The planet Beta Pictoris b was discovered in November 2008, but as mentioned in the last picture, it wasn't confirmed until the next year. Then, in 2010, this extraordinary image
was released. Composed of two separate pictures taken in 2003 and 2009, it shows the planet first on one side of the star (left), then on the other (right)! For the first time, an exoplanet was seen to move to the other side of its parent star.
That may not seem terribly important, but it is. For one thing, it helps nail down the orbital size and period of the planet. Also, in 2008 the planet wasn't seen at all; it was most likely behind or too close to the star to be seen. Again, that helps determine the orbit of the planet.
As mentioned in the previous entry, it's possible that the planet will transit the star. If it does, then we'll know the orbit even better, allowing things like the mass of the star to be better determined, as well as other orbital characteristics of the planet.Original blog post
: Astronomers see exoplanet orbiting its parent star!Credit: ESO