We present the discovery of four new giant planets from WASP-South , three hot Jupiters and one bloated sub-Saturn mass planet ; WASP-169b , WASP-171b , WASP-175b and WASP-182b .
Besides the discovery photometry from WASP-South we use radial velocity measurements from CORALIE and HARPS as well as follow-up photometry from EulerCam , TRAPPIST-North and -South and SPECULOOS . WASP-169b is a low density Jupiter ( M = 0.561 \pm 0.061 ~ { } \mathrm { M _ { Jup } } ,R = 1.304 ^ { +0.150 } _ { -0.073 } ~ { } \mathrm { R _ { Jup } } ) orbiting a V=12.17 F8 sub-giant in a 5.611 day orbit . WASP-171b is a typical hot Jupiter ( M = 1.084 \pm 0.094 ~ { } \mathrm { M _ { Jup } } ,R = 0.98 ^ { +0.07 } _ { -0.04 } ~ { } \mathrm { R _ { Jup } } , P = 3.82 ~ { } \mathrm { days } ) around a V=13.05 G0 star .
We find a linear drift in the radial velocities of WASP-171 spanning 3.5 years , indicating the possibility of an additional outer planet or stellar companion . WASP-175b is an inflated hot Jupiter ( M = 0.99 \pm 0.13 ~ { } \mathrm { M _ { Jup } } ,R = 1.208 \pm 0.081 ~ { } \mathrm { R _ { Jup } } , P = 3.07 ~ { } \mathrm { days } ) around a V=12.04 F7 star , which possibly is part of a binary system with a star 7.9 \arcsec away . WASP-182b is a bloated sub-Saturn mass planet ( M = 0.148 \pm 0.011 ~ { } \mathrm { M _ { Jup } } ,R = 0.850 \pm 0.030 ~ { } \mathrm { R _ { Jup } } ) around a metal rich V=11.98 G5 star ( [ Fe/H ] = 0.27 \pm 0.11 ) .
With a orbital period of P = 3.377 ~ { } \mathrm { days } , it sits right in the apex of the sub-Jovian desert , bordering the upper- and lower edge of the desert in both the mass-period and radius-period plane . WASP-169b , WASP-175b and WASP-182b are promising targets for atmospheric characterisation through transmission spectroscopy , with expected transmission signals of 121 , 150 and 264 ppm respectively .