The Helix Nebula with WFI

This raw image, straight from the WFI instrument on La Silla, was used together with many others to produce the iconic photo of the Helix Nebula. The images taken with astronomical instruments are always in intensity scale: the colour information is obtained by taking exposures through different glass filters. The 8 individual 8-Mpix detectors are visible, separated by black gaps. In the final image, these are filled combining images taken at slightly different positions. Some defects of the images are visible: long “bleeds” caused by bright stars saturating the detector, and bad columns causing bright or dark vertical lines.