Author reviews the worlds major plate collections and discuss their impact on various regions of X-ray astronomy and astrophysics including long-term studies and monitoring of flares and active states of both galactic and extragalactic X-ray sources.
Author reviews the worlds major plate collections and discuss their impact on various regions of X-ray astronomy and astrophysics including long-term studies and monitoring of flares and active states of both galactic and extragalactic X-ray sources. (en)