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We report results of a spectropolarimetric and photometric monitoring of theweak-line T Tauri stars (wTTSs) V819 Tau and V830 Tau within the MaTYSSEprogramme, involving the ESPaDOnS spectropolarimeter at theCanada-France-Hawaii Telescope. At ~3 Myr, both stars dissipated their discsrecently and are interesting objects for probing star and planet formation.Profile distortions and Zeeman signatures are detected in the unpolarized andcircularly-polarized lines, whose rotational modulation we modelled usingtomographic imaging, yielding brightness and magnetic maps for both stars.  We find that the large-scale magnetic fields of V819 Tau and V830 Tau aremostly poloidal and can be approximated at large radii by 350-400 G dipolestilted at ~30 degrees to the rotation axis. They are significantly weaker thanthe field of GQ Lup, an accreting classical T Tauri star (cTTS) with similarmass and age which can be used to compare the magnetic properties of wTTSs andcTTSs. The reconstructed brightness maps of both stars include cool spots andwarm plages. Surface differential rotation is small, typically ~4.4x smallerthan on the Sun, in agreement with previous results on wTTSs.  Using our Doppler images to model the activity jitter and filter it out fromthe radial velocity (RV) curves, we obtain RV residuals with dispersions of0.033 and 0.104 km/s for V819 Tau and V830 Tau respectively. RV residualssuggest that a hot Jupiter may be orbiting V830 Tau, though additional data areneeded to confirm this preliminary result. We find no evidence for close-ingiant planet around V819 Tau.

Magnetic activity and hot Jupiters of young Suns: the weak-line T Tauri stars V819 Tau and V830 Tau