Hi Paul, Peter and Andy,
Trappist-1 and its system of at least 7 planets is fascinating. Yesterday we held our second BAA/UCL exoplanet workshop in London and I finished the day able to read Gillon et al.’s 2017 paper in the journal Nature on the subject. Shame that I am away in Australia and so not able to attend Winchester Weekend.
I think I may have seen Didier Queloz in 1991 when I participated in a French-language workshop at Haute Provence Observatory – I was working in France at that time. The astronomers had plans to build a new high-res spectrometer for the telescope there with a view to detect planets by the radial velocity method: this led to the ELODIE spectrometer in 1993. People thought that they were ambitious at that time. Michel Mayor was also involved and Andre Baranne was the main protagonist at OHP.
As to the question of liquid water: despite not yet measuring its presence directly, we can infer it should exist on one or more of the Trappist-1 planets. H2O is a very common constituent in the universe and almost certainly should exist as a liquid somewhere on one or more of its planets!
Cheers, Richard