A new video released by NASA shows what the dynamics are like between the closest black holes to Earth and the stars that accompany them. The animation features 22 binary systems located in the Milky Way and our neighboring galaxy, the Large Magellanic Cloud, that host confirmed stellar-mass black holes.
In the images it is possible to see in each pair that the binary systems are formed by a star that orbits in a black hole. In each part of the animation, the black hole is represented by a black dot located in the center of the accretion disk.
The colors of the stars in the video range from bluish-white to reddish, indicating temperatures five times hotter or up to 45% cooler than the Sun, respectively.
According to the space agency, the star is shown as a bluish or yellowish white sphere sized to match its size.
Another detail is that the systems appear on the same physical scale, demonstrating diversity. The orbital motion is accelerated by 22,000 times and the viewing angles are the same as we see from Earth. Black holes are presented on a scale that reflects their respective masses, appearing larger than they actually are.
As the material heats up in the disk as it falls into the black hole, it glows in visible and ultraviolet light, and X-rays are able to capture images — due to the darkness, black holes cannot be seen through a telescope.
According to NASA, astronomers have not yet reached a consensus on how the system at the center of the video, GRS 1915, works. , a distance greater than that which separates Mercury from the Sun, for example.
what is a black hole
A black hole is a region in space where the force of gravity is so intense that not even light can escape from inside it. Once formed, the gravity in the region of the black hole is so strong that all matter attracted to it is compressed until it is destroyed.
Every star that has 20 times the mass of the Sun will turn into a black hole when it “dies”.
Despite what the name says, black holes shine — not on their own, but by interacting with a companion star to detect them. Therefore, astronomers observe the relationship of these celestial bodies. And the best way to do that is to look at X-rays.
A binary black hole can collect energy (feed on) its star in two ways. The first is that a stream of gas can flow directly from the host galaxy’s star to the black hole, swirling “like water down a drain.”
The second is when the star’s solar winds push material into the black hole. When matter is “consumed”, an immense amount of energy, in the form of X-rays, is released.
Cygnus X-1, the first of all
The first black hole known to researchers is Cygnus X-1, weighing 21 times the mass of the Sun.
Its surface, called the “event horizon”, is about 124 kilometers long — which is considered very small for a black hole. However, the visualization shows Cygnus X-1 to be much larger, more in line with the black hole’s mass than its volume.
The oversized spheres also mask visible distortions produced by the gravitational effects of black holes.