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Erratum
This article is an erratum for: [this article]

Issue
A&A
Volume 499, Number 2, May IV 2009
Page(s) 623 - 625
Section Planets and planetary systems
DOI https://doi.org/10.1051/0004-6361/200810241e
Published online 16 April 2009

Erratum

Extrasolar planets and brown dwarfs around A-F type stars

V. A planetary system found with HARPS around the F6IV-V star HD 60532

M. Desort1 - A.-M. Lagrange1 - F. Galland1 - H. Beust1 - S. Udry2 - M. Mayor2 - G. Lo Curto3

1 - Laboratoire d'Astrophysique de Grenoble, UMR5571 CNRS, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
2 - Observatoire de Genève, Université de Genève, 51 chemin des Maillettes, 1290 Sauverny, Switzerland
3 - European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile

A&A 491, 883-888 (2008), DOI: 10.1051/0004-6361:200810241

Abstract
The dynamical analysis in the original paper was erroneous due to a mismatch in the choice of angular parameters. The calculations had been made by assuming a pole-on ($\sin i=0$) instead of an edge-on $\sin i=1$orbit. In this framework, $\Omega_c-\Omega_b$ is just the mutual inclination between the orbital planes of the two planets. We also correct some stellar parameters given in the original paper ( $\log g = +3.83$, [Fe/H] $_{\rm updated} = -0.26$).

Key words: techniques: radial velocities - stars: early-type - stars: planetary systems - stars: oscillations - stars: individual: HD 60532 - errata, addenda

 \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig1.ps}\inclu...
...0241fig3.ps}\includegraphics[angle=-90,width=9cm,clip]{0241fig4.ps}
\end{figure} Figure 1:

Orbital evolution over 100 yr of the semi-major axes (top) and eccentricities (bottom) for planets b ( left) and c (right), under their mutual perturbations, in a 3:1 resonance configuration.

Open with DEXTER

In the original paper the calculations had been made by assuming a pole-on ($\sin i=0$) instead of an edge-on ($\sin i=1$) orbit. The dynamical study has been made again, but this time by assuming coplanarity of the orbits, hence $\Omega_c=\Omega_b$. The figures are changed but the main conclusions remain. Over 108 yr, the planetary system is chaotic but does not indicate any instability. The semi-major axes of the two planets oscillate between 0.754 AU and 0.752 AU for planet b, and between 1.568 AU and 1.595 AU for planet c. The eccentricity of planet b oscillates between 0.118 and 0.3, and that of planet c between 0.015 and 0.141. As before, we show that, given the error bars, the secular evolution of the semi-major axis of planet b should be detectable within $\sim$10 years from now. This would constitute a strong indication of a resonant configuration. The sense of this variation is not constrained, because of the error bar on the argument of the planet c periastron. Figure 2 shows the secular evolution of the semi-major axis of planet b (ab) in the same conditions as above, but for an initial choice of $\omega _c=-280\hbox {$^\circ $ }$instead of $-209\hbox {$^\circ $ }$. The initial evolution sense is reversed compared to Fig. 1.

As in the initial calculations, the size of the error bars in Table 2 does even not ensure that the orbital configuration is actually resonant, but here again in non resonant configurations (Fig. 4), the variations of the semi-major axis of planet b achieve a much lower amplitude than in the resonant case.

Our basic conclusions are thus unchanged: i) the resonant configuration cannot be stated, but it is probable; ii) the system is significantly chaotic; iii) in a resonant configuration, we should be able to detect semi-major axis variations in planet b's motion within $\sim$10 yrs.

Recently, a global analysis of this system by Laskar & Correia (2009) confirmed the resonant status, using numerical integration and frequency analysis. In fact, non resonant systems appear less stable than resonant ones of Gyr timescales. This further indicates a resonant configuration.

We must also correct the $\log g$ of the star, which is +3.83. And we can update the estimated metallicity, which is now -0.26 according to new calibrations of the data from Holmberg et al. (2007), thus slightly more metallic than before. An estimation from Gray et al. (2006) (from which we took the $\log g$) gives $\rm [Fe/H] = -0.05$.

 \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig5}
\end{figure} Figure 2:

Evolution of semi-major axis if planet b in the same conditions as in Fig. 1, but assuming an initial $\omega _c=-280\hbox {$^\circ $ }$ instead of $-209\hbox {$^\circ $ }$.

Open with DEXTER

 \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig6}
\end{figure} Figure 3:

Evolution of the 3:1 critical argument $\sigma $ over 1000 yr, in the same condition as described in Fig. 1. We note the $\sigma $-libration characteristic for resonant motion.

Open with DEXTER

 \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig7}\includegraphics[angle=-90,width=9cm,clip]{0241fig8}
\end{figure} Figure 4:

Evolution of the semi-major axes of planet b and of the critical angle $\sigma $ for 3:1 resonance in the same conditions as described in Fig. 1, but with ac=1.56 AU. This is a non-resonant configuration.

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Acknowledgements
We thank Daniel Fabrycky, Jacques Laskar, and Alexandre Correia for pointing out the dynamical inconsistencies of the initial version of the paper, and the referee for the stellar parameter corrections.

References

All Figures

  \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig1.ps}\inclu...
...0241fig3.ps}\includegraphics[angle=-90,width=9cm,clip]{0241fig4.ps}
\end{figure} Figure 1:

Orbital evolution over 100 yr of the semi-major axes (top) and eccentricities (bottom) for planets b ( left) and c (right), under their mutual perturbations, in a 3:1 resonance configuration.

Open with DEXTER
In the text

  \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig5}
\end{figure} Figure 2:

Evolution of semi-major axis if planet b in the same conditions as in Fig. 1, but assuming an initial $\omega _c=-280\hbox {$^\circ $ }$ instead of $-209\hbox {$^\circ $ }$.

Open with DEXTER
In the text

  \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig6}
\end{figure} Figure 3:

Evolution of the 3:1 critical argument $\sigma $ over 1000 yr, in the same condition as described in Fig. 1. We note the $\sigma $-libration characteristic for resonant motion.

Open with DEXTER
In the text

  \begin{figure}
\par\includegraphics[angle=-90,width=9cm,clip]{0241fig7}\includegraphics[angle=-90,width=9cm,clip]{0241fig8}
\end{figure} Figure 4:

Evolution of the semi-major axes of planet b and of the critical angle $\sigma $ for 3:1 resonance in the same conditions as described in Fig. 1, but with ac=1.56 AU. This is a non-resonant configuration.

Open with DEXTER
In the text


Copyright ESO 2009

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