2020/12/31 by G. Scandariato, F. Borsa, D. Sicilia +49 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/202039271
published as A&A 646, A159 (2021)
openalex publication_date 2021/01/05 · arxiv created 2021/01/06 · openalex created_date 2021/01/18 · arxiv updated 2021/02/24 · openalex updated_date 2026/07/28
The analysis of exoplanetary atmospheres by means of high-resolution spectroscopy is an expanding research field which provides information on chemical composition, thermal structure, atmospheric dynamics and orbital velocity of exoplanets. In this work, we aim at the detection of the light reflected by the exoplanet 51~Peg~b employing optical high-resolution spectroscopy. To detect the light reflected by the planetary dayside we use optical HARPS and HARPS-N spectra taken near the superior conjunction of the planet, when the flux contrast between the planet and the star is maximum. To search for the weak planetary signal, we cross-correlate the observed spectra with a high S/N stellar spectrum. We homogeneously analyze the available datasets and derive a 10-5 upper limit on the planet-to-star flux contrast in the optical. The upper limit on the planet-to-star flux contrast of 10-5 translates into a low albedo of the planetary atmosphere (\rm Ag\lesssim0.05-0.15 for an assumed planetary radius in the range \rm 1.5-0.9~RJup, as estimated from the planet's mass).