Two New HATNet Hot Jupiters around A Stars and the First Glimpse at the Occurrence Rate of Hot Jupiters from TESS^∗

Abstract

Wide-field surveys for transiting planets are well suited to searching diverse stellar populations, enabling a better understanding of the link between the properties of planets and their parent stars. We report the discovery of HAT-P-69 b (TOI 625.01) and HAT-P-70 b (TOI 624.01), two new hot Jupiters around A stars from the Hungarian-made Automated Telescope Network (HATNet) survey that have also been observed by the Transiting Exoplanet Survey Satellite. HAT-P-69 b has a mass of-+ 3.58 0.58 0.58 M Jup and a radius of-+ 1.676 0.033 0.051 R Jup and resides in a prograde 4.79 day orbit. HAT-P-70 b has a radius of-+ 1.87 0.10 0.15 R Jup and a mass constraint of s <6.78 3 ()M Jup and resides in a retrograde 2.74 day orbit. We use the confirmation of these planets around relatively massive stars as an opportunity to explore the occurrence rate of hot Jupiters as a function of stellar mass. We define a sample of 47,126 main-sequence stars brighter than T mag =10 that yields 31 giant planet candidates, including 18 confirmed planets, 3 candidates, and 10 false positives. We find a net hot Jupiter occurrence rate of 0.41±0.10% within this sample, consistent with the rate measured by Kepler for FGK stars. When divided into stellar mass bins, we find the occurrence rate to be 0.71±0.31% for G stars, 0.43±0.15% for F stars, and 0.26±0.11% for A stars. Thus, at this point, we cannot discern any statistically significant trend in the occurrence of hot Jupiters with stellar mass.

Exploring the Atmospheric Dynamics of the Extreme Ultrahot Jupiter KELT-9b Using TESS Photometry

“…The transits of KELT-9b show significant deviations from the typical transit light-curve shape. These asymmetries are attributable to the gravity-darkened photosphere of the rapidly rotating host star and have been reported for a handful of other transiting systems with hot host stars, including Kepler-13A (Barnes et al 2011), Kepler-462 (Ahlers et al 2015), HAT-P-70 (Zhou et al 2019), and MASCARA-4 (Ahlers et al 2020b). A detailed, dedicated analysis of the gravity-darkened transit of KELT-9b in TESS photometry is described in Ahlers et al (2020a).…”

KELT-9 b’s Asymmetric TESS Transit Caused by Rapid Stellar Rotation and Spin–Orbit Misalignment

“…KELT-9 b is an especially interesting target for hot Jupiter research. In its polar orbit, KELT-9 b follows the trend that gas giants around high-mass stars are frequently spin-orbit misaligned (e.g., Winn et al 2010;Albrecht et al 2012;Winn & Fabrycky 2015;Zhou et al 2019). Its high dayside temperature provides excellent opportunities for phase curve and secondary eclipse analyses (Hooton et al 2018;Wong et al 2019;Mansfield et al 2020).…”

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

“…To date, five new hot Jupiters initially detected by TESS have been confirmed: HD 202772A b (Wang et al 2019), HD 2685 b (Jones et al 2019), TOI 150 b (Cañas et al 2019a;Kossakowski et al 2019), HD 271181 b (Kossakowski et al 2019), and TOI 172 b (Rodriguez et al 2019). Additionally, the HATNet survey (Bakos et al 2004) detected two transiting hot Jupiter candidates in 2010, HATS-P-69 b and HATS-P-70 b, which were later observed by TESS, leading to their confirmation (Zhou et al 2019).…”

“…Our empirical knowledge of hot Jupiters is based on the foundation of our small but growing sample of these worlds (currently numbering ∼250). While small, rocky planets are understood to be present, on average, around every star (e.g., Fressin et al 2013;Petigura et al 2018), various studies have found that on the order of only ∼0.5% of stars host a hot Jupiter (e.g., Howard et al 2012;Petigura et al 2018;Zhou et al 2019), ∼10% of which will have a geometry resulting in a visible transit. Transiting hot Jupiters are therefore intrinsically rare; so, given the broad and abiding questions surrounding them, there is value in each additional example found, particularly around stars that are amenable to follow-up observations.…”