EDP Sciences
Free access
Volume 435, Number 1, May III 2005
Page(s) 289 - 301
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20042356

A&A 435, 289-301 (2005)
DOI: 10.1051/0004-6361:20042356

Is Arcturus a well-understood K giant?

Test of model atmospheres and potential companion detection by near-infrared interferometry
T. Verhoelst1, 2, P. J. Bordé3, G. Perrin2, L. Decin1, K. Eriksson4, S. T. Ridgway2, 5, P. A. Schuller3, W. A. Traub3, R. Millan-Gabet5, M. G. Lacasse3 and C. Waelkens1

1  Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
    e-mail: Tijl.verhoelst@ster.kuleuven.ac.be
2  Observatoire de Paris-Meudon, LESIA, 5 place Jules Janssen, 92195 Meudon, France
3  Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
4  Institute for Astronomy and Space Physics, Box 515, 75120 Uppsala, Sweden
5  National Optical Astronomy Observatories, PO Box 26732, Tucson, AZ 85726, USA

(Received 10 November 2004 / Accepted 23 January 2005)

We present near-IR interferometric measurements of the K1.5 giant Arcturus ($\alpha$ Bootis), obtained at the IOTA interferometer with the FLUOR instrument, in four narrow filters with central wavelengths ranging from 2.03 $\mu$m to 2.39 $\mu$m. These observations were expected to allow us to quantify the wavelength dependence of the diameter of a typical K giant. They are compared to predictions from both plane-parallel and spherical model atmospheres. Unexpectedly, neither can explain the observed visibilities. We show that these data suggest the presence of a companion, in accordance with the Hipparcos data on this star, and discuss this solution with respect to Arcturus' single star status.

Key words: techniques: interferometric -- stars: individual: Arcturus -- stars: atmospheres -- stars: binaries: general

SIMBAD Objects

© ESO 2005

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.