Protostars
DOI: 10.1063/1.3048411
Recent observations have placed a very narrow bound on the extent of the celestial x‐ray source in the constellation Scorpio (hereinafter designated “Sco X‐1”) and provoked a suggestion that it may represent a hitherto unseen class of objects, protostars. The observation, which placed a bound of 20 sec of arc on the angular diameter of Sco X‐1, was made on 8 March with a rocket‐borne experiment by Herbert Gursky, Riccardo Giacconi, Paul Gorenstein, John R. Waters of American Science and Engineering Corp.; Minoru Oda, Hale Bradt, Gordon Garmire and B. V. Sreekantan of MIT. It was published in the June issue of The Astrophysical Journal (144, 1249, 1966). The suggestion that Sco X‐1 is a protostar is by Oscar P. Manley of American Science and Engineering and appeared in the same issue of The Astrophysical Journal as a companion letter to that of Gursky and his associates.