Jeffrey Simpson (@DoctorJeph) is a postdoctoral fellow at the Australian Astronomical Observatory (AAO) based in Sydney. His research focuses on globular clusters, in particular, the chemical abundances of their stars. He makes use of spectra to investigate the abundances of elements like carbon, nitrogen, oxygen and sodium to try and unravel the multiple populations of stars that exist in these peculiar stellar conglomerations. Recently he has focused on low mass clusters to try and find if there is a mass limit to multiple populations. Along with research, he provides support for users of the Anglo-Australian Telescope (AAT), especially people making use of their fibre-fed spectrographs: HERMES and AAOmega. He is also trying (and will eventually succeed at) at putting together the AAT schedule for the six months starting in February 2017.
He is involved with the GALAH survey (@galahsurvey), where he occasionally tweets as well) which is using HERMES on the AAT to acquire high-resolution spectra of one million stars in our Milky Way. GALAH will determine the temperature, gravity, overall metallicity for these stars, but more crucially, the abundance of over 20 different elements. He spends a lot of nights observing for GALAH.
He grew up in the town of Invercargill, New Zealand, home to amongst other things tuatara and the southernmost large pyramid in the world. From there he did his undergraduate and PhD at the University of Canterbury in Christchurch from 2010 to 2014. He did a short stint at Macquarie University before moving down the road to the AAO in 2015.