Stellar age is one of the crucial parameters required to understand and characterise the evolution of young stars and their orbiting planets. Age-activity relation in based on decline of stellar magnetic activity over time. An order of magnitude age estimate is easily attainable in the range from a few tens of millions of years up to a few Gyr. Because a large portion of solar-like and later-type dwarf stars exhibit signs of chromospheric activity during their young ages, especially before they reach Solar age, this spectroscopic technique proved itself as very convenient to search for young star candidates.
In contrast to the excess emission flux in the Ca II HK lines being extensively studied in the literature, Gaia spectrograph covers Ca II infrared triplet lines. A correlation between these two activity measures will help to exploit relations discovered in the H&K lines (at ~390nm) in the Gaia sample and will thus play an important role in search for young stars, characterization of exoplanetary hosts and their environments.
This project will use data from the FunnelWeb survey, starting in October 2017 and aiming to robotically take spectra of the 2 million brightest stars in the southern hemisphere.