 Artistic rendering of WASP-4 b | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Phoenix[1] |
| Right ascension | 23h 34m 15.0857s[2] |
| Declination | −42° 03′ 41.048″[2] |
| Apparent magnitude (V) | 12.468±0.025[3] |
| Characteristics | |
| Evolutionary stage | Main sequence |
| Spectral type | G7V[4] |
| Apparent magnitude (V) | 12.468±0.025[3] |
| Apparent magnitude (B) | 13.216±0.020[3] |
| Variable type | Planetary transit variable[4] |
| Astrometry | |
| Radial velocity (Rv) | 57.61±0.76[2] km/s |
| Proper motion (μ) | RA: 9.950(12)mas/yr[2] Dec.: −87.620(10)mas/yr[2] |
| Parallax (π) | 3.6623±0.0147 mas[2] |
| Distance | 891 ± 4 ly (273 ± 1 pc) |
| Details[5] | |
| Mass | 0.89±0.01 M☉ |
| Radius | 0.920±0.060 R☉ |
| Surface gravity (log g) | 4.484+0.037 −0.047[6] cgs |
| Temperature | 5436±34 K |
| Metallicity [Fe/H] | −0.050±0.040 dex |
| Rotation | 22.2±3.3 d |
| Rotational velocity (v sin i) | 2.2+0.6 −1.0 km/s |
| Age | 7.0±2.9 Gyr |
| Other designations | |
| 1SWASP J233415.06-420341.1,TOI-232,TIC 402026209,WASP-4,TYC 8017-108-1,2MASS J23341508-4203411[7] | |
| Database references | |
| SIMBAD | data |
WASP-4 is aG-type main-sequence star approximately 891light-years away in theconstellation ofPhoenix.[4][1][2] Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by a giant planet on a close orbit.[8]
In 2007 theexoplanetWASP-4b was discovered orbiting this star. With an orbital period of just 1.3 days it is classified as ahot Jupiter.[4] The planet's orbital period appears to be decreasing at a rate of7.33±0.71 milliseconds per year, suggesting that its orbit is decaying, with a decay timescale of 15.77±1.57 million years. Anothersuperjovian planet in the system is suspected.[9]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.164±0.082 MJ | 0.02239±0.00084 | 1.338231587(22) | <0.0033[5] | 88.02±0.69° | 1.312±0.045 RJ |
| c(unconfirmed) | ≥5.47±0.44MJ | 6.82±0.25 | 7001.0±6.6 | — | — | — |
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