Astronomers have discovered the closest-known black hole to Earth, which is in the stellar-mass category.
The fact that this is the first clear finding of a dormant stellar-mass black hole in the Milky Way makes it much more intriguing. There are an estimated 100 million stellar-mass black holes in the Milky Way alone, each weighing five to one hundred times as much as the sun.
The Monthly Notices of the Royal Astronomical Society has published the findings.
It is currently three times closer to Earth than the previous record-holder, an X-ray binary in the constellation Monoceros, has a mass of around ten times that of the Sun and is situated about 1600 light-years distant in the constellation Ophiuchus.
What is a Black Hole?
Light cannot escape from a “black hole,” a region of space where gravity is so strong that it prevents it. Gravity is so powerful because energy has been compacted into a small area. This happens when the star dies.
Humans can’t see black holes because no light can escape. They are invisible. It can be found with the use of space telescopes that are fitted with specialist equipment. Using specialized equipment, it is possible to see how stars that are close to black holes behave differently from other stars.
Among all things in the universe, these are the most extreme. Most likely, the centers of all large galaxies contain supermassive versions of these inconceivably dense objects. With an estimated 100 million in the Milky Way alone, stellar-mass black holes—which weigh five to one hundred times as much as the sun—are much more prevalent.
Only a few of black holes have been identified so far, and practically all of them are “active,” which means that they generate strong X-rays as they devour material from a nearby star companion, as opposed to dormant ones, which do not.
Black Hole: The Sun-like-Star
A Sun-like star that circles the black hole at roughly the same distance as the Earth orbits the Sun was observed by astronomers using the Gemini North telescope on the island of Hawai’i, one of the twin telescopes of the International Gemini Observatory.
“You may create this system by taking the Solar System and placing a black hole where the Sun and Earth are. While numerous such systems have allegedly been discovered, practically all of these findings have since been disproved.” Lead author of the study and astrophysicist Kareem El-Badry said.
“This is the first unequivocal observation of a Sun-like star in a wide orbit around a stellar-mass in our galaxy.”
By examining data from the Gaia spacecraft of the European Space Agency, the team first determined that the system might contain one. They later used the Gemini Multi-Object Spectrograph instrument on Gemini North to determine that the central body is a black hole that is about ten times as massive as the sun.
The scientists precisely estimated the companion star’s orbital period by measuring its velocity as it orbited the black hole.
“We barely had one week until the two objects were at their closest separation in their orbits when we initially discovered the constellation had one. In a binary system, reliable mass estimations need measurements at this point. The capacity of Gemini to provide observations in a timely manner was vital to the project’s success. We would have had to wait an additional year if we had missed that narrow opportunity.” El-Badry explained.
The progenitor star that subsequently evolved into the recently discovered black hole was thought to have only had a brief lifetime of a few million years, according to astronomers.