MASCARA-3b: A hot Jupiter transiting a bright F7 star in an aligned orbit

Abstract

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 ($e=0.050_{-0.017}^{+0.020}$). 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 $\hat{I}»=1.2_{-7.4}^{+8.2}$ deg, which is consistent with alignment.

8 pages, 7 figures, 6 tables; accepted in A&A. Updated for the accepted and proof-readed version