High spatial resolution imaging of the star with a transiting planet WASP-33

Abstract

The recent discovery of a transiting planet around WASP-33, the misalignment of the stellar rotation axis and the planet orbit, the possible existence of an additional planet in the system, and the presence of $\delta$ Scuti pulsations in the hosting star make this system a highly interesting object to help us understand the origin and evolution of giant planets orbiting very close a star. High spatial resolution imaging allows the study of the presence of the predicted additional planet, and any other objects, constraining the possible formation scenarios of the system. In November 2010, we recorded high spatial resolution images from 1 to 2.5 $\mu$m using the W.M. 10m-Keck II telescope and its adaptive optics system, obtaining broad (Jc,Hc, and Kc) and narrow band (FeII) images of the system. After data reduction, the contrast and angular resolution provided by this instrument allowed us to constraint the multiplicity of this system and to detect one potential companion. We have found a new object at a distance of 1.961$"$ $\pm$ 0.003$"$ from the WASP-33, with a position angle of 276.32$\pm$0.24 deg. It could be a dwarf star/ brown dwarf or an extragalactic object. In the first case, and assuming the same distance from the Sun, the object is 227 AU from the central star. On the other hand, no additional objects have been found. This constraints the possible objects in the system, depending on its age and masses. A potential companion object to WASP-33 was obtained. The gravitational link must be confirmed, but this object could influence the evolution of the planetary system depending on its orbital eccentricity. We have ruled-out the existence of additional objects, depending on the age of the system.

5 pages, 5 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (6)

• Dynamical Outcomes of Planet-Planet Scattering
• Hot Stars with Hot Jupiters Have High Obliquities
• Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism
• Hot Jupiters in binary star systems
• WASP-33: The first delta Scuti exoplanet host star
• Masses of Astrometrically-Discovered and Imaged Binaries: G 78-28AB and GJ 231.1BC

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• An optical transmission spectrum of the ultra-hot Jupiter WASP-33b. First indication of AlO in an exoplanet
• TESS unveils the phase curve of WASP-33b. Characterization of the planetary atmosphere and the pulsations from the star
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• Comprehensive time series analysis of the transiting extrasolar planet WASP-33b
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• A temperature inversion in WASP-33b? Large Binocular Telescope occultation data confirm significant thermal flux at short wavelengths
• Spin-orbit alignments for Three Transiting Hot Jupiters: WASP-103b, WASP-87b, & WASP-66b
• The MgI line: a new probe of the atmospheres of evaporating exoplanets
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