Each time, the Bird Trail removes the star. The crowded star is usually pushed out of a chaotic area in the center of the galaxy, home to the Super Massive Black Hole (SMBH). However, at least one of them was displaced by the discovery of a relatively calm galaxy disc, in which astronomers rethinked this whole phenomenon of star crowding.
"This discovery is a major change in our approach to the origin of fast-changing stars."
Monica Valluri, U-M, Professor of Astronomy at the Department of Literature, Science and Arts.
The aforementioned star is a rapidly changing star, or is also called a hypervelocial star. Hypervelocity stars in our galaxy are quite rare. The first one was found in 2005, and so far scientists have discovered less than 30 of them. They travel more than 1
To understand what is happening, take a look at the overall structure of the Bird Path.
The Galactic Bubble is in the center and deep-seated in the heart is our Galaxy SMBH, Sagittarius A * (Sag. A Star). galaxy spiral weapons. In this study, less significant are the star halos and globular clusters.
When a star is pushed out of the galaxy, it is usually one star of a binary pair. Scientists believe that the binary pair is too close to SMBH and its huge gravity, the hole captures one of the stars. The other star is shot into space by "gravitational bands". The black hole must be super massive, because only they have a powerful enough gravity to accelerate these running stars to such high speeds.
However, scientists from the University of Michigan have identified a single "hypervelocity" star that seems to have been pushed out of the star disk rather than a galaxy bubble.
Monica Valluri and Kohei Hattori watched the hypervelocytic star called
LAMOST-HVS1, which is closer to the Sun than any other. They used one of the Magellan telescopes to measure the speed and position of the star. Then they joined other colleagues and merged their data with the ESA Gaia mission data to find the hypervelocity trajectory back to its origin. They were surprised when the star's origin was not a bubble, but a galaxy disc.
"This discovery dramatically changes our approach to the origin of fast-changing stars," said Monica Valluri, a scientific professor at the Department of Astronomy at the U-M Literature, Science and Arts College. "The fact that the trajectory of this massive, rapidly changing star appears on the disk rather than in the center of the galaxy indicates that the extremely extreme environment required to expel the fast moving stars can occur elsewhere than the supermassive black holes."  "We need to consider other stars
Kohei Hattori, PhD student at the University of Michigan
"We thought this star came from the center of the galaxy. But if you look at its trajectory, it is clear that it is not related to the Galactic Center, ”Hattori said. "We have to consider the other options of star origin."
What would be the possibilities?
The authors are currently not sure. One option is a different kind of meeting. The runaway star could come across a group of massive stars, and it was displaced by the intricate gravitational interaction.
This type of collision in the past has caused ugly stars. But nothing that happens as fast as LAMOST-HVS1. The Star-cluster run was held at 40-100 km / s (25-62 miles per second), but none of them was close to 500 stars per second that this star travels.
Another, more exotic option is the Black Hole . There may be other intermediate black holes in the galaxy disk that are heavy enough to push the star into space. But it's a little more than guessing.
If this is a star cluster pushing LAMOST-HVS1, no one has seen it yet. The Hypervellation Star was from Norma's spiral arm, which is not associated with any known massive star clusters. However, this area is well-covered with dust. There may be a cluster with enough mass to displace the star.
If astronomers were able to find a huge cluster, it could show that all the hypervelocal stars were pushed out of collisions with huge clusters, and SMBH has nothing to do with it. Or, with me here, a massive star cluster can have an intermediate black hole in its center, powerful enough to displace the star.
At present, the origin of LAMOST-HVS1 remains unclear.