Article · Wikipedia archive · Last revised Jul 17, 2026

WASP-29

WASP-29 is a binary star system 285 light-years away in the constellation of Phoenix. The primary star is a K-type main-sequence star. Its comoving companion, a red dwarf star, was discovered in 2021. The star system kinematically belongs to the thin disk of the Milky Way. The primary is an old star with small starspot activity and low x-ray flux.

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Jul 17, 2026
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WASP-29
Observation data
Epoch J2000      Equinox J2000
Constellation Phoenix1
Right ascension 23h 51m 31.08391s2
Declination −39° 54′ 24.2582″2
Apparent magnitude (V) 11.333
Characteristics
WASP-29A
Evolutionary stage main sequence star
Spectral type K4V4
B−V color index 0.82
J−H color index 0.478
J−K color index 0.570
WASP-29B
Spectral type M3V4
Astrometry
Radial velocity (Rv)24.31±0.202 km/s
Proper motion (μ) RA: −56.767(14) mas/yr2
Dec.: −88.988(13) mas/yr2
Parallax (π)11.4349±0.0151 mas2
Distance285.2 ± 0.4 ly
(87.5 ± 0.1 pc)
Position (relative to WASP-29A)4
ComponentWASP-29B
Epoch of observation2021
Angular distance125.2″
Projected separation10994 AU
Details5
WASP-29A
Mass0.825±0.033 M☉
Radius0.808±0.044 R☉
Surface gravity (log g)4.5±0.2 cgs
Temperature4800±150 K
Metallicity [Fe/H]0.11±0.14 dex
Rotational velocity (v sin i)1.50±0.60 km/s
Age14+0
−7 Gyr
WASP-29B
Mass0.384 M☉
Other designations
CD−40 15273, TOI-192, TIC 183537452, WASP-29, TYC 8015-1020-1, 2MASS J23513108-3954241, DENIS J235131.0-3954233
WASP-29A: Gaia DR3 6534414719318886144
WASP-29B: Gaia DR3 6534426740931264896
Database references
SIMBADdata
Exoplanet Archivedata

WASP-29 is a binary star system 285 light-years (87 parsecs) away in the constellation of Phoenix. The primary star is a K-type main-sequence star. Its comoving companion, a red dwarf star, was discovered in 2021.4 The star system kinematically belongs to the thin disk of the Milky Way.6 The primary is an old star with small starspot activity and low x-ray flux.7

Planetary system

The "hot Saturn" class planet WASP-29b was discovered around WASP-29 in 2010.6 The planet would have an equilibrium temperature of 960±30 K.8 The planetary atmosphere has abundant carbon monoxide but likely lacks methane9 and sodium,10 although the high and dense cloud deck of WASP-29b prevents high-quality spectroscopic measurements.11

A study in 2018 revealed the stability of planetary orbits in the habitable zone of WASP-29 is significantly affected by the WASP-29b planet.12

The WASP-29 planetary system8
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination
(°) 		Radius
b 0.243+0.020
−0.019 MJ 		0.0470±0.0025 3.92271218(25) <0.0595 89.468+0.018
−0.017 		0.775±0.031 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. "WASP-29". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 November 2023.
  4. Fontanive, Clémence; Daniella Bardalez Gagliuffi (2021), "The Census of Exoplanets in Visual Binaries: population trends from a volume-limited Gaia DR2 and literature search", Frontiers in Astronomy and Space Sciences, 8 625250: 16, arXiv:2101.12667, Bibcode:2021FrASS...8...16F, doi:10.3389/fspas.2021.625250
  5. 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. S2CID 118923163.
  6. Hellier, Coel; Anderson, D. R.; Collier Cameron, A.; Gillon, M.; Lendl, M.; Maxted, P. F. L.; Queloz, D.; Smalley, B.; Triaud, A. H. M. J.; West, R. G.; Brown, D. J. A.; Enoch, B.; Lister, T. A.; Pepe, F.; Pollacco, D.; Ségransan, D.; Udry, S. (2010). "WASP-29b: A SATURN-SIZED TRANSITING EXOPLANET". The Astrophysical Journal. 723 (1): L60–L63. arXiv:1009.5318. Bibcode:2010ApJ...723L..60H. doi:10.1088/2041-8205/723/1/L60. S2CID 64119308.
  7. Dos Santos, L. A.; Bourrier, V.; Ehrenreich, D.; Sanz-Forcada, J.; López-Morales, M.; Sing, D. K.; García Muñoz, A.; Henry, G. W.; Lavvas, P.; Lecavelier Des Etangs, A.; Mikal-Evans, T.; Vidal-Madjar, A.; Wakeford, H. R. (2021), "HST PanCET program: Non-detection of atmospheric escape in the warm Saturn-sized planet WASP-29 B", Astronomy & Astrophysics, 649: A40, arXiv:2103.15688, Bibcode:2021A&A...649A..40D, doi:10.1051/0004-6361/202140491, S2CID 232417342
  8. Saha, Suman; Sengupta, Sujan (2021), "Critical Analysis of Tess Transit Photometric Data: Improved Physical Properties for Five Exoplanets", The Astronomical Journal, 162 (5): 221, arXiv:2109.11366, Bibcode:2021AJ....162..221S, doi:10.3847/1538-3881/ac294d, S2CID 237605336
  9. Matthew Hardin, Joseph Harrington, K. Stevenson, "WASP-29b: Another Cool Exoplanet With Abundant CO?"
  10. A Gemini ground-based transmission spectrum of WASP-29b: a featureless spectrum from 515 to 720 nm
  11. Wong, Ian; Chachan, Yayaati; Knutson, Heather A.; Henry, Gregory W.; Adams, Danica; Kataria, Tiffany; Benneke, Björn; Gao, Peter; Deming, Drake; López-Morales, Mercedes; Sing, David K.; Alam, Munazza K.; Ballester, Gilda E.; Barstow, Joanna K.; Buchhave, Lars A.; Dos Santos, Leonardo A.; Fu, Guangwei; Muñoz, Antonio García; MacDonald, Ryan J.; Mikal-Evans, Thomas; Sanz-Forcada, Jorge; Wakeford, Hannah R. (2022), "The Hubble PanCET Program: A Featureless Transmission Spectrum for WASP-29b and Evidence of Enhanced Atmospheric Metallicity on WASP-80b", The Astronomical Journal, 164 (1): 30, arXiv:2205.10765, Bibcode:2022AJ....164...30W, doi:10.3847/1538-3881/ac7234, S2CID 248987053
  12. Georgakarakos, Nikolaos; Eggl, Siegfried; Dobbs-Dixon, Ian (April 2018). "Giant Planets: Good Neighbors for Habitable Worlds?". The Astrophysical Journal. 856 (2): 155. arXiv:1804.02183. Bibcode:2018ApJ...856..155G. doi:10.3847/1538-4357/aaaf72.