All Figures

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{Hh223_f1.eps}\end{figure}$ Figure 1: HARPS spectra of the Ca II H ( $\lambda = 3968.47$ $\AA$ ) line region for Gl 581 and three comparison stars with similar spectral type and apparent magnitude. The stars are displayed in order of ascending chromospheric activity, and from top to bottom are Gl 752A, Gl 908, Gl 832 and Gl 581. The chromospheric emission peaks look prominent against the weak blue continuum of these M dwarfs, but they actually denote very weak chromospheric emission relative to the bolometric luminosity. Amongst those 4 stars, Gl 581 has the weakest chromospheric activity.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{Hh223_f2.eps} \end{figure}$ Figure 2: Upper panel: phased radial velocities for Gl 581. Lower panel: residuals around the fitted solution versus time.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{Hh223_f3.eps} \end{figure}$ Figure 3: Bissectors of the HARPS correlation profiles for Gl 581. The shape of the bissector curve is independent of its position, eliminating the possibility that stellar spot cause the radial-velocity variations.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8.8cm,clip]{Hh223_f2.eps} \end{figure}$	Figure 2: Upper panel: phased radial velocities for Gl 581. Lower panel: residuals around the fitted solution versus time.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8cm,clip]{Hh223_f3.eps} \end{figure}$	Figure 3: Bissectors of the HARPS correlation profiles for Gl 581. The shape of the bissector curve is independent of its position, eliminating the possibility that stellar spot cause the radial-velocity variations.
Open with DEXTER