Exoplanets

an exoplanet is the name of any planet that orbits around a star other than our own sun. they are some times also called extrasolar planets.

finding exoplanets
due to being very far away they are very difficult to detect and often times can't be directly observed  like objects in our own system. there are several methods for detecting exoplanets

Direct observation: some times we get lucky. if the planet is bright enough and large enough it is posable to see directly. this is rare and requires the right conditions.

the transit method: this method involves measuring the light from a star and constantly observing it for changes in brightness. the light dimming in brightness can mean there's a object there. the more the light dims the bigger the object.

the wobble method: the star is observed and its motion is tracked. as the planet orbits the star it pulls it a little bit towards it. this movement can be used to work out the mass of the object and how far it orbits from its star.