FERMILWEEK ivo://nasa.heasarc/fermilweek NASA/GSFC HEASARC HEASARC 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Observation The Fermi LAT Weekly Data database table provides access to LAT data binned into weekly files by the FSSC's data servers. For each week, the FSSC provides two FITS files: an all-sky file of photons containing positions, energies, etc. and a spacecraft pointing history file. The underscore separated fields in the file names indicate the file type (photon or spacecraft), the Fermi mission week (e.g., w009 = week 9), the processing version (which will change with each major reprocessing of LAT data), and a version number for the file itself. Note that currently the data may include events from slightly after the official week boundaries, which will be reflected in the start and stop times in the table. Any "run" of LAT data the FSSC receives that starts in a given week is put into the weekly file for that week and not broken up. Note additional selections must be applied to the weekly files prior to use in a data analysis. See <a href="http://fermi.gsfc.nasa.gov/ssc/data/analysis/documentation/Cicerone/Cicerone_Data_Exploration/Data_preparation.html">LAT Data Selection Recommendations</a> and <a href="http://fermi.gsfc.nasa.gov/ssc/data/analysis/LAT_caveats.html">Caveats About Analyzing LAT Data</a> for more information. For queries based on position, energy, and exact times, use the <a href="http://fermi.gsfc.nasa.gov/cgi-bin/ssc/LAT/LATDataQuery.cgi">FSSC's LAT data server</a>. This database table is created by the HEASARC from FITS tables received from the Fermi Science Support Center (FSSC). It is updated on a weekly basis. This is a service provided by NASA HEASARC . https://heasarc.gsfc.nasa.gov/W3Browse/all/fermilweek.html Archive Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=fermilweek GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_fermilweek&Action=More+Options&Action=Parameter+Search&ConeAdd=1 FERMI 0.0166666666666667 Gamma-ray public fermilweek Fermi LAT Weekly Data week_number Fermi Mission Week Number meta.number;time short nullable "time" Observation Start Time mjd time.start;obs double nullable end_time Observation Start Time mjd time.end;obs double nullable met_end Observation Stop Time (MET seconds) s time.end;obs double nullable last_modified Last Modified Time mjd time.epoch;obs double nullable met_start Observation Start Time (MET seconds) s time.start;obs double nullable "__row" System index column char nullable