S.Chandrasekhar is credited for his work on white dwarfs and evolution of stars
Words by: Hazel Austin Image Source: thesun.co.uk
Subrahmanyan Chandrasekhar, was an Indian astrophysicist who was awarded the 1983 Nobel Prize for Physics with William A. Fowler “for his theoretical studies of the physical processes of importance to the structure and evolution of the stars.”
Today, 19th October, would have been Subrahmanyan Chandrasekhar’s 107th birthday and is the reason behind the day’s Doodle by Google.
Early years
Born to a Tamil family in Lahore, this child prodigy was home-schooled till the age of 12. He completed his graduation from the Presidency College in Madras and pursued his higher studies at the University of Cambridge on being awarded a scholarship by the government.
Coming from an illustrious family of intellectuals, Chandrasekhar’s uncle Sir CV Raman won the Nobel Prize in Physics in 1930. The astrophysicist himself was known for his theory on white dwarfs.
In layman terms, a white dwarf can be described as what stars like our Sun become after they have exhausted their nuclear fuel. Towards the end of its nuclear burning stage, these stars expel most of its outer material thereby creating a planetary nebula. Eventually, only the hot core of the star remains. This core becomes a very hot white dwarf, with temperatures exceeding 100,000 Kelvin. Unless it is able accrete matter from a nearby star, these white dwarfs cool down over the next billion years or so.
Chandrasekhar’s recognition comes from his contribution to the field of science, mainly on his discovery of the ‘The Chandrasekhar Limit’ – which explained the maximum mass a stable white dwarf star can have. With his theory, Chandrasekhar explained that the mass of a white dwarf could not exceed 1.44 times that of the Sun.
Size wise a typical white dwarf is half as massive as the Sun, yet interestingly, only slightly bigger than the Earth. Because a white dwarf is not able to create internal pressure, gravity compacts the matter inward until even the electrons that compose a white dwarf’s atoms are compressed together. Due to its nature a white dwarf is also one of the densest collections of matter, surpassed only by neutron stars.
Delayed Recognition
It was during his stint as a researcher at Cambridge that he made his breakthrough discovery, which was later on christened the Chandrasekhar Limit. But during the initial period, his colleagues sceptical of his discovery sought to discredit it. It was almost three decades later in 1966 that scientific research with computers and the hydrogen bomb gave credit to Chandrasekhar’s calculations.
Chandrasekhar was 43 when he was awarded the Gold Medal of the Royal Astronomical Society. By the age of 56, he was honoured with the National Medal of Science for his numerous contributions to stellar astronomy, physics and applied mathematics. And it was in the year 1983, at 73 years of age that Chandrasekhar received his Nobel Prize which he shared with William Fowler.