WASP-42
Star in the constellation Centaurus
From Wikipedia, the free encyclopedia
WASP-42 is a K-type main-sequence star about 580 light-years away in the constellation Centaurus. Its surface temperature is 5315±79 K.[7] WASP-42 is similar to the Sun in concentration of heavy elements, with metallicity ([Fe/H]) of 0.05±0.13, and is much older than the Sun at 11.3+1.5
−4.8 billion years.[4] The star does exhibit starspot activity as is typical for its spectral class.[3]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus[1] |
| Right ascension | 12h 51m 55.5581s[2] |
| Declination | −42° 04′ 25.096″[2] |
| Apparent magnitude (V) | 12.6[3] |
| Characteristics | |
| Evolutionary stage | main-sequence star |
| Spectral type | K1V[3] |
| Astrometry | |
| Radial velocity (Rv) | −4.22±0.41[2] km/s |
| Proper motion (μ) | RA: −49.875 mas/yr[2] Dec.: 4.963 mas/yr[2] |
| Parallax (π) | 5.6209±0.0153 mas[2] |
| Distance | 580 ± 2 ly (177.9 ± 0.5 pc) |
| Details | |
| Mass | 0.881+0.086 −0.081[4] M☉ |
| Radius | 0.850±0.035[4] R☉ |
| Luminosity | 0.48[5] L☉ |
| Surface gravity (log g) | 4.52[5] cgs |
| Temperature | 5,259[5] K |
| Metallicity [Fe/H] | 0.05±0.13[4] dex |
| Rotational velocity (v sin i) | 2.70±0.40[4] km/s |
| Age | 11.3+1.5 −4.8[4] Gyr |
| Other designations | |
| TOI-769, TIC 248075138, WASP-42, 2MASS J12515557-4204249[6] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Multiplicity surveys did not detect any stellar companions to WASP-42 in 2017.[8]
Planetary system
In 2012, one planet, named WASP-42b, was discovered[9] on a tight, mildly eccentric orbit.[4] The planetary equilibrium temperature is 1,021±19 K.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.501±0.034 MJ | 0.0548+0.0017 −0.0018 |
4.9816872±0.0000073 | 0.062+0.013 −0.011 |
88.30+0.26 −0.23° |
1.063±0.051 RJ |
