Unfortunately, it is impossible to tell accurately where a star is on the main sequence.
A red main sequence star would be a red dwarf or a branch red giant. To be on the main sequence, you have to have hydrogen nuclear fusion.
Algol is a blue main-sequence star in the constellation Perseus
Polaris - the current North star is a multiple star system., consisting of the main star and smaller companions. The main star Alpha Ursae Minoris is a bright star, a 6 solar mass supergiant and it is a main sequence star. Orbiting very close to this main star is a white dwarf of roughly 1.5 solar masses. This is not a main sequence star. Orbiting further out is the third companion, a 1.39 solar mass star. This is a main sequence star. There are also two more distant components (α UMi C and α UMi D) - Polaris is thought to be part of an open cluster - I do not know if these later two stars are main sequence or not.
.... until all the hydrogen is depleted.
It's the size. A dwarf star has reached the end of the road and has collapsed. It's a little old star and people don't notice it, mostly.
Rajesh Hamal was born on 1965-09-07.
Main Sequence
The sun is a main sequence star
its to the right of the middle of the main sequence.
There are billions of stars that are not on the main sequence.
No
No. They have the lowest temperatures on the main sequence. The hottest main sequence stars are blue.
Alpha Arietis (Hamal) is the brightest star in the constellation Aries. It is located about 66 light years from Earth.
Off the Main Sequence was created in 2005-11.
Off the Main Sequence has 738 pages.
The temperature of main sequence stars can vary quite a bit.
A red main sequence star would be a red dwarf or a branch red giant. To be on the main sequence, you have to have hydrogen nuclear fusion.