Hinode XRT Level0 FITS data are uncalibrated observational data acquired by the X-Ray Telescope (XRT) onboard the Hinode spacecraft. The Level0 FITS files contain telemetry-derived CCD images of the solar corona obtained through X-ray analysis filters and visible-light optics, together with instrument configuration parameters and observational metadata. Each file typically corresponds to a single exposure.

XRT is a grazing-incidence soft X-ray telescope designed to observe high-temperature coronal plasma with high spatial and temporal resolution. The instrument includes Wolter-I type X-ray optics, focal-plane filter wheels, a shutter mechanism, visible-light optics, and a 2048 × 2048 CCD detector.

The Level0 FITS data preserve the original observation content before calibration and scientific processing. These files provide the basis for higher-level calibrated products and support studies of active regions, flares, coronal heating, plasma dynamics, and eruptive phenomena such as coronal mass ejections. The XRT instrument was developed through a Japan–US collaboration involving the Harvard-Smithsonian Center for Astrophysics, NASA Marshall Space Flight Center, JAXA, and NAOJ.