view Abstract Citations (259) References (61) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Chemical Composition of Three Lambda Bootis Stars Venn, Kim A. ; Lambert, David L. Abstract Abundance analyses are reported for three certain members (Lambda Boo, 29 Cyg, Pi1 Ori) of the class of rapidly rotating, metal-poor A-type stars known as Lambda Bootis stars. Model atmosphere analysis of high-resolution, high signal-to-noise spectra shows that the metal deficiencies are more severe than previously reported: Fe/H = -2.0, -1.8, -1.3 for Lambda Boo, 29 Cyg, and Pi1 Ori, respectively. Other metals (Mg, Ca, Ti, and Sr) are similarly underabundant, with Na often having a smaller underabundance. C, N, O, and S have near-solar abundances. Vega is shown to be a mild Lambda Boo star. The abundance anomalies of the Lambda Boo stars resemble those found for the interstellar gas in which the metals are depleted through formation of interstellar grains. It is suggested that the Lambda Boo stars are created when circumstellar (or interstellar) gas is separated from the grains and accreted by the star. The bulk of the interstellar grains comprises a circumstellar cloud or disk that is detectable by its infrared radiation. Publication: The Astrophysical Journal Pub Date: November 1990 DOI: 10.1086/169334 Bibcode: 1990ApJ...363..234V Keywords: A Stars; Main Sequence Stars; Stellar Composition; Chemical Composition; Infrared Astronomy; Interstellar Gas; Metallicity; Stellar Mass Accretion; Stellar Rotation; Astrophysics; STARS: ABUNDANCES; STARS: ACCRETION; STARS: PECULIAR A full text sources ADS | data products SIMBAD (4)