FInding ExoeaRths: tackling the ChallengEs of stellar activity

Introduction

FIERCE aims at providing the long-needed step forward to tackle the challenges of stellar activity on the search for Exoearths.

Objectives

The detection and characterisation of other Earths, planets with the physical conditions to hold liquid water and thus potential life-sustaining environments, is a bold objective of present-day astrophysics. This goal continuously pushes the development of new ground- and space-based instrumentation.

However, the quest for other Earths is severely limited by astrophysical "noise" from the host stars, whose signatures distort the spectra that are used to detect and characterise them. Existing methods usually circumvent the problem without a detailed understanding of the individual sources of variability. This is insufficient to reach the required precision levels.

To enable the full scientific success of major exoplanet research facilities, a new approach is clearly needed.

Methodology

With FIERCE, the PI will employ his competitive team, together with the strong participation in cutting-edge ESO and ESA projects and missions, to break through this obstacle. The ultimate goal is to:

1. Develop novel approaches to identify, model, and correct stellar spurious signals in radial velocity measurements down to 10 cm/s.
2. Obtain a comprehensive understanding of the impact of stellar granulation and activity on the detection of exoplanet atmospheres.

Innovative Approach

To this end, FIERCE will approach the problem of stellar "noise" from a whole new angle, building a dedicated facility, the Paranal solar Espresso Telescope (PoET). PoET will connect to the recently commissioned ESPRESSO spectrograph and, using the Sun as a proxy, allow for the unambiguous identification and understanding of the sources of relevant variability in solar-type stars.

Conclusion

Ambitious, timely, and feasible, this project will provide crucial information for the success of present and future major efforts aiming at detecting and characterising other Earths.