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arXiv · 1203.6682

Mean angular diameters, distances and pulsation modes of the classical Cepheids FF Aql and T Vul - CHARA/FLUOR near-infrared interferometric observations

A. Gallenne·P. Kervella·A. Mérand·H. McAlister·T. ten Brummelaar·V. Coudé du Foresto·J. Sturmann·L. Sturmann·N. Turner·C. Farrington·P. J. Goldfinger
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Abstract

We report the first angular diameter measurements of two classical Cepheids, FF Aql and T Vul, that we have obtained with the FLUOR instrument installed at the CHARA interferometric array. We obtain average limb-darkened angular diameters of θ_LD = 0.878 +/- 0.013 mas and θ_LD = 0.629 +/- 0.013 mas, respectively for FF Aql and T Vul. Combining these angular diameters with the HST-FGS trigonometric parallaxes leads to linear radii R = 33.6 +/- 2.2 Rsol and R = 35.6 +/- 4.4 Rsol, respectively. The comparison with empirical and theoretical Period-Radius relations leads to the conclusion that these Cepheids are pulsating in their fundamental mode. The knowledge of the pulsation mode is of prime importance to calibrate the Period-Luminosity relation with a uniform sample of fundamental mode Cepheids.

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A. Gallenne, P. Kervella, A. Mérand, H. McAlister, T. ten Brummelaar, V. Coudé du Foresto, J. Sturmann, L. Sturmann, N. Turner, C. Farrington, P. J. Goldfinger. 2012-03-29. Mean angular diameters, distances and pulsation modes of the classical Cepheids FF Aql and T Vul - CHARA/FLUOR near-infrared interferometric observations. https://doi.org/10.1051/0004-6361%2F201219102

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