This page summarises the information held within TEPCat for the transiting planetary system HAT-P-18. Please see here for descriptions of the quantities given below.
| Quantity | Value | Unit |
|---|---|---|
| Reference of discovery paper | 2011ApJ...726...52H | |
| Date of discovery paper | 2010 / 7 / 29 | y / m / d |
| Data/telescope used for discovery | HAT | |
| Right ascension | 17 05 23.28 | h m s |
| Declination | +33 00 45.0 | d m s |
| Right ascension (decimal) | 256.34700 | degrees |
| Declination (decimal) | 33.01250 | degrees |
| V-band apparent magnitude | 12.76 | mag |
| K-band apparent magnitude | 10.23 | mag |
| Transit duration | 0.1131 ( 2.714 ) | day hour |
| Transit depth | 1.9 | % |
| Time of mid-transit | 2454715.02254 ± 0.00039 | HJD or BJD |
| Orbital period | 5.5080291 ± 0.0000042 | days |
| Reference for orbital ephemeris | 2015MNRAS.451.4060S |
| Quantity | Value | Unit |
|---|---|---|
| Stellar effective temperature | 4870 ± 50 | K |
| Stellar metal abundance ([Fe/H] or [M/H]) | +0.10 ± 0.06 | dex |
| Stellar mass | 0.770 ± 0.027 | Msun |
| Stellar radius | 0.717 ± 0.026 | Rsun |
| Stellar logarithmic surface gravity | 4.613 ± 0.031 | c.g.s. |
| Stellar mean density | 2.08 ± 0.21 ( 2.93 ± 0.30 ) | ρsun g cm-3 |
| Orbital eccentricity | 0.009 +0.03 −0.009 | |
| Orbital semimajor axis | 0.0559 ± 0.0007 | AU |
| Planetary mass | 0.196 ± 0.008 ( 62.3 ± 2.5 ) | Mjup Mearth |
| Planetary radius | 0.947 ± 0.044 ( 10.61 ± 0.49 ) | Rjup Rearth |
| Planetary surface gravity | 5.42 ± 0.55 2.73 ± 0.04 | m/s2 log(cgs) |
| Planetary mean density | 0.216 ± 0.032 ( 0.287 ± 0.042 ) | ρjup g cm-3 |
| Planetary equilibrium temperature | 841 ± 15 | K |
| Reference of detailed study | 2014A+A...564L..13E |
| Reference | λ (degrees) |
|---|---|
| Esposito et al. (2014) | 132 ± 15 |
Page generated on 2025/11/11 John Southworth (Keele University, UK)