EDP Sciences
Free access
Volume 505, Number 2, October II 2009
Page(s) 859 - 871
Section Planets and planetary systems
DOI http://dx.doi.org/10.1051/0004-6361/200912479
Published online 11 August 2009
A&A 505, 859-871 (2009)
DOI: 10.1051/0004-6361/200912479

The M dwarf planet search programme at the ESO VLT + UVES

A search for terrestrial planets in the habitable zone of M dwarfs
M. Zechmeister1, M. Kürster1, and M. Endl2

1  Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
    e-mail: zechmeister@mpia.de
2  McDonald Observatory, University of Texas, Austin, TX78712, USA

Received 13 May 2009 / Accepted 15 July 2009

We present radial velocity (RV) measurements of our sample of 40 M dwarfs from our planet search programme with VLT+UVES begun in 2000. Although with our RV precision down to 2–2.5 m/s and timebase line of up to 7 years, we are capable of finding planets of a 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 1 AU 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$\,<20\,$m/s. Some high proper motion stars exhibit a linear RV trend consistent with their secular acceleration. Furthermore, we examine our data sets for a possible correlation between RVs and stellar activity as seen in variations of the H$\alpha$ line strength. For Barnard's star we found a significant anticorrelation, but most of the sample stars do not show such a correlation.

Key words: stars: general -- stars: planetary systems -- techniques: radial velocities

© ESO 2009