Just 160,000 light-years from Earth, a latent black hole has been discovered, at least nine times the mass of the Sun, orbiting a star.
A team of researchers, known as the “black hole police” because they have denied so many black hole discoveries, searched about 1,000 stars for the tarantula nebula in the constellation Dorado before locating it.
They claim that this is the first latent black “star mass” black hole to be detected outside the Milky Way galaxy.
Black holes of stellar mass are formed when massive stars reach the end of their life and collapse under their own gravity.
The black hole is described as “latent” if it does not actively devour matter and, as a result, does not emit light or any other radiation.
The discovery has been compared to finding a “needle in a haystack,” as latent black holes are notoriously difficult to detect because they do not interact with their environment.
The co-author, Dr. Pablo Marchant, of KU Leuven, Belgium, said: “It’s amazing, we hardly know about latent black holes given how common they think astronomers are.”
Artistic Impression of the VFTS Binary System 243. The system, located in the Tarantula Nebula in the Large Magellanic Cloud, is composed of a hot blue star with 25 times the mass of the Sun and a black hole, which is at least new. times the mass of the Sun.
Artistic impression of the VFTS binary system 243. The background image shows an image of a visible and infrared exploration telescope (VISTA) of a segment of the Large Magellanic Cloud, which marks the region where the VFTS 243. The sizes of the star, black hole, and orbits are not to scale
WHAT IS A “BINARY SYSTEM”?
A binary star is a system of two stars that are linked by gravity and in orbit around each other.
One or both stars of the system could be a black hole.
When this is the case, they are often identified by the presence of bright X-ray emissions.
X-rays are produced by matter falling from one component, called a donor (usually a relatively normal star), to the other component, called the accretor (the black hole).
The matter is formed into a bright accretion disk that revolves around the black hole.
However, observations from NASA’s Chandra X-ray Telescope reveal that VFTS 243 is faint in X-rays.
The newly discovered black hole is in the Large Magellanic Cloud, a satellite galaxy adjacent to the Milky Way.
The Large Magellanic Cloud orbits a hot blue star that is almost three times larger than our galaxy.
It is believed that there are thousands of black holes of stellar mass in the Milky Way and Magellanic Clouds.
They are much smaller than the supermassive black hole 27,000 light-years from Earth that feeds the Milky Way, known as Sagittarius A *.
The black hole is part of a “binary” with a bright accompanying star, where they rotate around each other in a system known as VFTS 243.
Co-author Dr Julia Bodensteiner of the European Southern Observatory (ESO) in Germany said: “We have been looking for these black hole binary systems for over two years.
“I was very excited when I learned about VFTS 243, which in my opinion is the most convincing candidate ever reported.”
They needed six years of data from ESO’s Very Large Telescope (VLT) to officially identify VFTS 243.
The VLT’s FLAMES (Fiber Large Array Multi Element Spectrograph) scanner allows you to observe more than a hundred objects at a time.
Historically, binaries harboring black holes of stellar mass have been identified by the presence of bright X-ray emissions from the accretion disk.
The bright accretion disk is made up of gases from the atmosphere of the living star that flow into and surround the black hole.
However, observations from NASA’s Chandra X-ray Telescope reveal that VFTS 243 is faint in X-rays.
This image from the VLT Survey Telescope at the ESO Paranal Observatory in Chile shows the Tarantula Nebula and its surroundings within the Large Magellanic Cloud. Shows star clusters, bright gas clouds and the scattered remnants of supernova explosions
Historically, binaries harboring black holes of stellar mass have been identified by the presence of bright X-ray emissions from the accretion disk (pictured). The bright accretion disk is made up of gases from the living star’s atmosphere that flow into and surround the black hole (stock illustration).
The study, published today in Nature Astronomy, also sheds light on how black holes are created from the cores of dying stars.
The star that gave rise to VFTS 243 appears to have collapsed completely, leaving no trace of a powerful supernova explosion.
Dr Shenar explained: “Evidence of this‘ direct collapse ’scenario has emerged recently, but our study certainly provides one of the most direct indications.
“This has huge implications for the origin of black hole fusions in the cosmos.”
They needed six years of data from the Very Large Telescope of ESO (pictured) to identify the VFTS 243
The FLAMES instrument, mounted on the Nasmyth A platform of the Very Large Telescope in ESO. FLAMES is a high-resolution VLT spectrograph and can access lenses through a large corrected field of view. It allows you to observe more than a hundred objects at a time
Artistic representation of NASA’s Chandra X-ray Observatory space telescope
Despite the nickname “black hole police,” the international team of investigators actively encourages scrutiny of their work.
The lead author, Dr Tomer Shenar, of the University of Amsterdam, said: “As a researcher who has denied possible black holes in recent years, I was extremely skeptical about this discovery.
“For the first time, our team met to report on a discovery of a black hole, rather than rejecting one.”
Dr. Kareem El-Badry of Harvard University in Boston is nicknamed the “black hole destroyer” because of his notoriety for disproving the findings.
Dr. El-Badry said, “When Tomer asked me to review his findings, I had my doubts.
“But I could not find a plausible explanation for the data that does not involve a black hole.
“Of course, I hope that others in the field will carefully examine our analysis and try to develop alternative models.
“It’s a very exciting project to be involved in.”
WHAT’S IN A BLACK HOLE?
Black holes are strange objects in the universe that get their name from the fact that nothing can escape their gravity, not even light.
If you venture too close and cross the so-called event horizon, the point from which no light can escape, you will also be trapped or destroyed.
For the small black holes, you would never survive such a close approach anyway.
Tidal forces close to the event horizon are enough to stretch any matter until it is just a chain of atoms, in a process that physicists call “spaghetti.”
But for large black holes, such as supermassive objects in the nuclei of galaxies like the Milky Way, that weigh tens of millions if not billions of times the mass of a star, crossing the event horizon would be without events.
Since it should be possible to survive the transition from our world to the world of the black hole, physicists and mathematicians have long wondered what this world would be like.
They have resorted to the equations of Einstein’s general relativity to predict the world within a black hole.
These equations work well until an observer reaches the center or singularity, where, in theoretical calculations, the curvature of space-time becomes infinite.