Recently, a new achievement from the "Tianguan" satellite was published in the international academic journal "Astrophysical Journal Letters" - scientists have tracked for the first time the entire process of a peculiar binary system from sudden X-ray bursts to gradual fading, opening up new avenues for exploring the interactions and evolution of massive stars. The "Tianguan" satellite, developed under the leadership of our country, is the biggest "hero" of this discovery. Strange, a rare combination of celestial bodies. On May 27, 2024, the newly launched "Tianguan" satellite used its Wide Field X-ray Telescope (WXT, Ten Thousand Pupil) to capture a peculiar X-ray radiation event in the nearby galaxy, the Magellanic Cloud. Subsequently, the "Tianguan" satellite used its onboard Follow up X-ray Telescope (FXT) for directional observations, obtaining more detailed X-ray information during the source burst. This peculiar combination of celestial bodies includes a hot giant star with a mass over 10 times that of the Sun, as well as a dense white dwarf star with a mass comparable to the Sun. At present, only a few such systems have been discovered in the scientific community. After WXT detected the X-ray radiation of this peculiar celestial body, in order to trace the signal source of the new celestial body with the number EPJ0052, scientists immediately called on the FXT of "Tianguan" for directional observation. This discovery simultaneously triggered observations of the celestial body by NASA's Swift and NICER X-ray telescopes. The XMM Newton telescope of the European Space Agency also conducted follow-up observations 18 days after triggering the signal. Initially, scientists believed that this new celestial body could be a common X-ray binary system composed of a neutron star devouring the material of its massive stellar companion. However, further data analysis revealed a different truth. Thanks to the successful capture of signals by the "Tianguan" satellite during the initial eruption of celestial bodies, scientists were able to analyze multiple batches of data from different instruments. They studied the changes in light at a series of X-ray wavelengths over a period of 6 days and identified elements present in explosive materials, such as nitrogen, oxygen, and neon. These analysis results provide key clues for the study. We soon realized that this was an extremely rare and precious discovery, and they were a pair of very elusive celestial bodies This rare pair of celestial bodies is composed of a massive star we call Be star and the remains of a star called a white dwarf. Be star has a mass 12 times that of the Sun, while the white dwarf is a compact and ultra dense celestial body with a mass comparable to that of the Sun These two stars orbit closely around each other, and the white dwarf constantly pulls matter away from its companion star due to its strong gravitational field. As more and more matter (mainly hydrogen) continuously falls onto the compact celestial body of the white dwarf, its strong gravity compresses these substances until it triggers an uncontrollable nuclear explosion. This process produces an extremely bright flash, covering a wide range of wavelengths from visible light to ultraviolet and X-rays. The puzzle, a reasonable explanation for this discovery, has left astronomers somewhat confused. Because the life cycle of Be type massive stars is short and intense, lasting only about 20 million years. And its companion stars often have a lifespan of billions of years. So, the problem has arisen. Why did the binary star system formed together, which should have had a long lifespan, die, but those with a short lifespan are still alive? Scientists have proposed a reasonable explanation for this. This binary system initially consisted of two larger stars with masses 6 and 8 times that of the Sun, making it a highly compatible binary system. Larger stars exhaust their nuclear fuel earlier and begin to expand, ejecting material towards their companion stars. At first, its expanding outer gas was attracted by its companion star; Subsequently, the remaining outer shell was ejected, forming a envelope that enveloped two stars. This envelope later evolved into a disc-shaped structure and eventually dissipated. After this process is completed, the mass of the companion star increases to 12 times that of the Sun (i.e. Be star), while the core of the other star collapses into a white dwarf star with a slightly larger mass than the Sun. Nowadays, white dwarfs are beginning to extract and consume matter from the outer layers of Be stars. This study reveals an extremely rare stage in stellar evolution, which is the result of complex material exchange between two stars Ashley Clem, a researcher and X-ray astronomer at the European Space Agency, commented, "It is fascinating to observe such fascinating results from a pair of interacting massive stars." The European Space Agency's XMM Newton telescope conducted follow-up observations in the direction of EPJ0052 18 days after its first observation at the "Heavenly Pass," but failed to detect the signal again. This indicates that the duration of this flare up is relatively short. The duration of the brief eruption, as well as the presence of neon and oxygen, suggests that the mass of this white dwarf is quite large, possibly about 20% heavier than the Sun. Its mass is close to the so-called Chandrasekhar limit - once exceeded, the star will continue to collapse and may eventually become a denser neutron star or explode as a supernova. Tianguan "opens a new window for space observation and reviews the discovery process. Lixio Marino believes that this is due to the unique capabilities of the Tianguan satellite. We accidentally discovered this new X-ray bright spot in the Small Magellanic Cloud while monitoring the X-ray transient source. We realized that we were observing something unusual that only the 'Tianguan' satellite could capture. This is because among the telescopes currently monitoring X-ray space, WXT is the only one that can see low-energy X-rays with sufficient sensitivity Eric, a scientist in the European Space Agency's "Tianguan" satellite project, also said, "The eruption of Be stars and white dwarf binary systems is extremely rare, and they are best observed using low-energy X-rays Indeed, it is the unique capability of the "Tianguan" satellite that has opened up a new window for human observation of the universe. The "Tianguan" satellite is led by the Chinese Academy of Sciences and jointly developed by the European Space Agency, the German Max Planck Institute of Extraterrestrial Physics and the French National Space Research Center. On January 9, 2024, the "Tianguan" satellite was launched from the Xichang Satellite Launch Center in China, carrying two instruments - the Wide Field X-ray Telescope (WXT) - for continuous monitoring of X-ray transient sources appearing in the sky; Later, the X-ray telescope (FXT) focused on conducting more detailed observations of the X-ray sources discovered by WXT. The National Space Science Center of the Chinese Academy of Sciences is responsible for the overall "Tianguan" satellite project. The Micro Satellite Innovation Institute, the Shanghai Institute of Technical Physics, the National Astronomical Observatory and the Institute of High Energy Physics are respectively responsible for the development of the satellite platform and two payloads. The Night Vision Academy Group is responsible for the development of the lobster optometry device loaded with WXT. WXT is the world's first wide field X-ray focusing telescope, with detection capabilities leading other devices by a majority of orders of magnitude, capable of detecting even more distant and fainter X-ray bursts in the universe. The core scientific objectives of the "Tianguan" satellite are threefold: first, to discover celestial bodies with X-ray induced changes in the universe; Monitor the activity of known celestial bodies, explore the properties and physical mechanisms of related phenomena; The second is to discover and explore the brilliance of silent black holes in the universe; Mapping the distribution of black holes to further understand their origin, evolution, and material accretion processes; The third is to explore X-ray signals from gravitational wave sources to enhance our understanding of extremely dense celestial bodies and their merging processes. At the same time, the temporary source systematic survey of the "Tianguan" satellite will also discover more distant (early) gamma ray bursts in the universe, to track the first generation stars that illuminated the "dark ages" of the universe, and use them as "lighthouses" to explore the dawn and reionization periods of the early universe, as well as the first generation galaxies and early interstellar media. It will also detect the instantaneous X-ray burst radiation of supernova explosions. In addition, the "Tianguan" satellite will also accumulate a massive amount of all day time-domain survey data, which can be used to conduct X-ray time-varying monitoring and census of large sample celestial bodies, studying the activity, physical processes, and origins of celestial bodies including stars, compact celestial bodies, and active galactic nuclei. Yuan Weimin, the chief scientist of the "Tianguan" satellite, said, "The international cooperation of the" Tianguan "satellite has profound significance. It is not only jointly developed by multiple countries, but also has formed an international joint scientific team of about 300 people in data sharing and scientific management. The members are more than 300 scientists from more than 10 countries, providing extremely strong and extensive international power for the scientific achievements of the" Tianguan "satellite. The universe is deep, and the journey of capturing stars at the 'Heavenly Pass' is still ongoing. (New Society)