BEIJING (ANTARA) – An international team led by a Chinese astronomer announced that they have identified two new examples of a rare binary star system consisting of two central stars orbiting each other in the universe.
The two systems, called Bernhard-1 and Bernhard-2, are each surrounded by unusual disks of gas and dust that are at an inclination to the orbits of the central stars, said Zhu Wei of Tsinghua University who led the international team.
The findings were published in the Astrophysical Journal Letters.
The surrounding dense gas, or protoplanetary disk, is usually in the same orbital plane as the star, just as most planets and moons in the solar system have the same orbital plane.
However, this newly discovered binary star system is a rare breed, because the disk lies at an inclination to the plane of the orbiting star, Zhu said. The disk swayed like a spinning top because of its tilt, he added.
Zhu explained that when a disk wobbles, it moves between Earth and the binary stars for decades, causing the brightness of the binary stars to vary regularly.
As seen from Earth, the system dims as one of its binary stars moves behind the protoplanetary disk. When it can be observed again from Earth, the brightness of the system returns to normal. According to the findings, Bernhard-1 dims for 112 days every 192 days, and Bernhard-2 dims for 20 days every 62 days.
The two binary star systems are located 3,000-10,000 light-years from Earth, and the discovery of these two systems is crucial for understanding planet formation, according to Zhu.
The study was carried out in collaboration with a number of professional and amateur astronomers and researchers from China and abroad.
Reporter: Xinhua
Editor: Zita Meirina
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