Zooming in on the cosmos

Astronomers have created the world’s largest virtual optical telescope by using a special technique to combine images from four powerful devices as if they were a single unit.

“This weekend we managed to finish the process of merging the images after almost a year,” said scientist Jean-Philippe Berger, of the European Southern Observatory in Chile’s high northern desert

“For the first time, we made scientific observations through this new instrument, and we can say that it can be used.”

The Very Large Telescope complex in Paranal includes four large optical telescopes, each of which are about 30 metres high and have mirrors eight meters in diameter.

The astronomers brought together the signals received by the telescopes thanks to a technique known as interferometry, which combines the images to achieve a higher resolution.

This creates a virtual mirror which is the equivalent of 130 metres in diameter and, according to Mr Berger, improves the resolution and the ability to zoom in on the cosmos.

“We see the surface of stars, including objects that have never been observed before, such as some very young stars or galaxies,” he explained.

“It is very difficult to build large optical telescopes, so interferometry was used.”

“We have been working on this for a long time and are very excited to start doing science with it.”

The complex is operated by the ESO, created in 1962 and which has support from Austria, Belgium, Brazil, Britain, the Czech Republic, Denmark, Finland, France, Germany, Italy, the Netherlands, Portugal, Spain, Sweden and Switzerland.