We report the discovery of MASCARA-3b , a hot Jupiter orbiting its bright ( V = 8.33 ) late F-type host every 5.55149 \pm 0.00001 days in an almost circular orbit ( e = 0.050 ^ { +0.020 } _ { -0.017 } ) .
This is the fourth exoplanet discovered with the Multi-site All-Sky CAmeRA ( MASCARA ) , and the first of these that orbits a late-type star .
Follow-up spectroscopic measurements were obtained in and out of transit with the Hertzsprung SONG telescope .
Combining the MASCARA photometry and SONG radial velocities reveals a radius and mass of 1.36 \pm 0.05 R _ { \text { Jup } } and 4.2 \pm 0.2 M _ { \text { Jup } } .
In addition , SONG spectroscopic transit observations were obtained on two separate nights .
From analyzing the mean out-of-transit broadening function , we obtain v \sin i _ { \star } = 20.4 \pm 0.4 km s ^ { -1 } .
In addition , investigating the Rossiter-McLaughlin effect , as observed in the distortion of the stellar lines directly and through velocity anomalies , we find the projected obliquity to be \lambda = 1.2 ^ { +8.2 } _ { -7.4 } deg , which is consistent with alignment .