A fifth galactic source (unidentified), just above the center of the galactic plane, is intriguing because it is a variable source and has no clear counterpart at other wavelengths.

• 排在第五名的恰好位于银河盘面中心上方的星系伽马源（未命名）显得很诡异，因为它是在一个在其他波段没有清晰对应物的变伽马源。