Towards the solution of the λ Bootis problem |
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| Authors: | Sergei M Andrievsky Ernst Paunzen |
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| Institution: | Department of Astronomy, Odessa State University, Shevchenko Park, 270014 Odessa, Ukraine; Institut für Astronomie der Universität Wien, Türkenschanzstraße 17, A-1180 Wien, Austria |
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| Abstract: | Having analysed the accretion-based model of the dust–gas separation, which is regarded to be the most promising for the explanation of the anomalous properties of λ Bootis-type stars, we can conclude that: (i) for any reasonable density profiles of the shell, dust grains appear to be decoupled from the gaseous background within the region where the temperature drops to a value that is less than the condensation temperature of heavy elements such as Mg, Ca, Fe, etc; (ii) most likely, in the shell of λ Bootis-type stars only small dust particles (of less than ≈10−6 cm in size) can be created; (iii) significant alteration of the initial atmospheric chemical composition can take place in the case when the density in the shell changes as ∼ r −2. |
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| Keywords: | stars: chemically peculiar circumstellar matter stars: individual: λ Bootis |
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