HAT-P-24b: An inflated hot-Jupiter on a 3.36d period transiting a hot, metal-poor star

Abstract

We report the discovery of HAT-P-24b, a transiting extrasolar planet orbiting the moderately bright V=11.818 F8 dwarf star GSC 0774-01441, with a period P = 3.3552464 +/- 0.0000071 d, transit epoch Tc = 2455216.97669 +/- 0.00024 (BJD_UTC), and transit duration 3.653 +/- 0.025 hours. The host star has a mass of 1.191 +/- 0.042 Msun, radius of 1.317 +/- 0.068 Rsun, effective temperature 6373 +/- 80 K, and a low metallicity of [Fe/H] = -0.16 +/- 0.08. The planetary companion has a mass of 0.681 +/- 0.031 MJ, and radius of 1.243 +/- 0.072 RJ yielding a mean density of 0.439 +/- 0.069 g cm-3 . By repeating our global fits with different parameter sets, we have performed a critical investigation of the fitting techniques used for previous HAT planetary discoveries. We find that the system properties are robust against the choice of priors. The effects of fixed versus fitted limb darkening are also examined. HAT-P-24b probably maintains a small eccentricity of e = 0.052 +0.022 -0.017, which is accepted over the circular orbit model with false alarm probability 5.8%. In the absence of eccentricity pumping, this result suggests HAT-P-24b experiences less tidal dissipation than Jupiter. Due to relatively rapid stellar rotation, we estimate that HAT-P-24b should exhibit one of the largest known Rossiter-McLaughlin effect amplitudes for an exoplanet (deltaVRM ~ 95 m/s) and thus a precise measurement of the sky-projected spin-orbit alignment should be possible.

13 pages with 4 figures and 8 tables in emulateapj format. Minor changes. Accepted in The Astrophysical Journal

References in corpus (15)

• DHP Framework: Digital Health Passports Using Blockchain -- Use case on international tourism during the COVID-19 pandemic
• Hot Stars with Hot Jupiters Have High Obliquities
• Giant Planet Occurrence in the Stellar Mass-Metallicity Plane
• Prospects for the Characterization and Confirmation of Transiting Exoplanets via the Rossiter-McLaughlin Effect
• The On/Off Nature of Star-Planet Interactions
• HD147506b: A Super-Massive Planet in an Eccentric Orbit Transiting a Bright Star
• Spitzer Transit and Secondary Eclipse Photometry of GJ 436b
• Long Term Evolution of Close Planets Including the Effects of Secular Interactions
• TASS Mark IV Photometric Survey of the Northern Sky
• HAT-P-12b: A Low-Density Sub-Saturn Mass Planet Transiting a Metal-Poor K Dwarf
• On The Origins Of Eccentric Close-in Planets
• HAT-P-3b: A heavy-element rich planet transiting a K dwarf star
• TrES-4: A Transiting Hot Jupiter of Very Low Density
• Astrometry in Wide-field Surveys
• HAT-P-15b: A 10.9-day Extrasolar Planet Transiting a Solar-type Star

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