Obituary: R. Chidambaram, Eminent Physicist and Architect of India’s Nuclear Program
Rajagopala Chidambaram (1936–2025), a man whose work shaped the future of modern India, will always be remembered as the chief architect of India’s nuclear journey.
Rajagopala Chidambaram, a world-class physicist and the chief architect of India’s nuclear program, passed away on January 4, 2025, at the age of 88. Renowned for his unparalleled contributions to India’s nuclear defense and energy security, Chidambaram leaves a profound legacy in both the scientific community and the nation’s strategic defense apparatus.
Born on November 11, 1936, in India, Dr. Chidambaram was an alumnus of Presidency College, Chennai, Tamil Nadu, and the Indian Institute of Science, Bengaluru, Karnataka. His academic background, coupled with his innate curiosity and vision, led him to become one of India’s foremost scientific minds. Throughout his illustrious career, Dr. Chidambaram played an instrumental role in shaping India’s nuclear capabilities, overseeing both the Pokhran-I (1974) and Pokhran-II (1998) nuclear tests, which cemented India’s position as a nuclear power on the world stage.
As a physicist, Dr. Chidambaram’s groundbreaking research in high-pressure physics, crystallography, and materials science greatly advanced the understanding of these fields. His pioneering work laid the foundation for modern materials science research in India, contributing to the nation’s scientific progress in multiple areas. His expertise in these complex disciplines not only bolstered India’s nuclear research but also advanced its technological prowess.
In addition to his work in nuclear weapons development, Dr. Chidambaram made significant strides in nuclear energy, ensuring that India remained at the forefront of scientific and technological advancements. As Director of the Bhabha Atomic Research Centre (BARC) and later as Chairman of the Atomic Energy Commission of India, he was integral to India’s peaceful nuclear energy initiatives. As Principal Scientific Adviser to the Government of India, Dr. Chidambaram guided national policies on defense, energy, and nuclear research, shaping the future of India’s scientific endeavors.
He was a vital member of the team that conducted India’s first nuclear test, Smiling Buddha, at Pokhran in 1974. His leadership during the Pokhran-II tests in 1998, which confirmed India’s nuclear deterrent, was a defining moment in the nation’s history. Chidambaram’s steadfast commitment to India’s defense and scientific advancement earned him respect both at home and abroad.
Rajagopala Chidambaram captured during the session ‘Innovative India’ at the Annual Meeting 2008 of the World Economic Forum in Davos, Switzerland. Copyright by World Economic Forum/Photo by Monika Flueckiger
A visionary leader, Dr. Chidambaram believed in the power of science and technology to drive national development. His efforts were instrumental in championing key initiatives in energy, healthcare, and strategic self-reliance. He steered numerous projects that significantly advanced India’s science and technology landscape. Notably, he played a central role in the indigenous development of supercomputers and was the driving force behind the conceptualization of the National Knowledge Network, which connected research and educational institutions across India.
Dr. Chidambaram was also an ardent advocate for the application of science and technology to improve societal conditions. He established the Rural Technology Action Groups and the Society for Electronic Transactions and Security, among other programs. His emphasis on “Coherent Synergy” in India’s scientific efforts helped foster collaboration across various disciplines, accelerating the country’s scientific growth.
On the global stage, Dr. Chidambaram served as the Chairman of the Board of Governors of the International Atomic Energy Agency (IAEA) in 1994-1995 and contributed to several high-level international nuclear discussions. His expertise was sought worldwide, and in 2008, he was appointed to the Commission of Eminent Persons by the IAEA to assess the agency’s role in nuclear governance.
He was a vital member of the team that conducted India’s first nuclear test, Smiling Buddha, at Pokhran in 1974
In recognition of his exceptional contributions to science and national development, Dr. Chidambaram received several prestigious accolades, including the Padma Shri in 1975 and the Padma Vibhushan in 1999. He was also awarded honorary doctorates from several universities and was a fellow of several eminent Indian and international scientific academies.
Dr. Chidambaram’s passing marks the end of an era for India’s nuclear program and the global scientific community. His legacy as a scientist, visionary leader, and architect of India’s nuclear journey will continue to inspire future generations. His contributions to national security, energy, and technological innovation have left an indelible mark on India’s scientific and strategic landscape.
Rajagopala Chidambaram’s profound impact on India’s nuclear and scientific trajectory will be remembered for generations to come. His work in advancing both national defense and the peaceful use of nuclear energy stands as a testament to his vision of a self-reliant, scientifically empowered India.
“Deeply saddened by the demise of Dr Rajagopala Chidambaram. He was one of the key architects of India’s nuclear programme and made ground-breaking contributions in strengthening India’s scientific and strategic capabilities. He will be remembered with gratitude by the whole nation and his efforts will inspire generations to come,” Prime Minister Narendra Modi wrote on X.
Dr. Ajit Kumar Mohanty, Secretary, Department of Atomic Energy, in a statement issued, said, “Dr. Chidambaram was a doyen of science and technology whose contributions furthered India’s nuclear prowess and strategic self-reliance. His loss is an irreparable one for the scientific community and the nation.”
EP Staff is the editorial team at EdPublica, an independent media organisation focused on science, education, environment and public policy. The team produces evidence-based news, features, explainers and analysis on issues that shape society and everyday life.
The accretion of material from an evaporating second-generation giant planet accreting on a white dwarf star | Credit: Snehalata Sahu
A planet orbiting once every 4 days around a white dwarf star HS 0209+0832 – about 270 light years in the direction of the constellation Pisces – is steadily losing its atmosphere to its host star. While many stars in solar systems beyond our own often feed on their planets, this particular star feeds on its own ashes.
The gaseous planet HS 0209+0832 b was discovered in 2024, when the Transiting Exoplanet Survey Satellite, a NASA space telescope, found it orbiting the white dwarf star over the course of four days. The new study followed through with detailed observations from TESS data, NASA’s space-based Far Ultraviolet Spectroscopic Explorer, in addition to the ESO’s mountain-based Very Large Telescope, to study the star’s atmosphere and in turn inferring some chemistry occurring in the planet.
In a study published in the journal Nature Astronomy on Monday and funded by NASA, European Research Council, Fundación Occident and the Instituto de Astrofísica de Canarias, an international team of astronomers have reported imprints of niobium, a heavy element, in the atmosphere of a white dwarf star.
Astronomers predict the transiting young planet around the dead star is supplying that niobium back to its host. The sighting is evidence of a “second generation” planet, one of many candidates identified over several years, manifesting in a myriad different ways from spent gas ejected in the wake of stellar deaths.
It adds to a known coterie of planets now found orbiting dead stars, astronomers are busy studying to spot signs of life.
What are white dwarf stars?
White dwarves are an exotic stars, and are all that’s left off giant stars shedding their large gaseous skin in violent deaths. Our sun is destined one day to transform into a white dwarf, but only after swelling in size some five billion years from now to become a red giant when it will eclipse past the earth’s orbit. It would take several million years after that for the red giant sun to shed its gaseous exterior to become a white dwarf.
Planets if any, found orbiting these dead stars may have likely migrated from the new solar system’s outer reaches. All that’s left off the progenitor star’s past are imprints of light metals and other elements on the white dwarf’s atmosphere. Such planets have previously been spotted orbiting pulsars, a kind of neutron star, back in 1992. In fact, its discovery had marked the first ever detection of any planet orbiting a star beyond our sun.
Elements such as niobium don’t typically form in the core of stars like our sun. Chemical production usually limits to elements lighter than or until iron, with its 26 protons and 30 neutrons. Beyond that, slamming an extra proton or neutron will cause those to split, leaving iron to be the last element to be directly forged.
Niobium, with 41 protons and 52 neutrons, is thought to be born after absorbing slow passing neutrons when the red giant star dies to form a white dwarf star. This niobium hitches a ride along with rest of the contents of the red giant star, farther into the outer reaches of the system after the formation of the white dwarf.
These contents could create a new disc of circumstellar material with dust and gas that could condense one day to form new planets. The “second generation” planet found orbiting the white dwarf star from the new study, could have been born this way.
Alternatively, it may have been a planet in the outskirts like Neptune, migrating inwards, and enriching itself with niobium-rich star material.
Either way, the planet got too close to its host star, which is irradiating its newfound niobium-rich atmosphere, stripping it away and devouring it.
While it’s likely not a candidate planet for life as we know it to be found, it’s discovery can help ascertain how such worlds are formed in the aftermath of a star’s various phases of evolution.
Representational image of astronauts collecting lunar samples as international missions prepare for a new era of Moon exploration. Image credit: NASA
The Artemis Accords now have 76 signatories, expanding the international framework around the next phase of lunar exploration. For India, the milestone comes weeks after NASA invited the Indian Space Research Organisation (ISRO) to participate in its planned Moon Base programme.
Albania, Croatia, Côte d’Ivoire and San Marino joined the Accords in September, taking participation to 76 countries. NASA says nearly 40% of the world’s nations are now part of the framework, which sets principles for peaceful, transparent and responsible exploration of the Moon, Mars and beyond.
India became the 27th signatory in June 2023. At the India-US Civil Space Joint Working Group meeting in Bengaluru in August, NASA invited ISRO to participate in its Moon Base programme. The two countries also agreed to advance discussions on open scientific-data sharing under the Accords.
India is among the 76 countries that have signed the Artemis Accords, a framework for peaceful and responsible exploration of the Moon and beyond. Source: NASA
India’s Moon Base opportunity
The invitation does not specify what India will contribute. NASA has said every Artemis Accords signatory can participate through scientific payloads, technology demonstrations, CubeSats and other capabilities. Any specific Indian contribution would require further agreements.
India, however, is developing its own increasingly ambitious lunar programme. ISRO’s Chandrayaan-4 is planned as a lunar sample-return mission, designed to collect samples from the Moon’s polar region and bring them back to Earth. Chandrayaan-5/LUPEX, being developed with Japan’s JAXA, will study lunar polar volatiles in situ.
These missions could give India experience and scientific capabilities relevant to a future international lunar infrastructure.
ISRO Shaping the Data Conversation
Scientific data could be another area of Indian participation. In May 2026, ISRO led an initial Artemis Accords discussion on advancing open-data practices. NASA subsequently held two workshops focused on making lunar scientific data more accessible, interoperable and reproducible across countries.
That is significant as more lunar missions target the same regions. Shared standards could allow researchers to combine observations from different spacecraft instead of treating each mission’s data separately.
Moon – Space Coperation
India-US space cooperation is also expanding into human spaceflight. ISRO’s 2025–26 annual report records that Indian astronaut Shubhanshu Shukla travelled to the International Space Station in June 2025 as part of the Axiom-4 mission and conducted seven microgravity experiments. ISRO also held discussions with NASA on potential cooperation related to Gaganyaan.
The Artemis relationship therefore sits alongside an existing programme of India-US cooperation, including the NASA-ISRO Synthetic Aperture Radar (NISAR) mission.
What Changes for India?
The significance of the 76-country milestone lies in the network developing around it. The Artemis Accords cover scientific-data sharing, interoperability, non-interference between missions, emergency assistance and protection of historically significant lunar sites. NASA says signatories are now working through technical meetings and workshops to put these principles into practice.
For India, that creates several possible avenues: contributing technology or science to NASA’s Moon Base effort, sharing lunar data, and working with a growing group of countries on standards for increasingly crowded lunar operations. What India’s specific contribution to the Moon Base remains undecided. But with Chandrayaan-4, LUPEX and its human-spaceflight programme advancing alongside deeper NASA cooperation, India is entering the next phase of lunar exploration with its own capabilities already taking shape.
A dense field of stars, gas and dust surrounds the centre of the Milky Way in this infrared view from the James Webb Space Telescope. The region includes the environment around Sagittarius A* and nearby stars such as IRS 3. Image credit: ESA/Webb, NASA & CSA, F. Peißker, J. Lu, F. Yusef-Zadeh, N. B. Sabha, C. Chan
A dying star nearing the end of its life is shedding material into space just 0.55 light-years from the Milky Way’s central black hole. And somehow, some of that material is holding on. New observations from the James Webb Space Telescope have revealed water and oxygen-rich dust surrounding IRS 3, an evolved star living remarkably close to Sagittarius A*, the supermassive black hole at the heart of our galaxy.
The finding gives astronomers a rare view of what happens when an ordinary stage of stellar evolution unfolds in an anything-but-ordinary neighbourhood.
A Dying Star Beside a Black Hole
IRS 3 is an asymptotic giant branch (AGB) star, a late stage in the life of stars like this one. As such stars age, they swell, cool and lose material through powerful stellar winds. IRS 3 is doing exactly that. Gas and dust are streaming away from the star, creating a large envelope around it.
The star sits only about 0.55 light-years from Sagittarius A*. That may sound distant, but on the scale of the Galactic Centre it is remarkably close. Earth is about 26,000 light-years away from the same black hole.
A series of observations zooms from the Milky Way’s central region to IRS 3, the dying star located about 0.55 light-years from Sagittarius A*. The JWST infrared view reveals the crowded environment around the star and the Milky Way’s central black hole. Image credit: ESA/Webb, NASA & CSA, F. Peißker, J. Lu, F. Yusef-Zadeh, N. B. Sabha, C. Chan
Around Sagittarius A* is a crowded, energetic environment filled with intense radiation, dense gas and powerful gravitational forces. Astronomers have long wondered how stars manage to evolve and shed material there. IRS 3 is offering an answer.
Webb Finds Water in the Stellar Outflow
NASA‘s James Webb Space Telescope looked at IRS 3 using its Mid-Infrared Instrument, or MIRI. Infrared observations are particularly useful here because the dust surrounding the star glows strongly at these wavelengths.
The observations revealed oxygen-rich dust in the star’s envelope. They also produced the first detection of water in this material. This does not mean Webb found a pool, cloud or droplets of water. The water exists as molecules mixed into the hot gas and dust surrounding the star.
That distinction matters because molecules can be vulnerable in the harsh environment around the Galactic Centre. Radiation can break them apart, while the conditions around a supermassive black hole can affect the material being expelled by nearby stars. Yet water molecules are present around IRS 3.
The Star is Feeding Its Surroundings
IRS 3 is losing material rapidly as it approaches the end of its life. Researchers estimate that the star is shedding roughly the mass of Earth every 18 days. That enormous outflow is important beyond IRS 3 itself.
When evolved stars lose their outer layers, they return material to the space between stars. The gas carries elements produced during the star’s lifetime, while newly formed dust becomes part of the reservoir from which future cosmic structures can emerge. IRS 3 is therefore caught in a familiar cycle of stellar life: a star is dying, but the material it releases can become part of something else.
What makes this case unusual is that the recycling process is happening almost next door to a supermassive black hole.
How Much Can Survive Here?
The observation does not mean that the black hole has little influence on its surroundings. Sagittarius A* still creates an extreme environment, and the researchers are interested precisely because IRS 3 shows that stellar material can persist within it.
“Galactic centres are among the most extreme environments,” said Florian Peißker of the University of Cologne, the study’s lead author to media. With Webb, researchers can now examine the material around stars such as IRS 3 in much greater detail and ask how stellar winds, dust formation and molecular chemistry behave so close to a black hole. The answer emerging from IRS 3 is intriguing: the environment may be extreme, but it does not necessarily shut down the chemistry of a dying star.
For IRS 3, the end of its stellar life is already underway. Its outer layers are drifting away into the Galactic Centre, carrying dust, molecules and the chemical ingredients of future cosmic systems with them. Even in the shadow of the Milky Way’s central black hole, a dying star is still leaving something behind.