If some stars that are lightyears away are dead, does that mean the exoplanets we find are also dead?

Question

I get really excited over exoplanets that are Earth-like so I’m wondering how this works.

In: Planetary Science

Answer 1

When you look off into deep space you’re also looking back in time.

But those stars you see at night aren’t *millions* of light years away like people often romanticize, they’re dozens or maybe a few hundred tops. Close neighbors in our corner of the galaxy. The entire galaxy is “only” 90,000 light years across.

Most of the exoplanets we’ve found are relatively close, so it’s unlikely they’ve changed considerably in the few decades their light has been in transit. Stars die and planets get immolated on geologic timescales taking millions or billions of years. If we spot an exoplanet 139 light years away orbiting an uninteresting star, only an exceedingly rare massive collision or the Death Star could destroy it in that time.