3d) Explain the difference between rigid body rotation and Keplerian motion. What is
galactic longitude?
3c) The mass and radius of a neutron star is 2M and 15 km, respectively. Calculate the
value of gravitational red shift for light of wavelength 6000 Å at a distance of 2 m
from its surface
3b) What is planetary nebula? Explain the concept of Chandrasekhar limit.
3. a) Explain the concept of degeneracy pressure. What role does it play in the evolution
of a star after its death?
2e) What are the characteristic features of the H II region of ISM? How is it different
from the molecular cloud?
2d) What is solar nebula? Explain the formation of nebular disk.
2c) What are the main differences between the terrestrial and jovian planets? How does
the ring system of jovian planets persist for so long?
2b) Explain helioseismology. How does it help in understanding the internal structure
of the Sun?
2. a) What is the nature of radiation generated in the Sun’s interior? How does it differ
from the radiation we receive from the Sun? What causes granulation of the
photosphere?
1e) The average density of a white dwarf of radius 109
cm is 106
gm/cm3
. Is general
theory of relativity needed to study the dynamics of this star? What happens if the
star shrinks to a radius thousand times smaller?