Jeffrey Simpson

I'm an astrophysicist in the School of Physics at the University of New South Wales, Sydney, Australia.

My current research focuses on groups of stars: clusters and streams. I am using these groups of stars to understand how the Milky Way formed and evolved, and to try and map the gravitational field of our Galaxy.

I am involved with two large international surveys based in Australia: The GALAH Survey, and the Southern Stellar Stream Spectroscopic Survey

You can find me in all the usual places: GitHub, Twitter, ORCID. Or email me at