New system of measurement of cosmic distances

2000/06/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Astronautika

A group of astronomers has developed a new system to measure the distance to which astronomical objects are located. Knowing where an astronomical object is is very important in astronomy, both to know its characteristics and to understand the nature of the Universe through its behavior.

The measurement system itself is not new, but to date it has been technically impossible. The system uses the dispersion of X-rays, which suffer X-rays when they expand through the Universe and collide with dust particles. As these rays have a higher energy than that of light, the dispersion angle is much smaller, so it can be calculated the dispersion suffered by the rays coming from very distant objects. This would not be possible with light, since the scatter is too large.

The scientific team has used NASA's Chandra X-ray Observatory to stop the system. This observatory offers a higher resolution than the previous ones, which has allowed astronomers to calculate exactly the distances of the most important X-ray emitters. Astronomers have set an example of a traffic light to understand the new measurement system. When there is fog, around the traffic light there is a halo per dispersion. When the traffic light changes color, this halo changes color, but a billion of a second later. With objects at 30,000 light-years, this effect is more important, so it is easier to measure the delay to get the value of the distance.