TDRSS lightcurve for Trigger=1348587

Notes:

GCN BAT Position Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 11 Sep 25 01:28:23 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1348587,   Seg_Num: 0
GRB_RA:          263.762d {+17h 35m 03s} (J2000),
                 264.135d {+17h 36m 32s} (current),
                 263.038d {+17h 32m 09s} (1950)
GRB_DEC:         -16.844d {-16d 50' 36"} (J2000),
                 -16.859d {-16d 51' 31"} (current),
                 -16.812d {-16d 48' 41"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       11003 [cnts]    Image_Peak=310 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   301     E_range: 25-100 keV
BKG_INTEN:       91660 [cnts]
BKG_TIME:        5211.69 SOD {01:26:51.69} UT
BKG_DUR:         40 [sec]
GRB_DATE:        20929 TJD;   254 DOY;   25/09/11
GRB_TIME:        5266.15 SOD {01:27:46.15} UT
GRB_PHI:          -4.69 [deg]
GRB_THETA:        50.01 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.92 [sigma]
IMAGE_SIGNIF:    9.60 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +2  +0  +0  +1  +9  +0 
SUN_POSTN:       169.50d {+11h 18m 00s}   +4.52d {+04d 30' 59"}
SUN_DIST:         95.74 [deg]   Sun_angle= -6.3 [hr] (East of Sun)
MOON_POSTN:       29.65d {+01h 58m 37s}  +15.97d {+15d 58' 22"}
MOON_DIST:       127.91 [deg]
MOON_ILLUM:      86 [%]
GAL_COORDS:        9.04,  8.43 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      263.99,  6.47 [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 = 334.85,-11.22 [deg].  

GCN BAT Lightcurve Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 11 Sep 25 01:45:02 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     16629759,   Seg_Num: 0
GRB_RA:          263.762d {+17h 35m 03s} (J2000),
                 264.135d {+17h 36m 32s} (current),
                 263.038d {+17h 32m 09s} (1950)
GRB_DEC:         -16.844d {-16d 50' 36"} (J2000),
                 -16.859d {-16d 51' 31"} (current),
                 -16.812d {-16d 48' 41"} (1950)
GRB_DATE:        20929 TJD;   254 DOY;   25/09/11
GRB_TIME:        5266.15 SOD {01:27:46.15} UT
TRIGGER_INDEX:   301
GRB_PHI:          -4.69 [deg]
GRB_THETA:        50.01 [deg]
DELTA_TIME:      2572.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     0.00 [sigma]
IMAGE_SIGNIF:    0.00 [sigma]
LC_URL:          sw01348587000msb.lc

GCN template for BAT paragraph

  • Click here!
    At 01:27:46 UT, the Swift Burst Alert Telescope (BAT) triggered and
    located GRB 250911 ***A*** (trigger=1348587).  Swift slewed immediately to the burst.
    The BAT on-board calculated location is 
    RA, Dec 263.762, -16.844 which is 
       RA(J2000) = 17h 35m 03s
       Dec(J2000) = -16d 50' 36"
    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 ~2604 counts/sec (15-350 keV), at ~101 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

    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: 12.288 s +/- 0.461511 s
      Estimated T50 duration: 7.936 s +/- 0.362039 s
      Estimated Peak Interval: MET   779246903.93599987 +/- 0.500000 s
      Estimated background rate 1:     4616.498 near MET 779246889.280000 s
      Estimated background rate 2:     4800.163 near MET 779246960.320000 s
      Estimated total duration: 14.08 s (for data selection)
           (from MET 779246900.160000 to MET 779246914.240000)
      Estimated total fluence: 5461.954015 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 263.762 -16.844 0.083
    No match
    

    Search for this GRB position to the source locations in BAT transient monitor (search radius within 12 arcmin)

    python compare_catalog.py 263.762 -16.844
    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: 2025 9 11 1 112.334960  -18.658834
     Obj: 2025 9 11 1 26.443355  29.832476
    
  • the object visibility at GSFC, Greenbelt, Maryland
     
    MMT Observatory, Mt. Hopkins, Arizona
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 90.947617  7.060405
     Obj: 2025 9 11 1 347.124684  40.449913
    
  • the object visibility at MMT, Mt. Hopkins, Arizona
     
    Hale Telescope, Palomar Mountain, California
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 87.434512  12.082088
     Obj: 2025 9 11 1 340.361846  37.435119
    
  • the object visibility at Hale Telescope, Palomar Mt., California
     
    Mauna Kea, Hawaii
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 73.812959  48.269667
     Obj: 2025 9 11 1 300.473282  24.846512
    
  • the object visibility at Mauna Kea, Hawaii
     
    Siding Spring Obs., Australia
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 205.351602  51.197899
     Obj: 2025 9 11 1 295.062672  -7.649209
    
  • the object visibility at Siding Spring Obs., Australia
     
    Tokyo, Japan
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 307.741617  47.740254
     Obj: 2025 9 11 1 263.655076  -39.642515
    
  • the object visibility at Tokyo, Japan
     
    William Herschel Telescope, La Palma, Canary Islands, Spain
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 175.364668  -56.653624
     Obj: 2025 9 11 1 71.810911  -2.003832
    
  • the object visibility at William Hershel Telescope, La Palma, Canary Islands, Spain
     
    Gemini South, Cerro Pachon, Chile
          TimeUT       Azimuth     Elevation
     Sun: 2025 9 11 1 75.295776  -31.715010
     Obj: 2025 9 11 1 109.678253  59.746393
    
  • the object visibility at Gemini South, Cerro Pachon, Chile
     
     
     
    The data/results are in /local/data/bat1/prebascript/trigger1348587/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:
    Wed Sep 10 21:46:23 EDT 2025