HARPS-N radial velocities confirm the low densities of the Kepler-9 planets

Borsato, L;Malavolta, L;Piotto, G;Buchhave, L A;Mortier, A;Rice, K;Cameron, A C;Coffinet, A;Sozzetti, A;Charbonneau, D;Cosentino, R;Dumusque, X;Figueira, P;Latham, D W;Lopez-Morales, M;Mayor, M;Micela, G;Molinari, E;Pepe, F;Phillips, D;Poretti, E;Udry, S;Watson, C

2019