Question

Sunspots are cooler than the surrounding region of the Suns surface True or False

The Sun is a main-sequence star  True or False

All stars are made primarily of hydrogen and helium at birth : True or False

The distance to nearby stars can be measured by parallax   True or False

It is impossible to measure stellar mass in binary systems   True or False

Stars near the lower right of the main sequence are lower in mass and have longer lifetimes than stars further up the main sequence : True or F

High mass stars die in supernovae explosion: tRUE OF False

Pulsars are rotating neutron stars with magnetic fields : True or False

A white dwarf is supported by electron degeneracy pressure : True or False

Answer 1

1. Sunspots are cooler than the surrounding region of the Sun's surface.
Answer : TRUE
Sunspots are comparatively cooler because strong magnetic fields slow convection and prevent hot plasma from entering the region.

2. The Sun is a main-sequence star.
Answer : TRUE
All main sequence stars fuse hydrogen atoms to form helium atoms at their core. Since Sun is made up of helium, it is a main sequence star.

3. All stars are made primarily of hydrogen and helium at birth.
Answer : TRUE
Stars are big balls of gas mostly comprising of hydrogen and helium as these are the two lightest elements. Stars shine bright by burning hydrogen into helium. They form heavier elements at a later stage in their life.

4. The distance to nearby stars can be measured by parallax.
Answer : TRUE
Parallax is the most common method used by the astronomers to measure the distance of nearby stars. They calculate the position of the star once and then measure the change in its apparent position.

5. It is impossible to measure stellar mass in binary systems.
Answer : FALSE
The most feasible way of measuring stellar mass is through binary systems. Mostly a combination of visual and eclipsing binaries are used.

6. Stars near the lower right of the main sequence are lower in mass and have longer lifetimes than stars further up the main sequence.
Answer : TRUE
The stars further up the main sequence has more material but it burns through it faster due to the higher core temperatures caused by the gravitational forces. The stars with lower mass on the other hand has a chance to stick around for much longer.

7. High mass stars die in supernovae explosion.
Answer : TRUE
Supernovae explosion is the catastrophic death of a star. After shining for many years, when the hydrogen supply at the core begins to run out, the core becomes unstable and contracts while the outer shell starts expanding. The star reaches the red giant phase. At a later stage of evolution, the star is blown apart by a supernovae explosion.

8. Pulsars are rotating neutron stars with magnetic fields.
Answer : TRUE
Pulsars are rotating neutron stars having pulses of radiation at very regular intervals. They have strong magnetic fields which funnel jets of particles out along the two magnetic poles.

9. A white dwarf is supported by electron degeneracy pressure.
Answer : TRUE
A white dwarf has no source of energy left. It cannot support itself against the gravitational collapse. The only way for a white dwarf to exist is by being supported by electron degeneracy pressure which causes it to be extremely dense.