Astronomers working at the ALMA (Atacama Large Millimeter / submillimeter Array) telescope have managed to capture the best image to date and with extraordinary detail of the formation of planets around a young star. These are the first observations made by ALMA in its near-complete configuration and the highest resolution images made at submillimeter wavelengths. The groundbreaking image shows the formation of a planetary disk around the star HL Tau , located about 450 light-years from Earth in the constellation Taurus.
Unexpected details are also seen in the disc of material left over after the star’s birth, as well as a series of bright concentric rings, separated by gaps. According to Stuartt Corder, deputy director of ALMA, “what we have observed is almost certainly the result of the formation of young planetary bodies in the disk. This is a surprise, since young stars of this type are not expected to have large planetary bodies capable of producing the structures that we see in the images. “
For the astronomer Catalina Vlahakis, the image will “revolutionize the theories of planetary formation .” And it is that HL Tauri’s album appears much more developed than would be expected with the age of the system. Therefore, the ALMA image also suggests that the planet formation process may be faster than previously thought. Young stars like HL Tauri are born in clouds of gas and fine dust, in regions that have collapsed under the effects of gravitation, forming dense hot cores that eventually ignite to become young stars. These are surrounded by a “cocoon” formed by the gas and the remaining dust, which is finally deposited in a protoplanetary disk.
After many collisions, the dust particles stick together, forming lumps the size of grains of sand and pebbles. Ultimately, asteroids, comets, and even planets can form from that disk. The young planets will interrupt the trace of the disk to create rings, holes and holes, like those seen in the structures that are now observed with ALMA.
