Article · Wikipedia archive · Last revised Jul 30, 2026

WASP-159

WASP-159 is a star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 12.84, making it readily visible in telescopes with an aperture of at least four inches, but not to the naked eye. The star is located relatively far at a distance of 2,380 light-years based on recent parallax measurements from the Gaia spacecraft, but it is receding with a heliocentric radial velocity of 35.2 km/s.

Last revised
Jul 30, 2026
Read time
≈ 2 min
Length
507 w
Citations
25
Source
WASP-159
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Caelum1
Right ascension 04h 32m 32.75581s2
Declination −38° 58′ 05.9529″2
Apparent magnitude (V) 12.84±0.243
Characteristics
Evolutionary stage subgiant2
Spectral type F94
B−V color index −0.213
Astrometry
Radial velocity (Rv)35.16±0.014 km/s
Proper motion (μ) RA: −0.586 mas/yr2
Dec.: +5.347 mas/yr2
Parallax (π)1.3723±0.0098 mas2
Distance2,380 ± 20 ly
(729 ± 5 pc)
Details4
Mass1.41±0.12 M
Radius2.11±0.10 R
Luminosity4.674+0.064
−0.053
2 L
Surface gravity (log g)3.94±0.04 cgs
Temperature6,120±140 K
Metallicity [Fe/H]+0.22±0.12 dex
Rotational velocity (v sin i)5.7±0.4 km/s
Age3.40±0.95 Gyr
Other designations
TOI-1903, TIC 77156657, WASP-159, TYC 7579-251-15
Database references
SIMBADdata
Exoplanet Archivedata

WASP-159 is a star located in the southern constellation Caelum, the chisel. It has an apparent magnitude of 12.84,3 making it readily visible in telescopes with an aperture of at least four inches, but not to the naked eye. The star is located relatively far at a distance of 2,380 light-years based on recent parallax measurements from the Gaia spacecraft,2 but it is receding with a heliocentric radial velocity of 35.2 km/s.4

WASP-159 has a stellar classification of F9 indicating that it is a late F-type star.4 It appears to be ceasing hydrogen fusion at its core and evolving towards the red giant branch.4 It has 1.41 times the Sun's mass and 2.11 times the radius of the Sun.4 It radiates 4.674 times the luminosity of the Sun2 from its photosphere at an effective temperature of 6,120 K,4 giving it a whitish-yellow hue when viewed in a telescope. WASP-159 is metal enriched with an iron abundance 166% that of the Sun, and it is estimated to be 3.4 billion years old.4

Planetary system

In 2019, SuperWASP discovered a transiting exoplanet orbiting the star after spectral and radial velocity observations. WASP-159b is a "bloated" hot Jupiter that takes roughly 3.8 days to revolve around its host star in a circular orbit.4

The WASP-159 planetary system4
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(days)
Eccentricity Inclination
(°)
Radius
b 0.55±0.08 MJ 0.0538±0.0015 3.8404008+0.0000063
−0.0000064
0.00 (fixed) 88.1±1.4 1.38±0.09 RJ
References

References

  1. 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.
  2. 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.
  3. Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (1 March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
  4. Hellier, Coel; Anderson, D. R.; Bouchy, F.; Burdanov, A.; Collier Cameron, A.; Delrez, L.; Gillon, M.; Jehin, E.; Lendl, M.; Nielsen, L. D.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Smalley, B.; Triaud, A. H. M. J.; Udry, S.; West, R. G. (1 January 2019). "New transiting hot Jupiters discovered by WASP-South, Euler/CORALIE, and TRAPPIST-South". Monthly Notices of the Royal Astronomical Society. 482 (1): 1379–1391. arXiv:1803.02224. Bibcode:2019MNRAS.482.1379H. doi:10.1093/mnras/sty2741. ISSN 0035-8711.
  5. "WASP-159". SIMBAD. Centre de données astronomiques de Strasbourg.