Article · Wikipedia archive · Last revised Jul 17, 2026

WASP-49

WASP-49 is a binary star system about 636 light-years away in the constellation Lepus. The two stars are separated by 443 AU. The primary is a G-type main-sequence star, with a surface temperature of 5,600 K. WASP-49 is depleted of heavy elements relative to the Sun. It has a metallicity Fe/H index of –0.23, meaning it has 59% the iron level of the Sun.

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Jul 17, 2026
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WASP-49
Observation data
Epoch J2000      Equinox ICRS
Constellation Lepus1
WASP-49 A
Right ascension 06h 04m 21.474s2
Declination −16° 57′ 55.109″2
Apparent magnitude (V) 11.353
WASP-49 B
Right ascension 06h 04m 21.480s4
Declination −16° 57′ 57.382″4
Characteristics
WASP-49 A
Evolutionary stage Main sequence2
Spectral type G6V5
WASP-49 B
Evolutionary stage Main sequence
Spectral type K6
Astrometry
WASP-49 A
Radial velocity (Rv)41.81±0.382 km/s
Proper motion (μ) RA: +54.671 mas/yr2
Dec.: −19.055 mas/yr2
Parallax (π)5.1315±0.0158 mas2
Distance636 ± 2 ly
(194.9 ± 0.6 pc)
WASP-49 B
Proper motion (μ) RA: +55.154±0.0764 mas/yr4
Dec.: −18.334±0.1084 mas/yr4
Parallax (π)5.2287±0.0978 mas4
Distance620 ± 10 ly
(191 ± 4 pc)
Position (relative to WASP-49 A)7
Angular distance2.26416±0.00015″
Position angle177.53314±0.00247°
Projected separation443 AU7
Details
A
Mass1.003±0.105 M☉
Radius1.038±0.0385 R☉
Luminosity0.8848 L☉
Surface gravity (log g)4.5±0.15 cgs
Temperature5,600±1509 K
Metallicity [Fe/H]−0.230±0.0709 dex
Rotational velocity (v sin i)0.90±0.309 km/s
Age11.9+0.8
−3.29 Gyr
B
Mass0.337+0.009
−0.0247 M☉
Temperature3454+10
−257 K
Other designations
WDS J06044-1658AB, TOI-479, TIC 306362738, WASP-49, TYC 5936-2086-1, 2MASS J06042146-165755010
Database references
SIMBADA
B
Exoplanet Archivedata

WASP-49 is a binary star system about 636 light-years (195 parsecs) away in the constellation Lepus. The two stars are separated by 443 AU.7 The primary is a G-type main-sequence star, with a surface temperature of 5,600 K (5,330 °C; 9,620 °F). WASP-49 is depleted of heavy elements relative to the Sun. It has a metallicity Fe/H index of –0.23, meaning it has 59% the iron level of the Sun.9

Planetary system

In 2012, one exoplanet, designated WASP-49b, was discovered around the primary star by a team led by Monika Lendl.11 This is a hot Jupiter with an equilibrium temperature of 1369±39 K.11

In 2017, WASP-49b was found to have an extensive sodium envelope.5 A study in 2019 using data from the Hubble Space Telescope in near-UV found clear absorption features caused by metals, including magnesium and iron. The gaseous magnesium and iron is not gravitationally bound to the planet, but could be magnetically confined to it.1213 The sodium layer around WASP-49b could be due to a tidally-heated Io-like exomoon.1415 In October 2024, a 5-year study was published indicating that the sodium envelope most likely comes from a distinct body orbiting WASP-49b rather than the star or the planet, although the exact dynamics of the envelope remains to be settled.1617

The WASP-49 A planetary system9
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination
(°) 		Radius
b 0.399+0.029
−0.027 MJ 		0.0379+0.0010
−0.0011 		2.7817387(56) <0.026 84.89±0.19 1.115±0.047 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.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
  4. "WASP-49B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2026-05-21.
  5. Wyttenbach, A.; Lovis, C.; Ehrenreich, D.; Bourrier, V.; Pino, L.; Allart, R.; Astudillo-Defru, N.; Cegla, H. M.; Heng, K.; Lavie, B.; Melo, C.; Murgas, F.; Santerne, A.; Ségransan, D.; Udry, S.; Pepe, F. (2017). "Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS)". Astronomy & Astrophysics. 602: A36. arXiv:1702.00448. Bibcode:2017A&A...602A..36W. doi:10.1051/0004-6361/201630063. S2CID 55988055.
  6. Sucerquia, Mario; Cuello, Nicolás (February 1, 2025). "Extreme exomoons in WASP-49 Ab: Dynamics and detectability". Astronomy & Astrophysics. 694: L8. arXiv:2501.05866. doi:10.1051/0004-6361/202452968. ISSN 0004-6361.
  7. Mugrauer, M. (December 2019). "Search for stellar companions of exoplanet host stars by exploring the second ESA-Gaia data release". Monthly Notices of the Royal Astronomical Society. 490 (4): 5088–5102. Bibcode:2019MNRAS.490.5088M. doi:10.1093/mnras/stz2673.
  8. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  9. Bonomo, A. S.; et al. (2017), "The GAPS Programme with HARPS-N at TNG", Astronomy & Astrophysics, 602: A107, arXiv:1704.00373, Bibcode:2017A&A...602A.107B, doi:10.1051/0004-6361/201629882, S2CID 118923163
  10. "WASP-49". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-29.
  11. Lendl, M.; Anderson, D. R.; Collier-Cameron, A.; Doyle, A. P.; Gillon, M.; Hellier, C.; Jehin, E.; Lister, T. A.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Smalley, B.; Ségransan, D.; Smith, A. M. S.; Triaud, A. H. M. J.; Udry, S.; West, R. G.; Wheatley, P. J. (2012), "WASP-42 b and WASP-49 b: Two new transiting sub-Jupiters", Astronomy & Astrophysics, 544: A72, arXiv:1205.2757, Bibcode:2012A&A...544A..72L, doi:10.1051/0004-6361/201219585, S2CID 54186638
  12. Sing, David K.; Lavvas, Panayotis; Ballester, Gilda E.; Etangs, Alain Lecavelier des; Marley, Mark S.; Nikolov, Nikolay; Ben-Jaffel, Lotfi; Bourrier, Vincent; Buchhave, Lars A.; Deming, Drake L.; Ehrenreich, David; et al. (2019-08-01). "The HST PanCET Program: Exospheric Mg II and Fe II in the Near-UV transmission spectrum of WASP-121b using Jitter Decorrelation". The Astronomical Journal. 158 (2): 91. arXiv:1908.00619. doi:10.3847/1538-3881/ab2986. hdl:10150/634666. ISSN 1538-3881. S2CID 199405274.
  13. "Hubble Uncovers a 'Heavy Metal' Exoplanet Shaped Like a Football". HubbleSite.org. Retrieved 2020-01-01.
  14. 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 (2019-08-28). "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.
  15. "Hints of a volcanically active exomoon". Portal. 2019-08-29. Retrieved 2020-01-01.
  16. Cowing, Keith (October 2024). "Does Distant Planet WASP-49 b Host Volcanic Moon Like Jupiter's Io?". Astrobiology. Retrieved 2024-10-12.
  17. Oza, Apurva V.; Seidel, Julia V.; Hoeijmakers, H. Jens; Unni, Athira; Kesseli, Aurora Y.; Schmidt, Carl A.; Sivarani, Thirupathi; Bello-Arufe, Aaron; Gebek, Andrea; Meyer zu Westram, Moritz; Sousa, Sérgio G.; Lopes, Rosaly M. C.; Hu, Renyu; de Kleer, Katherine; Fisher, Chloe (2024-10-01). "Redshifted Sodium Transient near Exoplanet Transit". The Astrophysical Journal Letters. 973 (2): L53. arXiv:2409.19844. Bibcode:2024ApJ...973L..53O. doi:10.3847/2041-8213/ad6b29. ISSN 2041-8205.
Further reading

Further reading