Doppler imaging of stellar surface structure

Free access article

Issue		A&A Volume 389, Number 1, July I 2002


Page(s)		202 - 212
Section		Stellar atmospheres
DOI		http://dx.doi.org/10.1051/0004-6361:20020506

A&A 389, 202-212 (2002)
DOI: 10.1051/0004-6361:20020506

XVIII. The very active RS CVn binary UZ Librae revisited

K. Oláh¹, K. G. Strassmeier² and M. Weber²

¹ Konkoly Observatory of the Hungarian Academy of Sciences, 1525 Budapest, Hungary
e-mail: olah@konkoly.hu
² Astrophysical Institute Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany

(Received 7 December 2001 / Accepted 3 April 2002)

Abstract
We present eight Doppler images of UZ Librae from the years 1994, 1996, 1997, 1998 and 2000. These maps indicate a preferred temperature distribution from one year to the other and suggest preferred spot locations for at least the seven years of our observations. Two equatorial active regions appear facing towards and opposite the (unseen) companion star. A large and cool polar spot, with two or maybe three appendages extending down to a latitude of 40°-50°, is present and causes the long-term light variability of UZ Lib. The appendages appear at longitudes very similar to the two equatorial active regions and sometimes are possibly even attached to them. No coherent sign of differential rotation is found for the equatorial regions up to a latitude of approximately +50°, but the polar appendages may indicate a general acceleration of the polar regions. If interpreted as being due to differential rotation, if real at all, then UZ Lib clearly exhibits a non-solar flow pattern.

Key words: starspots -- stars: activity -- stars: atmospheres -- stars: late-type -- stars: individual: UZ Lib -- stars: binaries: close

Offprint request: K. G. Strassmeier, Kstrassmeier@aip.de, Mweber@aip.de

SIMBAD Objects

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.