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.[6] 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.[5]
In 2017, WASP-49b was found to have an extensive
sodium envelope.[3] 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 magnesium and iron gas is not
gravitationally bound to the planet, but could be
magnetically confined to it.[9][10] The sodium envelope around WASP-49b could be due to an
Io-like
exomoon.[11][12] This idea, however, is speculative.[13]
^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.
^
abLendl, 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,
S2CID54186638