MARVEL : a 4-telescope array with a high resolution radial velocity spectrograph for measuring thousands of exoplanet masses, orbits and host star activity for the TESS, PLATO and ARIEL exoplanet space missions (MARVEL)

Since the first discovery of a planet outside of our Solar System in 1995, the exoplanet research has shifted from detecting to characterising worlds around other stars. The TESS (NASA, launched 2019) and PLATO mission (ESA, launch 2026) will find and constrain the size of thousands of exoplanets around bright stars all over the sky.  Radial velocity measurements are needed to characterise the orbit and mass, and complete the picture of densities and composition of the exoplanet systems found. The ARIEL mission (ESA, launch 2028) will characterise exoplanet atmospheres with infrared spectroscopy. Characterisation of stellar activity using optical ground spectroscopy is key to retrieve the planet atmosphere spectral footprint in ARIELs spectra.  To enable the scientific harvest of the TESS, PLATO and ARIEL space missions, we propose to construct MARVEL. Four telescopes are linked via optical fibers to a custom-built spectrograph, which is kept stable in a vacuum chamber to allow the simultaneous measurement of the radial motions of 4 stars. MARVEL is constructed by a KU Leuven-led collaboration, with contributions from the UK, Austria, Australia, Sweden and Spain.