We have Black Holes and we have Mini Black Holes, a new study recently revealed.
The universe is getting stranger by the minute. The more we learn about the cosmic neighborhood we live in, the more surprised and baffled we are left by the many mysteries of the universe. A recent study by an international group of astronomers has revealed the existence of an entirely new type of black holes that have gone unnoticed so far for astronomers: mini Black Holes. Just as their larger counterparts, miniature black holes are also mighty cosmic objects.
Mini Black Holes are a thing
The new study, led by Todd Thompson, a professor of astronomy at Ohio State University, offers a completely new way of looking for black holes and shows that it is very possible that in the vastness of space there is an unknown type of cosmic monsters, smaller than the supermassive black holes astronomers are familiar with.
According to professor Thompson, what we know so far would be compared to a census of a city in which only the inhabitants of more than 1.70 meters in height had been taken into account, and in which no one, in addition, even knew that it is possible that there are shorter people. Of course, the data from that census would not represent the real population of the city, and for Thompson, that is exactly what is happening with the search for black holes.
Hunting for (mini)black holes
For decades have astronomers searched the cosmos for black holes that have a force of gravity so strong that nothing, neither matter nor radiation, can escape from its claws once crossed the event horizon, the imaginary line from which nothing can escape.
Normally, black holes form when stars with a high mass contract and explode. If, on the contrary, the original star is smaller and does not have the critical mass, at death, it can form another object of great interest, a neutron star, a “cosmic phenomenon” that is also highly coveted by researchers.
As explained by astronomers, both types of cosmic objects, black holes as well as neutron stars, can contain valuable data about the elements on Earth (the heaviest are formed during stellar explosions), and also about how stars form and collapse.
To access all that information, astronomers have to find out where the black holes are. And to discover them, the starting point is to know precisely what is being searched for.
As revealed by professor Thompson precisely, there is where we make the greatest mistake. We have some clues, of course, that prevent our search from being completely blind, and the most prolific are given to astronomers by binary systems.
When one of the stars in the binary system dies, its companion remains and shines around the space where its companion star once existed, and which may have become a neutron star or a black hole–Mini Black Hole.
Professor Thompson and his colleagues analyzed the data obtained by the Apache Point Observatory Galactic Evolution Experiment (APOGEE), which has already collected light spectra of around 100,000 stars in the Milky Way.
These spectra, in effect, are able to show if a star is orbiting around another object: if the luminous spectrum first changes to more blue wavelengths, and then changes back to more red wavelengths, it suggests that it was approaching (blue) and then moving away (red).
If the pattern repeats, (blue, red, blue, red), the star is likely orbiting a partner in a binary system.
But if a star shows that behavior and the companion star is invisible, then it is very likely that the second star has become a black hole.
Thompson reduced the 100,000 stars studied by APOGEE to the 200 most interesting. And then he compared the data of those potential binary systems with the images of those same stars in another instrument, the All-Sky Automated Survey for Supernovae ASAS-SN, which tracks the sky in search of supernovae.
After comparing the data, the astronomers revealed the presence of a red giant that was orbiting something. That something, according to calculations, was much smaller than the black holes known in our galaxy, although much larger than any of the neutron stars we are familiar with.
After carrying out additional calculations with the Echelle Reflector Tillinghast spectrograph and the Gaia satellite, the researchers realized that they had found a black hole of low mass, about 3.3 times the mass of the Sun.
“We’re pretty sure that there must be many, many of these black holes in binary systems with stars out there in the galaxies, just that we haven’t found them because they’re hard to find,” Thompson told Live Science. But “it’s always interesting to try to find things that can’t be seen.”