Alexei Filippenko

Hertz Fellow: Alexei Filippenko

California Institute of Technology

Area of Study


Fellowship Years

1979 - 1984

Alexei (Alex) Filippenko, PhD, is the Richard & Rhoda Goldman Distinguished Professor in the Physical Sciences at UC Berkeley. Alex and his collaborators are determining the nature of the progenitor stars and the explosion mechanisms of different types of supernovae and gamma-ray bursts. He is also using supernovae as cosmological distance indicators, and he was a member of both teams that discovered (in 1998) the accelerating expansion of the Universe, probably driven by "dark energy" -- a discovery that was honored with the 2011 Nobel Prize in Physics to the teams' leaders. He also works on quantifying the physical properties of quasars and active galaxies, and he searches for black holes in both X-ray binary stars and nearby galactic nuclei. His group has developed the 0.76-meter Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory, which is conducting one of the world's most successful searches for relatively nearby supernovae, having discovered about 1000 of them. He is a frequent user of Lick Observatory, the 10-meter Keck telescopes, and the Hubble Space Telescope.

Alex's accomplishments, documented in more than 850 research papers, have been recognized by several major prizes, including a share of both the Gruber Cosmology Prize (2007) and the Breakthrough Prize in Fundamental Physics (2015). One of the world's most highly cited astronomers, he is an elected member of the National Academy of Sciences (2009) and the American Academy of Arts and Sciences (2015). In 2017, he was selected for the Caltech Distinguished Alumni Award. He has won the most prestigious teaching awards at UC Berkeley and has also been voted the "Best Professor" on campus a record 9 times. Selected in 2006 as the Carnegie/CASE National Professor of the Year among doctoral institutions, he has also received the Richard H. Emmons Award for undergraduate teaching (2010). He produced five astronomy video courses with "The Great Courses", coauthored an award-winning astronomy textbook, and appears in more than 100 TV documentaries, including about 50 episodes of "The Universe" series. He has given about 1000 public lectures or other presentations, and he was awarded the 2004 Carl Sagan Prize for Science Popularization. With his Hertz Fellowship, Alex pursued his PhD in astronomy at the California Institute of Technology.

Outside of the lab, Alex is an avid tennis player, hiker, skier, whitewater rafter, snorkler, scuba diver, and enjoys world travel and is addicted to observing total solar eclipses (15 so far, all successful).


1984 - Physical Conditions in Low-Luminosity Active Galactic Nuclei