Indian-origin scientist Shrinivas Kulkarni honoured with UK’s Royal Astronomical Society Gold Medal

US-based astronomer Shrinivas Kulkarni has received the Royal Astronomical Society’s Gold Medal for his groundbreaking work in time-domain astronomy. The Caltech professor is known for discovering cosmic events and building powerful instruments to study the changing night sky.

London: US-based astronomer Professor Shrinivas Kulkarni has been awarded the prestigious Gold Medal by the Royal Astronomical Society (RAS) in London for his “field-defining” discoveries in time-domain astronomy.

Maharashtra-born Kulkarni is the George Ellery Hale Professor of Astronomy and Planetary Science at the California Institute of Technology (Caltech), where he has discovered a wide range of astronomical objects, including brown dwarfs and remote bursts of gamma rays.

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His RAS Gold Medal citation from last week recognises his “sustained, innovative and ground-breaking contributions to multi-wavelength transient astrophysics”.

In receiving the highest honour from the historic organisation, awarded annually since 1824, he joins great scientific minds such as Stephen Hawking, Jocelyn Bell Burnell, Albert Einstein and Edwin Hubble.

“I was very surprised to hear the news, especially given the stellar list of past winners,” said Kulkarni. “I would like to thank my long-term collaborators and the engineering crew and members of the Palomar Transient Factory and the Zwicky Transient Facility for their immense contribution to the projects,” he said.

The scientist described this discovery of the first millisecond pulsar as “the most fun achievement in my life”, adding, “I was a graduate student when I made the discovery. I could not sleep for several days!”

Kulkarni, who also won the 2024 Shaw Prize in Astronomy recently, joined Caltech in 1985 and has since made many landmark findings, including demonstrating in 1997 that powerful gamma-ray bursts originate outside our galaxy.

He went on to lead the development of the Palomar Transient Factory (PTF) and its successor, the Zwicky Transient Facility (ZTF), which have caught thousands of real-time cosmic events as they blink, explode, and otherwise light up the skies. ZTF, based at Caltech’s Palomar Observatory near San Diego, is still going strong and surveying the entire Northern sky every two nights.

His RAS award citation notes that these “have revolutionised time domain astrophysics at optical wavelengths”.

In his 2024 Watson Lecture at Caltech titled ‘Illuminating the Dynamic Night Sky: Discoveries from the Zwicky Transient Facility’, Kulkarni discussed his passion for building instruments to explore uncharted areas in astronomy. He has built a total of 10 instruments in his career. “My motto has been to build a big enough gizmo and things will happen,” he said at the time.

Currently, Kulkarni is involved with developing NASA’s Ultraviolet Explorer (UVEX) mission, led by Fiona Harrison, the Harold A. Rosen Professor of Physics at Caltech. The mission, targeted to launch in 2030, will perform the most sensitive sky survey in ultraviolet light to date.

He is the principal investigator of Z-Shooter, a very powerful and versatile spectrometer for the W M Keck Observatory in Hawai’i that is under development with a first light expected in 2029.

Kulkarni received his Master’s from the Indian Institute of Technology Delhi in 1978, his PhD from UC Berkeley in 1983 and has been based at Caltech for over 40 years.

Each year the RAS recognises significant achievement in the fields of astronomy and geophysics through a number of awards, medals and prizes, encompassing different types of talent from research to education and outreach.

This year’s Gold Medal in Geophysics has been won by Professor Andrew Jackson of ETH Zurich for his instrumental work in the field of geomagnetism.