Solar X-Ray Image Obtained Using Grazing-Incidence Optics. Giacconi, R. ; Reidy, W. P. ; Zehnpfennig, T. ; Lindsay, J. C. ; Muney, W. S. Abstract Publication: The Astrophysical Journal Pub Date: October 1965 DOI: 10.1086/148404 Bibcode: 1965ApJ...142.1274G