Discovery of Exoplanet systems part 2

The second indirect method of exoplanet detection is the transit method.  The transit method can determine an  exoplanet's radius. Astronomers use this method to determine the presence of an exoplanet by visualizing a stars decrease in brightness. If an exoplanet is present, when it passes in front of its companion star, there is a detectable drop in the star's apparent brightness. The amount that the star's brightness drops depends completely on the size of the exoplanet.  Here are some images and a video:

 

 

 

Direct detection of exoplanets is completed through direct imaging.  Planets are very faint in brightness when compared to stars. They produce little radiation.  A planets radiation can be easily lost due to the brightness of its parent star.  Consequently, it is extremely difficult to detect planets using this method when a planet is small.  This method is usually used to detect planets much larger than Jupiter. Here is an image: