Astronomers have discovered a fast-moving star moving across a dark hole in the middle of the Milky Way. The star, designated S4716, completes the orbit of the Sagittarius A (Sgr A ) giant in about four years.
This means a star travels at about 18 million mph (29 million kph), or about 5,000 miles per second. During this rapid rotation of Sagittarius A *, with an estimated diameter of 14.6 million kilometers (23.5 million kilometers), the S4716 reaches close to 9.2 billion miles (15 billion miles) in the most central black hole.
While this may seem a bit far-fetched, it is only a hundred times the distance between the Earth and the sun, which is a small distance in cosmic terms. For example, the sun revolves around Sgr A * at a distance of 26,000 light-years, each light year 5.9 trillion miles (9.5 trillion km).
The S4716 is part of a dense, solid star cluster called the S cluster orbiting near the center of the galaxy and the Milky Way galaxy. These S cluster stars move very fast but vary in brightness and size.
The discovery of a star closest to Sgr * could change our understanding of how our galaxy came to be, especially its fast-moving mid-range stars.
“In the short term, the combined orbit of the S4716 is weird,” Masaryk Brno astronomer Michael Zajaček said in a statement (opens in a new tab). “The stars could not quickly form near the black hole.
The most famous star in the S-cluster is undoubtedly the S2, which has an orbital period around the Sgr A of 16 years and once comes close to the most prominent black hole of 11 billion kilometers (18 million km). But while S2 has been incredibly useful in Sgr A research, it does not always work.
“S2 behaves like a big man sitting in front of you in a theater – it blocks your view of what’s important. So viewing the center of our galaxy is often obscured by S2,” said Florian Peissker, an astronomer at the University of Cologne and co-author of a new study, the statement said. “However, in short, we can see the surrounding area of the black hole in the middle.”
By continuing to refine analytical techniques over two decades and integrating them with 20 years of observation, Peissker and his team could finally ensure the fastest time for orbital S4716.