TDRSS lightcurve for Trigger=1405083

Notes:

GCN BAT Position Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 18 Oct 25 03:12:22 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1405083,   Seg_Num: 0
GRB_RA:          282.071d {+18h 48m 17s} (J2000),
                 282.507d {+18h 50m 02s} (current),
                 281.224d {+18h 44m 54s} (1950)
GRB_DEC:         -37.028d {-37d 01' 41"} (J2000),
                 -36.998d {-36d 59' 51"} (current),
                 -37.085d {-37d 05' 04"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3459 [cnts]    Image_Peak=181 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       19293 [cnts]
BKG_TIME:        11507.47 SOD {03:11:47.47} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20966 TJD;   291 DOY;   25/10/18
GRB_TIME:        11522.38 SOD {03:12:02.38} UT
GRB_PHI:         128.29 [deg]
GRB_THETA:        10.74 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     18.65 [sigma]
IMAGE_SIGNIF:    8.46 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -1  +0  +1 -25  +0 
SUN_POSTN:       203.16d {+13h 32m 39s}   -9.68d {-09d 40' 30"}
SUN_DIST:         75.72 [deg]   Sun_angle= -5.3 [hr] (East of Sun)
MOON_POSTN:      168.34d {+11h 13m 21s}   +5.07d {+05d 03' 55"}
MOON_DIST:       112.26 [deg]
MOON_ILLUM:      11 [%]
GAL_COORDS:      358.81,-15.36 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      279.91,-14.00 [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 = 226.91,20.25 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(2.0<100sec) coincident with the FERMI_GBM event (trignum=782449925).

GCN BAT Lightcurve Notice

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sat 18 Oct 25 03:30:57 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1405083,   Seg_Num: 0
GRB_RA:          282.071d {+18h 48m 17s} (J2000),
                 282.507d {+18h 50m 02s} (current),
                 281.224d {+18h 44m 54s} (1950)
GRB_DEC:         -37.028d {-37d 01' 41"} (J2000),
                 -36.998d {-36d 59' 51"} (current),
                 -37.085d {-37d 05' 04"} (1950)
GRB_DATE:        20966 TJD;   291 DOY;   25/10/18
GRB_TIME:        11522.38 SOD {03:12:02.38} UT
TRIGGER_INDEX:   146
GRB_PHI:         128.29 [deg]
GRB_THETA:        10.74 [deg]
DELTA_TIME:      -50.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     18.65 [sigma]
IMAGE_SIGNIF:    8.46 [sigma]
LC_URL:          sw01405083000msb.lc

GCN template for BAT paragraph

  • Click here! 
    At 03:12:02 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 251018 ***A*** (trigger=1405083).  Swift slewed immediately to the burst.
The BAT on-board calculated location is 
RA, Dec 282.071, -37.028 which is 
   RA(J2000) = 18h 48m 17s
   Dec(J2000) = -37d 01' 41"
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 ~2138 counts/sec (15-350 keV), at ~1 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: 33.024 s +/- 1.20755 s
  Estimated T50 duration: 12.288 s +/- 0.286217 s
  Estimated Peak Interval: MET   782449966.40000010 +/- 0.500000 s
  Estimated background rate 1:     5016.981 near MET 782449942.880000 s
  Estimated background rate 2:     4719.551 near MET 782450078.784000 s
  Estimated total duration: 61.888 s (for data selection)
       (from MET 782449951.360000 to MET 782450013.248000)
  Estimated total fluence: 25540.405877 count
  Created GTI with 11 entries
------------------------------------------

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

    bat_grb_pos_cat.sh 282.071 -37.028 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 282.071 -37.028
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 10 18 3 131.175394  -51.094379
 Obj: 2025 10 18 3 50.630049  -10.796531
  • the object visibility at GSFC, Greenbelt, Maryland 
     
MMT Observatory, Mt. Hopkins, Arizona
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 96.168650  -28.287816
 Obj: 2025 10 18 3 30.248229  12.650826
  • the object visibility at MMT, Mt. Hopkins, Arizona 
     
Hale Telescope, Palomar Mountain, California
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 93.542237  -23.121389
 Obj: 2025 10 18 3 25.806375  13.552379
  • the object visibility at Hale Telescope, Palomar Mt., California 
     
Mauna Kea, Hawaii
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 74.709722  12.556281
 Obj: 2025 10 18 3 353.722093  32.795580
  • the object visibility at Mauna Kea, Hawaii 
     
Siding Spring Obs., Australia
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 139.691887  63.072590
 Obj: 2025 10 18 3 294.394804  39.181821
  • the object visibility at Siding Spring Obs., Australia 
     
Tokyo, Japan
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 0.937668  45.888258
 Obj: 2025 10 18 3 306.759755  -12.203709
  • the object visibility at Tokyo, Japan 
     
William Herschel Telescope, La Palma, Canary Islands, Spain
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 242.249364  -55.794285
 Obj: 2025 10 18 3 65.432097  -48.495649
  • the object visibility at William Hershel Telescope, La Palma, Canary Islands, Spain 
     
Gemini South, Cerro Pachon, Chile
      TimeUT       Azimuth     Elevation
 Sun: 2025 10 18 3 32.272988  -44.417952
 Obj: 2025 10 18 3 60.897306  26.628271
  • the object visibility at Gemini South, Cerro Pachon, Chile 
     
 
 
The data/results are in /local/data/bat1/prebascript/trigger1405083/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:
Fri Oct 17 23:31:42 EDT 2025