733d {+31d 43' 58"} (J2000)
POINT_ROLL:      170.296d
IMG_START_DATE:  17003 TJD;   346 DOY;   14/12/12
IMG_START_TIME:  48630.91 SOD {13:30:30.91} UT,   402.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.847
N_STARS:         25
X_OFFSET:        355 [pixels]
Y_OFFSET:        569 [pixels]
X_MAX:           1314 [pixels]
Y_MAX:           1528 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw00621234000msufc0402.fits
SUN_POSTN:       259.60d {+17h 18m 25s}  -23.09d {-23d 05' 32"}
SUN_DIST:         55.41 [deg]   Sun_angle= 0.6 [hr] (West of Sun)
MOON_POSTN:      150.01d {+10h 00m 03s}   +8.25d {+08d 15' 10"}
MOON_DIST:        94.88 [deg]
MOON_ILLUM:      68 [%]
GAL_COORDS:       52.94, 39.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      242.16, 53.34 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Dec 14 13:37:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     621234,   Seg_Num: 0
POINT_RA:        250.864d {+16h 43m 27s} (J2000)
POINT_DEC:       +31.733d {+31d 43' 58"} (J2000)
POINT_ROLL:      170.296d
IMG_START_DATE:  17003 TJD;   346 DOY;   14/12/12
IMG_START_TIME:  48630.91 SOD {13:30:30.91} UT,   402.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        7.847
N_STARS:         25
X_OFFSET:        355 [pixels]
Y_OFFSET:        569 [pixels]
X_MAX:           1314 [pixels]
Y_MAX:           1528 [pixels]
DET_THRESH:      24
PHOTO_THRESH:    15
SL_URL:          sw00621234000msufc0402.fits
SUN_POSTN:       259.60d {+17h 18m 25s}  -23.09d {-23d 05' 33"}
SUN_DIST:         55.41 [deg]   Sun_angle= 0.6 [hr] (West of Sun)
MOON_POSTN:      150.01d {+10h 00m 03s}   +8.25d {+08d 15' 08"}
MOON_DIST:        94.88 [deg]
MOON_ILLUM:      68 [%]
GAL_COORDS:       52.94, 39.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      242.16, 53.34 [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:     Fri 12 Dec 14 13:38:52 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     621234,   Seg_Num: 0
POINT_RA:        250.864d {+16h 43m 27s} (J2000)
POINT_DEC:       +31.733d {+31d 43' 58"} (J2000)
ROLL:            170.296d
IMG_START_DATE:  17003 TJD;   346 DOY;   14/12/12
IMG_START_TIME:  48630.91 SOD {13:30:30.91} UT,   402.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     440083843
X_OFFSET:        674 [pixels]
Y_OFFSET:        888 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1048
BINNING_INDEX:   1
IM_URL:          sw00621234000msuni0415.fits
SUN_POSTN:       259.61d {+17h 18m 25s}  -23.09d {-23d 05' 33"}
SUN_DIST:         55.41 [deg]   Sun_angle= 0.6 [hr] (West of Sun)
MOON_POSTN:      150.03d {+10h 00m 06s}   +8.25d {+08d 14' 56"}
MOON_DIST:        94.88 [deg]
MOON_ILLUM:      68 [%]
GAL_COORDS:       52.94, 39.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      242.16, 53.34 [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:     Fri 12 Dec 14 13:39:01 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     621234,   Seg_Num: 0
POINT_RA:        250.864d {+16h 43m 27s} (J2000)
POINT_DEC:       +31.733d {+31d 43' 58"} (J2000)
ROLL:            170.296d
IMG_START_DATE:  17003 TJD;   346 DOY;   14/12/12
IMG_START_TIME:  48630.91 SOD {13:30:30.91} UT,   402.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     440083843
X_OFFSET:        674 [pixels]
Y_OFFSET:        888 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       834
Y_GRB_POS:       1048
BINNING_INDEX:   1
IM_URL:          sw00621234000msuni0415.fits
SUN_POSTN:       259.61d {+17h 18m 25s}  -23.09d {-23d 05' 33"}
SUN_DIST:         55.41 [deg]   Sun_angle= 0.6 [hr] (West of Sun)
MOON_POSTN:      150.03d {+10h 00m 06s}   +8.25d {+08d 14' 55"}
MOON_DIST:        94.87 [deg]
MOON_ILLUM:      68 [%]
GAL_COORDS:       52.94, 39.86 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      242.16, 53.34 [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 Circular #17165
J. A. Kennea (PSU), K. L. Page (U Leicester) and T. N. Ukwatta (LANL) report on behalf of the Swift/XRT Team:
At 13:25:13.4 UT on December 12, 2014, 85.2 seconds after the BAT trigger, XRT began observing GRB 141212B. We find a uncatalogued source at an XRT count rate of 2-3 c/s during the first orbit, and 0.4 c/s during the 2nd orbit observations. Based on 140s of PC mode data, we find a preliminary localization of RA/Dec(J2000) = 250.87573, 31.752983, equivalent to:
```
RA(J2000)  = 16h 43m 30.1s
Dec(J2000) = 31d 45m 10.7s
```
with an estimated uncertainty of 10 arc-seconds radius (90% confidence). We expect this position to be improved as we collect more data.
GCN Circular #17166
S. R. Oates (IAA-CSIC/UCL-MSSL), M. H. Siegel (PSU) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift-UVOT team:
UVOT took a finding chart exposure of GRB 141212B of 127 seconds with the White filter starting 402 seconds after the BAT trigger (trigger=621234). No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers the preliminary XRT error circle (Kennea et al. GCN Circ. 17165). 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 BAT 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 0.03.
GCN Circular #17174
K.L. Page, P.A. Evans, M.R. Goad and B.P. Gompertz (U. Leicester) report on behalf of the Swift-XRT team:
Using 152 s of XRT Photon Counting mode data and 1 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 = 250.87617, 31.75045 which is equivalent to:
```
RA (J2000):  16 43 30.28
Dec (J2000): +31 45 01.6
```
with an uncertainty of 2.3 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177).
This circular is an official product of the Swift-XRT team.
GCN Circular #17176
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+459 sec from the recent telemetry downlink, we report further analysis of BAT GRB 141212B (trigger #621234) (Stamatikos, et al., GCN Circ. 17159). The BAT ground-calculated position is RA, Dec = 250.866, 31.749 deg which is
```
   RA(J2000)  =  16h 43m 27.9s
   Dec(J2000) = +31d 44' 55.3"
```
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%.
BAT light curve shows a single multi-peaked episode starting around T+0 sec, and ending around T+15 sec. The two main peaks of the light curve can be seen at T+5 sec and T+6 sec. T90 (15-350 keV) is 10.5 +- 0.7 sec (estimated error including systematics).
The time-averaged spectrum from T-0.06 to T+12.14 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.46 +- 0.09. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+4.10 sec in the 15-150 keV band is 3.9 +- 0.3 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/621234/BA/
GCN Circular #17179
S. R. Oates (IAA-CSIC/UCL-MSSL) and M. Stamatikos (OSU/NASA/GSFC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 141212B 403 s after the BAT trigger (Stamatikos et al., GCN Circ. 17159). No optical afterglow consistent with the XRT position (Page et al. GCN Circ. 17174) 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           403          530          125         >19.8
v                 3819         3975          153         >18.9
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #17181
B. P. Gompertz, K. L. Page (U. Leicester) and M. Stamatikos (OSU/NASA/GSFC) reports on behalf of the Swift-XRT team:
We have analysed 2.1 ks of XRT data for GRB 141212B (Stamatikos et al. GCN Circ. 17159), from 350 s to 45.2 ks after the BAT trigger. The data comprise 179 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode.
The enhanced XRT position for this burst was given by Page et al. (GCN Circ. 17174)
The light curve can be modelled with a power-law decay with a decay index of alpha=1.05 (+0.08, -0.06).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.1 (+0.4, -0.3). The best-fitting absorption column is 7 (+12, -5) x 10^20 cm^-2, consistent with the Galactic value of 2.2 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 3.0 x 10^-11 (3.6 x 10^-11) erg cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
```
Total column:	     7 (+12, -5) x 10^20 cm^-2
Galactic foreground: 2.2 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     2.1 (+0.4, -0.3)
```
If the light curve continues to decay with a power-law decay index of 1.05, the count rate at T+24 hours will be 7.2 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.1 x 10^-13 (2.5 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/00621234.
This circular is an official product of the Swift-XRT team.
GCN Circular #17182
S. Golenetskii, R. Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
The long-duration, weak GRB 141212B (Swift-BAT trigger #621234: Stamatikos et al., GCN 17159; Sakamoto et al., GCN 17176 ) triggered Konus-Wind at T0=48230.404 s UT (13:23:50.404).
The burst light curve shows a multipeak structure started at ~T0-6.8 s with a duration of ~8.0 s. The emission is seen up to ~500 keV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB141212_T48230/
As observed by Konus-Wind, the burst had a fluence of 1.65(-0.22,+0.38)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.014 s, of 1.48(-0.24,+0.40)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 1 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.44(-0.28,+0.33) and Ep = 150(-46,+136) keV (chi2 = 57/60 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -1.9 (chi2 = 56/59 dof)
All the quoted errors are at the 1 sigma confidence level. All the quoted values are preliminary.
GCN Circular #17183
Y. Yano, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, S. Kurita, Y. Ono, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 141212B (M. Stamatikos et al., GCN Circular #17159) 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 on 2014-12-12 19:31:43 UT (~6 h after the burst). We did not find any new point source within the enhanced XRT circle (K. L. Page et al., GCN Circular #17174) in all the three bands.
The measured magnitudes are listed below.
```
T0+[sec]     MID-UT    T-EXP[sec]        g'         Rc        Ic
------------------------------------------------------------------------------
25180        20:31:06        840            >19.0  >18.8  >18.3
------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
```
We used GSC2.3 catalog for flux calibration.

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Jochen Greiner, last update: 13-Dec-2014 [Disclaimer]