WP3: Eruptive activity of late-type and sun-like stars

The main goal of WP3 is to achieve a better understanding of the magnetic activity of late-type stars with deep convective zones and to determine their XUV and plasma fluxes over wide range of ages. This will advance our comprehension of the magnetic past of the Sun by utilizing carefully selected solar analogues (with different ages and rotation-rates) that serve as proxies for the Sun over its main-sequence lifetime and the most powerful magnetic-field related solar/stellar eruptive processes.


T3.1. Preparations of observing capacities

The main goal of T3.1 is to prepare the HO 1-m telescope for the foreseen observations, i.e., to install the spectrograph and adjust hardware and software needed for the photometric and spectrographic use. HO 1-m Austro-Croatian telescope is used for long observing runs and to concentrate on brighter stars in order to ensure temporal cadence high enough for the observations. Spectra in the H-alpha and/or lithium spectral regions are recorded by the Shelyak eShell echelle spectrogtraph of the Gothard Astrophysical Obsarvatory, Lorand Eotvos University spectrograph attached to the HO 1-m telescope.


T3.2. Observations, data analysis and interpretation

The research activity will be focused on monitoring young pre-main sequence objects using HO 1-m telescope, in particular the T Tauri stars, representing youthful versions of the sun-like stars, with masses of a few tenths to a few times the mass of the Sun. On young stars prominences are large enough to be seen in disk-integrated H-alpha spectra. Stellar CMEs can be detected in spectra as extra blue shifted emission in the Balmer lines (H-alpha, H-beta, and H-gamma). Two types of observations are performed: photometric monitoring of selected stars in blue filters (U & B) and in the narrow band H-alpha filter, and spectrographic observations in the H-alpha and/or lithium spectral regions. Radial and rotational velocities, effective temperatures, and gravity of the observed objects are determined, and an estimate of the age and the chromospheric activity level is performed.