Beta Pictoris and the lambda Bootis stars : testing the accretion hypothesis.
Abstract
It is suggested that Beta Pic may be an unrecognized Lambda Boo star, based on the recent discussion of its evolutionary status by Paresce and the proposal by Venn and Lambert linking circumstellar material with the Lambda Boo phenomenon. The star's metallicity, photometric indices and UV spectrum support this interpretation. If confirmed as a Lambda Boo star, Beta Pic would lend support to the accretion hypothesis of Venn and Lambert (1990) and would be the first Lambda Boo object recognized a priori from surrounding circumstellar material. In light of this classification, other workers' results suggesting that Beta Pic would be undergoing possible enrichment in metals from infalling, comet-like bodies is discussed. Though both the depleted, circumstellar and enriched cometry accretion rates are weakly constrained, the best evidence suggests that the metal-poor, circumstellar accretion rate is above 1 order of magnitude larger than that for metal-rich, cometary material.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- June 1992
- DOI:
- 10.1093/mnras/256.3.571
- Bibcode:
- 1992MNRAS.256..571K
- Keywords:
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- Accretion Disks;
- Peculiar Stars;
- Stellar Composition;
- Stellar Envelopes;
- Stellar Mass Accretion;
- Comets;
- Stellar Evolution;
- Stellar Spectra;
- Astrophysics