Small, high-velocity stars surround the supermassive black hole Sgr A* like a swarm of bees

Observational astronomy shows that newly discovered young interstellar objects (YSOs) in the vicinity of the supermassive black hole Sagittarius A* at the center of our galaxy behave differently than expected. They describe orbits similar to the already known evolved young stars and are arranged in a distinctive pattern around the supermassive black hole.

Studies show that Sgr A* causes stellar objects to adopt certain formations. The study is titled “New candidate stellar objects in the S cluster: Kinematic analysis of a subpopulation of low-mass G objects near Sgr A*” and is published in Astronomy & Astrophysics.

It included researchers from the University of Cologne, Masaryk University in Brno (Czech Republic), Charles University in Prague (Czech Republic), the Academy of Sciences of the Czech Republic and the Max Planck Institute for Radio Astronomy in Bonn.

About 30 years ago, highly dynamic stars were discovered in the vicinity of the supermassive black hole Sgr A* at the center of the Milky Way.

These stars, also known as S stars, orbit the supermassive black hole at speeds of several thousand kilometers per hour every few years. The stars are surprisingly young and their presence is strange, since according to popular theories only old and faint stars can be expected in the vicinity of the supermassive black hole.

The technological progress that has occurred in recent decades and the long periods of observation of the galactic center using a modern telescope currently raise further questions. In 2012, for example, an object was discovered that researchers assumed was a cloud of gas that had been ‘sucked up’ by the supermassive black hole.

While this theory has not been confirmed, it has long been unclear what kind of object this could be. In recent years, increasing evidence has shown that it may be a YSO surrounded by a dust cloud.

In addition to S stars, researchers are currently searching for a dozen objects in the immediate vicinity of the supermassive black hole, which also have very similar properties. They found that the objects were even significantly younger than the already known high-velocity stars.

“Interestingly, these YSOs exhibit the same behavior as S-stars. This means that YSOs orbit the supermassive black hole at speeds of several thousand kilometers per hour in a few years,” explained Dr. Florian Peißker from the Institute for Astrophysics at the University of Cologne. and the corresponding author of the study.

“The S stars were found to be surprisingly young. According to conventional theories, the additional presence of a stellar garden composed of YSOs is completely unexpected,” added Dr. Peissker.

Moreover, this cluster of high-velocity objects, consisting of YSOs and S stars, appears to resemble a chaotic swarm of bees at first glance. However, in the same way that a swarm of bees has a regular pattern and formations, so do YSOs and S stars.

In this way, the researchers were able to demonstrate that YSOs as well as S stars are arranged in a specific way and organized within three-dimensional space.

“This means that there are specific star preferences. The distribution of both star variations resembles a disk, which gives the impression that the supermassive black hole forces the stars to take an organized orbit,” said Peißker.