Question

The star nearest to the sun is:
A. Sirius
B. Proxima centauri
C. Alpha centauri
D. Cygni

Answer 1

Hint: A star is a self-glowing body which is having a heavy mass and it is glowing because of its own internal self-energy. Only a few stars are visible to the naked eye and the universe has a billion or trillion of stars.

 Complete step by step answer:

Sirius is one of the most glowing stars in the dawn sky. It is actually a binary form of star and its glowing intensity is twenty-five times more than that of the sun. It is nearer to our solar system. The mass of Sirius is twice times more than that of the central star sun.
Proxima centauri is the most nearest star to the sun situated at 4.45 light years far from the sun. It is basically a type of red-dwarf star and the mass of proxima centauri is eight times heavier than that of the mass of the sun. But its brightness is far less than that of the brightness of the sun.
The distance between alpha centauri and sun is 4.34 light years and hence it is not too close to the sun compared to proxima centauri.
The distance between cygni and sun is 11 light years and hence it is not too close compared to the sun and proxima centauri.
Therefore, the nearest star to the sun is Proxima centauri and the option (B) is correct.

Note:
There are a lot of reactions happening inside the stars. Probably the nuclear reactions such as nuclear fusion means a lot of hydrogen which is contained in the stars keeps changing into helium and that is why the star has its own heat and light.