WASP-8
File:Artist’s impression of an exoplanet in a retrograde orbit (without additional graphics).jpg Artist's impression of a star like WASP-8 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sculptor[1] |
| Right ascension | 23h 59m 36.07119s[2] |
| Declination | −35° 01′ 52.9236″[2] |
| Apparent magnitude (V) | 9.87[3] |
| Characteristics | |
| WASP-8A | |
| Evolutionary stage | main-sequence |
| Spectral type | G8V[4] |
| WASP-8B | |
| Spectral type | M[5] |
| Astrometry | |
| Radial velocity (Rv) | −1.38±0.26[2] km/s |
| Proper motion (μ) | RA: 109.752 mas/yr[2] Dec.: 7.615 mas/yr[2] |
| Parallax (π) | 11.1052±0.0175 mas[2] |
| Distance | 293.7 ± 0.5 ly (90.0 ± 0.1 pc) |
| Position (relative to WASP-8A)[5] | |
| Component | WASP-8B |
| Epoch of observation | 2016 |
| Angular distance | 4.520±0.005″ |
| Position angle | 170.9±0.1° |
| Projected separation | 408 AU |
| Details[6] | |
| WASP-8A | |
| Mass | 1.093±0.024 M☉ |
| Radius | 0.976±0.020 R☉ |
| Luminosity | 0.79 L☉ |
| Surface gravity (log g) | 4.498±0.018 cgs |
| Temperature | 5600±80 K |
| Metallicity [Fe/H] | 0.29±0.03 dex |
| Rotational velocity (v sin i) | 1.90±0.05[7] km/s |
| Age | 0.3+0.9 −0.1 Gyr |
| WASP-8B | |
| Mass | 0.53±0.02 M☉ |
| Temperature | 3758+47 −43 K |
| Other designations | |
| CD−35 16019, CPD−35 9465, SAO 214901, PPM 304426, WDS J23596-3502A, TOI-191, TIC 183532609, WASP-8, TYC 7522-505-1, 2MASS J23593607-3501530[3] | |
| Database references | |
| SIMBAD | A |
| B | |
| Exoplanet Archive | data |
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WASP-8 is a binary star system 294 light-years (90 parsecs) away. The star system is much younger than the Sun at 300 million to 1.2 billion years age, and is heavily enriched in heavy elements, having nearly twice the concentration of iron compared to the Sun.[6]
The primary, WASP-8A, is a magnitude 9.9 main-sequence yellow dwarf star. It is reported to be a G-type star with a temperature of 5600 K and has a mass 1.093±0.024, a radius 0.976±0.020 and a luminosity of 0.79 times that of the Sun. There is a companion star WASP-8B located 4.5 arcseconds away with the same proper motion, indicating a stellar binary system.[8] The binarity was confirmed in 2020.[5] The axis orientation of the primary star is uncertain, but it is close to pointing one of the poles to the Earth.[7]
Planetary system
[edit | edit source]The primary star is orbited by two known exoplanets, designated WASP-8b and WASP-8c. WASP-8b was discovered in 2010 by the astronomical transit method and was catalogued as part of the SuperWASP mission.[8] WASP-8c was discovered in late 2013 with the radial velocity method.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 2.216±0.035 MJ | 0.0817±0.0006 | 8.158715(16)[10] | 0.3057±0.0046[10] | 88.51±0.09° | 1.165±0.032 RJ |
| c | ≥9.45+2.26 −1.04 MJ |
5.28+0.63 −0.34 |
4323+740 −380 |
0 | — | — |
See also
[edit | edit source]References
[edit | edit source]- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Constellation record for this object at VizieR.
- ^ a b c d e Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value). Gaia DR3 record for this source at VizieR.
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b c Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
External links
[edit | edit source]- WASP planets
- Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
