About
Stellar abundances and nucleosynthesis
Ian Roederer uses ancient stars in the Milky Way to study the origins of the heaviest elements found on Earth. Every star retains a chemical memory of the time and place where it was born. By studying the abundance patterns of common elements (like carbon, magnesium, or iron) and obscure elements (like arsenic, tellurium, europium, platinum, or lead), Dr. Roederer can probe the physics that produced these elements in ancient supernovae. He frequently uses the high-resolution spectrographs at Magellan and on board the Hubble Space Telescope to make these observations. An understanding of which stars were responsible for producing the elements enabling life and surrounding us on Earth can in turn be used to learn about the earliest epochs in the history of our Galaxy.
Related research interests
Origin of the elements, Galactic chemical evolution, globular cluster formation, Milky Way formation and evolution
Research highlights
- Discovered half of all r-process enhanced stars known [32, 51, 59, 72, 73]
- First to publish on the first-known r-process enhanced galaxy, Reticulum II [39]
- Published the most complete chemical inventory for any object beyond the Solar System, HD 222925 [56]
- Made the first detections of Ga, As, Se, Cd, In, Sb, Te, Lu, W, and Re—more than 15% of the elements detectable—in the spectra of cool stars useful for probing nucleosynthesis [7, 15, 17]
- Released the largest set of hand-crafted abundance derivations (48 elements in each of 313 metal-poor stars), which is widely used as a calibration and comparison sample [27]
- Produced the first study of the orbital kinematics of r-process enhanced stars, revealing probable dwarf galaxy or extragalactic origins [57]
- Published the first study of the detailed chemistry of stars in a stellar stream representing one of the major building blocks of the Milky Way [6]
- Found the first evidence that the Milky Way globular/star cluster metallicity floor may extend to [Fe/H] ~ −3, a factor of 2.5 times lower than previously thought [66]
Publications
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