The center-to-limb variation across the Fraunhofer lines of HD 189733; Sampling the stellar spectrum using a transiting planet

Abstract

The center-to-limb variation (CLV) describes the brightness of the stellar disk as a function of the limb angle. Across strong absorption lines, the CLV can vary quite significantly. We obtained a densely sampled time series of high-resolution transit spectra of the active planet host star HD 189733 with UVES. Using the passing planetary disk of the hot Jupiter HD 189733 b as a probe, we study the CLV in the wings of the Ca II H and K and Na I D1 and D2 Fraunhofer lines, which are not strongly affected by activity-induced variability. In agreement with model predictions, our analysis shows that the wings of the studied Fraunhofer lines are limb brightened with respect to the (quasi-)continuum. The strength of the CLV-induced effect can be on the same order as signals found for hot Jupiter atmospheres. Therefore, a careful treatment of the wavelength dependence of the stellar CLV in strong absorption lines is highly relevant in the interpretation of planetary transit spectroscopy.

Accepted in A&A

References in corpus (16)

• Molecfit: A general tool for telluric absorption correction. I. Method and application to ESO instruments
• Improved parameters for extrasolar transiting planets
• Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
• Molecfit: A general tool for telluric absorption correction II. Quantitative evaluation on ESO-VLT X-Shooter spectra
• Sodium Absorption From the Exoplanetary Atmosphere of HD189733b Detected in the Optical Transmission Spectrum
• Spectrally resolved detection of sodium in the atmosphere of HD189733b with the HARPS spectrograph
• Ground-based detection of sodium in the transmission spectrum of exoplanet HD209458b
• Near-UV Absorption, Chromospheric Activity, and Star-Planet Interactions in the WASP-12 system
• HST/STIS Optical Transit Transmission Spectra of the hot-Jupiter HD209458b
• Measurement of the Spin-Orbit Alignment in the Exoplanetary System HD 189733
• Multiwavelength observations of a giant flare on CN Leonis I. The chromosphere as seen in the optical spectra
• On the Age of Stars Harboring Transiting Planets
• Transiting the Sun: The impact of stellar activity on X-ray and ultraviolet transits
• Looking for Super-Earths in the HD 189733 System: A Search for Transits in Most Space-Based Photometry
• The centre-to-limb variations of solar Fraunhofer lines imprinted upon lunar eclipse spectra - Implications for exoplanet transit observations
• Defocussed Transmission Spectroscopy: A potential detection of sodium in the atmosphere of WASP-12b

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