M dwarfs radial velocities

Although with our RV precision down to 2-2.5m/s and timebase line of up to 7 years we are capable of finding planets of few Earth masses in the close-in habitable zones of M dwarfs, there is no detection of a planetary companion. To demonstrate this we present mass detection limits allowing us to exclude Jupiter mass planets up to 1AU for most of our sample stars.

We identified 6 M dwarfs that host a brown dwarf or low mass stellar companion. With the exception of these, all other sample stars show low RV variability with an rms <20m/s. Some high proper motion stars exhibit a linear RV trend consistent with their secular acceleration.