For many years now, astronomers have given their best to learn more about planets orbiting other stars than our own, and thanks to technological developments, they’ve even managed to detect over 300 of them through various indirect methods. However, they were unable to establish the presence of exoplanets through direct imaging until recently, when Hubble sent back a snapshot of a distant planet circling the star Fomalhaut, located in the constellation Piscis Australis.

For astronomers, exoplanets have been very difficult to spot, and this one in particular orbits the 20th brightest star known, which makes it very difficult to see due to the glare of Fomalhaut. But eight years of continuous search for exoplanets gave UC Berkeley astronomer Paul Kalas the reward of a lifetime, after Hubble captured a snapshot of a planet probably close to the mass of Jupiter, 25 light years away from Earth, orbiting Fomalhaut at a distance four times that between Neptune and the Sun (in an estimated 870 years).

Fomalhaut is a very bright star, believed to be 200 million years old, and expected to burn out in one billion years. Astronomers explained the short life is a result of being 16 times brighter than our Sun (which is 4.5 billion years old and has only lived half its life).

Four years ago, Hubble Space Telescope’s Advanced Camera for Survey first indicated the existence of the exoplanet, after managing to capture a sharply defined inner edge to the dust belt around the star suggesting the presence of a planet performing an elliptical orbit. “The gravity of Fomalhaut b (how the planet was called) is the key reason that the vast dust belt surrounding Fomalhaut is cleanly sculpted into a ring and offset from the star,” Kalas explained. “We predicted this in 2005, and now we have the direct proof.”

Confirming that Fomalhaut b is indeed an exoplanet was very difficult to do, since unlike other planets, it was undetectable by the standard techniques or even by infrared imaging. The exoplanet was instead photographed in visible light, and luckily enough for Kalas, it was situated far enough from its star so as not to be obstructed by the bright glare of Fomalhaut.

“To make this discovery at optical wavelengths is a complete surprise,” Kalas said. “If we’re seeing light in reflection, then it must be because Fomalhaut b is surrounded by a planetary ring system so vast it would make Saturn’s tings look pocket-sized by comparison. Fomalhaut b may actually show what Jupiter and Saturn resembled when the solar system was about a hundred million years old.”

Thanks to two different images of the exoplanet, one from 2004 and one from 2006, astronomers have managed to establish the movement of the Fomalhaut b, which completes an orbiting cycle every 872 years at a distance of 119 astronomical units, or 11 billion miles.

Fomalhaut b’s presence is also supported by the dust belt of the star it orbits, which extends from 133 to 200 AU from the star, and it has a mass solid enough to allow a planet like Fomalhaut b to form in situ, at such an unexpectedly large distance.

At this point, astronomers eagerly await for Hubble Space Telescope’s Advanced Camera for Surveys and the Near Infrared Camera to resume observations. The current findings appear in the Science Express today.