Just once.
That would mainly depend on the star's mass.
Our sun is expected to become a red giant within a few billion years. The red giant star Antares has a diameter 800 times that of the Sun.
it doesn't because the star may be already dead before its ready to become a giant.
A star become a red giant when the core contracts, the temperature increases and the outer layers of the star begin to expand. By the end of this phase, the star can be 10 to 100 times it diameter. When the temperature in the core reaches 100 000 000°C, the helium start fusing into carbon. Because the star has expanded to such an enormous size, that the outer layer are much cooler than when the star was a main sequence star. It therefore appears red, earning the name of red giant.
A star's entire fate is tied into its initial mass. Nothing else matters.
A giant star would experience a supernova explosion, in order to become a white dwarf.
super-giant star
I am pretty sure it becomes a giant if I'm not mistaken.
a super giant.
red giant
A red giant is a star, at a particular phase of its development. It can be a star that has approximately the mass of our Sun (the Sun is expected to become a red giant eventually), or several times that mass.
yes. in about five billion years the sun will become a red giant.