See all articles of this topical issue

A&A 506, 245-254 (2009)
DOI: 10.1051/0004-6361/200911942

Short-lived spots in solar-like stars as observed by CoRoT

B. Mosser¹, F. Baudin², A. F. Lanza³, J. C. Hulot², C. Catala¹, A. Baglin¹, and M. Auvergne<sup>1

1</sup>  LESIA, CNRS, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, 92195 Meudon Cedex, France
    e-mail: benoit.mosser@obspm.fr
²  Institut d'Astrophysique Spatiale, UMR8617, Université Paris XI, Bâtiment 121, 91405 Orsay Cedex, France
³  INAF – Osservatorio Astrofisico di Catania, via S. Sofia, 78, 95123 Catania, Italy

Received 24 February 2009 / Accepted 5 June 2009

Abstract
Context. CoRoT light curves have an unprecedented photometric quality, having simultaneously a high signal-to-noise ratio, a long time span and a nearly continuous duty-cycle.
Aims. We analyse the light-curves of four bright targets observed in the seismology field and study short-lived small spots in solar-like stars.
Methods. We present a simple spot modeling by iterative analysis. Its ability to extract relevant parameters is ensured by implementing relaxation steps to avoid convergence to local minima of the sum of the residuals between observations and modeling. The use of Monte-Carlo simulations allows us to estimate the performance of the fits.
Results. Our starspot modeling gives a representation of the spots on these stars in agreement with other well tested methods. Within this framework, parameters such as rigid-body rotation and spot lifetimes seem to be precisely determined. Then, the lifetime/rotation period ratios are in the range 0.5-2, and there is clear evidence for differential rotation.

Key words: stars: activity -- stars: rotation -- starspots -- techniques: photometric

© ESO 2009

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.