Wang Kechao, director of science popularization at the Purple Mountain Observatory of the Chinese Academy of Sciences, said that on December 12, Beijing time, the asteroid Leona 319 will occultate the star Betelgeuse. The first time to see the occultation process was in Kashgar, Hotan and other areas of Xinjiang, China, and the starting time was 9:08 on the same day. The maximum duration of this occultation in the center of the occultation zone is about 116 seconds.
Starting in Xinjiang, the shelter passes from east to west through Asian countries such as Uzbekistan, as well as European countries such as Greece, Italy, and Spain, and finally ends in Central America. The latest occultation will be seen in Mexico, starting at 9:26 a.m. EDT. Wang Kechao said that the public in the center of the occultation zone will have the opportunity to see Betelgeuse dim or "disappear" for more than ten seconds.
Why is Betelgeuse darkened or "disappeared" after being hidden by asteroid Leona 319?Wang Kechao explained that this is because the diameter of asteroid Leona 319 and Betelgeuse is relatively close, and considering the impact of measurement errors, it is not yet certain whether the occultation is full or circumferential. If asteroid 319 Leona has a smaller apparent diameter than Betelgeuse, an occultation will occur, in which the central part of Betelgeuse is partially obscured, but the edges are still bright, forming a halo, in which case Betelgeuse will be briefly darkened. However, if the apparent diameter of asteroid 319 Leona exceeds Betelgeuse, total occultation will occur, that is, Betelgeuse will be completely obscured, and Betelgeuse will briefly "disappear" from public view.
When planets and asteroids in the solar system move, they often obscure distant stars. However, bright objects as bright as Betelgeuse are rare for the asteroid to occultus. "It would be a rare experience to see Betelgeuse visibly dim or 'disappear' with the naked eye. Wang Kechao said that the occultation is not only ornamental, but also has scientific value. By aggregating the luminosity curves (i.e., brightness curves) observed from multiple places, astronomers may be able to calculate the shape of Betelgeuse and asteroid Leona 319 more accurately.
In Western astronomy, Betelgeuse is the famous bright orange star on the "shoulder" of the constellation Orion, named Orion. As a red supergiant, Betelgeuse has a large radius, about several hundred times the radius of the Sun. At present, it has entered the stage of "aging" and is a "star of old age". It is the first time that a star other than the Sun has been measured in diameter.
*Xinhua.
Edited by Xu Weiwei.
Second instance Li Jie.
Third trial Min Jie.