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The Variable Ca II Absorption in β Pictoris during 1998

Published online by Cambridge University Press:  05 March 2013

S. I. Barnes ,
William Tobin  and
K. R. Pollard
S. I. Barnes
Affiliation:
Mount John University Observatory & Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020, New Zealand; [email protected]
William Tobin
Affiliation:
Mount John University Observatory & Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020, New Zealand; [email protected]
K. R. Pollard
Affiliation:
Mount John University Observatory & Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8020, New Zealand; [email protected]
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Abstract

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Variable absorption features were observed in the visible and ultraviolet spectrum of β Pictoris soon after this star gained attention in the early 1980s due to its large IRAS infrared excess and the discovery, from optical imaging, of an edge-on dust disk. The absorption has been attributed to the evaporation of infalling planetesimals or comet-like bodies (the falling evaporating bodies, or FEB, hypothesis). With a view to confronting this hypothesis with fuller observations, we monitored the Ca II H and K lines in β Pictoris simultaneously during 1998, obtaining sequences of spectra on 50 nights. Variable absorption was usually present. The different oscillator strengths of the H and K lines permit the determination of covering factors, but detailed modelling is required to test whether all features can be explained by the FEB hypothesis. The blend of Ca II H with Balmer H ε means that the H and K photospheric profiles are different, and that the variable absorption features do not evolve in parallel. The behaviour of the variable absorption on November 27 is evocative of a body passing in front of the stellar disk in a prograde equatorial orbit.

Keywords

circumstellar matterline: profilesstars: individual (β Pictoris)
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 17 , Issue 3 , 2000 , pp. 241 - 243
Copyright
Copyright © Astronomical Society of Australia 2000

References

Artymowicz, P. 1997, Ann. Rev. Earth Planet. Sci., 25, 175 Google Scholar
Barnes, S. I. 1999, MSc thesis, University of Canterbury Google Scholar
Beust, H., & Lissauer, J. J. 1994, A&A, 282, 804 Google Scholar
Beust, H., Lagrange, A.-M., Crawford, I. A., Goudard, C., Spyromilio, J., & Vidal-Madjar, A. 1998, A&A, 338, 1015 Google Scholar
Hubeny, L., & Heap, S. R. 1996, ApJ, 470, 1144 CrossRefGoogle Scholar
Lagrange, A.-M., et al. 1996, A&A, 310, 547 Google Scholar
Lagrange, A.-M., et al. 1998, A&A, 330, 1091 Google Scholar
Persson, S. I. 1998, MSc thesis, University of Canterbury Google Scholar
Petterson, O. K. L., & Tobin, W. 1999, MNRAS, 304, 733 CrossRefGoogle Scholar
Tobin, W., et al. 1998, Southern Stars, 37, 197 Google Scholar
Vidal-Madjar, A., Lecavelier des Etangs, A., & Ferlet, R. 1998 Planet. Space Sci., 46, 629 Google Scholar