A dusty disc around an ancient star can provide information about how planets form, a group of astronomers from the European Southern Observatory (ESO) believe.
The scientists released a new image showing the spectacular display of gas and dust. Their observations are the latest chapter in the understanding of how exoplanets form around alien suns.
Astronomers utilized the Very Large Telescope Interferometer at ESO's Paranal Observatory in Chile in order to image the dusty double star system. The image created is the sharpest view yet seen of a dusty disc around an aging star.
Older stars often form disks of material that surround the space around the stellar body. Material left over from a period when the star existed as a massive red giant star is blown by solar winds from the now-collapsed star, forming the feature.
These disks are much like those seen around other younger stars that can lead to the development of planets. However, until now, astronomers have been unable to adequately compare the two types of features in a way that could suggest how worlds come into being in developing stellar systems. Part of the problem is the lack of old stellar bodies in the vicinity of Earth, resulting in a lack of highly-detailed images of the features.
The double star system IRAS 08544-4431 consists of a red giant star that has shed its excess materials, orbiting together with a "normal" main-sequence star. The pair was imaged by astronomers using the recently renovated Rapid detector at the observatory.
"By combining light from several telescopes of the Very Large Telescope Interferometer, we obtained an image of stunning sharpness - equivalent to what a telescope with a diameter of 150 meters (492 feet) would see. The resolution is so high that, for comparison, we could determine the size and shape of a one euro coin seen from a distance of 2,000 kilometers (6,562 feet)," Jacques Kluska of the University of Exeter said.
This instrument and technique is the latest in a string of developments in the search for planets orbiting distant stars. The light from stars drowns out views of exoplanets, making direct observations of alien worlds challenging at best, at least for now. Therefore, evidence of their existence must be gleaned from the effect the planets have on their parent star. This can include blocking light from the star, or moving the stellar bodies back and forth through the influence of gravity.
Until 1992, no planets had ever been detected orbiting stars other than our own sun. At the beginning of that year, astronomers Aleksander Wolszczan and Dale Frail told the world they found a pair of planets near the pulsar PSR 1257+12.
The new image of IRAS 08544-443 shows one expected feature - the formation of the disk into a ring around the star. This is driven by radiation from the star evaporating dust near the stellar body. This is thought to be similar to the process by which young stars form planets.
Over 1,000 exoplanets are currently known to astronomers. As more systems are explored, researchers will get a better understanding of how planetary systems come into being and evolve over time.
