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 ($v\sin i_\star > 100~\rm{ km~s}^{ -1}$) A8 star with a period of $2.148780\pm8\times10^{ -6} ~\rm{ days}$. The planet has a mass and radius of $3.7\pm0.9~\rm{ M}_{ \rm{ Jup}}$ and $1.5\pm0.3~\rm{ R}_{ \rm{ Jup}}$, 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 $1.5\pm0.9~\rm{ g~cm^{ -3}}$ and an equilibrium temperature of $2570^{ +50}_{ -30}~\rm{ K}$, 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.
Categories: astro-ph.EP