Gamma-ray Burst 180407A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sat 07 Apr 18 01:55:37 UT
  NOTICE_TYPE:     Swift-BAT GRB Position
  TRIGGER_NUM:     823001,   Seg_Num: 0
  GRB_RA:           35.241d {+02h 20m 58s} (J2000),
                    35.514d {+02h 22m 03s} (current),
                    34.495d {+02h 17m 59s} (1950)
  GRB_DEC:         +33.499d {+33d 29' 56"} (J2000),
                   +33.582d {+33d 34' 54"} (current),
                   +33.270d {+33d 16' 14"} (1950)
  GRB_ERROR:       3.00 [arcmin radius, statistical only]
  GRB_INTEN:       16130 [cnts]    Image_Peak=422 [image_cnts]
  TRIGGER_DUR:     4.096 [sec] 
  TRIGGER_INDEX:   291     E_range: 15-50 keV
  BKG_INTEN:       145632 [cnts]
  BKG_TIME:        6835.25 SOD {01:53:55.25} UT
  BKG_DUR:         40 [sec]
  GRB_DATE:        18215 TJD;    97 DOY;   18/04/07
  GRB_TIME:        6889.78 SOD {01:54:49.78} UT
  GRB_PHI:         -98.28 [deg]
  GRB_THETA:        25.74 [deg]
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     7.74 [sigma]
  IMAGE_SIGNIF:    9.45 [sigma]
  MERIT_PARAMS:     +1  +0  +0  +2  +1  +0 -100  +0 -84  +0 
  SUN_POSTN:        15.87d {+01h 03m 28s}   +6.76d {+06d 45' 33"}
  SUN_DIST:         32.41 [deg]   Sun_angle= -1.3 [hr] (East of Sun)
  MOON_POSTN:      274.15d {+18h 16m 37s}  -20.20d {-20d 12' 08"}
  MOON_DIST:       126.72 [deg]
  MOON_ILLUM:      62 [%]
  GAL_COORDS:      143.58,-25.76 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:       44.14, 18.36 [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 = 176.17,6.89 [deg].  
  

• red DSS finding chart ps-file
  
  
• GCN NOTICE
  

  TITLE:           GCN/SWIFT NOTICE
  NOTICE_DATE:     Sat 07 Apr 18 01:58:48 UT
  NOTICE_TYPE:     Swift-BAT GRB Lightcurve
  TRIGGER_NUM:     823001,   Seg_Num: 0
  GRB_RA:           35.241d {+02h 20m 58s} (J2000),
                    35.514d {+02h 22m 03s} (current),
                    34.495d {+02h 17m 59s} (1950)
  GRB_DEC:         +33.499d {+33d 29' 56"} (J2000),
                   +33.582d {+33d 34' 54"} (current),
                   +33.270d {+33d 16' 14"} (1950)
  GRB_DATE:        18215 TJD;    97 DOY;   18/04/07
  GRB_TIME:        6889.78 SOD {01:54:49.78} UT
  TRIGGER_INDEX:   291
  GRB_PHI:         -98.28 [deg]
  GRB_THETA:        25.74 [deg]
  DELTA_TIME:      -11.00 [sec]
  TRIGGER_DUR:     4.096 [sec] 
  SOLN_STATUS:     0x3
  RATE_SIGNIF:     7.74 [sigma]
  IMAGE_SIGNIF:    9.45 [sigma]
  LC_URL:          sw00823001000msb.lc
  SUN_POSTN:        15.87d {+01h 03m 29s}   +6.76d {+06d 45' 36"}
  SUN_DIST:         32.41 [deg]   Sun_angle= -1.3 [hr] (East of Sun)
  MOON_POSTN:      274.18d {+18h 16m 44s}  -20.20d {-20d 12' 12"}
  MOON_DIST:       126.70 [deg]
  MOON_ILLUM:      62 [%]
  GAL_COORDS:      143.58,-25.76 [deg] galactic lon,lat of the burst (or transient)
  ECL_COORDS:       44.14, 18.36 [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 = 176.17,6.89 [deg].  
  

  
• GCN Circular #22612
  A. Deich (PSU), C. Gronwall (PSU), S. J. LaPorte (PSU), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL) and A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
  At 01:54:49 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 180407A (trigger=823001). Swift could not slew to the location due to an observing constraint. The BAT on-board calculated location is RA, Dec 35.241, +33.499 which is

     RA(J2000) = 02h 20m 58s
     Dec(J2000) = +33d 29' 56"
  

  with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure structure with a duration of about 70 sec. The peak count rate was ~1600 counts/sec (15-350 keV), at ~0 sec after the trigger.
  Due to a Sun observing constraint, Swift cannot slew to the BAT position until 12:55 UT on 2018 June 19. There will thus be no XRT or UVOT data for this trigger before this time.
  Burst Advocate for this burst is A. Deich (aud375 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/too.html.)
• GCN Circular #22614
  Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra (UNAM), William H. Lee (UNAM), Carlos Rom=E1n-Z=FA=F1iga (UNAM), Alexander Kutyrev (GSFC), and Eleonora Troja (GSFC), report:
  We observed the field of GRB 180407A (Deich et al., GCN 22612) with the COATLI 50-cm telescope and interim imager (http://coatli.astroscu.unam.mx) at the Observatorio Astron=F3mico Nacional on the Sierra de San Pedro M=E1rtir from 2018-04-07 02:26:12 to 03:01:38 (0.52 to 1.12 hours after trigger) obtaining a total of 510 seconds of exposure in the w filter.
  The images were obtained at high airmass (above 3.1) and during twilight.
  For a source within the Swift/BAT error circle, in comparison with the USNO-B1 catalog, we obtain the following 10-sigma upper limit:
  w > 16.53
  This magnitude is in the USNO system and is not corrected for Galactic extinction in the direction of the GRB.
  We thank the COATLI technical team (Fernando =C1ngeles, Oscar Chapa, Salvador Cuevas, Alejandro Farah, Jorge Fuentes, Rosal=EDa Langarica, Fernando Quir=F3s, and Carlos Tejada) and the staff of the Observatorio Astron=F3mico Nacional.
• GCN Circular #22615
  Klotz A., Noysena.K., Atteia J.L. (CNRS-OMP-IRAP), Boer, M., Eymar, L. (CNRS-ARTEMIS), Gendre B. (UVI - Etelman Obs.) report:
  We imaged the field of GRB 180407A detected by SWIFT (trigger 823014) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
  The observations started 30.5s after the GRB trigger (13.7s after the notice). The elevation of the field decreased from 53 degrees above horizon but the event occured during the dawn. Moreover the eky was partly cloudy. We do not detect any OT with the following limiting magnitudes:

    Tstart     Tend   LimMag
      30.5s    90.5s  R > 11.6
     104.2s   134.2s  R > 10.8
     144.3s   174.3s  R > 9.5
     184.1s   214.1s  R > 9.5
     223.9s   253.9s  R > 13.2
     263.7s   293.7s  R > 13.2
     303.8s   393.8s  R > 15.4
     403.9s   493.9s  R > 15.4
     504.4s   594.4s  R > 14.8
  

  Magnitudes were estimated with the nearby NOMAD1 stars.
• GCN Circular #22616
  H. A. Krimm (NSF/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (CPI), A. Deich (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-240 to T+144 sec from the recent telemetry downlink, we report further analysis of BAT GRB 180407A (trigger #823001) (Deich et al., GCN Circ. 22612). Note that due to the Sun constraint, Swift could not slew to the burst location, and no data were collected for the burst after ~ T+144 s. The BAT ground-calculated position is RA, Dec = 35.236, 33.513 deg which is

    RA(J2000)  =  02h 20m 56.6s
    Dec(J2000) = +33d 30' 48.4"
  

  with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 52%.
  The mask-weighted light curve shows a weak pulse that starts at ~ T-20 s and ends at ~ T+110 s. The pulse consists of several overlapping peaks. The largest peak occurs at ~ T+2 s. T90 (15-350 keV) is 95.9 +- 29.8 sec (estimated error including systematics). Note that because the burst went out of the BAT field of view at T+144 s, T90 reported here might not capture the entire burst duration.
  The time-averaged spectrum from T-20.58 to T+107.48 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.94 +- 0.20. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+2.18 sec in the 15-150 keV band is 0.9 +- 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/823001/BA/