Abstract

Astrometry from space has unique advantages over ground-based observations: the all-sky coverage, relatively stable and temperature- and gravity-invariant operating environment delivers precision, accuracy and sample volume several orders of magnitude greater than ground-based results. Even more importantly, absolute astrometry is possible. The European Space Agency Cornerstone mission Gaia is delivering that promise. Gaia provides 5-D phase space measurements, 3 spatial coordinates and two space motions in the plane of the sky, for a representative sample of the Milky Wayʼs stellar populations (over 1 billion stars, being ~1% of the stars over 50% of the volume). Full 6-D phase space data is delivered from line-of-sight (radial) velocities for the 300million brightest stars. These data make substantial contributions to astrophysics and fundamental physics on scales from the Solar System to cosmology. A few example results will be given.

The talk will be followed by refreshments outside the lecture theatre. The talk will be at 7:30pm at the usual location of Wolfson lecture theatre in the Department of Chemistry. The entrance is the opposite side of the building to Bristol-Myers-Squibb Lecture theatre and is opposite the car park- shown by the red arrow on the map. https://map.cam.ac.uk/Department+of+Chemistry#52.197964,0.125242,18 Tickets are £2 (free for members) and annual membership (£7) and life membership (£12) can also be purchased at the event – please bring cash.