Gamma-ray Burst 120118A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Wed 18 Jan 12 00:39:09 UT
  NOTICE_TYPE:    INTEGRAL Weak
  TRIGGER_NUM:    6441,   Sub_Num: 0
  GRB_RA:         195.3647d {+13h 01m 28s} (J2000),
                  195.5521d {+13h 02m 13s} (current),
                  194.5918d {+12h 58m 22s} (1950)
  GRB_DEC:        -61.6033d {-61d 36' 11"} (J2000),
                  -61.6679d {-61d 40' 03"} (current),
                  -61.3343d {-61d 20' 03"} (1950)
  GRB_ERROR:      3.18 [arcmin, radius, statistical only]
  GRB_INTEN:      8.73 [sigma]
  GRB_TIME:       2344.60 SOD {00:39:04.60} UT
  GRB_DATE:       15944 TJD;    18 DOY;   12/01/18
  SC_RA:          196.69 [deg] (J2000)
  SC_DEC:         -63.19 [deg] (J2000)
  SUN_POSTN:      299.37d {+19h 57m 28s}  -20.70d {-20d 41' 48"}
  SUN_DIST:        78.17 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:     225.86d {+15h 03m 26s}  -19.47d {-19d 27' 56"}
  MOON_DIST:       47.19 [deg]
  GAL_COORDS:     304.12,  1.25 [deg] galactic lon,lat of the burst
  ECL_COORDS:     225.43,-49.20 [deg] ecliptic lon,lat of the burst
  COMMENTS:       INTEGRAL GRB Coordinates -- this is the weak/subthreshold trigger notice.  
  COMMENTS:       This notice may or may not be followed by a Wakeup/Refined/Offline notice.  
  COMMENTS:       Possibly real GRB event (WEAK detection)  
  

• red DSS finding chart ps-file
  
  
• GCN/BACODINE POSITION NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Wed 18 Jan 12 06:05:07 UT
  NOTICE_TYPE:    INTEGRAL Wakeup
  TRIGGER_NUM:    6443,   Sub_Num: 0
  GRB_RA:         195.2918d {+13h 01m 10s} (J2000),
                  195.4790d {+13h 01m 55s} (current),
                  194.5198d {+12h 58m 05s} (1950)
  GRB_DEC:        -61.5525d {-61d 33' 08"} (J2000),
                  -61.6172d {-61d 37' 01"} (current),
                  -61.2835d {-61d 17' 00"} (1950)
  GRB_ERROR:      3.30 [arcmin, radius, statistical only]
  GRB_INTEN:      8.00 [sigma]
  GRB_TIME:       21903.66 SOD {06:05:03.66} UT
  GRB_DATE:       15944 TJD;    18 DOY;   12/01/18
  SC_RA:          198.58 [deg] (J2000)
  SC_DEC:         -60.68 [deg] (J2000)
  SUN_POSTN:      299.61d {+19h 58m 26s}  -20.65d {-20d 39' 05"}
  SUN_DIST:        78.36 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:     229.22d {+15h 16m 53s}  -20.06d {-20d 03' 49"}
  MOON_DIST:       47.69 [deg]
  GAL_COORDS:     304.09,  1.30 [deg] galactic lon,lat of the burst
  ECL_COORDS:     225.34,-49.18 [deg] ecliptic lon,lat of the burst
  COMMENTS:       INTEGRAL GRB Coordinates.  
  COMMENTS:       Possibly real GRB event  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:          GCN/INTEGRAL NOTICE
  NOTICE_DATE:    Wed 18 Jan 12 07:32:31 UT
  NOTICE_TYPE:    INTEGRAL Offline
  TRIGGER_NUM:    6443,   Sub_Num: 1
  GRB_RA:         195.4026d {+13h 01m 37s} (J2000),
                  195.5902d {+13h 02m 22s} (current),
                  194.6292d {+12h 58m 31s} (1950)
  GRB_DEC:        -61.6439d {-61d 38' 37"} (J2000),
                  -61.7085d {-61d 42' 30"} (current),
                  -61.3750d {-61d 22' 29"} (1950)
  GRB_ERROR:      2.70 [arcmin, radius, statistical only]
  GRB_INTEN:      8.00 [sigma]
  GRB_TIME:       21903.66 SOD {06:05:03.66} UT
  GRB_DATE:       15944 TJD;    18 DOY;   12/01/18
  SC_RA:          198.58 [deg] (J2000)
  SC_DEC:         -60.68 [deg] (J2000)
  SUN_POSTN:      299.67d {+19h 58m 41s}  -20.64d {-20d 38' 22"}
  SUN_DIST:        78.32 [deg]   Sun_angle= 6.9 [hr] (West of Sun)
  MOON_POSTN:     230.13d {+15h 20m 30s}  -20.21d {-20d 12' 48"}
  MOON_DIST:       47.88 [deg]
  GAL_COORDS:     304.14,  1.20 [deg] galactic lon,lat of the burst
  ECL_COORDS:     225.49,-49.22 [deg] ecliptic lon,lat of the burst
  COMMENTS:       INTEGRAL GRB Coordinates.  
  COMMENTS:       refined_coordinates_after_offline_analysis  
  

• GCN Circular #12849
  D. Gotz (CEA Saclay), S.Mereghetti (IASF-Milano), J. Borkowski (CAMK, Torun), C.Ferrigno, E.Bozzo, C. Tchernin (ISDC, Versoix), on behalf of the IBAS Localization Team report:
  a long gamma ray burst lasting about 60 s has been detected by IBAS in the IBIS/ISGRI data at 06:04:44 UT on January 18.
  Its refined coordinates (J2000) are:

    RA: 195.403 [degrees]
    DEC: -61.644 [degrees]
  

  with an uncertainty of 2.7 arcmin (90% c.l.).
  The GRB is detected only in the 20-40 keV energy band. Due to its soft spectrum, we consider this event an XRF. The 20-200 keV fluence is about 2e-7 erg/cmsq, while its peak flux over 5 s in the same energy band is about 0.1 ph/cmsq/s. A plot of the light curve will be posted at
  http://ibas.iasf-milano.inaf.it/IBAS_Results.html
• GCN Circular #12850
  D. Gotz (CEA Saclay) and E. Bozzo (ISDC Versoix) on behalf of the IBAS Localisation Team report:
  A deeper analysis of an extended IBIS/ISGRI dataset shows that the HMXB GX 304-1 is in an active state. Being this source just 3.4 arcmin away from the position derived for XRF120118A (Gotz et al., GCN Circ. 1248), even if not formally compatible with the 90% c.l. error circle of the latter, we note that the chance of XRF120118A being produced by GX 304-1 can not be completely excluded at this stage.
• GCN Circular #12851
  J.C. Tello (IAA-CSIC), R. Sanchez-Ramirez (IAA-CSIC), J. Gorosabel (IAA-CSIC), A.J. Castro-Tirado (IAA-CSIC), P. Kubanek (CTU Praha), W. Allen (Vintage Lane Obs, New Zealand), Ph. Yock (Auckland Univ.), Kuan-Yu Lin (Auckland Univ.), report on behalf of a larger collaboration:
  We observed the field of XRF 120118A (Gotz et al., GCNC 12849), detected by INTEGRAL, with the 0.6m Yock-Allen telescope at the BOOTES-3 station in Blenheim (New Zealand). Unfiltered images were obtained starting on 09:21:00 UT (03h16m after the burst, limited by setting of the Sun) and were combined in two sets of 53x60s of exposure each.
  We detect a fading source at

  RA(J2000):    13:01:22.72 (195.344 [degrees])
  DEC(J2000): -61:39:23.20 (-61.656 [degrees])
  

  In the first set with a mean observation time of 09:31:06 UT we observe a magnitude of 18.60 (calibrated against USNO-B1 R2 filter). Roughly an hour later it's decayed more than 2 magnitudes.
  This source is well within the INTEGRAL 2.7 arcmin 90% c.l. and is not observed in catalog USNO-B1
  Spectroscopic observations are encouraged. This message may be cited.
• GCN Circular #12855
  T.Batsch,A.Majcher,A.Majczyna,K.Nawrocki,M.Sokolowski,G.Wrochna (NCBJ, Swierk), M.Cwiok,L.W.Piotrowski,A.F.Zarnecki (University of Warsaw), K.Malek,L.Mankiewicz,R.Opiela,M.Siudek,V.Repei (CFT PAN), G.Kasprowicz,M.Zaremba (Warsaw University of Technology), from the "Pi of the Sky" collaboration ( http://grb.fuw.edu.pl ).
  The wide field "Pi of the Sky South" telescope, installed in the private observatory of Alain Maury in San Pedro de Atacama (http://grb.fuw.edu.pl/pi/index.html#spda_site.htm) observed field of XRF 120118A few minutes before and ~100s after the flash. No new source brighter than about 11.3 mag has been identified on 10s exposures and no source brighter than 11.7 mag on 20 coadded frames:

  t_start - t0 [s]    t_exp     start (UT)  end (UT)     3-sigma limit
  
       -290             10s          06:00:14    06:00:24     11.2
        +99             10s          06:06:43    06:06:53     11.3
       +129           20x10s         06:07:13    06:12:12     11.7
  

  where limit is based on the reference star magnitudo in V filter.
  We acknowledge great support received from Alain Maury at SPdA Observatory.