WASP-22
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Eridanus[1] |
| Right ascension | 03h 31m 16.32671s[2] |
| Declination | −23° 49′ 10.8406″[2] |
| Apparent magnitude (V) | 11.99[3] |
| Characteristics | |
| Evolutionary stage | main sequence[4] |
| Spectral type | G1V[4] |
| Astrometry | |
| Radial velocity (Rv) | −5.67±0.50[2] km/s |
| Proper motion (μ) | RA: +2.012 mas/yr[2] Dec.: −26.579 mas/yr[2] |
| Parallax (π) | 3.1532±0.0327 mas[2] |
| Distance | 1,030 ± 10 ly (317 ± 3 pc) |
| Details[5] | |
| Mass | 1.109±0.026 M☉ |
| Radius | 1.219+0.052 −0.033 R☉ |
| Surface gravity (log g) | 4.310+0.020 −0.032 cgs |
| Temperature | 5958±98 K |
| Metallicity [Fe/H] | +0.05±0.08 dex |
| Rotation | 14±3 d |
| Rotational velocity (v sin i) | 4.5±0.4 km/s |
| Age | 4.3+1.6 −1.1[6] Gyr |
| Other designations | |
| Tojil, TOI-403, TIC 257567854, WASP-22, TYC 6446-326-1[3] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
WASP-22, also named Tojil, is a G-type main-sequence star about 1,030 light-years (320 parsecs) away in the constellation Eridanus. With an apparent magnitude of 12, it is much too faint to be visible to the naked eye. The star is similar to the Sun, but slightly larger. It hosts one known exoplanet, WASP-22b; the nature of a likely third body is unclear.
Nomenclature
[edit]The designation WASP-22 comes from the Wide Angle Search for Planets. This was one of the systems selected to be named in the 2019 NameExoWorlds campaign during the 100th anniversary of the IAU, which assigned each country a star and planet to be named. This system was assigned to Guatemala. The approved names were Tojil for the star, after a Mayan deity related to rain, storms and fire, and Koyopaʼ for the planet, the word for lightning in the Kʼicheʼ language.[7][8]
Planetary system
[edit]The planet WASP-22b, later named Koyopaʼ, is a hot Jupiter, about half the mass of Jupiter but with a larger radius, discovered in 2010 by the Wide Angle Search for Planets using the transit method.[4] Its orbit is prograde but may be slightly misaligned with the star's equator.[5] A long-period trend in the star's radial velocity indicates a third body in the system, which may be either a second planet or a companion star.[4][9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b / Koyopaʼ | 0.570+0.017 −0.016 MJ |
0.04700+0.00036 −0.00037 |
3.5327313(58) | <0.021 | 88.26±0.91 | 1.158+0.061 −0.038 RJ |
References
[edit]- ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
- 1 2 3 4 5 6 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.
- 1 2 "WASP-22". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 18 September 2026.
- 1 2 3 4 Maxted, P. F. L.; Anderson, D. R.; et al. (December 2010). "WASP-22 b: A Transiting "Hot Jupiter" Planet in a Hierarchical Triple System". The Astronomical Journal. 140 (6): 2007–2012. arXiv:1004.1514. Bibcode:2010AJ....140.2007M. doi:10.1088/0004-6256/140/6/2007. ISSN 0004-6256.
- 1 2 Anderson, D. R.; Collier Cameron, A.; et al. (October 2011). "Spin-orbit measurements and refined parameters for the exoplanet systems WASP-22 and WASP-26". Astronomy & Astrophysics. 534: A16. arXiv:1106.6092. Bibcode:2011A&A...534A..16A. doi:10.1051/0004-6361/201117597. ISSN 0004-6361.
- 1 2 Bonomo, A. S.; Desidera, S.; et al. (June 2017). "The GAPS Programme with HARPS-N at TNG: XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy & Astrophysics. 602: A107. arXiv:1704.00373. Bibcode:2017A&A...602A.107B. doi:10.1051/0004-6361/201629882. ISSN 0004-6361.
- ↑ "Approved names". NameExoWorlds. IAU. Retrieved 18 September 2026.
- ↑ "Guatemala". NameExoWorlds. IAU. Retrieved 18 September 2026.
- ↑ "WASP-22". WASP Planets. 14 July 2019. Retrieved 18 September 2026.
Further reading
[edit]- Southworth, John; Tregloan-Reed, J.; et al. (April 2016). "High-precision photometry by telescope defocussing – VIII. WASP-22, WASP-41, WASP-42 and WASP-55". Monthly Notices of the Royal Astronomical Society. 457 (4): 4205–4217. arXiv:1512.05549. Bibcode:2016MNRAS.457.4205S. doi:10.1093/mnras/stw279. ISSN 0035-8711.
