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Table 2
Star and planet parameters of the system HAT-P-18.
| Parameter [Units] | Value |
|
|
|
| Stellar spectra characterization | |
|
|
|
| Effective temperature, Teff [K] | 4870 ± 50 |
| Surface gravity, log g⋆ [cm s-2] | 4.57 ± 0.07 |
| Iron abundance, [Fe/H] | 0.10 ± 0.06 |
| Microturbulence, vmic [km s-1] | 0.89 ± 0.08 |
| Macroturbulence, vmac [km s-1] | 2.5 ± 0.5 |
| Proj. rot. vel., VsinI⋆ [km s-1] | 1.40 ± 0.35 |
|
|
|
| RV and photometric data fit | |
|
|
|
| Star mass, M⋆ [M⊙] | 0.770 ± 0.027 |
| Planet mass, Mp [MJ] | 0.196 ± 0.008 |
| Star radius, R⋆ [R⊙] | 0.717 ± 0.026 |
| Planet radius, Rp [RJ] | 0.947 ± 0.044 |
| Orbital period, P [days] | 5.507978 ± 0.000043 |
| Eccentricity, e |
|
| Longitude of periastron, ω [deg] | 104 ± 50 |
| Orbital inclination, ip [deg] | 88.79 ± 0.25 |
| Epoch of periastron, τ [BJD] | 2 455 706.7 ± 0.7 |
| Barycentric RV, γ [m s-1] | − 11098.2 ± 2.5 |
| H11 RVs offset, γ2 [m s-1] | − 0.3 ± 1.0 |
| Proj. spin-orbit angle, λ [deg] | 132 ± 15 |
| Proj. rot. vel., VsinI⋆ [km s-1] | 1.58 ± 0.18 |
| Limb dark. – HARPS-N band, uRV | 0.58 ± 0.12 |
| Limb dark. – r band, ur | 0.56 ± 0.07 |
Normalized chi-square,  |
1.39 |
|
|
|
| Derived parameters | |
|
|
|
| Orbital semi-major axis, a [AU] | 0.0559 ± 0.0007 |
| Transit duration, T14 [hours] | 2.69 ± 0.06 |
| Impact parameter, b | 0.352 ± 0.057 |
| Transit depth – r band, | 0.02179 ± 0.00048 |
| RV-curve semi-amplitude, K [m s-1] | 26.9 ± 1.1 |
| Star density, ρ⋆ [g cm-3] | 2.94 ± 0.30 |
| Star surface gravity, log g⋆ [cm s-2] | 4.613 ± 0.031 |
| Planet density, ρp [g cm-3] | 0.286 ± 0.042 |
| Planet surface gravity, log gp [cm s-2] | 2.734 ± 0.044 |
| Planet equilibrium temperature, Tp [K] | 841 ± 15 |
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