Fermi LAT Light Curve Repository (LCR)

Please reference Abdollahi et al. 2023 for use of any results presented in the Fermi LAT Light Curve Repository. Also be sure to consult the LCR Usage Notes for important details and caveats about the LCR analysis.

Frequently Asked Questions

  • Why is there no light curve data for some of the sources listed in the source table on the index page?
  • The light curve repository (LCR) provides flux estimates at three different cadences for >1500 sources from the 10-year Fermi-LAT point source catalog data release 2 (4FGL-DR2) which have a variability index above 21.67. While the table in the main page lists all 4FGL-DR2 sources, only the ones with variability index above 21.67 show embedded hyperlinks to the data products of the source.

  • Can I download the light curves of more than one source at the time?
  • The API links to the LCR backend interface allows for scripted access to the LCR database. Alternatively, you could use a script like this one, or install pyLCR.

  • Is it possible to fix the pop out charts that appear when I hover over a source in the map? They disappear before I can click on the links within them.
  • Double clicking on the desired source in the map will fix the chart.

  • Is there a document describing the data formats available for download?
  • The light curve and JSON data formats are described here.

    If your issue is not described in the list above, send a message to fermilcr@athena.gsfc.nasa.gov for additional support.