Broad-band spectrophotometry of HAT-P-32 b: Search for a scattering signature in the planetary spectrum

Abstract

Multi-colour broad-band transit observations offer the opportunity to characterise the atmosphere of an extrasolar planet with small- to medium-sized telescopes. One of the most favourable targets is the hot Jupiter HAT-P-32 b. We combined 21 new transit observations of this planet with 36 previously published light curves for a homogeneous analysis of the broad-band transmission spectrum from the Sloan u' band to the Sloan z' band. Our results rule out cloud-free planetary atmosphere models of solar metallicity. Furthermore, a discrepancy at reddest wavelengths to previously published results makes a recent tentative detection of a scattering feature less likely. Instead, the available spectral measurements of HAT-P-32 b favour a completely flat spectrum from the near-UV to the near-IR. A plausible interpretation is a thick cloud cover at high altitudes.

12 pages, 6 figures, accepted for publication in MNRAS

References in corpus (12)

• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• ULTRACAM: an ultra-fast, triple-beam CCD camera for high-speed astrophysics
• The Transit Light Curve Project. IX. Evidence for a Smaller Radius of the Exoplanet XO-3b
• Using Stellar Limb-Darkening to Refine the Properties of HD 209458b
• HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering
• The effect of stellar limb darkening values on the accuracy of the planet radii derived from photometric transit observations
• Impact of occultations of stellar active regions on transmission spectra: Can occultation of a plage mimic the signature of a blue sky?
• High accuracy transit photometry of the planet OGLE-TR-113b with a new deconvolution-based method
• A photometric study of the hot exoplanet WASP-19b
• Transit Timing Analysis in the HAT-P-32 system
• Characterization of the atmosphere of the hot Jupiter HAT-P-32Ab and the M-dwarf companion HAT-P-32B

Cited by in corpus (8)

• Hubble PanCET: An isothermal day-side atmosphere for the bloated gas-giant HAT-P-32Ab
• Low albedos of hot to ultra-hot Jupiters in the optical to near-infrared transition regime
• The HST PanCET Program: An Optical to Infrared Transmission Spectrum of HAT-P-32Ab
• Ephemeris refinement of 21 Hot Jupiter exoplanets with high timing uncertainties
• Possible detection of a bimodal cloud distribution in the atmosphere of HAT-P-32\,A\,b from multi-band photometry
• Near-UV transit photometry of HAT-P-32 b with the LBT: Silicate aerosols in the planetary atmosphere
• On the parameter refinement of inflated exoplanets with large radius uncertainty based on TESS observations
• A Two-limb Explanation for the Optical-to-infrared Transmission Spectrum of the Hot Jupiter HAT-P-32Ab