Hi Claudio,

yes you can create a .tdf from the Gaia catalogue. I downloaded one of the Gaia source files, extracted it with the software "7z" (.gz to .csv) and openened imported it in excel to identify the columns (and their headers).

But to access the full Gaia catalogue via a .tdf, you first need to download the full Gaia source catalogue from here: http://cdn.gea.esac.esa.int/Gaia/gdr2/gaia_source/csv/ (with 550 GB (!), ... compared to 8 GB for the UCAC 4 catalogue for instance).

It would be ways more efficient to access this very huge Gaia catalogue directly from the internet. But I do not have enough programming knowledge to tell you how to do that.

Sorry.

Rudi