The truth about the unprecedented "great dimming event" in astronomy history
Bring new insights into the structure and evolution of stars
Science and Technology Daily, Beijing, June 17 (Reporter Zhang Mengran) The Betelgeuse "Explosion Theory", which is very close to us and has a diameter equivalent to 1,700 suns, is not only a hot spot in astronomy, because it will have a huge impact on life on earth, but also cause global discuss.
According to an astronomical study published in the British journal Nature on the 17th, the “great dimming event” of the first red supergiant star in the history of human observation finally “find out the truth”: the dust cluster and coldness formed by its southern hemisphere. Caused by spots.
This observation may help explain the mechanism of the most common major mass loss events at the end of the evolution of massive stars.
Betelgeuse is the second closest red supergiant star to the earth. From November 2019 to March 2020, observations have shown that the visible brightness of the entire Betelgeuse has dimmed unprecedentedly, which has triggered a lot of speculation about its cause.
At that time, some researchers believed that this "great dimming event" foretells that Betelgeuse will explode as a supernova soon, but no explosion has been observed since then.
Research teams from the French National Center for Scientific Research, the Sorbonne University, and the University of Paris analyzed the surface of Betelgeuse before and during the "Great Darkening Event".
The high angular resolution observations of the Chilean Very Large Telescope revealed that the southern hemisphere of Betelgeuse was 10 times darker than usual during the dimming period, and the shape and intensity of the dark area evolved rapidly during the three months of observation.
Observation and modeling show that a cold zone formed on the visible surface of Betelgeuse has a local temperature drop, that is, the darkening is caused by dust clusters and cold spots formed in the southern hemisphere.
This result refutes the theory that the dimming event foreshadows the imminent supernova explosion in Betelgeuse.
The research team believes that this diverse and rapidly evolving local surface behavior is related to unique non-uniform mass loss events. This is the first time that humans have observed such events in real time on a red supergiant star.
Earlier observations by the Hubble Space Telescope suggested that the unprecedented dimming of Betelgeuse was probably caused by a large amount of hot material ejected into space, and the formation of dust clouds blocked the starlight on the surface of Betelgeuse, but this is not the case. Was finalized.
Today's research has brought new insights into the dimming process of red supergiant stars and the structure and evolution of stars.
The reason why Betelgeuse is so impressive is that it is incredibly large-its mass is 11 times that of the sun, and its diameter is equivalent to 1,700 suns lined up in a row.
This means that if it is placed in the position of the sun, its outer surface will extend to Jupiter's orbit.
Many people believe that a supernova explosion within about 1,000 light-years will have a fatal impact on life on Earth.
Editor-in-chief
A monster-level superstar has been dimming continuously in the past year, reaching a level visible to the naked eye on Earth, which has never been recorded before.
People try to explain this sudden change, but according to theory, it is generally a precursor to an explosion.
We must know that with the quality and distance of this star, once it fails to protect itself, it will not only be a violent astronomical event, but may also affect our own destiny process.
Now we are fortunate that this red supergiant star has temporarily lifted the crisis, but we still don't know the clues of the supernova that can affect the ecology of the earth.
On the cosmic scale, supernova explosions are actually quite ordinary.