WASP-69, also named Wouri, is a K-type main-sequence star 164 light-years (50 parsecs) away.[6] Its surface temperature is 4782±15 K. WASP-69 is slightly enriched in heavy elements compared to the Sun, with a metallicity Fe/H index of 0.10±0.01,[4] and is much younger than the Sun at 2 billion years. The data regarding starspot activity of WASP-69 are inconclusive, but spot coverage of the photosphere may be very high.[7]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 00m 06.19682s[1] |
| Declination | −05° 05′ 40.0349″[1] |
| Apparent magnitude (V) | 9.87±0.03[2] |
| Characteristics | |
| Evolutionary stage | main-sequence star |
| Spectral type | K5V[3] |
| Astrometry | |
| Radial velocity (Rv) | −9.83±0.13[1] km/s |
| Proper motion (μ) | RA: 33.778 mas/yr[1] Dec.: −93.581 mas/yr[1] |
| Parallax (π) | 19.8858 ± 0.0170 mas[1] |
| Distance | 164.0 ± 0.1 ly (50.29 ± 0.04 pc) |
| Details | |
| Mass | 0.826±0.029[2] M☉ |
| Radius | 0.813[2] R☉ |
| Surface gravity (log g) | 4.59±0.02[4] cgs |
| Temperature | 4782±15[4] K |
| Metallicity [Fe/H] | 0.10±0.01[4] dex |
| Rotation | 23.07 d[2] |
| Rotational velocity (v sin i) | 1.27±0.22[4] km/s |
| Age | 2[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Multiplicity surveys did not detect any stellar companions to WASP-69 as of 2020.[8]
Nomenclature
editThe designation WASP-69 indicates that this was the 69th star found to have a planet by the Wide Angle Search for Planets.
In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project.[9] The approved names, proposed by a team from Cameroon, were announced in June 2023. WASP-69 is named Wouri and its planet is named Makombé, after the Wouri and Makombé rivers.[10]
Planetary system
editIn 2013, one planet, named WASP-69b,[6] was discovered on a tight, circular orbit.[2] Its equilibrium temperature is 886 K,[11] but the measured terminator temperature is significantly higher by at least 200 K.[7] The planet is losing mass at a moderate rate of 0.5 ME per billion years, not producing a visible cometary tail,[11] although it was detected in 2024 and measured to be at least 7 times its own radius.[12]
The planetary atmosphere is extremely hazy and contains a partial cloud deck with cloud tops rising to a pressure of 100 Pa. Its composition is mostly hydrogen and helium, and sodium was also detected in low concentration.[7][13] The sodium may originate from volcanic moons, not from the planet itself.[14]
By 2021, the presence of hazes in atmosphere of WASP-69b was confirmed, along with a solar or super-solar water abundance.[15]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Makombé | 0.260±0.017 MJ | 0.04525±0.00053 | 3.8681382±0.0000017 | 0 | 86.71±0.20° | 0.945+0.007 −0.017[7] RJ |
References
edit- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c d e f g Anderson, D. R.; Collier Cameron, A.; Delrez, L.; Doyle, A. P.; Faedi, F.; Fumel, A.; Gillon, M.; Gómez Maqueo Chew, Y.; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Skillen, I.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.; West, R. G. (2014). "Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary". Monthly Notices of the Royal Astronomical Society. 445 (2): 1114–1129. arXiv:1310.5654. doi:10.1093/mnras/stu1737. S2CID 54750890.
- ^ France, Kevin; Arulanantham, Nicole; Fossati, Luca; Lanza, Antonino F.; Loyd, R. O. Parke; Redfield, Seth; Schneider, P. Christian (2018), "Far-ultraviolet Activity Levels of F, G, K, and M Dwarf Exoplanet Host Stars", The Astrophysical Journal Supplement Series, 239 (1): 16, arXiv:1809.07342, Bibcode:2018ApJS..239...16F, doi:10.3847/1538-4365/aae1a3, S2CID 119368148
- ^ a b c d e Gill, S.; Maxted, P. F. L.; Smalley, B. (2018). "The atmospheric parameters of FGK stars using wavelet analysis of CORALIE spectra". Astronomy & Astrophysics. 612: A111. arXiv:1801.06106. Bibcode:2018A&A...612A.111G. doi:10.1051/0004-6361/201731954. S2CID 119331772.
- ^ "BD-05 5432". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-01-08.
- ^ a b Andrews, Robin George (12 January 2024). "This Distant Planet Has a 350,000-Mile-Long Comet-Like Tail - The stream of helium trailing WASP-69b, a "Hot Jupiter," allows astronomers to study how planets lose their atmospheres". The New York Times. Archived from the original on 12 January 2024. Retrieved 12 January 2024.
- ^ a b c d Murgas, F.; Chen, G.; Nortmann, L.; Pallé, E.; Nowak, G. (2020). "The GTC exoplanet transit spectroscopy survey XI. Possible detection of Rayleigh scattering in the atmosphere of the Saturn-mass planet WASP-69b". Astronomy & Astrophysics. A158: 641. arXiv:2007.02741. Bibcode:2020A&A...641A.158M. doi:10.1051/0004-6361/202038161. S2CID 220363912.
- ^ Bohn, A. J.; Southworth, J.; Ginski, C.; Kenworthy, M. A.; Maxted, P. F. L.; Evans, D. F. (2020), "A multiplicity study of transiting exoplanet host stars. I. High-contrast imaging with VLT/SPHERE", Astronomy & Astrophysics, 635: A73, arXiv:2001.08224, Bibcode:2020A&A...635A..73B, doi:10.1051/0004-6361/201937127, S2CID 210861118
- ^ "List of ExoWorlds 2022". nameexoworlds.iau.org. IAU. 8 August 2022. Retrieved 27 August 2022.
- ^ "2022 Approved Names". nameexoworlds.iau.org. IAU. Retrieved 7 June 2023.
- ^ a b Wang, Lile; Dai, Fei (2021). "Metastable Helium Absorptions with 3D Hydrodynamics and Self-consistent Photochemistry. I. WASP-69b, Dimensionality, X-Ray and UV Flux Level, Spectral Types, and Flares". The Astrophysical Journal. 914 (2): 98. arXiv:2101.00042. Bibcode:2021ApJ...914...98W. doi:10.3847/1538-4357/abf1ee. S2CID 230433986.
- ^ Tyler, Dakotah; Petigura, Erik A.; Oklopčić, Antonija; David, Trevor J. (9 January 2024). "WASP-69b's Escaping Envelope Is Confined to a Tail Extending at Least 7 Rp". The Astrophysical Journal. 960 (2): 123. arXiv:2312.02381. Bibcode:2024ApJ...960..123T. doi:10.3847/1538-4357/ad11d0.
- ^ Casasayas-Barris, N.; Palle, E.; Nowak, G.; Yan, F.; Nortmann, L.; Murgas, F. (2017), "Detection of sodium in the atmosphere of WASP-69b", Astronomy & Astrophysics, 608: A135, arXiv:1710.06479, Bibcode:2017A&A...608A.135C, doi:10.1051/0004-6361/201731956, S2CID 67777582
- ^ Oza, Apurva V.; Johnson, Robert E.; Lellouch, Emmanuel; Schmidt, Carl; Schneider, Nick; Huang, Chenliang; Gamborino, Diana; Gebek, Andrea; Wyttenbach, Aurelien; Demory, Brice-Olivier; Mordasini, Christoph; Saxena, Prabal; Dubois, David; Moullet, Arielle; Thomas, Nicolas (2019), "Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets", The Astrophysical Journal, 885 (2): 168, arXiv:1908.10732, Bibcode:2019ApJ...885..168O, doi:10.3847/1538-4357/ab40cc, S2CID 201651224
- ^ Khalafinejad, S.; et al. (2021), "Probing the atmosphere of WASP-69 b with low- and high-resolution transmission spectroscopy", Astronomy & Astrophysics, 656: A142, arXiv:2109.06335, Bibcode:2021A&A...656A.142K, doi:10.1051/0004-6361/202141191, S2CID 237503489