Suitability of SONG for long-term studies of stellar activity: asteroseismology and spectroscopy

Titolo: Suitability of SONG for long-term studies of stellar activity: asteroseismology and spectroscopy

Relatore: Pere L. Palle' - on behalf of the SONG-Team (Instituto de Astrofisica de Canarias, La Laguna, Spain and Dpto. Astrofisica Universidad La Laguna, Spain)

Coordinate: mercoledì 1 marzo, ore 11:30, aula ovest OACT

Abstract: The Hertzsprung SONG telescopic installation at Observatorio del Teide is now completing its third-year
of continuous operations. Throughout this period, the proposed challenges and objectives have been achieved
and satisfactorily overcome: continuity of the observations, robustness (~8% technical downtime over 3 years),
flexible and robotic scientific operations (more than 150 targets observed in many different time cadences ),
continuous time series long enough to enable asteroseismic studies (more than 85 night-length for at least 6 stars),
high spectral resolution (80 to 110 000 obtained with the right targets and slits’ size)
and radial velocity precision ( below 1.5 m/s per velocity point for the brighter stars).
Because of the above capabilities, SONG is undoubtedly an appropriate facility to study
stellar activity cycles by means of two complementary approaches: the sensitivity of
the stellar eigenmodes and the changes on the properties of particular spectral line profiles
(H-alpha, Mg, CaII H& K , etc). In this talk we will illustrate these outcomes with
some of most relevant results obtained so far and also future prospects will be discussed.