EDP Sciences
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Volume 391, Number 2, August IV 2002
Page(s) 595 - 608
Section Formation, structure and evolution of stars
DOI http://dx.doi.org/10.1051/0004-6361:20020814

A&A 391, 595-608 (2002)
DOI: 10.1051/0004-6361:20020814

Spectroscopy of T Tauri stars with UVES

Observations and analysis of RU Lup
H. C. Stempels and N. Piskunov

Department of Astronomy and Space Physics Box 515, 751 20 Uppsala, Sweden
(Received 25 February 2002 / Accepted 28 May 2002 )

We present the first results of our observations of classical T Tauri Stars with UVES/VLT. The data consists of high signal-to-noise ( $\ge$150) and high spectral resolution ( $R \sim 60\,000$) spectra. A large simultaneous wavelength coverage throughout most of the visible spectrum and comparatively short integration times allow us to study variability on short time-scales, using a number of diagnostics reflecting a wide range of physical processes. In particular we concentrate on the properties and geometry of the accretion process in the strongly accreting and highly variable CTTS RU Lup. We use the evolution of the level of veiling, the shapes of absorption and emission lines, and correlations between these diagnostics, to make new measurements of the fundamental stellar parameters as well as constraints on the accretion process and its geometry. We also derive the shortest time-scale of incoherent changes, which has implications for the nature of the accretion process in RU Lup.

Key words: accretion, accretion disks -- stars: pre-main sequence -- stars: individual: RU Lup

Offprint request: H. C. Stempels, Eric.Stempels@astro.uu.se

© ESO 2002