Meet Caltech Astronomer Shrinivas Kulkarni, Winner Of The Royal Astronomical Society Gold Medal

Photo: CalTech

India-West News Desk

PASADENA, CA – Long before he became one of the world’s most influential astronomers, Shrinivas Kulkarni grew up in a tightly knit, unusually accomplished Indian family, moving from town to town across Karnataka as the son of a government doctor. The youngest of four siblings, he would go on to chart the most fleeting and violent events in the universe, even as his sisters carved out distinguished paths of their own in medicine, education, philanthropy, and global technology.

Now, Kulkarni, the George Ellery Hale Professor of Astronomy and Planetary Science at Caltech, has been awarded the Gold Medal of the Royal Astronomical Society, the highest honor bestowed by the London based institution since 1824. The citation recognized his “sustained, innovative and ground breaking contributions to multi wavelength transient astrophysics,” placing him in a lineage that includes Albert Einstein, Stephen Hawking and Edwin Hubble.

The honor also only the second Indian to receive the RAS Gold Medal, following Subrahmanyan Chandrasekhar, and the award explicitly acknowledged his “field defining” role in shaping time domain astronomy, the study of cosmic phenomena that change or explode over short timescales.

Born in Maharashtra, Kulkarni was educated in Hubli before moving on to the Indian Institute of Technology Delhi. Excellence comes naturally to the family. His eldest sister, Sunanda, pursued medicine and served as a gynaecologist at a hospital in Bengaluru. Another sister, Jayshree, an alumnus of IIT Madras, is married to the billionaire Boston based technology entrepreneur Gururaj “Desh” Deshpande. His sister Sudha Murty is a celebrated author, educator and philanthropist, and the wife of Infosys founder Narayana Murthy.

Kulkarni’s scientific rise began early. In 1982, while still a graduate student, he and his colleagues discovered the first millisecond pulsar, a rapidly spinning neutron star that reshaped understanding of stellar remnants. After earning his PhD from the University of California, Berkeley, he arrived at Caltech in 1985 on a Millikan Fellowship and joined the faculty two years later.

Over the decades, his work has repeatedly opened new windows on the universe. He played a key role in the discovery of brown dwarfs in 1995, objects too small to sustain nuclear fusion like stars. In 1997, he helped demonstrate that powerful gamma ray bursts originate far beyond the Milky Way, settling a long standing debate. In 2020, he was part of the team that identified the first fast radio burst erupting within our own galaxy, showing that these mysterious flashes can arise from magnetars, highly magnetized dead stars.

Beyond individual discoveries, Kulkarni has been instrumental in building the tools that make such science possible. He led the creation of the Palomar Transient Factory and later its successor, the Zwicky Transient Facility, both based at Caltech’s Palomar Observatory near San Diego. These projects have captured thousands of cosmic events in real time as they flare, blink or explode, and, as the award citation noted, “have revolutionized time domain astrophysics at optical wavelengths.” The Zwicky Transient Facility continues to survey the entire Northern sky every two nights.

Kulkarni has often described himself as an instrument builder at heart. Speaking during his 2024 Watson Lecture at Caltech, he reflected on a career spent constructing new ways to observe the universe. “My motto has been to build a big enough gizmo and things will happen,” he said. Over his career, he has built or helped build 10 astronomical instruments.

He remains deeply engaged in future missions. Kulkarni is currently involved in developing NASA’s Ultraviolet Explorer mission, slated for launch around 2030, which aims to conduct the most sensitive ultraviolet sky survey to date. He is also the principal investigator of Z Shooter, a powerful new spectrometer under development for the W M Keck Observatory in Hawaii, with first light expected in 2029.

During his doctoral years at Berkeley, Kulkarni met Hiromi Komiya, a fellow PhD student from Japan. He learned Japanese within weeks, and the two married soon after. They have two daughters, Anju and Maya.

Over his career, Kulkarni has received numerous major honors, including the Shaw Prize, the National Science Foundation’s Alan T Waterman Award and the Dan David Prize from Tel Aviv University. He is a member of the US National Academy of Sciences, the Royal Society of London, the Indian Academy of Sciences and the Royal Netherlands Academy of Arts and Sciences.