Spergel Lecture Series: The Alchemy of Stars

Medieval alchemists longed to turn lead into gold. In this talk, I will discuss how stars transform the elements through nuclear reactions, focusing on the formation of the heavy elements such as lead, tin, silver, platinum, and, yes, gold.

Medieval alchemists longed to turn lead into gold. In this talk, Dr. Jennifer Johnson, the Henry L. Cox Professor of Astronomy at The Ohio State University, will discuss how stars transform the elements through nuclear reactions, focusing on the formation of heavy elements such as lead, tin, silver, platinum, and, yes, gold.

Dr. Johnson, will highlight how the formation and release of neutrons in dying low‑mass stars, collapsing high‑mass stars, and merging neutron stars create the rare conditions needed to forge the heaviest elements in the periodic table. New observations, ranging from the chemical signatures of the earliest stars in the Milky Way to gravitational‑wave detections from inspiraling black holes and neutron stars are poised to drive major breakthroughs in our understanding over the next decade.

Biography

Jennifer Johnson is the current Henry L. Cox Professor of Astronomy at Ohio State University. She received her Ph.D. in Astronomy and Astrophysics from the University of California, Santa Cruz. After postdoctoral fellowships at Carnegie Observatories in Pasadena, CA, and the Herzberg Institute of Astrophysics in Victoria, BC, she joined the faculty at Ohio State in 2005. She has been involved in the Sloan Digital Sky Survey for over twenty years, serving as Spokesperson and Milky Way Mapper Program Head. She uses measurements of the motions, ages, and composition of millions of stars to understand the origin of the elements and the formation of the Milky Way.  Her favorite element is arsenic.