TDRSS lightcurve for Trigger=828953

Notes:

GCN BAT Position Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 26 Apr 18 05:57:02 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     828953,   Seg_Num: 0
GRB_RA:          245.197d {+16h 20m 47s} (J2000),
                 245.457d {+16h 21m 50s} (current),
                 244.486d {+16h 17m 57s} (1950)
GRB_DEC:         -15.593d {-15d 35' 35"} (J2000),
                 -15.636d {-15d 38' 08"} (current),
                 -15.475d {-15d 28' 29"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       0 [cnts]    Image_Peak=3675 [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:        18234 TJD;   116 DOY;   18/04/26
GRB_TIME:        21347.15 SOD {05:55:47.15} UT
GRB_PHI:         -171.94 [deg]
GRB_THETA:        17.89 [deg]
SOLN_STATUS:     0x513
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    16.77 [sigma]
MERIT_PARAMS:     +1  +0  +0  +6  +1  +5  +0  +0 +85  +0 
SUN_POSTN:        33.66d {+02h 14m 37s}  +13.51d {+13d 30' 32"}
SUN_DIST:        149.18 [deg]   Sun_angle= 9.9 [hr] (West of Sun)
MOON_POSTN:      171.18d {+11h 24m 42s}   +7.23d {+07d 14' 04"}
MOON_DIST:        77.01 [deg]
MOON_ILLUM:      84 [%]
GAL_COORDS:      359.28, 23.65 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      246.04,  5.81 [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 matches a source in the ground catalog: Sco_X-1,   delta=0.214 [deg].  
COMMENTS:        This is not a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 311.74,10.69 [deg].  
COMMENTS:           
COMMENTS:        This trigger occured while the StarTracker had lost lock, so it is possibly bogus.  

GCN BAT Lightcurve Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 26 Apr 18 06:12:59 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     828953,   Seg_Num: 0
GRB_RA:          245.197d {+16h 20m 47s} (J2000),
                 245.457d {+16h 21m 50s} (current),
                 244.486d {+16h 17m 57s} (1950)
GRB_DEC:         -15.593d {-15d 35' 35"} (J2000),
                 -15.636d {-15d 38' 08"} (current),
                 -15.475d {-15d 28' 29"} (1950)
GRB_DATE:        18234 TJD;   116 DOY;   18/04/26
GRB_TIME:        21347.15 SOD {05:55:47.15} UT
TRIGGER_INDEX:   20000
GRB_PHI:         -171.94 [deg]
GRB_THETA:        17.89 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     64.000 [sec] 
SOLN_STATUS:     0x513
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    16.77 [sigma]
LC_URL:          sw00828953000msb.lc

GCN template for BAT paragraph

  • Click here!
    At 05:55:47 UT, the Swift Burst Alert Telescope (BAT) triggered and
    located GRB 180426 ***A*** (trigger=828953).  Swift slewed immediately to the burst.
    The BAT on-board calculated location is 
    RA, Dec 245.197, -15.593 which is 
       RA(J2000) = 16h 20m 47s
       Dec(J2000) = -15d 35' 35"
    with an uncertainty of 3 arcmin (radius, 90% containment, including 
    systematic uncertainty).  The BAT light curve showed a [**double-peaked**]
    structure with a duration of about TTT sec.  The peak count rate
    was ~1318 counts/sec (15-350 keV), at ~171 sec after the trigger.
    
  • Test version of draft template

    Initial TDRSS lightcurve and spacecraft attitude plot

    TDRSS lightcurve from T0-30 to T0+50 (zoom in)

    TDRSS light curve from T0-1 to T0+2 (More zoom in)

    1.6s binned TDRSS light curve

    Tilan's background subtracted TDRSS light curves

    Extended TDRSS light curve and spacecraft attitude plot(s)

    Extended TDRSS lc No.1

    Extended TDRSS lc No.2

    Extended TDRSS lc No.3

    Extended TDRSS lc No.4

    TDRSS extended lightcurve from T0-1 to T0+2

    T50 and T90 calculation

    ******************************************
             battblocks v1.18
    ------------------------------------------
         Input Data: bat_raw_lc.fits
         Output GTI: bb.gti
     Events to Skip: 128     Changepoint log(prob) Prior: 6.000000
      Internal Tick: 1.000000e-04 s
      Lookback time: 0 s
     Bkg. Subtract?: yes (for fluence/T50/T90 calculations)
    ------------------------------------------
      Estimated T90 duration: 53.248 s +/- 45.2418 s
      Estimated T50 duration: 53.248 s +/- 49.83 s
      Estimated Peak Interval: MET   546415110.91199994 +/- 0.500000 s
      Estimated background rate 1:     5579.648 near MET 546414999.808000 s
      Estimated background rate 2:     6216.264 near MET 546415131.392000 s
      Estimated total duration: 53.248 s (for data selection)
           (from MET 546415055.616000 to MET 546415108.864000)
      Estimated total fluence: -3253.117715 count
      Created GTI with 5 entries
    ------------------------------------------
     
    

    Search for this GRB position to the previously BAT detected GRB positions (search radius within 5 arcmin)

    bat_grb_pos_cat.sh 245.197 -15.593 0.083
    No match
    

    Link to SIMBAD

  • Click here for the SIMBAD search!

    Frank's UVOT result

  • Click here!

    Frank's UVOT Blinking images

  • Click here!

    Elevation angle of GRB/Sun at the ground telescope locations

    GSFC, Greenbelt, Maryland
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 195.888197  -36.090184
     Obj: 2018 4 26 6 338.559675  32.617367
    
  • the object visibility at GSFC, Greenbelt, Maryland
     
    MMT Observatory, Mt. Hopkins, Arizona
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 152.904428  -40.602611
     Obj: 2018 4 26 6 305.017500  20.802237
    
  • the object visibility at MMT, Mt. Hopkins, Arizona
     
    Hale Telescope, Palomar Mountain, California
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 146.867551  -36.630377
     Obj: 2018 4 26 6 301.346693  15.667530
    
  • the object visibility at Hale Telescope, Palomar Mt., California
     
    Mauna Kea, Hawaii
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 111.989782  -17.554467
     Obj: 2018 4 26 6 282.537105  -11.885088
    
  • the object visibility at Mauna Kea, Hawaii
     
    Siding Spring Obs., Australia
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 118.816595  17.737853
     Obj: 2018 4 26 6 326.779463  -36.275862
    
  • the object visibility at Siding Spring Obs., Australia
     
    Tokyo, Japan
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 72.090722  46.329511
     Obj: 2018 4 26 6 209.780313  -68.925492
    
  • the object visibility at Tokyo, Japan
     
    William Herschel Telescope, La Palma, Canary Islands, Spain
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 249.380904  -8.591111
     Obj: 2018 4 26 6 46.623492  30.876781
    
  • the object visibility at William Hershel Telescope, La Palma, Canary Islands, Spain
     
    Gemini South, Cerro Pachon, Chile
          TimeUT       Azimuth     Elevation
     Sun: 2018 4 26 6 309.579745  -65.691721
     Obj: 2018 4 26 6 221.290312  71.216113
    
  • the object visibility at Gemini South, Cerro Pachon, Chile
     
     
     
    The data/results are in /local/data/bat1/prebascript/trigger828953/tdrss_ql/
     
    bat_raw_lc.fits  : TDRSS FITS light curve from GCN
    gcn_position.txt : GCN BAT position notice
    ratelc_tdrss.qdp : QDP file of the TDRSS light curve
    tdrss_lc.gif     : GIF TDRSS light curve
    sc_att.qdp       : QDP file of the spacecraft attitude
    sc_att.gif       : GIF spacecraft attitude
    bb.gti           : Bayesian block GTI file (battblocks)
    dur.gti          : Duration GTI file (battblocks)
    battblocks.log   : Output log of battblocks
     
    
    
    Plot creation:
    Thu Apr 26 02:13:42 EDT 2018