Define the natural fibre​

Ithink it is c ,i hope i you

During the 1800s. hope this !

We can infer that star y is closer but other factors must be considered including the heat of the star, the mass, and the brightness of the star. even though star x seems dimmer it may just be less bright or contain less heat.

Ican’t exactly answer this, but i can try to give a bit more info here.
astronomers are able to calculate a star’s life expectancy depending on its mass. (a larger star burns more gas, therefore having a shorter life span).
so astronomers can definitely predict the death of stars and the times they will die.
i hope this was in some way : )