Nearby stars: published parallaxes (RECONS / Gaia), spectral types per SIMBAD
Exoplanets: NASA Exoplanet Archive. Orbit sizes and periods are real; the drawn positions around other stars are estimates (phase and orientation unmeasured) and say so in their panels
scale notes
Orbits and distances between bodies: true scale (1 AU consistent)
Planet and moon sizes: true scale relative to each other, uniformly magnified so they are visible at all
The Sun is shown smaller than that magnification implies, and moon orbital distances are compressed; both would otherwise swallow everything nearby
Star distances beyond 50 AU are compressed for navigation; real values in every info panel