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

So “dead” is a term that will probably confuse your understanding of exoplanets because planets themselves are not alive.

Most of the exoplanets we find, we can see them because they are around active stars and they affect the star, or the light from the star, in some way.

We think that for life to be on exoplanets, one of the (many) conditions is that they need to be orbiting an active star. So most of the exoplanets we find pass this criteria. That said we also look for planets similar in size to earth, and that are a distance from the star that is not too cold or not too hot (the Goldilocks or habitable zone).

So while we’ve found over 5,000 exoplanets, less than 5 are earth size and in the stars habitable zone.