Photograph courtesy of Anna Frebel.
Anna Frebel has been looking at the stars since she was a kid, except now she studies them through some of the largest instruments in the world. “I consider myself very fortunate that my inital passion indeed led me to become a professional astronomer and that my work centers around the oldest stars in the universe,” she says. “I use these stars to unravel the details of the cosmic evolution of the chemical elements.”
Frebel has been setting records in her field since 2005. That year, she discovered the most chemically primitive star, likely a member of the second generation of stars to have formed in the universe. Then in 2007, Frebel uncovered the oldest known star at the time, a red giant about 13.2 billion years old.
But Frebel wasn’t done. In 2010, she discovered stars like the red giant S1020549 in dwarf galaxies with remarkably similar chemical makeups to the Milky Way’s oldest members. “This has been helping us gain a better picgture of how the Milky Way assembled and how the oldest stars … actually got incorporated into our galaxy, where we can observe them today,” she says. The effort keeps Frebel busy: “At the moment, I am working toward a better understanding of the processes of galaxy assembly by studying the chemical composition of individual stars with a focus on what kind of supernova explosion created the observed element prior to the star’s formation.”
All in all, Frebel plans to continue looking into the past as part of her future. “My long-term goal is to understand the physical and chemical conditions that goverened the early universe soon after the Big Bang, at a time when the first stars and first galaxies began to form,” she says. “My colleagues and I are working on this by closely combining the many observational results with the latest theoretical simulations of galaxy evolution.”
- Astronomy’s rising stars (PDF) [Astronomy Magazine, July 2013]
- Stellar Archeology [Harvard Magazine, May-June 2013]