Complex sentence: An object with the same diameter as Neptune has not been excluded by previous surveys in visible light, and the infrared survey by the Wide-field Infrared Survey Explorer (WISE) would not have seen a Neptune-sized object beyond 700 AU.
Split into simpler sentences: An object with the same diameter as Neptune has not been excluded by previous surveys. An infrared survey by the Wide-field Infrared Survey Explorer (WISE) beyond 700 AU.