White giant stars are rare, they tend to be classified as Blue Giant Stars. Thuban, the brightest star in the constellation of Draco, the Dragon is sometimes seen as a White Giant star, other times its blue. Thuban was once the Pole Star before Polaris received the title.
Giant White Stars will have a Spectral type of A rather than D. White Giants tend to be at the hotter end of the star spectrum. The opposite end are red, brown and black stars.
The Sun although it is a G Type star, a yellow star is actually a white star when looked at from space. The atmosphere causes the star to appear yellow. The Sun has been referred to as a Yellow Dwarf Star because it is smaller than the larger supergiant yellow stars such as HR 5171. It is incorrect to refer to it as a White Dwarf Star therefore.
When a star dies, it will either become a neutron star, black hole if it has high mass otherwise a nebula. At the heart of the nebula will be a neutron or a white dwarf star. What dictates how a star will become either a white dwarf or a neutron is the following :-
A white dwarf will exist for many more years as a white dwarf than as it did as a main sequence star. After an unimaginably long time, it will turn into a black dwarf having run out of energy to shine. Whilst no black dwarf exists yet, there are a number of white dwarf stars out there, the nearest being a mere 8.6 light years away as the companion star to Sirius.
There's no register feature and no need to give an email address if you don't need to. All messages will be reviewed before being displayed. Comments may be merged or altered slightly such as if an email address is given in the main body of the comment.