EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 460/3 Article
Free access article

Issue A&A
Volume 460, Number 3, December IV 2006
Page(s) 751 - 758
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20065242



A&A 460, 751-758 (2006)
DOI: 10.1051/0004-6361:20065242

First Doppler images of the very young K2-dwarf PW Andromedae = HD 1405

K. G. Strassmeier1 and J. B. Rice2

1  Astrophysical Institute Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
    e-mail: KStrassmeier@aip.de
2  Department of Physics, Brandon University, Brandon, Manitoba R7A 6A9, Canada
    e-mail: rice@BrandonU.ca

(Received 21 March 2006 / Accepted 13 June 2006)

Abstract
Aims.We present the first Doppler images of the single pre-main-sequence star PW And. Its position in the HR-diagram suggests it to be in the rapid-braking phase just prior to arrival on the ZAMS.
Methods.Images are obtained from seven individual spectral lines as well as from 5-nm wide chunks of spectrum that invert a total of 58 line profiles simultaneously.
Results.Cool spots with temperature differences with respect to the stellar photosphere of up to 1200 K are detected. Spot occurrence is mostly within an equatorial band up to $\pm$40° of the stellar equator and thus contradicts magnetic-flux tube emergence models based on young K-star properties that predict an emerging latitude in two distinct bands of +45-55°. This confirms previous suggestions that current magnetic-flux tube models predict emergence latitudes too low for G-dwarfs and too high for K-dwarfs, which may be caused by the fact that the G-dwarf models heavily rely on comparisons with the Sun. We also redetermine the absolute parameters of PW And in the light of a missing Hipparcos parallax and revise its age to be more near 20 Myr, in agreement with its logarithmic lithium abundance of $2.87\pm0.05$. A precise rotational period of 1$\fd$ $76159\pm0.00006$ was found from our photometric data in 2004.


Key words: stars: activity -- stars: starspots -- stars: imaging -- stars: individual: PW Andromedae -- stars: pre-main sequence -- stars: fundamental parameters



© ESO 2006


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.