THREE WASP-SOUTH TRANSITING EXOPLANETS: WASP-74b, WASP-83b, AND WASP-89b

• Published in: The Astronomical journal 2015-07, Vol.150 (1), p.1-9
• Main Authors: Hellier, Coel, Anderson, D. R., Collier Cameron, A., Delrez, L., Gillon, M., Jehin, E., Lendl, M., Maxted, P. F. L., Pepe, F., Pollacco, D., Queloz, D., Ségransan, D., Smalley, B., Smith, A. M. S., Southworth, J., Triaud, A. H. M. J., Turner, O. D., Udry, S., West, R. G.
• Format: Article
• Language: English
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; Aérospatiale, astronomie & astrophysique; Eccentric orbits; Extrasolar planets; MASS; ORBITS; PHOTOMETERS; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; planetary systems; ROTATION; Space science, astronomy & astrophysics; SPECTROMETERS; SPIN; Spots; STARS; stars: individual (WASP-74, WASP-83, WASP-89); stars: individual: WASP-74; TELESCOPES; Transits; WASP-83; WASP-89
• ISSN: 0004-6256; 1538-3881; 1538-3881
• DOI: 10.1088/0004-6256/150/1/18

ABSTRACT We report the discovery of three new transiting hot Jupiters by WASP-South together with the TRAPPIST photometer and the Euler/CORALIE spectrograph. WASP-74b orbits a star of V = 9.7, making it one of the brighter systems accessible to southern telescopes. It is a 0.95MJup planet with a moderately bloated radius of 1.5 in a 2 day orbit around a slightly evolved F9 star. WASP-83b is a Saturn-mass planet at 0.3 with a radius of 1.0 . It is in a 5 day orbit around a fainter (V = 12.9) G8 star. WASP-89b is a 6 MJup planet in a 3 day orbit with an eccentricity of e = 0.2. It is thus similar to massive, eccentric planets such as XO-3b and HAT-P-2b, except that those planets orbit F stars whereas WASP-89 is a K star. The V = 13.1 host star is magnetically active, showing a rotation period of 20.2 days, while star spots are visible in the transits. There are indications that the planet's orbit is aligned with the stellar spin. WASP-89 is a good target for an extensive study of transits of star spots.