We report the discovery of MASCARA-1 b , the first exoplanet discovered with the Multi-site All-Sky CAmeRA ( MASCARA ) .
It is a hot Jupiter orbiting a bright m _ { V } = 8.3 , rapidly rotating ( v \sin i _ { \star } > 100 ~ { } { km~ { } s } ^ { -1 } ) A8 star with a period of 2.148780 \pm 8 \times 10 ^ { -6 } ~ { } days .
The planet has a mass and radius of 3.7 \pm 0.9 ~ { } M _ { Jup } and 1.5 \pm 0.3 ~ { } R _ { Jup } , respectively .
As with most hot Jupiters transiting early-type stars we find a misalignment between the planet orbital axis and the stellar spin axis , which may be signature of the formation and migration histories of this family of planets .
MASCARA-1 b has a mean density of 1.5 \pm 0.9 ~ { } { g~ { } cm ^ { -3 } } and an equilibrium temperature of 2570 ^ { +50 } _ { -30 } ~ { } K , one of the highest temperatures known for a hot Jupiter to date .
The system is reminiscent of WASP-33 , but the host star lacks apparent delta-scuti variations , making the planet an ideal target for atmospheric characterization .
We expect this to be the first of a series of hot Jupiters transiting bright early-type stars that will be discovered by MASCARA .