Previously, astronomers discovered the Milky Way’s “Netherworld” – the burial place of the “Dead Star”. The so-called “dead stars” are the inner remains of stars, and in this case, the remains of massive stars, including black holes and neutron stars. They are scattered throughout the Milky Way, but together they form a structure that is larger and puffier than the Milky Way itself. Massive stars, on the other hand, end their lives in tragic supernova explosions, which throw off the star’s outer shell and shrink the star’s core. The giant shock wave also accelerates the remnant stellar core enough to fly into the vast intergalactic space. It can be seen that the distribution characteristics of dead stars are different from ordinary stars. Since the birth of the Milky Way, at least billions of dead stars have been created.
This time, researchers from the Institute of Astronomy at the University of Sydney have restored the life cycles of these ancient dead stars one by one, and drawn the first detailed 3D distribution map of the Milky Way’s dead stars in human history. Drawing such a star map can be described as extremely difficult, the most difficult thing is to find where the Death Star is. Black holes and neutron stars that have just died may still be nearby, but those ancient ones don’t know where to go. Asymmetric shock waves from supernova explosions can accelerate them to millions of kilometers per hour in random directions. So the Death Star, in space with little resistance, can never stop once it gains speed. After billions of years, those ancient black holes and neutron stars have become ghosts traveling through interstellar space.
To understand the distribution of dead stars in the Milky Way, the researchers built a sophisticated model. Inputting information about the positions of key nodes in the stellar evolution period into this model yields a map of the distribution of dead stars in the Milky Way. From preliminary results, a dead galaxy is much larger than a living galaxy. Viewed from the side, the Milky Way “Hades” is three times thicker than the Milky Way itself; if you look down, you will find that it has lost the Milky Way’s iconic spiral arms. This is due to the kinetic energy exerted on the dead star by the supernova explosion, erasing this feature. Most of the dead stars flying around enter the halo, and a third will leave the Milky Way and enter intergalactic space. And to the surprise of the researchers, the Death Star also came close to the solar system.
The solar system is relatively outer in the Milky Way, and it is also easier to encounter dead stars thrown from the interior in this region. The closest dead star to the sun is only 65 light-years away, which is very close on the scale of the universe. So the solar system is actually traveling through the graveyard of the dead star, but that just happens to be more convenient for us to observe it. The sun will go out of the main sequence star stage, become an unstable red giant star, and eventually die in the explosion leaving a white dwarf star, but it is almost not of the same magnitude as the dead star we mentioned above. It does not have the energy of a dead star, and the sun does not have the acceleration of the shock wave generated by the supernova explosion, so it cannot rush to the periphery, so the sun cannot enter the cemetery of the Milky Way.