| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Eridanus[1] |
| Right ascension | 04h 15m 01.5043s[2] |
| Declination | −22° 06′ 59.103″[2] |
| Apparent magnitude (V) | 12.0[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | F8[3] |
| Astrometry | |
| Radial velocity (Rv) | 1.26[4] km/s |
| Proper motion (μ) | RA: −0.367(11)mas/yr[2] Dec.: 6.395(13)mas/yr[2] |
| Parallax (π) | 1.3851±0.0136 mas[2] |
| Distance | 2,350 ± 20 ly (722 ± 7 pc) |
| Details | |
| Mass | 1.33±0.09[3] M☉ |
| Radius | 2.20±0.12[3] R☉ |
| Luminosity | 5.2±0.1[2] L☉ |
| Surface gravity (log g) | 3.88±0.04[3] cgs |
| Temperature | 6,100±150[3] K |
| Metallicity[Fe/H] | −0.35±0.14[3] dex |
| Rotation | 0.4±0.4[3] |
| Rotational velocity (v sin i) | 6.63±0.16[5] km/s |
| Age | 3.4+1.5 −0.8[5] Gyr |
| Other designations | |
| Gaia DR3 5089851638095503616,TYC 5889-271-1,GSC 05889-00271,2MASS J04150149-2206591[4] | |
| Database references | |
| SIMBAD | data |
WASP-78, is a singleF-type main-sequence star about 2350 light-years away. It is likely to be younger than the Sun at 3.4+1.5
−0.8 billion years.[5] WASP-78 is depleted in heavy elements, having a 45% concentration of iron compared to the Sun.
In 2012 atransitinghot Jupiter planetb was detected on a circular orbit. The planetary equilibrium temperature is 2350±80K,[3] while the nightside temperature measured in 2019 is 2200±41K.[6] The dayside planetary temperature measured in 2020 is2,560±130 K.[7]
A survey in 2016 measured aRossiter-McLaughlin effect and found the planetary orbit is well aligned with the equatorial plane of the star, misalignment equal to −6.4±5.9°[5] The planet cannot have formed in its current orbit and has likely undergone in the past a migration from the initial highly eccentric orbit.[8]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.89±0.08 MJ | 0.0362±0.0008 | 2.17517632±0.0000047 | 0 | 83.2+2.3 −1.6° | 1.70±0.11 RJ |
