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 | |
Mass | 0.899+0.033 −0.031 [5] M☉ |
Radius | 0.9150+0.0089 −0.0091 [5] R☉ |
Surface gravity (log g) | 4.472+0.013 −0.012 [5] cgs |
Temperature | 5488+29 −28 [5] K |
Metallicity [Fe/H] | −0.050±0.040 [6] dex |
Rotation | 22.2±3.3 [6] days |
Rotational velocity (v sin i) | 2.2+0.6 −1.0 [6] km/s |
Age | 7.0±2.9 [6] 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 |
Exoplanet Archive | data |
WASP-4 is a G-type main-sequence star approximately 891 light-years away in the constellation of Phoenix. [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 the exoplanet WASP-4b was discovered orbiting this star. With an orbital period of just 1.3 days, it is classified as a hot Jupiter. [4] The planet's orbital period appears to be decreasing at a rate of 7.33±0.71 milliseconds per year, suggesting that its orbit is decaying, with a decay timescale of 15.77±1.57 million years. Another superjovian planet in the system is suspected. [9] The orbital decay was confirmed in a 2025 study. [5]
Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 1.200+0.032 −0.030 MJ | 0.02294+0.00028 −0.00026 | 1.338230994(84) | 0.0013+0.0005 −0.0009 | 88.05+0.85 −0.53 ° | 1.349+0.011 −0.012 RJ |
c [9] (unconfirmed) | ≥5.47±0.44 MJ | 6.82±0.25 | 7001.0±6.6 | — | — | — |