EAS Publications Series
Volume 17, 2005Element Stratification in Stars: 40 Years of Atomic Diffusion
|Page(s)||91 - 101|
|Published online||13 January 2006|
G. Alecian, O. Richard and S. Vauclair (eds)
EAS Publications Series, 17 (2005) 91-101
A high resolution spectroscopic survey of the roAp stars
Centre for Astrophysics, University of Central Lancashire, Preston PR1 2HE, UK
2 European Southern Observatory, Casilla 19001, Santiago 19, Chile
We have begun a general high resolution spectroscopic survey of the entire class of roAp stars to study systematics of the pulsations for the class, and to make detailed studies of individual stars. We have high spectral resolution (R ~ 110 000), high time resolution VLT UVES data for 16 of the 35 known members of the class, two of which were discovered during this survey. We show here some examples of studies of pulsation amplitude and phase as a function of line depth in Hα and in the 6145 Å line of Nd iii. The two of these lines together give a nearly continuous map of pulsation amplitude and phase as a function of optical depth from about -5 ≤ log τ5000 ≤ -2, or even higher. Our results for these lines and those of Fe support studies showing settling of Fe and levitation of Nd. The pulsation behaviour provides an independent constraint on atmospheric structure and abundance distribution in roAp stars, hence is important in tests of radiative diffusion calculations.
© EAS, EDP Sciences, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.