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  A super-Earth orbiting the M dwarf Gl 176
  Last update: January 16 2009

 
 
  • "The HARPS search for southern extra-solar planets: XIV. Gl 176b, a super-Earth rather than a Neptune, and at a different period"
    T. Forveille, X. Bonfils, X. Delfosse, M. Gillon, S. Udry, F. Bouchy, C. Lovis, M. Mayor, F. Pepe, C. Perrier, D. Queloz, N. Santos, J.-L. Bertaux, 2009
    A&A 493, 645 (ADS)
  • The orbital solution proposed in Endl et al. is invalidated by the more accurate HARPS data presented in Forveille et al.

    •  
    Larger image
    Gl 176 radial-velocity data obtained with HARPS
    ToP: Phase-folded orbit of Gl 176 b
    Middle: Phase-folded additional signal.
    This signal is induced by spots on the stellar surface.
    Bottom: Residuals of the 2-planet best fit.


  • Orbital solution (from Forveille et al. 2008):

    Object
    Period
    (days)
    T0
    (JD - 2 400 000)
    Eccentricity
    V
    (km/s)
    Omega
    (deg)
    K1
    (m/s)
    m2sini
    (M_Earth)
    a
    (AU)
    N
    Residuals
    (m/s)
    Gl 176 b
    8.7836
    +/- 0.0.0054
    54399.79
    +/- 0.33
    0.0
    (fixed)
    26.4105
    +/- 0.0004
    0.0
    (fixed)
    4.12 +/- 0.52
    8
    0.066
    57
    2.5


  • Stellar properties:

    Parameter
    Value
    Reference
    Sp. Type
    M2.5V
    Hipparcos
    pi (mas)
    106.2
    Hipparcos
    d (pc)
    9.4
    Hipparcos
    m_v (mag)
    9.97
    Hipparcos
    M_v (mag)
    10.10
    Hipparcos
    m_k (mag)
    5.607
    Struskie et al. 2006
    M_k (mag)
    5.74
    -
    L (L_sol)
    0.022
    -
    L_x/L_Bol
    3.5e-05
    -
    M_1 (M_sol)
    0.50
    Forveille et al. 2008
    P_rot (d)
    38.92
    Kiraga & Stepien 2007
    Vsini (km/s)
    <0.8
    Forveille et al. 2008
    Age (Gyr)
    -
    -
    [Fe/H]
    -0.1 +/- 0.2
    Forveille et al. 2008


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    stephane.udry@obs.unige.ch