Many planets may have double suns

The dual suns that rise and set over Luke Skywalker's homeworld in the film Star Wars may be more than just fantasy, according to data from Nasa. In a classic scene from the 1977 movie, the hero gazes into the distance as two yellow suns set on the horizon. Nasa's Spitzer Space Telescope has found that planetary systems are as common around double stars as they are around single stars, like our own Sun. Details of the research have been published in the Astrophysical Journal. In the study, a team of researchers used an infrared camera on the Spitzer telescope to search for so-called dusty discs around binary, or double, stars. Dusty discs are made from the leftover debris of planet formation. "We knew the stars would be there, the question was whether there was a planet to be the place where you could stand and see these sunsets," said Karl Stapelfeldt, a scientist at Nasa's Jet Propulsion Laboratory (JPL) in Pasadena, California.

"The inference is getting stronger now that there must be such planets based on what Spitzer has found." The presence of planets in dusty discs is thought likely, but is by no means certain. "In our Solar System, asteroids collide with each other and produce showers of dust and that is, we assume, what we're seeing in these other discs - the dust produced by the collision of two bigger bodies," lead author David Trilling, from the University of Arizona, told BBC News.