Observing stars containing forming planetary systems allows astronomers to obtain clues about the origins of our own solar system. A study published in The Astrophysical Journal has analyzed a region 3,000 light years from Earth for signs of planet formation.
The area, known as Cepheus OB2, offers scientists an idea of the environment in which the Sun moved when it formed 4.6 billion years ago. In it are several stars surrounded by accumulations of gas and dust called protoplanetary disks. These discs have disappeared from older stars, so scientists deduce that planet formation must have happened in intermediate stages.
The study, in which researchers from the Autonomous University of Madrid have participated, has taken advantage of the temperature differences in each part of the discs to be able to study them. As the central star heats up the protoplanetary disk, the inner parts reach temperatures of up to 1,200 degrees, while the outer zones are at – 240 degrees. Because of this, each region of the disk emits light of one color, and the longer wavelengths indicate colder areas. In this way, by combining observations at different wavelengths it is possible to obtain information about the different areas of the disk.
Scientists have found discs in which there are signs of the formation of comets and planets similar to those in our Solar System. For example, some discs lack gas and fine dust in their innermost part and could lead to the formation of giant planets like Jupiter. In the discs of intermediate ages, the dust grains have agglomerated into particles that have a composition and organization similar to that observed in comet dust in the Solar System. Other discs, however, pose unknowns, since they are older than 10 million years and yet there are no signs of planetary formation.
