Should be when the Sun implodes. Odd thing is that every deduction made about the exact age of the star and eventual death is based on gross errors. The Sun can on a whim no more shine. What we are looking at in that Sun is a being not a body. A complex chain of a conscious, seeing and thinking Space machine above us. Every strain of matter emanating from the Sun is calculated to the barest, leaving nothing to chance. The conceited man cannot reinvent core knowledge by fashioning phrases. Learning is via no one, fair or dark, but by the radiance of what our solar Regency dictates.
We prob wouldnt see anything, light would prob get brighter as it got to us and poof we would be gone no pain, no tears, no regrets, no fear, no feeling, no nothing, just gone with a flash of blazing light!. We wouldn't even notice we were about to die for 8 minutes until the shockwave hit then we wouldn't worry about much of anything on account of us being dead. Betelgeuse is due to explode. We can see that star from earth with our unaided eye. I've read that the explosion won't hurt us but will be apparent when it happens. It's a huge star 700 times the size of our sun.
In about five billion years it will explode as it comes to the end of it natural life but all life will have died around two or three billion years before then In 6billion years it will enlarge and eat up the orbits of all the planets then boom! Then the humans will watch from another galaxy perhaps. Every atom of our flesh, bone, and blood would instantly be stripped and dispersed. Our bodies would disintegrate. So "let us hear the conclusion of the whole matter; Fear God and keep His commandments, for this is man's all. For God will bring every work into judgement, including every secret thing, whether it be good or evil. Ecclesiastes 12:13-14.