Gamma-ray Burst 191213A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 13 Dec 19 04:07:42 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     944091,   Seg_Num: 0
GRB_RA:          224.507d {+14h 58m 02s} (J2000),
                 224.776d {+14h 59m 06s} (current),
                 223.833d {+14h 55m 20s} (1950)
GRB_DEC:          -9.726d {-09d 43' 33"} (J2000),
                  -9.805d {-09d 48' 18"} (current),
                  -9.527d {-09d 31' 34"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=1803 [image_cnts]
TRIGGER_DUR:     64.000 [sec] 
TRIGGER_INDEX:   20000     E_range: 15-50 keV
BKG_INTEN:       0 [cnts]
BKG_TIME:        0.00 SOD {00:00:00.00} UT
BKG_DUR:         0 [sec]
GRB_DATE:        18830 TJD;   347 DOY;   19/12/13
GRB_TIME:        14783.92 SOD {04:06:23.92} UT
GRB_PHI:         -100.89 [deg]
GRB_THETA:        26.11 [deg]
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    11.12 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +1 -100  +0 -80  +0 
SUN_POSTN:       260.04d {+17h 20m 09s}  -23.12d {-23d 07' 10"}
SUN_DIST:         36.21 [deg]   Sun_angle= 2.4 [hr] (West of Sun)
MOON_POSTN:       92.83d {+06h 11m 19s}  +22.78d {+22d 46' 59"}
MOON_DIST:       132.32 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      347.07, 42.05 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      224.93,  6.88 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This is an image trigger.  (The RATE_SIGNIF & BKG_{INTEN, TIME, DUR} are undefined.)  
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 = 50.14,-18.20 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 13 Dec 19 04:10:15 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     944091,   Seg_Num: 0
GRB_RA:          224.507d {+14h 58m 02s} (J2000),
                 224.776d {+14h 59m 06s} (current),
                 223.833d {+14h 55m 20s} (1950)
GRB_DEC:          -9.726d {-09d 43' 33"} (J2000),
                  -9.805d {-09d 48' 18"} (current),
                  -9.527d {-09d 31' 34"} (1950)
GRB_DATE:        18830 TJD;   347 DOY;   19/12/13
GRB_TIME:        14783.92 SOD {04:06:23.92} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -100.89 [deg]
GRB_THETA:        26.11 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x13
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    11.12 [sigma]
LC_URL:          sw00944091000msb.lc
SUN_POSTN:       260.04d {+17h 20m 09s}  -23.12d {-23d 07' 11"}
SUN_DIST:         36.21 [deg]   Sun_angle= 2.4 [hr] (West of Sun)
MOON_POSTN:       92.85d {+06h 11m 25s}  +22.78d {+22d 47' 06"}
MOON_DIST:       132.29 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      347.07, 42.05 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      224.93,  6.88 [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 an image 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 = 50.14,-18.20 [deg].

GCN Circular #26398
S. B. Cenko (GSFC), A. D'Ai (INAF-IASFPA), V. D'Elia (SSDC), J.D. Gropp (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift Observatory Team:
At 04:06:23 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 191213A (trigger=944091). Due to a Sun constraint, Swift did not slew to this burst. The BAT on-board calculated location is RA, Dec 224.507, -9.726 which is
```
   RA(J2000) = 14h 58m 02s
   Dec(J2000) = -09d 43' 33"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). As is typical for an image trigger, there is no obvious variation in the immediately-available lightcurve.
Due to a Sun observing constraint, Swift cannot slew to the BAT position until 16:25 UT on 2019 December 23. There will thus be no XRT or UVOT data for this trigger before this time.
Burst Advocate for this burst is S. B. Cenko (brad.cenko 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/)
GCN Circular #26418
A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC), J. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (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+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 191213A (trigger #944091) (Cenko et al., GCN Circ. 26398). The BAT ground-calculated position is RA, Dec = 224.530, -9.745 deg which is
```
   RA(J2000)  =  14h 58m 07.2s
   Dec(J2000) = -09d 44' 41.9"
```
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 56%.
The mask-weighted light curve shows some weak emission that starts at ~T-30 s and remains detectable until the burst went out of the BAT FOV at T+139 s. It is likely that the emission continues beyond T+139 s. The burst did not come back into the BAT FOV within the next ~ 2 hours.
The time-averaged spectrum from T-33.52 to T+104.01 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.49 +- 0.16. The fluence in the 15-150 keV band is 2.1 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+99.95 sec in the 15-150 keV band is 0.5 +- 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/944091/BA/
GCN Circular #26420
I. Carrasco (UMA), Y.-D. Hu, E. Fernandez-Garcia, M. A. Castro Tirado and A. J. Castro-Tirado (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), S. Jeong and I. H. Park (SKKU) and M. D. Caballero-Garcia (ASU-CAS, CZ) on behalf of a larger collaboration, report:
The 60cm BOOTES-5/JGT robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) observed GRB 191213A ( Cenko et al., GCNC 26398 ) starting at 13:16 UT (~9.17 hr after trigger) at high airmass. Within the refined Swift/BAT error position ( Lien et al., GCNC 26418 ), no optical afterglow is found down to 18.6 mag in the clear filter on the co-added 15 images (60s each).
We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for its excellent support.
GCN Circular #26484
A. Ridnaia, S. Golenetskii, R.Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, and T. Cline on behalf of the Konus-Wind team, report:
The ultra-long GRB 191213A (Swift-BAT trigger #944091: Cenko et al., GCN 26398; Lien et al., GCN 26418) was detected by Konus-Wind (KW) in the waiting mode.
The burst light curve shows the main multipeaked episode of emission started at ~T0(BAT)-25 s and lasted until ~T0(BAT)+1815 s (the duration is ~1790 s; T0(BAT)=14781.499 s UT (04:06:21.499)). There is also a weaker broad pulse of emission seen before the main pulse from ~T0(BAT)-834 s to ~T0(BAT)-772 s. It might be related to GRB 191213A (it was detected by the same KW detector, and the KW ecliptic latitude response for it is consistent with the common origin with the main episode).
As observed by KW, the burst (main episode) had a fluence of 1.12(-0.06,+0.07)x10^-4 erg/cm2 and a 2.944-s peak flux, measured from ~T0(BAT)+676.012s, of 2.5(-0.41,+0.41)x10^-7 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The emission shows no signs of strong spectral variability. Modeling the KW 3-channel time-integrated spectrum (from ~T0(BAT)-24.660 s to ~T0(BAT)+1815.340 s) by a power law with exponential cutoff model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -1.16 (-0.12,+0.14), and Ep = 409 (-71,+110) keV.
Thus, the prompt gamma-ray emission properties of this GRB: fluence, peak flux, Ep, and duration are similar to those observed in other ultra-long GRBs.
The KW light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB191213A/
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: 18-Dec-2019 [Disclaimer]