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arXiv · 0807.4622

delta Cen: a new binary Be star detected by VLTI/AMBER spectro-interferometry

Anthony Meilland·Florentin Millour·Philippe Stee·Alain Spang·R. G. Petrov·D. Bonneau·Karine Perraut·Fabrizio Massi
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Abstract

We study the Be star $δ$ Cen circumstellar disk using long-baseline interferometry which is the only observing technique capable of resolving spatially and spectroscopically objects smaller than 5 mas in the H and K b and. We used the VLTI/AMBER instrument on January 6, 8, and 9, 2008, in the H and K bands to complete low (35) and medium (150 0) spectral resolution observations. We detected an oscillation in the visibility curve plotted as a function of the spatial frequency which is a clear signat ure of a companion around $δ$ Cen. Our best-fit soltution infers a binary separation of 68.7 mas, a companion flux co ntribution in the K band of about 7% of the total flux, a PA of 117.5 $\degr$, and an envelope flux around the Be primary that contributes up to about 50 % of the total flux, in agreement with our Spectral Energy Distribution (SED) fit. The e nvelope size is estimated to be 1.6 mas in K but no departure from spherical symmetry is detected.

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Anthony Meilland, Florentin Millour, Philippe Stee, Alain Spang, R. G. Petrov, D. Bonneau, Karine Perraut, Fabrizio Massi. 2008-08-07. delta Cen: a new binary Be star detected by VLTI/AMBER spectro-interferometry. https://doi.org/10.1051/0004-6361%3A200810624

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