Research interests

• Galactic archaeology
• Near-field cosmology
• Extrasolar planets

Research

I employ a combination of physical models and data from various observatories (e.g. Gaia, the James Webb Space Telescope) to study populations of stars, with the aim of using the derived properties of these populations to inform our understanding of the formation and evolution of extrasolar planets, of the Milky Way, and of the Universe as a whole.  We have broad ideas of how the Universe and its galaxies formed and evolved, my interest lies in testing and evaluating these ideas to the highest precision possible.

In one of my recent publications, I inferred the ages and metallicities for 400,000 nearby stars, yielding one of the most robust star-formation histories of the solar neighborhood. These observations challenge our models of stellar evolution and of cosmology, as many of the stars have derived uncomfortably close to the age of the Universe (13.7 billion years). In another recent study, I evaluated a controversy as to the distance and extinction to the Large Magellanic Cloud, the Milky Way’s largest satellite galaxy and a zero-point to the extragalactic distance scale, using three different methods, and my result is indicative of the higher end of values suggested for the expansion rate of the Universe (Hubble’s constant).  

Research interests

• The star-formation history of the solar neighborhood, and of nearby galaxies such as the Andromeda and Triangulum Galaxies.
• The extragalactic distance scale, RR Lyrae, Mira variables.
• The interstellar extinction curve and variations thereof, particularly toward the inner Galaxy.
• The Galactic Exoplanet Survey of the Nancy Grace Roman Space Telescope, which is expected to detect over 100 Earth-like planets.

Referred publications

Google Scholar