"The Crab Nebula as an observed point source of cosmic rays" in Physical Review, 1951. **Among the Earliest Attempts to Identify a Specific Astronomical Object as a Source of Cosmic Rays**

**Among the Earliest Attempts to Identify a Specific Astronomical Object as a Source of Cosmic Rays** Sekido, Y.; Masuda, T.; Yoshida, S.; Wada, M. (1951). "The Crab Nebula as an observed point source of cosmic rays" in Physical Review, vol  83 (3): 658–659. Original wrappers. The spine has been beautifully reconstructed with a new paper cover with matching typography—an excellent piece of work. The issue is housed in a folding clamshell box, in calf. The issue of the Physical Review is in near-FINE condition. There is an old owner's rubber stamp at the bottom of the front wrapper (see photo). The custom folding box is NEW. "Early speculation on the sources of cosmic rays included a 1934 proposal by Baade and Zwicky suggesting cosmic rays originated from supernovae. A 1948 proposal by Horace W. Babcock suggested that magnetic variable stars could be a source of cosmic rays. Subsequently, Sekido et al. (1951) identified the Crab Nebula as a source of cosmic rays. Since then, a wide variety of potential sources for cosmic rays began to surface, including supernovae, active galactic nuclei, quasars, and gamma-ray bursts."--wikipedia 714.3.…