This web page provides a well-exposed spectrum of the old planet host star Kepler-444. A total of twelve sub-exposures were combined for this deep spectrum and cover the wavelength range 423 – 912 nm. The spectrum has a two-pixel resolution of R=250,000 and S/N of between 150 to 550 depending on wavelength. Details are provided in the paper: C. E. Mack III, K. G. Strassmeier, I. Ilyin, S. C. Schuler, F. Spada, and S. A. Barnes, PEPSI deep spectra. III. A chemical analysis of the ancient planet-host star Kepler-444, A&A, 612, A46 (2018).
Data are stored as FITS files which contain three columns in double floating point format and one extra column in byte format for masking pixels in the spectrum. The first column is the wavelength for each pixel in the stellar rest frame with the Solar barycentric and SIMBAD stellar radial velocities removed, the second is the continuum normalized intensity, and the last one is the variance for each pixel.