- First ever visible light image of an exoplanet!
Standing in the cold outdoors under the majestic night sky, you might be inclined to wonder if any of the stars that you can see have planets around them. One of the stars that can be seen during autumn is Fomalhaut, the 18th brightest star in the night sky.
The Hubble Space Telescope has found a planet around Fomalhaut, although this discovery pales in comparison to achieving what some people deemed impossible, actually imaging a planet around another star! What makes this even more special is that this is the very first time an extrasolar planet has been imaged in visible light!
As with other momentous achievements, the imaging of the planet wasn't quick and easy. Astronomer Paul Kalas repeatedly imaged Fomalhaut with the HST for eight years and has now made history!
Fomalhaut is a quick jaunt away at a distance of 25 light years and is surrounded by a ring of gas and dust. This gas and dust is what planets form out of and our Sun would have most likely had this type of feature 4.5 billion years ago.
Paul Kalas was certain of the existence of the planet due to perturbations in the ring. Images taken in 2005 with the HST showed a sharp edge to the ring and it seemed evident that the ring of material was being affected by another object. The only thing the object could be was a planet.
Pictures taken apart in 2004 and 2006 clearly show the planet moving. From this it is known that the planet is 11 billion miles away from Fomalhaut and has an orbit of 872 years.
The picture shows the star being blacked out by a coronagraph mask, this blocked the overwhelming light of blazing Fomalhaut and this allowed the planet to be visible. The ring of dust can be seen around the star and is affected by the gravity of the planet.
Almost 20 years after it was launched, the Hubble Space Telescope has achieved a milestone in astronomy and the next decade will open the floodgates for more direct pictures of exoplanets with new advanced observatories such as the James Webb Space Telescope, scheduled for launch in 2013. The next frontier is discovering exomoons around exoplanets, they will hopefully be detected in the years to come.