TOI 564 b and TOI 905 b: Grazing and Fully Transiting Hot Jupiters Discovered by TESS

We report the discovery and confirmation of two new hot Jupiters discovered by the Transiting Exoplanet Survey Satellite (TESS): TOI 564 b and TOI 905 b. The transits of these two planets were initially observed by TESS with orbital periods of 1.651 d and 3.739 d, respectively. We conducted follow-up observations of each system from the ground, including photometry in multiple filters, speckle interferometry, and radial velocity measurements.

For TOI 564 b, our global fitting revealed a classical hot Jupiter with a mass of 1.463+0.10−0.096 MJ and a radius of 1.02+0.71/−0.29 RJ. TOI 905 b is a classical hot Jupiter as well, with a mass of 0.667+0.042/−0.041 MJ and radius of 1.171+0.053/−0.051 RJ. Both planets orbit Sun-like, moderately bright, mid-G dwarf stars with V ~ 11.

While TOI 905 b fully transits its star, we found that TOI 564 b has a very high transit impact parameter of 0.994+0.083/−0.049, making it one of only ~20 known systems to exhibit a grazing transit and one of the brightest host stars among them. TOI 564 b is therefore one of the most attractive systems to search for additional non-transiting, smaller planets by exploiting the sensitivity of grazing transits to small changes in inclination and transit duration over the time scale of several years.