         The gravitational field of a star is strong enough to noticeably bend light. When one star passes directly in front of a more distant star as seen from Earth it can bend and focus the light of the distant star causing it to appear brighter for a short period of time. This is known as gravitational microlensing and the closer star is called the lens. If there is a planet orbiting the lens it will sometimes add a noticeable component to the lens effect allowing us to confirm its existence.
         """
       figure: "./images/mini-course/17-micro-lensing.jpg"
-      figure_credits: "NASA"
+      figure_credits: "Image credit: Maggy Wassilieff"
 
   }
 

        The first ever confirmed exoplanet was not actually discovered orbiting a Sun-like star. It was found around an object known as a pulsar. Pulsars are the extremely dense, rapidly spinning cores of dead stars which have beams of radiation that sweep out like an interstellar lighthouse. The rotation-rate of pulsars is extremely reliable and can be measured to very high accuracy. However, if a planet in in orbit its gravitational pull on the pulsar will manipulate the rotation-rate in a way that allows its existence to be inferred.
        """
      figure: "./images/mini-course/slide-19.gif"
      figure_credits: "NASA"

  }


        The idea of planets orbiting other stars in our galaxy has been around for hundreds of years (in fact 16th century Italian astronomer Giordano Bruno was burnt at the stake at least in part for his beliefs on the matter!). However, it was not until 1992 that the first exoplanet was confirmed. It was found orbiting a pulsar, the rapidly-spinning, dense core of a dead star. The first confirmed planet orbiting a Sun-like star, 51 Pegesi b, was announced in 1995. Since then over one thousand exoplanets have been confirmed and many more candidates identified. The graph below shows the distribution of planet candidates discovered by the Kepler mission as of November 2013.
        """
      figure: "./images/mini-course/8-size-candidates.jpg"
      figure_credits: ""

  }

