X-Ray Stars Identified As Blue Stellar Objects

Abstract

Point sources of cosmic x rays have now been identified with bluish starlike objects in two cases—Scorpio X-l and Cygnus X-2. The Sco X-l identification was established after precise observations of position were made on a rocket flight on 8 March 1966. The position data were published by Herbert Gursky, Riccardo Giacconi, P. Gorenstein and J. R. Waters of American Science and Engineering, and Minoru Oda, H. Bradt, G. Garmire and B. V. Sreekantan of MIT in The Astrophysical Journal for October (page 310). Identification of Cygnus X-2 results from a rocket flight of 11 Oct. 1966 by the ASE group and was announced by Giacconi at the Texas [sic] Symposium on Relativistic Astrophysics, which was held in New York from 23 to 27 Jan. The second identification prompted Giacconi to hazard the remark: “If you want to make statistics on two objects, this could establish the existence of a new class of objects with main emission in the x-ray region through some part of their lives.”