Nov 4, 2026

Second Fermi-LAT Catalog of Low-Energy Sources (2FLE) Released

The Second Fermi-LAT Catalog of Low-Energy Sources (2FLE) is now officially available. The catalog details 450 significant gamma-ray sources detected between 20 MeV and 200 MeV over 14 years of Fermi mission data (August 2008 to August 2022).
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Sep 30, 2026

4FHL and GBM Catalog Releases

The FSSC is pleased to announce the official release of the Fourth Fermi-LAT Catalog of High-Energy Sources (4FHL) and the Fermi-GBM SGR/Magnetar Catalog. The 4FHL catalog contains 673 sources detected in the 50 GeV-2 TeV energy range using 16 years of Fermi Large Area Telescope (LAT) observations. The GBM catalog contains 1254 short bursts from 17 years of observations, representing the most comprehensive catalog of magnetar burst activity to date.

Jul 31, 2026

Fermitools 2.5.3 Released

An updated version (2.5.3) of the Fermitools is now available. This update includes a number of user reported bug fixes and several backend library updates and changes. These changes include the removal of the Xerces-C XML parsing interface and its replacement with the header-only rapidXML interface, moving from python 3.11 to 3.12, and a range of bug fixes reported by users as well as FSSC team members. This update is also fixes a critical bug preventing the accurate generation of radial gaussian and radial disk source maps and patches a performance issue affecting analysis using Fermipy that were found in the previous release (2.5.2).
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