The diameters of $\alpha$ Centauri A and B - A comparison of the asteroseismic and VINCI/VLTI views
Pierre Kervella,Frédéric Thévenin,Damien Ségransan,Gabrielle Berthomieu,Bruno Lopez,Pierre Morel,Janine Provost +6 more
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TLDR
In this paper, the first direct angular diameter measurements were obtained on the closest stellar neighbor, Centauri, by using the VINCI instrument installed at ESO's VLT Interferometer (VLTI).Abstract:
We compare the first direct angular diameter measurements obtained on our closest stellar neighbour, Centauri, to recent model diameters constrained by asteroseismic observations. Using the VINCI instrument installed at ESO's VLT Interferometer (VLTI), the angular diameters of the two main components of the system, Cen A and B, were measured with a relative precision of 0.2% and 0.6% respectively. Particular care has been taken in the calibration of these measurements, considering that VINCI is estimating the fringe visibility using a broadband K filter. We obtain uniform disk angular diameters for Cen A and B ofUD(A) = 8:314 0:016 mas andUD(B) = 5:856 0:027 mas, and limb darkened angular diameters ofLD(A)= 8:511 0:020 mas andLD(B)= 6:001 0:034 mas. Combining these values with the parallax from Soderhjelm (1999), we derive linear diameters of D(A)= 1:224 0:003 D and D(B)= 0:863 0:005 D. These values are compatible with the masses published by Thevenin et al. (2002) for both stars.read more
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The Solar-Stellar Connection and Disconnection
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Posted Content
VINCI / VLTI observations of Main Sequence stars
Pierre Kervella,F. Thévenin,Pierre Morel,Janine Provost,Gabrielle Berthomieu,D. Segransan,D. Queloz,Pascal Bordé,E. Di Folco,T. Forveille +9 more
TL;DR: In this article, the angular diameters of the main sequence stars in the K band were measured from recent VINCI/VLTI interferometric observations, with spectral types between A1V and M5.5V.
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