Direct Imaging Method to Detect Exoplanets:
Taking a picture of an extrasolar planet sounds like the easiest way to discover one, but in reality, it is probably the most difficult. Seeing the faint glow of a planet amidst the brilliant glare of its star is very very difficult.
Nonetheless, astronomers have used this technique to discover exoplanets.
Astronomers currently use a dark 'mask' called coronagraph to cover up the star and most of its glare. If a planet around this star AND it is not covered by the coronagraph, then a keen eyed telescope might be able to pick out the dim reflected light of the planet shining through. And that is how Direct Imaging technique functions.
Another method in the works is to use a 'starshade', a device that's positioned to block light from a star before it even enters a telescope. For a space telescope that is looking for exoplanets, a starshade would be a separate spacecraft, designed to position itself at just the right distance and angle to block starlight from the star that is under observation.
Direct imaging is still in its beginning stages as an exoplanet-finding method, but there are high hopes that it will eventually be a key tool for finding and characterizing exoplanets.
Cosmos channel: https://www.youtube.com/channel/UC9XEPixVLrJHl4lppet88Dw
Methods to Detect Exoplanets:
http://www.youtube.com/playlist?list=PL10JmIrFKLduQLO62_MtI3QSZG4PoiiC1
