EAS Publications Series
Volume 69-70, 2014What the Highest Angular Resolution Can Bring to Stellar Astrophysics?
|Page(s)||249 - 256|
|Published online||10 September 2015|
F. Millour, A. Chiavassa, L. Bigot, O. Chesneau, A. Meilland and Ph. Stee (eds)
EAS Publications Series, 69–70 (2014) 249-256
Cepheid pulsations resolved by interferometry
1 Laboratoire Lagrange, UMR 7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d'Azur, Nice, France
2 LESIA, Observatoire de Paris, CNRS UMR 8109, UPMC, Université Paris Diderot, 5 place Jules Janssen, 92195 Meudon, France
The very high spatial resolution provided by current interferometers (VLTI, CHARA, …) makes it possible to measure directly the change in angular diameter of more than thirty Cepheids over their pulsation cycle. When combined with radial velocity measurements, this allows us to measure precisely their distances in a quasi-geometrical way. This is an essential information to calibrate the Cepheid's Period-Luminosity law. On the other hand, a careful analysis of the dynamical structure of their atmosphere is required to avoid biases in their distance determination.
© EAS, EDP Sciences, 2015