Subrahmanyan Chandrasekhar was an Indian-American astrophysicist who won the 1983 Nobel Prize in Physics for his work on stellar structure and evolution. His most notable work calculated the maximum mass of a white dwarf star, known as the Chandrasekhar limit, which he determined to be approximately 1.44 solar masses. This limit describes the threshold above which a star will collapse into a neutron star or black hole rather than remaining a white dwarf. Chandrasekhar made this seminal calculation in 1930 and contributed significantly to the understanding of stellar evolution and late stage massive stars.

2. Sl. No Topic Page no
1 Pertaining to the scientist 1
2 Chandrasekhar’s works 2
3 Chandrasekhar’s most notable work 3
4 Chandrasekhar’s Legacy 4
5 List of notable awards 5
6 The Chandrasekhar Limit 6
7 According to the limit 7

3. Sl. No Topic Page no
8 Limit according to Physics 8
9 Calculated values for the limit 9
10 Limit value calculation formula 10
11 Application of limit 12
12 Super Chandrasekhar mass supernovae 14
13 Tolman-Oppenheimer-Volkoff limit 15
14 Conclusions 16
15 Bibliography 17

4. 1910 –1995
Indian-
American astrophysici
st
Nobel Prize Winner

5. Subrahmanyan Chandrasekhar (October 19, 1910 –
August 21, 1995) was an Indian-
American astrophysicist who, with William A. Fowler,
was awarded the 1983 Nobel Prize for Physics for his
mathematical theory of black holes, which was a key
discovery that led to the currently accepted theory on
the later evolutionary stages of massive stars.
Chandrasekhar was the nephew of Sir Chandrasekhara
Venkata Raman, who was awarded the Nobel Prize for
Physics in 1930.

6. Chandrasekhar worked in various areas, including
stellar structure, theory of white dwarfs, stellar
dynamics, theory of radiative transfer, quantum
theory of the negative ion of Hydrogen,
hydrodynamic and hydro magnetic stability,
equilibrium and the stability of ellipsoidal figures
of equilibrium, general relativity, mathematical
theory of black holes and theory of colliding
gravitational waves.

7. Chandrasekhar's most notable work was
the astrophysical Chandrasekhar limit. The limit
describes the maximum mass of a white dwarf star,
~1.44 solar masses, or equivalently, the minimum
mass which must be exceeded for a star to ultimately
collapse into a neutron star or black hole . The limit
was first calculated by Chandrasekhar in 1930 during
his maiden voyage from India to Cambridge,
England for his graduate studies.

8.  In 1999, NASA named the third of its four "Great
Observatories" after Chandrasekhar. The Chandra X-ray
Observatory was launched and deployed by Space
Shuttle Columbia on July 23, 1999. The Chandrasekhar
number, an important dimensionless number of magneto
hydrodynamics, is named after him. The asteroid 1958
Chandra is also named after Chandrasekhar. American
astronomer Carl Sagan, who studied Mathematics under
Chandrasekhar, at the University of Chicago, praised him
in the book The Demon-Haunted World: "I discovered what
true mathematical elegance is from Subrahmanyan

9. Award Year
Fellow of the Royal
Society
1944
Henry Norris Russell
Lectureship
1949
Bruce Medal 1952
Gold Medal of the Royal
Astronomical Society
1953
Rumford Prize of
the American Academy
of Arts and Sciences
1957
National Medal of
Science, USA
1966
Award Year
Padma Vibhushan 1968
Henry Draper Medal of
the National Academy of
Sciences
1971
Nobel Prize in Physics 1983
Copley Medal of the Royal
Society
1984
Honorary Fellow of
the International Academy of
Science
1988
Gordon J. Laing Award 1989

10. The Chandrasekhar limit is the maximum mass of
a stable white dwarf star. The limit was first published
by Wilhelm Anderson and E. C. Stoner, and was named
after Subrahmanyan Chandrasekhar, the Indian-
American astrophysicist who improved upon the accuracy
of the calculation in 1930, at the age of 19. This limit was
initially ignored by the community of scientists because
such a limit would logically require the existence of black
holes, which were considered a scientific impossibility at
the time. The currently accepted value of the limit is about
1.39M ( 2.765 × 1030 kg).

11. White dwarfs, unlike main sequence stars,
resist gravitational collapse primarily through electron
degeneracy pressure, rather than thermal pressure. The
Chandrasekhar limit is the mass above which electron
degeneracy pressure in the star's core is insufficient to
balance the star's own gravitational self-attraction.
Consequently, white dwarfs with masses greater than the
limit undergo further gravitational collapse, evolving into
a different type of stellar remnant, such as a neutron
star or black hole. Those with masses under the limit
remain stable as white dwarfs

12. Electron degeneracy pressure is a quantum-mechanical effect
arising from the Pauli exclusion principle.
Since electrons are fermions, no two electrons can be in the same
state, so not all electrons can be in the minimum-energy level.
Rather, electrons must occupy a band of energy levels.
Compression of the electron gas increases the number of
electrons in a given volume and raises the maximum energy
level in the occupied band. Therefore, the energy of the electrons
will increase upon compression, so pressure must be exerted on
the electron gas to compress it, producing electron degeneracy
pressure. With sufficient compression, electrons are forced into
nuclei in the process of electron capture, relieving the pressure.

13. Calculated values for the limit will vary
depending on the nuclear composition of
the mass.
Chandrasekhar gives the limit’s
expression, based on the equation of
state for an ideal Fermi gas.

15. where;
w is the reduced Planck constant
c is the speed of light
G is the gravitational constant
e is the average molecular weight per electron, which
depends upon the chemical composition of the star.
mH is the mass of the hydrogen atom.
 2.018236is a constant connected with the solution to
the Lane-Emden equation.

16. The core of a star is kept from collapsing by the heat
generated by the fusion of nuclei of
lighter elements into heavier ones. At various stages
of stellar evolution, the nuclei required for this process
will be exhausted, and the core will collapse, causing it
to become denser and hotter. A critical situation arises
when iron accumulates in the core, since iron nuclei are
incapable of generating further energy through fusion.
If the core becomes sufficiently dense, electron
degeneracy pressure will play a significant part in
stabilizing it against gravitational collapse.

17. If a main-sequence star is not too massive less than approximately
8 solar masses, it will eventually shed enough mass to form a white
dwarf having mass below the Chandrasekhar limit, which will
consist of the former core of the star. For more massive stars,
electron degeneracy pressure will not keep the iron core from
collapsing to very great density, leading to formation of a neutron
star, black hole, or, speculatively, a quark star. During the
collapse, neutrons are formed by the capture
of electrons by protons in the process of electron capture, leading to
the emission of neutrinos. The decrease in gravitational potential
energy of the collapsing core releases a large amount of energy
which is on the order of 1046 joules (100 foes). Most of this energy is
carried away by the emitted neutrinos. This process is believed to be
responsible for supernovae of types Ib, Ic, and II.

18. In April 2003, the Supernova Legacy Survey observed a type Ia
supernova, designated SNLS-03D3bb, in a galaxy approximately 4
billion light years away. According to a group of astronomers at
the University of Toronto and elsewhere, the observations of this
supernova are best explained by assuming that it arose from a white
dwarf which grew to twice the mass of the Sun before exploding.
They believe that the star, dubbed the "Champagne Supernova" by
University of Oklahoma astronomer David R. Branch, may have been
spinning so fast that centrifugal force allowed it to exceed the limit.
Alternatively, the supernova may have resulted from the merger of
two white dwarfs, so that the limit was only violated momentarily.
Nevertheless, they point out that this observation poses a challenge to
the use of type Ia supernovae as standard candles.

19. After a supernova explosion, a neutron star may be left
behind. Like white dwarfs these objects are extremely
compact and are supported by degeneracy pressure, but a
neutron star is so massive and compressed that electrons
and protons have combined to form neutrons, and the
star is thus supported by neutron degeneracy pressure
instead of electron degeneracy pressure. The limit of
neutron degeneracy pressure, analogous to the
Chandrasekhar limit, is known as the Tolman–
Oppenheimer–Volkoff limit.

20. Subrahmanyan Chandrasekhar was an Indian-American
astrophysicist, best known for his work on the theoretical structure
and evolution of stars, and particularly on the later evolutionary
stages of massive stars and the calculation of the Chandrasekhar
limit. He won the Nobel Prize in Physics shared with William Fowler
in 1983 largely for this early work, although his research also
covered many other areas within theoretical physics and
astrophysics. he calculated the maximum non-rotating mass which
can be supported against gravitational collapse
by electron degeneracy pressure. This limit describes the
maximum mass of a white dwarf star, or, alternatively, the minimum
mass above which a star will ultimately collapse into a neutron
star or a black hole, following a supernova event, rather than
remaining as a white dwarf. His calculations revealed that this was

21. scienceworld.wolfram.com
en.wikipedia.org
www.physicsoftheuniverse.c
om
farside.ph.utexas.edu