Chandra - the man after whom the telescope celebrating a decade of its activity in space is named

These days the symposium "A Decade of Discoveries for the Chandra Space Telescope" is taking place and this is a wonderful opportunity to praise the man after whom one of the four largest telescopes launched by NASA into space is named.

These days the symposium "A Decade of Discoveries for the Chandra Space Telescope" is taking place and this is a wonderful opportunity to praise the man after whom one of the four largest telescopes launched by NASA into space is named.

The Indian-American inventor Subrahmanyan Chandraskar, or as his colleagues called him, Chandra, was an impressive and gifted astrophysicist and mathematician.

Science is still divided on whether genius is a product of genetics or whether the environment also influences and takes part in the creation of genius, but in Chandraskar's case, it seems to be both heredity and a supportive environment.

He was born into a wealthy and educated Indian family that included ten children. His uncle Raman was the famous physicist who won the Nobel Prize in 1930 after whom the Raman effect (or Raman scattering) is called.

Until the age of 12 he studied with a private teacher, and at the age of 15 he began his studies at the University of Madras in India.

Around this age, Chandraskar discovered the book "The Internal Structure of Stars" by Sir Arthur Eddington and was deeply impressed by it. Since then he has been greatly influenced by the work and ideas of Eddington, who later became his lecturer during his doctoral studies in the 30s and even after the crisis point between the two, which we will talk about later.

The old-fashioned university curriculum did not include modern physics, and Chandraskar learned quantum theory on his own, which was then a new theory in the making, from reading scientific papers and journals in the Madras University library.

In 1930, Chandraskar won a scholarship from the Indian government and began his doctoral studies at the University of Cambridge. In the third year of his studies, and when he was only 23 years old, he moved to the Institute of Theoretical Physics in Copenhagen, which at that time was under the management of Nils Bohr. Among his instructors was Eddington, whose story as mentioned was what motivated Chandraskar to engage in astrophysics.

Eddington claimed in his book that all stars end their lives as white dwarfs - very compact bodies whose mass is roughly the mass of our sun, but one teaspoon of white dwarf material would weigh about 6 tons.

Chandraskar's research eventually led him to the surprising conclusion that not all stars end their lives as white dwarfs as Eddington claimed. When stars that are only 1.4 times more massive than our Sun use up their nuclear fuel, gravity overcomes the process of repulsion between electrons, causing the star to collapse to a density greater than that of a white dwarf.

The stars that Chandraskar predicted would be stars made mostly of neutrons after the collapse process causes the electrons and protons to become neutrons. The diameter of a neutron star is only a few tens of kilometers and its mass is of the order of tens of millions of tons per cubic meter.

But there are stars that surpass white dwarfs and neutron stars in their density, these stars, he said, will collapse without limit...

In 1935 he lectured on his new theory before the Royal Astronomical Society of Great Britain. At the end of the lecture Eddington stood up and mocked him, he claimed that "this theory is wrong and ridiculous, and really an example of something absurd".

Chandraskar was deeply hurt by Eddington's disparaging criticism, which had been a source of admiration for him since childhood, and this may have influenced his decision a year later to leave England and Cambridge and move to the University of Chicago, where he remained until the end of his life.

According to him, "There was no point in fighting all the time, and making claims that I am right and everyone else is wrong. I preferred to write a book. I will present my views, and then I will leave the field."

And that's exactly what he did, not only in this specific issue, but that's how his whole life went. He devoted several years to one subject, then would move on to other matters. After the publication of his book "Introduction to the Investigation of the Structure of the Stars" he began investigating the dynamics of stars and from there he moved on to the study of stellar atmospheres and so on. In the 60s he came to applied research of general relativity in astrophysics, and finally in the 70s and 80s to a mathematical theory of black holes.

Neutron stars, by the way, were only proven in 1967 by a group of British astronomers who discovered for the first time a pulsar - a neutron star that rotates on its axis at an enormous speed and therefore emits electromagnetic radiation at a periodic frequency, hence its name, pulsar, pulsating.

Chandraskar won many awards and distinctions in his life, among them: the Nobel Prize in 1983 for the Chandraskar limit, the maximum mass that a white dwarf can have, the Henry Norris Fellowship in 49, the Bruce Medal in 52, the Gold Medal of the Royal Astronomical Society in 53 , the Henry Draper Medal in '71 and the Copley Medal in '84.

He worked at the University of Chicago and the Yerkes Observatory until the day of his death and also became the editor of the important "Astrophysical Journal" in 1953.

And as for Eddington, the person thanks to whom he discovered and was attracted to the world of astrophysics and finally because of him he left England and the world of spotlights in Cambridge, Chandraskar published a memoir that presents Eddington in a loving light and even said of him that he was "the most excellent astrophysicist of his time".

In 1999, on the 4th anniversary of Chandraskar's death, NASA decided to name its third X-ray space telescope, launched on the space shuttle Columbia, after him, Chandra.

Chandra in Hinduism is the moon god, he comes out at night riding the white light to heal and illuminate, and he mediates between the gods and life on earth. Likewise, the Chandra Space Telescope, the first X-ray telescope in space, is an intermediary between us and the distant celestial objects. Its sensitive X-ray eyes enable the most precise spectroscopic measurement and help us decipher the nature of distant events.

The Chandra Space Telescope's observations have led to insights into many topics such as black holes at the centers of galaxies, including the Milky Way Galaxy, interactions in nova and supernova explosions, galaxy collisions, the background radiation, brown dwarfs, comets, stellar winds and interstellar matter.

For (partial) information on the NASA website

Sources:

• "Devir Lexicon of Astronomy and Astrophysics" by John Gribbin
• "Scientists who changed the world" by Felix Dotan
• Wikipedia