Credit: Ö. H. Detre et al./MPIA
These images explain how the Uranian moons were extracted from the data.
Left: The original image contains the infrared signals from Uranus and its five main moons, measured at a wavelength of 70 µm. Uranus is several thousand times brighter than a single moon. Its image is dominated by artifacts due to interference from the telescope and the camera. Titania and Oberon are barely visible.
Center: Using these data, a sophisticated procedure created a model for the brightness distribution of Uranus alone. This is subtracted from the original image.
Right: Finally, the signals of the moons remain after the subtraction. At the location of Uranus the not quite perfect extraction method slightly affects the result.
Source / Image Courtesy