ner_tags: B-Wavelength O O O O O O O O O O O O O O O O B-ObservationalTechniques I-ObservationalTechniques O O O O O O O O O O O O O O O O O O B-ObservationalTechniques I-ObservationalTechniques O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Instrument O O O O O O O O O O B-EntityOfFutureInterest I-EntityOfFutureInterest O O O O O O O O O O B-CelestialObject I-CelestialObject I-CelestialObject O O O O O B-Instrument O O O O O O O B-EntityOfFutureInterest I-EntityOfFutureInterest O B-EntityOfFutureInterest I-EntityOfFutureInterest O O O O O O O O O O B-CelestialObject I-CelestialObject I-CelestialObject O O O O B-CelestialObject I-CelestialObject I-CelestialObject O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Instrument B-Instrument O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-ObservationalTechniques I-ObservationalTechniques O O O O O O O O O O O O O O
tokens: optical reflected spectra from exoplanets. The major results of this work can be summarized as follows: the CCF technique permits the recovery of the wavelength dependence of reflected spectra of exoplanets, and consequently their albedo function; the CCF technique is able to distinguish between possible albedo configurations and hint at the planetary atmosphere composition; it will be possible to probe at planetary atmospheres for planets in a vastly accessible orbital parameter range; even in cases where a low number of wavelength bins are possible, the ratio between the albedo at redder and bluer wavelengths should help constrain possible chemical and physical atmospheric configurations. as close as 2018, ESPRESSO should already be able to recover the albedo function from hot Jupiter class exoplanets with a few hours of exposure time (e.g. 51 Pegasi b with 1h); the advent of HIRES will allow to probe smaller planets (e.g. hot Neptunes and Super Earths) with just with a few hours of exposure time (e.g. HD 76700 b with around 5h and 55 Cnc e with about 4h) However, the albedo from an exoplanet is not the only factor that modulates the reflected spectrum from an exoplanet. An exciting prospect to further characterize the planet comes from the observation of the phase function of the planet and how it varies with wavelength. This function describes the light curve of a planet as a function of orbital phase. It depends not only on the fraction of the planet illuminated by the host star but also on the general scattering properties of the planet’s atmosphere. The detection of the reflected optical from exoplanets is a daunting task that requires a broad spectral coverage and a extremely high-resolution to achieve the level of S/N we require, as well as an extremely high PSF stability for long periods of time. This can be achieved with ESPRESSO@VLT, HIRES@ELT, and similar observing facilities, which will lead the way towards a more detailed characterization of exoplanets and their atmospheres. The sheer collecting power of giant telescopes, combined with the precision and stability of next-generation high-resolution spectrographs, will put researchers in a position to not only look at the reflected light from exoplanets, but use it to characterize their atmospheres in great detail. A very bright future awaits exoplanetology indeed. APPENDIX A: OPTIMAL OBSERVATION WINDOWS AND DETECTABILITY The reflected signal of the planet is small, and to detect it is essential to choose orbital phases where that signal is close to its maximum. As per equation ( 2 ), this occurs at superior conjunction (or opposition in case of a transiting planet). Unfortunately at that point of the orbit, both the planet and star will have matching radial velocities and thus be difficult – if not impossible – to separate. Even with the precise stellar template built with the CCF technique, fluctuations on the stellar flux will leave residuals in the radial velocity domain at