For the first time astronomers were able to detect light bouncing off planets our of the solar system.
The new method developed by a group of Portuguese astronomers may give researchers more information on the atmospheres of exoplanets.
Radial Velocity is currently used to find planets. Starting in the ’90s t has been sucessfully applied to hundreds of planets now. It provides good information on the orbit and mass, but are not so good in providing evidence of atmosphere composition. We can see a bit more, now.
To be precise:
“Methods. Our method makes use of the cross-correlation function (CCF) of a binary mask with high-resolution spectra to amplify the minute planetary signal that is present in the spectra by a factor proportional to the number of spectral lines when performing the cross correlation. The resulting cross-correlation functions are then normalized by a stellar template to remove the stellar signal. Carefully selected sections of the resulting normalized CCFs are stacked to increase the planetary signal further. The recovered signal allows probing several of the planetary properties, including its real mass and albedo.
Results. We detect evidence for the reflected signal from planet 51 Peg…
Conclusions. We confirm that the method we perfected can be used to retrieve an exoplanet’s reflected signal, even with current observing facilities. The advent of next generation of instruments (e.g. VLT-ESO/ESPRESSO) and observing facilities (e.g. a new generation of ELT telescopes) will yield new opportunities for this type of technique to probe deeper into exoplanets and their atmospheres.”