Black hole in the Milky Way: New images reveal the “secrets of the galaxy”

The team, led by Nobel laureate Reinhard Jensel, is researching the black hole Sagittarius A * in the center of the Milky Way – and have discovered previously unknown things in the process.

Corching – Black holes can be very mysterious objects in space. They have a large crowd and attract anything that comes too close to them. But not only do they stimulate the imagination of science fiction writers, they also attract research. A popular research object is the black hole Sagittarius A *, located in the center of our Milky Way galaxy. Now a study team led by Reinhard Jensel, an astronomer at the Max Planck Institute for Extraterrestrial Physics (MBE) in Korching, has achieved something remarkable: researchers have taken sharp and deep images of the area around the vast hole. .

“We want to know more about the black hole at the center of the Milky Way, Sagittarius A *,” said Jensel, winner of the 2020 Nobel Prize in Physics for his research on Sagittarius A *. “How exactly is it? Does it rotate? Do the stars in his orbit act as we expect from Einstein’s general theory of relativity?”

Black hole in the center of the Milky Way: “Secrets of the galaxy”

The largest telescope interferometer (VLTI) in Chile connects the light of four large telescopes with a technique called interferometry, which was used for the work of the research team. The GRAVITY tool was used for this. The technology is complex, “but in the end you get 20 times sharper images than with telescopes, and it reveals the secrets of the galaxy,” says Frank Eisenhauer, president of GRAVITY.

“VLTI gives us incredible spatial resolution, and with new images we can go deeper than ever before,” says Julia Statler, a scientist at the Max Planck Institute for Astrophysics in Korching. “We are amazed at the amount of detail and number of stars that can be seen around the black hole.” Among the stars discovered by researchers is a previously unknown star near the black hole: S300 – This shows how well the system can do. Detection of blurred objects. Last year, a team led by Genzel released data on a star orbiting Sagittarius A *, which proved Albert Einstein’s general theory of relativity.

Black hole Sagittarius A *: Researchers indicate distance to Earth

Between March and July 2021, researchers focused on measuring stars approaching the black hole at the center of the Milky Way to learn more about the black hole. One of these observed stars is S29, the closest star to the black hole in May 2021 – moving only 13 billion kilometers and moving Sagittarius A at 8,740 kilometers (approximately 31.4 million km / h) per second. *. According to the ESO, no star has ever been observed moving too close to the black hole or moving so fast around it.

Black hole in the center of the galaxy: researchers want to measure its rotation

Nobel laureate Jensel explains that “by observing the stars in a tight orbit around Sagittarius A *, one can accurately explore the gravitational field around the massive black hole closest to Earth, and test the general relativity to determine the properties of the black hole.” New research data, along with the group’s previous data, show that stars accurately follow the general relative prediction orbit for objects orbiting a black hole weighing 4.30 million suns. To date researchers have reached the most accurate estimate of the Sagittarius A * mass. They were also able to specify the distance from Sagittarius A * to Earth: 27,000 light years.

In the future, researchers will want to explore the black hole at the center of the Milky Way in more detail. With the help of the largest telescope (ELT) currently under construction, and an instrument developed into GRAVITY +, the team wants to measure the velocity of weak stars in the black hole with the utmost accuracy. Also find out how fast the black hole in the center of the Milky Way spins. “No one has managed it before,” Eisenhower explains. Two studies by the Reinhard Jensel team have been published in the specialized journal Astronomy & Astrophysics.doi: 10.1051 / 0004-6361 / 202142465 And doi: 10.1051 / 0004-6361 / 202142459) (Tab)