Felicitas Arias, Ph.D., is Director of the Time Department, International Bureau for Weights and Measures in Sèvres near Paris.Responsible for the maintenance of Universal Coordinated Time.
Ludwig Combrinck, Ph.D., is Acting Managing Director of the Hartebeesthoek Radio Astronomy Observatory (HartRAO), National Research Foundation, South Africa. His main interests are space geodesy and general relativity.
Pavel Gabor, Ph.D., is Vice Director of the Vatican Observatory responsible for its observational facilities in Arizona. He is involved in the robotic upgrades of three telescopes and other astronomical instrumentation projects. As a Jesuit priest and an official of the Holy See, he also studies timekeeping, its history and symbolism.
Catherine Hohenkerk, HM Nautical Almanac Office (HMNAO), UK Hydrographic Office, a long standing member of HMNAO, fellow of the Royal Institute of Navigation, Chair of the long standing IAU Division Aworking group Standards of Fundamental Astronomy (SOFA) and President of IAU Division A Commission for Fundamental Standards.
P.Kenneth Seidelmann, Research Professor of Astronomy at the Universityof Virginia; former director of astrometry directorate at the U.S. Naval Observatory, Co-editor of the Explanatory Supplement to the Astronomical Almanac, Co-author of books on astrometry, time, and celestial mechanics and astrodynamics, and author of many scientific papers.