We report the independent discovery and characterisation of a hot Jupiter in a 4.5-d , transiting orbit around the star TYC 7282-1298-1 ( V = 10.8 , F5V ) .
The planet has been pursued by the NGTS team as NGTS-2b and by ourselves as WASP-179b .
We characterised the system using a combination of photometry from WASP-South and TRAPPIST-South , and spectra from CORALIE ( around the orbit ) and HARPS ( through the transit ) .
We find the planet ’ s orbit to be nearly aligned with its star ’ s spin .
From a detection of the Rossiter-McLaughlin effect , we measure a projected stellar obliquity of \lambda = -19 \pm 6 ^ { \circ } .
From line-profile tomography of the same spectra , we measure \lambda = -11 \pm 5 ^ { \circ } .
We find the planet to have a low density ( M _ { P } = 0.67 \pm 0.09 M _ { Jup } , R _ { P } = 1.54 \pm 0.06 R _ { Jup } ) , which , along with its moderately bright host star , makes it a good target for transmission spectroscopy .
We find a lower stellar mass ( M _ { * } = 1.30 \pm 0.07 M _ { \odot } ) than reported by the NGTS team ( M _ { * } = 1.64 \pm 0.21 M _ { \odot } ) , though the difference is only 1.5 \sigma .