Scientists have captured the sharpest view ever of a dusty disk around an aging star. With the help of the Very Large Telescope, researchers have captured the last moments around an elderly star.
Stars that approach the ends of their lives usually develop stable discs of gas and dust around them. These discs form during the red giant stage of the star's evolution, when stellar winds eject the material into space. While these discs resembles the ones around young stars that form into planets over time, the ones around older stars actually herald their demise. With that said, astronomers have had trouble learning more about the discs that appear at the beginning and end of a star's life.
Although there are many discs around young stars that are close enough to Earth to be studied, there are very few old stars with discs that are close enough for detailed imaging.
Now though, researchers have used the full power of the Very Large Telescope Interferometer (VLTI) at ESO's Paranal Observatory in Chile in order to get a better view of an old star. In this case, they looked at the old double star IRAS 08544-4431, which is located about 4,000 light-years from Earth in the southern constellation of Vela. This double star consists of a red giant star, which expelled the material in the surrounding dusty disc, and a less-evolved and more normal star orbiting close to it.
"By combining light from several telescopes of the Very Large Telescope Interfermoter, we obtained an image of stunning sharpness-equivalent to what a telescope with a diameter of 150 meters would see," Jacques Kluska from Exeter University said. "The resolution is so high that, for comparison, we could determine the size and shape of one euro coin seen from a distance of two thousand kilometers."
Thanks to the unprecedented sharpness of the images and a new imaging technique that can remove the central stars from the image to reveal what lies around them, the researchers could dissect what are essentially the building blocks of the system.
"Our observations and modelling open a new window to study the physics of these discs, as well as stellar evolution in double stars," said Hans Van Wiinckel, one of the researchers. "For the first time the complex interactions between close binary systems and their dusty environments can now be resolved in space and time."
