WASP-80
Star in the constellation Aquila
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WASP-80 is a K-type main-sequence star about 162 light-years away from Earth. The star's age is much younger than the Sun's at 1.352±0.222 billion years.[9] WASP-80 could be similar to the Sun in concentration of heavy elements, although this measurement is highly uncertain.[8]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila[1] |
| Right ascension | 20h 12m 40.1694s[2] |
| Declination | −02° 08′ 39.187″[2] |
| Apparent magnitude (V) | 11.939 |
| Characteristics | |
| Evolutionary stage | Main sequence[3] |
| Spectral type | K7V – M9V[3] |
| Astrometry | |
| Radial velocity (Rv) | +9.82±0.77[2] km/s |
| Proper motion (μ) | RA: −132.913[2] mas/yr Dec.: −50.683[2] mas/yr |
| Parallax (π) | 20.1141±0.0207 mas[2] |
| Distance | 162.2 ± 0.2 ly (49.72 ± 0.05 pc) |
| Details | |
| Mass | 0.614+0.014 −0.012[4] M☉ |
| Radius | 0.586+0.017 −0.018[5] R☉ |
| Luminosity | 0.093[6] L☉ |
| Surface gravity (log g) | 4.60±0.02[7] cgs |
| Temperature | 4,066±22[7] K |
| Metallicity [Fe/H] | 0.13±0.11[8] dex |
| Rotation | 23.5±3[9] |
| Rotational velocity (v sin i) | 5.04±0.19[7] km/s |
| Age | 1.352±0.222[9] Gyr |
| Other designations | |
| Petra, TYC 5165-481-1, GSC 05165-00481, 2MASS J20124017-0208391, Gaia DR2 4223507222112425344[10] | |
| Database references | |
| SIMBAD | data |
The star was named Petra in 2019 by Jordanian amateur astronomers as part of the NameExoWorlds contest.[11]
Three multiplicity surveys in 2015-2018 did not detect any stellar companions to WASP-80, but a survey in 2020 detected a 0.07M☉ companion candidate at an angular separation 2.132±0.010 arcseconds, with a false alarm probability of 3%.[12]
Planetary system
In 2013 a transiting hot Jupiter planet WASP-80 b was detected on a tight, circular orbit.[3] The planet was named Wadirum by Jordanian astronomers in December 2019.[11] Its equilibrium temperature is 825±19 K, while measured temperature of the dayside is 937±48 K and temperature of the nightside is 851±14 K. This temperature difference indicates a rather low planetary albedo and weak global transport of heat.[13]
Measurement of the Rossiter–McLaughlin effect in 2015 revealed WASP-80b's is orbit is well-aligned with the equatorial plane of the star, with orbital obliquity equal to 14±14°.[5]
Although one transmission spectrum of the planetary atmosphere showed signs of ionised potassium,[14] another measurement in 2017 yielded a gray and featureless spectrum, probably due to a high cloud deck[15] or haze[16] in the atmosphere of WASP-80b. [13] Evidence for water vapour and methane molecules (CH4) were found for the planet through observations of JWST.[17] This discovery helped uncovers the origin and evolution of the planet.[17]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| WASP-80b | 0.571±0.02[4] MJ | 0.0344+0.0011 −0.0010[5] |
3.067852[5] | 0[5] | 89.02+0.11 −0.10[5]° |
1.0091+0.011 −0.0095[4] RJ |