We report the discovery by the WASP transit survey of three new hot Jupiters , WASP-68 b , WASP-73 b and WASP-88 b. WASP-68 b has a mass of 0.95 \pm 0.03 M _ { \mathrm { Jup } } , a radius of 1.24 _ { -0.06 } ^ { +0.10 } R _ { \mathrm { Jup } } , and orbits a V=10.7 G0-type star ( 1.24 \pm 0.03 M _ { \odot } , 1.69 _ { -0.06 } ^ { +0.11 } R _ { \odot } , T _ { \mathrm { eff } } = 5911 \pm 60 K ) with a period of 5.084298 \pm 0.000015 days .
Its size is typical of hot Jupiters with similar masses .
WASP-73 b is significantly more massive ( 1.88 _ { -0.06 } ^ { +0.07 } M _ { \mathrm { Jup } } ) and slightly larger ( 1.16 _ { -0.08 } ^ { +0.12 } R _ { \mathrm { Jup } } ) than Jupiter .
It orbits a V=10.5 F9-type star ( 1.34 _ { -0.04 } ^ { +0.05 } M _ { \odot } , 2.07 _ { -0.08 } ^ { +0.19 } R _ { \odot } , T _ { \mathrm { eff } } = 6036 \pm 120 K ) every 4.08722 \pm 0.00022 days .
Despite its high irradiation ( \sim 2.3 10 ^ { 9 } erg \mathrm { s } ^ { -1 } \mathrm { cm } ^ { -2 } ) , WASP-73 b has a high mean density ( 1.20 _ { -0.30 } ^ { +0.26 } \rho _ { \mathrm { Jup } } ) that suggests an enrichment of the planet in heavy elements .
WASP-88 b is a 0.56 \pm 0.08 M _ { \mathrm { Jup } } planet orbiting a V=11.4 F6-type star ( 1.45 \pm 0.05 M _ { \odot } , 2.08 _ { -0.06 } ^ { +0.12 } R _ { \odot } , T _ { \mathrm { eff } } = 6431 \pm 130 K ) with a period of 4.954000 \pm 0.000019 days .
With a radius of 1.70 _ { -0.07 } ^ { +0.13 } R _ { \mathrm { Jup } } , it joins the handful of planets with super-inflated radii .
The ranges of ages we determine through stellar evolution modeling are 4.2-8.3 Gyr for WASP-68 , 2.7-6.4 Gyr for WASP-73 and 1.8-5.3 Gyr for WASP-88 .
WASP-73 appears to be a significantly evolved star , close to or already in the subgiant phase .
WASP-68 and WASP-88 are less evolved , although in an advanced stage of core H-burning .