Using the Very Large Array (VLA) and the Atacama Large Millimeter and Submillimeter Array (ALMA), astronomers detected 97 disks of gas and dust around young protostars in the constellation Orion. Orion is not only the brightest constellation in the winter sky, but also the star-forming region closer to Earth.
The researchers said that the gas and dust clouds collapse to form stars under their own gravitational instability. The collapsed material is affected by the initial angular momentum. Most of the material in the cloud will form a disk, and the material will be accreted to the star through the disk, and the planets are also in the disk. If we can understand the characteristics of the entire evolution process, it will be an important key to unravel the formation of planets.
About 1,400 light-years from Earth, this molecular cloud in the constellation Orion is a massive star-forming region. Dust around young stars blocks most of the star’s visible light, and radio waves can travel through the dust clouds to learn more about young star systems. Astronomers analyzing VLA and ALMA data, known as VANDAM, is the largest ever survey of young stars.
The survey measured the size and mass of many young protoplanetary disks and compared them with older protoplanetary disks studied by ALMA, and found that new protoplanetary disks are larger than older protoplanetary disks at the same size. This result is actually quite reasonable, because the star will capture nearby material and make the surrounding disk smaller, but it means that the young disk has more material to form planets, and the largest planets in the planetary system may have formed around very young stars.
Older protoplanetary disks usually have rings and significantly less material inside them. These gaps are usually regions where planets are forming, but may also be disk resonance structures, where the gaps are formed by the gravitational pull of young planets, similar to Jupiter in the asteroid belt. Create track clearance. The research team found a similar gap structure in a protoplanetary disk that was only 100,000 years old. The time was unexpectedly early. The researchers said that in the first 1 million years of the system, the disk structure was similar to the older disk. The survey saw that some systems have very different shapes. Irregular, it is suspected that the system may be young, so that the disk has not yet formed, or maybe even the protostar has not fully formed. The research was published in The Astrophysical Journal.