This page summarises the information held within TEPCat for the transiting planetary system WASP-18. Please see here for descriptions of the quantities given below.
| Quantity | Value | Unit |
|---|---|---|
| Reference of discovery paper | 2009Natur.460.1098H | |
| Date of discovery paper | 2009 / 8 / 27 | y / m / d |
| Right ascension | 01 37 25.03 | h m s |
| Declination | −45 40 40.4 | d m s |
| V-band apparent magnitude | 9.27 | mag |
| K-band apparent magnitude | 8.13 | mag |
| Transit duration | 0.09089 ( 2.1814 ) | day hour |
| Transit depth | 1.2 | % |
| Time of mid-transit | 2455265.5525 ± 0.0001 | HJD or BJD |
| Orbital period | 0.9414523 ± 0.0000003 | days |
| Reference for orbital ephemeris | 2013MNRAS.428.2645M |
| Quantity | Value | Unit |
|---|---|---|
| Stellar effective temperature | 6400 ± 70 | K |
| Stellar metal abundance ([Fe/H] or [M/H]) | +0.10 ± 0.08 | dex |
| Stellar mass | 1.295 ± 0.059 | Msun |
| Stellar radius | 1.255 ± 0.028 | Rsun |
| Stellar logarithmic surface gravity | 4.353 ± 0.017 | c.g.s. |
| Stellar mean density | 0.655 ± 0.035 ( 0.924 ± 0.049 ) | ρsun g cm-3 |
| Orbital eccentricity | 0.0092 ± 0.0028 | |
| Orbital semimajor axis | 0.02055 ± 0.00031 | AU |
| Planetary mass | 10.52 ± 0.32 ( 33442 ± 1017 ) | Mjup Mearth |
| Planetary radius | 1.204 ± 0.028 ( 13.50 ± 0.31 ) | Rjup Rearth |
| Planetary surface gravity | 179.9 ± 6.4 4.26 ± 0.02 | m/s2 log(cgs) |
| Planetary mean density | 5.64 ± 0.31 ( 7.48 ± 0.41 ) | ρjup g cm-3 |
| Planetary equilibrium temperature | 2411 ± 35 | K |
| Reference of detailed study | 2013MNRAS.428.2645M |
| Reference | λ (degrees) |
|---|---|
| Triaud et al. (2010) | 4.0 ± 5.0 |
| Albrecht et al. (2012) | 13 ± 7 |
WASP-18 has been examined as part of the Homogeneous Studies of Transiting Extrasolar Planets project. The details from this work have been given below. In most instances they are the same as the physical properties given above, but in some cases the Homogeneous Studies results given below have been superseded by newer analyses. Separate statistical and systematic errorbars are given where relevant.
| Measured parameters | Value | Unit |
|---|---|---|
| Orbital velocity amplitude | 1816.7 ± 1.9 | m/s |
| Stellar effective temperature | 6455 ± 70 | K |
| Stellar metal abundance ([Fe/H] or [M/H]) | +0.00 ± 0.09 | dex |
| Orbital inclination | 85.0 ± 2.1 | degrees |
| Fractional stellar radius (R* / a) | 0.2795 ± 0.0084 | |
| Fractional planetary radius (Rpl / a) | 0.0272 ± 0.0012 | |
| Light curve analysis reference | 2009ApJ...707..167S | |
| Derived parameters | Value | Unit |
| Stellar mass | 1.274 ± 0.054 ± 0.027 | Msun |
| Stellar radius | 1.228 ± 0.042 ± 0.009 | Rsun |
| Stellar logarithmic surface gravity | 4.365 ± 0.027 ± 0.003 | c.g.s. |
| Stellar mean density | 0.687 ± 0.062 | ρsun |
| Orbital semimajor axis | 0.02043 ± 0.00029 ± 0.00014 | AU |
| Planetary mass | 10.38 ± 0.30 ± 0.15 | Mjup |
| Planetary radius | 1.163 ± 0.054 ± 0.008 | Rjup |
| Planetary surface gravity | 190 ± 16 | m/s2 |
| Planetary mean density | 6.18 ± 0.83 ± 0.04 | ρjup |
| Planetary equilibrium temperature | 2413 ± 44 | K |
| Safronov number | 0.286 ± 0.013 ± 0.002 | |
| Main analysis reference | 2012MNRAS.426.1291S | |
Page generated on 2017/08/07 John Southworth (Keele University, UK)