ESPaDOnS large program: characterising stellar magnetic fields throughout the HR diagram
JF Donati, J Bouvier, M Deleuil, T Forveille, C Neiner, K Perraut, A Lopez-Ariste, JP Zahn

Abstract: We propose to start a large observing program with ESPaDOns, aimed at investigating magnetic fields of stars throughout the HR diagram. In particular, this program will focus on magnetic fields of protostars and protostellar accretion discs, on magnetic fields of low-mass stars, on magnetic fields of massive stars, as well as on magnetic fields of stars hosting closely-orbiting exoplanets. This program will also provide ground-based support to COROT and GAIA by deriving precise magnetic properties on a selection of reference stars. , , All scientific topics included in this large program require the same kinds of observations, ie regular monitorings of all targets over their rotation cycles, as well as regular visits over a multi-yr period to study the long-term evolution of their magnetic fields (activity cycles). Since observations need to be carried out over a significant sample of stars, this large program requires at least 500 clear nights with ESPaDOnS over a timescale of at least 5yr. This large program will also imply coordinated NARVAL observations for the brightest sample targets, requiring at least 1200 clear nights with NARVAL over at least 5 yr. , , This large program is strongly supported by the CNRS National Program on Stellar Physics (PNPS). More information about it (in french) can be found at , http:--www-laog.obs.ujf-grenoble.fr-heberges-pnps-PLAIN-spol