Exoplanet (for astronomers) is simply any planet not in this solar system. Are any in that “goldilocks zone”, which give the capability of harboring life as we know it? Can we even see it, given its immense distance?
One must define “goldilocks zone” properly: [Habitable zone - Wikipedia, the free encyclopedia ]. That zone is considered the habitable area just far enough away from its sun, where it’s warm enough life can flourish, but not too cold to freeze water.
Astronomer Michael Hart’s computer simulations describe a habitable planet in the “goldilocks zone”. Its orbit must be almost circular, and must make the right sized orbit. Calculations indicate a 5% smaller orbit point to a runaway “greenhouse effect”, or a 1% larger orbit would have resulted in a glacier effect—the freezing of all oceans.
The solar system must be free of large planets with elliptical orbits, which would eject or destroy other planets. Large planets with circular orbits are needed to clear out rogue asteroids that would strike inner planets much more frequently.