Photo courtesy of Christopher Prentiss Michel
Observer Alex Filippenko, UC Berkeley’s expert on supernovae and black holes, has been named co-recipient of the 2026 Gruber Cosmology Prize. Filippenko shares this honor with Ken’ichi Nomoto of the University of Tokyo and fellow Keck observer Stanford E. Woosley of UC Santa Cruz.
Keck Observatory has played a leading role in Filippenko’s research over the years, particularly in observations that contributed to the groundbreaking discovery that the expansion of the universe is accelerating.
“I obtained many of the spectra of high-redshift Type Ia supernova candidates using Keck Observatory in the mid-1990s, leading to the Nobel-worthy discovery of the accelerating expansion of the Universe, driven by mysterious dark energy,” said Filippenko.
The prize — one of the world’s most prestigious honors recognizing research on the origin and fate of the universe — includes a $500,000 award to be shared equally among the three recipients. Together, their trailblazing work connected stellar evolution, explosive nucleosynthesis, the origin of heavy elements, and the chemical evolution of the universe. Their research also helped establish supernovae as essential tools for precision cosmology.
The recognition further highlights the central role Keck Observatory observations have played in advancing our understanding of the evolving universe.
Ho‘omaika‘i to Alex, Stan, and Ken’ichi on this monumental achievement!
From UC Berkeley News:
An astrophysicist, professor of astronomy and one of Berkeley’s most popular teachers, Filippenko played a major role in clarifying the varieties of Type Ia supernovae, allowing these exploding stars to be standardized so that their intrinsic brightness could be used to measure the expansion of the universe. He also was cited for discovering two other variants of Type I supernovae.
“I’m honored, though I can think of numerous other astronomers in this field who are equally deserving,” Filippenko said.
At different times, he was a member of two groups of scientists that, in 1998, announced the expansion of the universe was speeding up, leading to the idea that a mysterious dark energy permeates the universe and is fueling the accelerated expansion. The 2011 Nobel Prize in Physics was awarded to the leaders of the two groups — Berkeley physicist Saul Perlmutter and American-Australian astronomer Brian Schmidt — and to Adam Riess, a postdoctoral fellow in Filippenko’s group at the time the research was conducted.