The Sun is very much a main sequence star, in the G-type category (G2V to be precise). It’s been fusing hydrogen for 4.6 billion years, but it still has almost three times as much as it has helium.

"A hot white dwarf star, about the size of the Earth but having mass comparable with that of the sun, siphons off material from its cool companion star," explained Nye Evans of Keele University to ...