Chilean telescope captures halo

Spiral Structure around the old star R Sculptoris Santiago - Agencies Astronomers using a powerful Chile-based telescope on Wednesday released a rare image of a spiral shell of cosmic dust and gas surrounding a red giant star. The discovery marks the first time that scientists have found such a structure and obtained full three-dimensional information about the spiral. Researchers said a hidden companion start probably created the shape while orbiting the red giant. The find was made possible by the high sensitivity of the Atacama Large Millimeter/submillimeter Array, located 5,000 metres (16,400 feet) above sea level deep in Chile's Atacama Desert. ALMA has 66 antennas exploring the universe via radio waves emitted by galaxies, stars and other bodies not captured by optical and infrared telescopes, which only receive light. "We've seen shells around this kind of star before, but this is the first time we've ever seen a spiral of material coming out from a star, together with a surrounding shell," said Matthias Maercker of the European Southern Observatory (ESO), lead author of a paper to be published in the journal Nature this week. Astronomers were previously unaware that the star, R Sculptoris, had a spiral-shaped halo around it. Red giants are major contributors to the dust and gas that provide the bulk of the raw materials of newly formed stars and planetary systems. "We always expected ALMA to provide us with a new view of the universe, but to be discovering unexpected new things already, with one of the first sets of observations, is truly exciting," said Maercker, who is also affiliated with the Argelander Institute for Astronomy at the University of Bonn. The ESO, a collaboration involving 15 mainly European countries, operates a number of high-powered telescopes in Chile, including the Very Large Telescope array (VLT) in Paranal, the world's most advanced telescope.