SIMPLE = T / file does conform to FITS standard BITPIX = 8 / number of bits per data pixel NAXIS = 0 / number of data axes EXTEND = T / FITS dataset may contain extensions COMMENT FITS (Flexible Image Transport System) format is defined in 'AstronomyCOMMENT and Astrophysics', volume 376, page 359; bibcode: 2001A&A...376..359H TELESCOP= 'SWIFT ' / Telescope (mission) name INSTRUME= 'XRT ' / Instrument name OBS_ID = '01315630000' / Observation ID TARG_ID = '1315630 ' / Target ID SEG_NUM = '0 ' / Segment number TIMESYS = 'TT ' / time system MJDREFI = 51910 / MJD reference day 01 Jan 2001 00:00:00 MJDREFF = 0.00074287037 / MJD reference (fraction of day) 01 Jan 2001 00:TIMEUNIT= 's ' / Time unit for timing header keywords TIERRELA= 1.0E-08 / [s/s] Estimated relative clock rate error TIERABSO= 1. / [s] Estimated absolute clock offset error TSTART = 769401919.20962 / Start time DATE-OBS= '2025-05-20T02:42:11' TSTOP = 769402147.03548 / Stop time DATE-END= '2025-05-20T02:49:02' CLOCKAPP= F / If clock correction are applied (F/T) ORIGIN = 'GSFC ' / Source of FITS file CREATOR = 'TDRSS2FITS V3.22' / Program that created this FITS file TLM2FITS= 'V3.22 ' / Telemetry converter version number DATE = '2025-05-30T05:49:02' / file creation date (YYYY-MM-DDThh:mm:ss UT) UTCFINIT= -35.6353200000000 / [s] UTCF at TSTART CHECKSUM= 'jpA4jn24jn84jn84' / HDU checksum updated 2025-05-30T06:14:38 DATASUM = ' 0' / data unit checksum updated 2025-05-30T05:49:02 OBJECT = 'GRB250520a' XOBS_ID = 01315630000 / Generating sequence PROCVER = '3.20.02 ' / Processing script version SOFTVER = 'Hea_21Mar2024_V6.33.1_Swift_Rel5.8(Bld47)_30Jun2023_SDCpatch_2' CALDBVER= 'b20230607_u20240201_x20240522_m20250515' / CALDB index versions used END XTENSION= 'BINTABLE' / binary table extension BITPIX = 8 / 8-bit bytes NAXIS = 2 / 2-dimensional binary table NAXIS1 = 18 / width of table in bytes NAXIS2 = 100 / number of rows in table PCOUNT = 0 / size of special data area GCOUNT = 1 / one data group (required keyword) TFIELDS = 3 / number of fields in each row TTYPE1 = 'TIME ' / label for field 1 TFORM1 = '1D ' / data format of field: 8-byte DOUBLE TUNIT1 = 's ' / physical unit of field TTYPE2 = 'RATE ' / label for field 2 TFORM2 = '1D ' / data format of field: 8-byte DOUBLE TUNIT2 = 'count/s ' / physical unit of field TTYPE3 = 'XRTMODE ' / label for field 3 TFORM3 = '1I ' / data format of field: 2-byte INTEGER EXTNAME = 'RATE ' / name of this binary table extension MESGNAME= 'XRT_LIGHTCURVE' / Name of the message COMMENT XRTMODE values COMMENT 1=null 2=Short Image 3=Long Image 4=Pile-Up Photodiode COMMENT 5=Low Rate Photodiode 6=Windowed Timing 7= Photon-Counting COMMENT 8=RAW data 9=Bias map 10=Stop TELESCOP= 'SWIFT ' / Telescope (mission) name INSTRUME= 'XRT ' / Instrument name OBS_ID = '01315630000' / Observation ID TARG_ID = '1315630 ' / Target ID SEG_NUM = '0 ' / Segment number CREATOR = 'TDRSS2FITS V3.22' / Program that created this FITS file ORIGIN = 'GSFC ' / Source of FITS file TLM2FITS= 'V3.22 ' / Telemetry converter version number EQUINOX = 2000 / Equinox RADECSYS= 'FK5 ' / Coordinates system TIMESYS = 'TT ' / Time system MJDREFI = 51910. / Reference MJD Integer part MJDREFF = 0.00074287037 / Reference MJD fractional TIMEUNIT= 's ' / Time unit for the time header keywords TIERRELA= 1.0E-8 / [s/s] relative errors expressed as rate TIERABSO= 1.0 / [s] timing precision in seconds CLOCKAPP= F / If clock correction are applied (F/T) TIMEREF = 'LOCAL ' / Time reference (barycenter/local) TASSIGN = 'SATELLITE' / Time assigned by clock DATE = '2025-05-30T05:49:02' / file creation date (YYYY-MM-DDThh:mm:ss UT) TSTART = 769401919.20962 / Start time DATE-OBS= '2025-05-20T02:45:14' TSTOP = 769402147.03548 / Stop time DATE-END= '2025-05-20T02:49:02' UTCFINIT= -35.6353200000000 / [s] UTCF at TSTART TIMEPIXR= 0. / Bin time beginning=0.0 middle=0.5 end=1. HDUCLASS= 'OGIP ' / Format conforms to OGIP standards HDUCLAS1= 'LIGHTCURVE' / Time ordered data HDUCLAS2= 'TOTAL ' / Source + background HDUCLAS3= 'RATE ' / Data provided as rate NUMBINS = 100 / Number of valid bins in the lightcurve TRIGGER = 1315630 / Trigger Number XRA_OBJ = 282.259826660156 / [deg] XRT RA location GRB or Object XDEC_OBJ= -11.8387212753296 / [deg] XRT DEC location GRb or Object TERMMODE= 0 / XRT termination mode TELAPSE = 227.825860023499 / TSTOP - TSTART ONTIME = 225.423065185547 / Time on target LIVETIME= 225.423065185547 / Ontime multiplied by DEADC EXPOSURE= 225.423065185547 / Total exposure, with all known correction DEADC = 1. / dead time correction UTCCTIME= -35.63532 / [s] UTC Correction TIME UTCCSEC = -36 / UTC Correction Seconds UTCCSUBS= 18234 / [2*10**(-5) s] UTC Correction SUBSeconds PKTTIME = 769402147.12504 / [s] ccsds PacKeT TIME=PKTSEC+PKTSUBS*2e-5 PKTSEC = 769402147 / ccsds PacKeT SEConds PKTSUBS = 6252 / [2*10**(-5) s] ccsds PacKeT SUBSeconds APID = 1253 / Application Process Identifier CHECKSUM= 'Amg6AlZ3Alf3AlZ3' / HDU checksum updated 2025-05-30T06:14:38 DATASUM = '408650681' / data unit checksum updated 2025-05-30T05:49:02 PROCVER = '3.20.02 ' / Processing script version SOFTVER = 'Hea_21Mar2024_V6.33.1_Swift_Rel5.8(Bld47)_30Jun2023_SDCpatch_2' CALDBVER= 'b20230607_u20240201_x20240522_m20250515' / CALDB index versions used END AAѫA w@UǤA D@:A!*@;*A!]@XA"<-@,aA"л@{A#Ms@ApA#r@{A$^@*:A$\@1pA%p@@A%@1pA&E@"@A' @EA'n@BDXA(.A*@,UA+@5 A-;p@8T6A.|`@5 A/P@7A0@d@7!`A2?/@7A3u@5 A4R@5 A6@8PA7B@7A8@3A9@4KA;@8PAȍ@7!`A@ }k@7!`AAJmH@4W1AB]%@6U@ACM@5 AE <6@6@AFN,@8T6AG@6U@AH @8PAJ@5 AKQ@6@ALں@6@AMʗ@5 AOs@7APUP@6@AQ@5 AR׉a@4KATy>@7!`AUYi@8T6AVX@3AWH,@4KAY8 @5 AZ]'@5#fA[@4KA\@3A^@4KA_`@5#fA`֌@3$Aai@5 Ac#@4KAddz@3AeW@3Af4@6@Ah'u@3AihdE@4KAjT"@5 AkC@4KAm+3@5#fAnl#@6@Ao@3$Ap@4KAr.@9Aso@3Atѷ@4KAu@4KAw2p@6U@AxsM@3Ay*@5 Az^@5 A|6p;@7A}w`@5#fA~O@4KA?)@5 A:/@3A{@4KA@4W1A@5#fA=@4W1A~ݭ@5#fA͊@2XAf@5 AA@3$Ax@5#fAÌT@4W1A|1@6U@AEl @5