New York: The US space agency’s 18-year- old Hubble Telescope has captured for the first time visible- light snapshot of a planet circling another star outside our solar system.
Estimated to be about three times Jupiter’s mass, the planet - Fomalhaut b - orbits the bright southern star Fomalhaut, located at 25 light-years away in the constellation Piscis Australis or the “Southern Fish,” the NASA said.
Fomalhaut has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early 1980s by NASA’s Infrared Astronomy Satellite IRAS.
In 2004, the coronagraph in the High Resolution Camera on Hubble’s Advanced Camera for Surveys produced the first- ever resolved visible-light image of the region around Fomalhaut. It clearly showed a ring of protoplanetary debris approximately 21.5 billion miles across and having a sharp inner edge.
This large debris disk is similar to the Kuiper Belt, which encircles the solar system and contains a range of icy bodies from dust grains to objects the size of dwarf planets, such as Pluto.
Hubble astronomer Paul Kalas of the University of California at Berkeley and team members proposed in 2005 that the ring was being gravitationally modified by a planet lying between the star and the ring’s inner edge.
Circumstantial evidence came from Hubble’s confirmation that the ring is offset from the center of the star. The sharp inner edge of the ring is also consistent with the presence of a planet that gravitationally “shepherds” ring particles. Independent researchers have subsequently reached similar conclusions, NASA said.