TDRSS lightcurve for Trigger=1337165

Notes:

GCN BAT Position Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Jul 25 22:49:19 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1337165,   Seg_Num: 0
GRB_RA:          251.779d {+16h 47m 07s} (J2000),
                 252.246d {+16h 48m 59s} (current),
                 250.867d {+16h 43m 28s} (1950)
GRB_DEC:         -45.871d {-45d 52' 14"} (J2000),
                 -45.915d {-45d 54' 52"} (current),
                 -45.782d {-45d 46' 53"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       419 [cnts]    Image_Peak=72 [image_cnts]
TRIGGER_DUR:     0.064 [sec] 
TRIGGER_INDEX:   10411     E_range: 15-50 keV
BKG_INTEN:       21362 [cnts]
BKG_TIME:        82131.96 SOD {22:48:51.96} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20882 TJD;   207 DOY;   25/07/26
GRB_TIME:        82145.08 SOD {22:49:05.08} UT
GRB_PHI:         -81.05 [deg]
GRB_THETA:        25.16 [deg]
SOLN_STATUS:     0x10D
RATE_SIGNIF:     19.49 [sigma]
IMAGE_SIGNIF:    9.81 [sigma]
MERIT_PARAMS:     +0  +0  +2  -4  +1  +0  +0  +1 +61  +0 
SUN_POSTN:       126.52d {+08h 26m 05s}  +19.21d {+19d 12' 24"}
SUN_DIST:        128.31 [deg]   Sun_angle= -8.4 [hr] (East of Sun)
MOON_POSTN:      153.61d {+10h 14m 25s}  +12.54d {+12d 32' 15"}
MOON_DIST:       104.95 [deg]
MOON_ILLUM:      5 [%]
GAL_COORDS:      339.54, -0.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      256.29,-23.30 [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 matches a source in the on-board catalog: Num=14112=CXOU_J1647-4552,   delta=0.009 [deg].  
COMMENTS:        This matches a source in the ground catalog: CXOU_J1647-4552,   delta=0.009 [deg].  
COMMENTS:        This is not a GRB.  
COMMENTS:        This is an interesting source.  
COMMENTS:        This trigger occurred at longitude,latitude = 318.50,16.36 [deg].  

GCN BAT Lightcurve Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 26 Jul 25 23:01:49 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1337165,   Seg_Num: 0
GRB_RA:          251.779d {+16h 47m 07s} (J2000),
                 252.246d {+16h 48m 59s} (current),
                 250.867d {+16h 43m 28s} (1950)
GRB_DEC:         -45.871d {-45d 52' 14"} (J2000),
                 -45.915d {-45d 54' 52"} (current),
                 -45.782d {-45d 46' 53"} (1950)
GRB_DATE:        20882 TJD;   207 DOY;   25/07/26
GRB_TIME:        82145.16 SOD {22:49:05.16} UT
TRIGGER_INDEX:   10411
GRB_PHI:         -81.05 [deg]
GRB_THETA:        25.16 [deg]
DELTA_TIME:      -39.00 [sec]
TRIGGER_DUR:     0.064 [sec] 
SOLN_STATUS:     0x10D
RATE_SIGNIF:     19.49 [sigma]
IMAGE_SIGNIF:    9.81 [sigma]
LC_URL:          sw01337165000msb.lc

GCN template for BAT paragraph

  • Click here!
    At 22:49:05 UT, the Swift Burst Alert Telescope (BAT) triggered and
    located GRB 250726 ***A*** (trigger=1337165).  Swift slewed immediately to the burst.
    The BAT on-board calculated location is 
    RA, Dec 251.779, -45.871 which is 
       RA(J2000) = 16h 47m 07s
       Dec(J2000) = -45d 52' 14"
    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 ~2703 counts/sec (15-350 keV), at ~0 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

    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: 0.128 s +/- 0.286217 s
      Estimated T50 duration: 0.128 s +/- 0.128 s
      Estimated Peak Interval: MET   775262981.37599993 +/- 0.500000 s
      Estimated background rate 1:     4185.332 near MET 775262969.024000 s
      Estimated background rate 2:     4157.539 near MET 775263074.048000 s
      Estimated total duration: 0.128 s (for data selection)
           (from MET 775262981.248000 to MET 775262981.376000)
      Estimated total fluence: 286.391766 count
      Created GTI with 3 entries
    ------------------------------------------
     
    

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

    bat_grb_pos_cat.sh 251.779 -45.871 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 251.779 -45.871
    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 7 26 23 102.800626  14.950042
     Obj: 2025 7 26 23 333.574705  -2.117409
    
  • the object visibility at GSFC, Greenbelt, Maryland
     
    MMT Observatory, Mt. Hopkins, Arizona
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 88.034832  41.870552
     Obj: 2025 7 26 23 316.894879  -12.245687
    
  • the object visibility at MMT, Mt. Hopkins, Arizona
     
    Hale Telescope, Palomar Mountain, California
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 82.797960  46.769586
     Obj: 2025 7 26 23 314.310407  -16.964840
    
  • the object visibility at Hale Telescope, Palomar Mt., California
     
    Mauna Kea, Hawaii
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 86.128109  82.999121
     Obj: 2025 7 26 23 312.626127  -33.685416
    
  • the object visibility at Mauna Kea, Hawaii
     
    Siding Spring Obs., Australia
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 229.085571  21.579434
     Obj: 2025 7 26 23 355.574002  -12.629177
    
  • the object visibility at Siding Spring Obs., Australia
     
    Tokyo, Japan
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 267.090206  31.235638
     Obj: 2025 7 26 23 31.370529  -76.045240
    
  • the object visibility at Tokyo, Japan
     
    William Herschel Telescope, La Palma, Canary Islands, Spain
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 140.630412  -31.342488
     Obj: 2025 7 26 23 13.643532  13.276909
    
  • the object visibility at William Hershel Telescope, La Palma, Canary Islands, Spain
     
    Gemini South, Cerro Pachon, Chile
          TimeUT       Azimuth     Elevation
     Sun: 2025 7 26 23 105.873260  -11.157988
     Obj: 2025 7 26 23 310.260973  59.474581
    
  • the object visibility at Gemini South, Cerro Pachon, Chile
     
     
     
    The data/results are in /local/data/bat1/prebascript/trigger1337165/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:
    Sat Jul 26 19:02:42 EDT 2025