Extreme ultraviolet Imaging Telescope
The Extreme ultraviolet Imaging Telescope (EIT) is an instrument on the SOHO spacecraft used to obtain high-resolution images of the solar corona in the ultraviolet wavelength range. The EIT instrument is sensitive to light of four different wavelengths: 17.1, 19.5, 28.4 and 30.4 nm, corresponding respectively to light produced by highly ionized iron (XI)/(X), (XII), (XV) and helium (II).
Source: Wikipedia — Extreme ultraviolet Imaging Telescope (CC BY-SA 4.0)