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  HD 40307: A system with 3 super-Earths
  Last update: January 16 2009

 
 
  • "The HARPS search for southern extra-solar planets. XIII. A planetary system with 3 Super-Earths (4.2, 6.9, & 9.2 Earth masses)"
    M. Mayor, S. Udry, C. Lovis, F. Pepe, D. Queloz, W. Benz, J.-L. Bertaux, F. Bouchy, C. Mordasini, D. Ségransan, 2009
    A&A 493, 639 (ADS)
  • Announced during the "Extra-solar Super-Earths" conference held in Nantes (F), June 16-18 2008

    •  
     
    Larger image
     
    Larger image
    HARPS phase-folded
    velocities for the
    3 planets orbiting
    HD 40307.
     
    Time window of HARPS relative radial velocities of HD 40307.
    The solid lines shows the 3-keplerian orbital solution


  • Orbital solution (from Mayor et al. 2009):

    Object
    Period
    (days)
    T0
    (JD - 2 400 000)
    Eccentricity
    V
    (km/s)
    Omega
    (deg)
    K1
    (m/s)
    m2sini
    (M_Earth)
    a
    (AU)
    Drift
    (m/s/yr)
    N
    Residuals
    (m/s)
    HD 40307 b
    4.3115
    +/- 0.0006
    54562.77
    +/- 0.08
    0.0
    (fixed)
    31.332
    0.0
    (fixed)
    1.97 +/- 0.11
    4.2
    0.047
    0.51
    0.10
    135
    0.85
    HD 40307 c
    9.620
    +/- 0.002
    54551.53
    +/- 0.15
    0.0
    (fixed)
    -
    0.0
    (fixed)
    2.47 +/- 0.11
    6.8
    0.081
    -
    "
    "
    HD 40307 d
    20.46
    +/- 0.01
    54532.42
    +/- 0.29
    0.0
    (fixed)
    -
    0.0
    (fixed)
    4.55 +/- 0.12
    9.2
    0.134
    -
    "
    "


  • Stellar properties:

    Parameter
    Value
    Reference
    Sp. Type
    K2.5V
    Hipparcos
    pi (mas)
    77.95
    Hipparcos
    d (pc)
    12.8
    Hipparcos
    m_v (mag)
    7.12
    Hipparcos
    B-V (mag)
    0.92
    Hipparcos
    T_eff (K)
    4977 +/- 59
    Sousa et al. 2008
    M_v (mag)
    6.62
    Mayor et al. 2009
    L (L_sol)
    0.23
    Mayor et al. 2009
    log(g) (CGS)
    4.47 +/- 0.16
    Sousa et al. 2008
    M_1 (M_sol)
    0.77 +/- 0.05
    Sousa et al. 2008
    log(R'HK)
    -4.99
    Mayor et al. 2009
    P_rot (d)
    48
    Mayor et al. 2009
    Vsini (km/s)
    <1.0
    Mayor et al. 2009
    Age (Gyr)
    -
    -
    [Fe/H]
    -0.31 +/- 0.03
    Sousa et al. 2008


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    stephane.udry@obs.unige.ch