How are exoplanets detected?
Exoplanets are detected in many ways but the two most common are the transit passing method & the ‘wobble’ method.
The transit passing method is when you observe a specific star over a period of days to weeks. Over that period, a planet that may be orbiting that star could come into view between the telescope and the star, thus blocking out some of its starlight from our view.
The ‘wobble’ method is measuring the point for which a star orbits. If a star has planets orbiting them, the star will orbit a point that is outside its center of mass called the barycenter and not its own center of mass. The barycenter is determined by the mass of two (or more) objects and the distance between them. For all of the planets in our own solar system, the barycenter is still inside the Sun, all except for Jupiter-Sun system. When we’re observing a star and notice a pattern of red shifts to blue shifts on the electromagnetic spectrum, we can deduce that planet(s) are orbiting it.
The downside about using the ‘wobble’ method is that, looking back at our own solar system, it’s far better at detecting exoplanets like gas giants and hot Jupiters due to their vast mass and thus dominance in their solar system.
With more observation, the combinations of these methods, and the use of other telescopes, more details can be determined about these exoplanets and their potential habitability.