Metallicism in border regions of the Am domain. I. Extremely young Am stars in the Orion 1c association

view Abstract Citations (43) References (38) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Metallicism in Border Regions of the AM Domain. I. Extremely Young AM Stars in the Orion 1c Association Smith, Myron A. Abstract A search for metallic4ine stars by means of 127 and 63 A spectrograms and iivby photometry has resulted in the discovery of five such stars in the extremely young Orion Ic association. A number of arguments in favor of their membership are made. It appears that Am stars in the pre-main-sequence- contraction phase occupy the same domain of the H-R diagram as do evolving Am stars. From the general properties of these stars it is concluded that the Am mechanism becomes operative and stabilizes within about 106 years. Evidence is also presented that in open clusters the characteristic rotation of stars, and not age directly, is important in determining the probability that an A star will become metallic lined. These conclusions are in best accord with an interpretation of metallicism in terms of subsurface diffusion. Publication: The Astrophysical Journal Pub Date: August 1972 DOI: 10.1086/151597 Bibcode: 1972ApJ...175..765S full text sources ADS | data products SIMBAD (53) GCPD (1) Related Materials (2) Part 2: 1973ApJS...25..277S Part 3: 1974ApJ...189..101S