Transmission spectroscopy of the inflated exo-Saturn HAT-P-19b

Abstract

Context. Transiting highly inflated giant planets offer the possibility of characterizing their atmospheres. A fraction of the starlight passes through the high-altitude layers of the planetary atmosphere during transit. The resulting absorption is expected to be wavelength dependent for cloud-free atmospheres with an amplitude of up to 10-3 of the stellar flux, while a high-altitude cloud deck would cause a gray opacity.