THE US astrophysicist John Bahcall was best known for his research into what makes the Sun shine.

In 1964, after investigating sound waves in the Sun, he worked, with the astrophysicist Ray Davis, on solar neutrinos. These mysterious and barely detectable particles carry no electric charge, have no mass and travel at the speed of light. The Nobel prize-winning physicist Richard Feynman said of the neutrino: “All you have to do is imagine something that does practically nothing except exist. You can use your son-in-law for a prototype.”

Bahcall and Davis suggested that the Sun’s properties could be studied — on the analogy of the X-ray revealing the inner structure of a body — by observing neutrinos produced inside the Sun as hydrogen is converted into helium by nuclear fusion. Most neutrinos arriving from the Sun pass right through the Earth.

In 1968 Davis placed a very large tank filled with cleaning fluid deep underground in a goldmine in South Dakota, to detect these passing particles. In 1987 a flux of neutrinos from a supernova was detected, and Bahcall and Davis were able to show that the Sun shines because of the fusion reactions within it.

In 2002 Davis shared the Nobel Prize for Physics with Masatoshi Koshiba for their work on the neutrino — a prize that many colleagues thought Bahcall should have shared, though he later showed no disappointment or resentment about this.

Bahcall’s other great contribution to science was his work on the Hubble Space Telescope. In the 1970s he and the astronomer Lyman Spitzer led the effort to develop the Hubble Telescope that became a joint European Space Agency/Nasa project.

The Hubble observatory was deployed in space in 1990 by the Space Shuttle Discovery into a circular orbit 600km (370 miles) above the Earth. Carrying instruments that allow high-resolution photography free of atmospheric distortion, it takes about 96 minutes to complete one orbit. It can record the optical spectrum from infra-red, through the visible, to ultraviolet. It can therefore access the ultraviolet part of spectrum and areas of the infra-red which are invisible from the ground. Hubble has come to be seen as one of the most important scientific projects ever undertaken.

John Norris Bahcall was born in Shreveport, Louisiana. He spent a year at Louisiana State University studying philosophy, and considered becoming a rabbi but after a year he moved to the University of California, Berkeley, graduating in 1956 with a degree in physics. He took a masters degree at the University of Chicago in 1957 and a PhD in physics at Harvard in 1961.

From 1960 to 1962 he was a research fellow in physics at Indiana University and then joined the California Institute of Technology where he worked until 1970, becoming an associate professor of physics. In 1971 he was appointed professor of natural sciences at the Institute of Advanced Study, Princeton University, a post he held until 1997. He then became the Richard Black Professor of Natural Sciences at Princeton.

He published more than 500 scientific papers and five books, including Neutrino Astrophysics (1989), Unsolved Problems in Astrophysics (1997), and The Decade of Discovery in Astronomy and Astrophysics (1991). He received numerous awards and honours. In 1992 he received Nasa’s Distinguished Public Service Medal for his work on the development of the Hubble telescope and the USNational Medal of Science. He received honorary doctorates from the Universities of Pennsylvania, Chicago, Notre Dame, Ohio State, Hebrew University (Jerusalem) and Milan.

His wife, two sons and a daughter survive him.

Professor John Bahcall, astronomer and astrophysicist, was born on December 10, 1934. He died on August 17, 2005, aged 70.