1 research outputs found
Chronos - take the pulse of our galactic neighbourhood. After Gaia: Time domain information, masses and ages for stars
Understanding our Galaxy’s structure, formation, and evolution will, over the next
decades, continue to benefit from the wonderful large survey by Gaia, for astrometric,
kinematic, and spectroscopic characterization, and by large spectroscopic surveys for
chemical characterization. The weak link for full exploitation of these data is age
characterization, and stellar age estimation relies predominantly on mass estimates.
The ideas presented in this White Paper shows that a seismology survey is the way
out of this situation and a natural complement to existing and planned surveys. These
ideas are strongly rooted in the past decade’s experience of the so-called Seismology
revolution, initiated with CoRoT and Kepler. The case of red giant stars is used here
as the best current illustration of what we can expect from seismology for large
samples, but premises for similar developments exist in various other classes of stars
covering other ranges of age or mass. Whatever the star considered, the first
information provided by stellar pulsations is always related to the mean density
and thus to the mass (and age). In order to satisfy the need for long-duration and allsky
coverage, we rely on a new instrumental concept which decouples integration
time and sampling time. We thus propose a long (~1 year) all-sky survey which
would perfectly fit between TESS, PLATO, and the Rubin Observatory (previously
known as LSST) surveys to offer a time domain complement to the current and
planned astrometric and spectroscopic surveys. The fine characterization of host
stars is also a key aspect for the interpretation and exploitation of the various projects
– anticipated in the framework of the Voyage 2050 programme – searching for
atmospheric characterization of terrestrial planets or, more specifically, looking for a
signature of life, in distant planets