In the depths of the “Vacuum Cleaner” constellation, and at a distance of only 82 light-years from our planet, astronomers have discovered a unique system composed of four stars, dancing in harmony by the forces of gravity. This system includes a pair of small stars known as red dwarfs, as well as another pair of fainter and cooler objects, which are classified as brown dwarfs.
According to the “study” published by researchers in the “Monthly Notices” of the British Royal Astronomical Society, this system has a complex name “UBM J1040-3551”, but scientists prefer to call it a “two-tiered cosmic family.”
At the heart of this cosmic family lies a pair of red dwarf stars, each with a mass estimated at about 17% of the Sun’s mass, and their brightness reaches a temperature of about 3200 Kelvin, which is much lower than the Sun’s temperature. It is worth mentioning that Kelvin is a measure of temperature, and is equivalent to Celsius plus 373 degrees.
As for the outer edges of this system, there is another, more bizarre duo, consisting of two brown dwarfs, whose temperatures do not exceed 820 Kelvin and 690 Kelvin, respectively, which is much lower than the melting point of iron!
Brown dwarfs are perplexing astronomical objects, occupying the middle ground between stars and planets. They are larger than giant gas planets like Jupiter, but do not have enough mass to trigger nuclear fusion reactions of hydrogen in their core, as stars do. Therefore, they are sometimes called “failed stars.”
Brown dwarfs consist of gases similar in composition to stars, but emit faint light in the infrared range instead of visible light, and gradually cool down over time.
A vast distance of 1650 astronomical units separates the “families” (where one astronomical unit equals 150 million kilometers), and the entire system takes more than 100,000 years to complete one orbit around each other.
This system was first discovered through data from the European Space Agency’s “Gaia” satellite, which is characterized by its ability to measure the positions and movements of stars with high accuracy, and aims to draw the most accurate three-dimensional map of the Milky Way galaxy.
According to the study, the researchers noticed that one of the red dwarf stars appears brighter than expected, and that its position is shaking slightly, indicating the presence of an invisible companion object.
After that, the scientists used the “SOAR” telescope in Chile to follow up on spectral and infrared observations, so that the image gradually became clear, revealing the presence of a harmonious quadruple system, consisting of two central red stars, and two brown stars orbiting in the outer edges of the central system.
The lead researcher in the study, Zhiang Zhang, describes this system as a “perfect laboratory for understanding how small and multiple star systems form.”
The existence of a pair of brown dwarfs orbiting a pair of red stars suggests that brown dwarfs may form in the same way as stars, that is, through the collapse of the same clouds of gas and dust, and not as a side result or “formation failure” as previously thought.
What is even more interesting is that the large distance between the two binaries shows that gravity alone is able to maintain the cohesion of the system over hundreds of thousands of years, despite the weakness of the masses of its components. This is what prompts scientists to reconsider the limits of the stability of low-mass star systems.
The impact of this discovery extends beyond simply adding a new star to the astronomical maps. Thanks to this system, astronomers will be able to calibrate the physical models of brown dwarfs, and understand how their temperature and luminosity change with time and mass change.
This discovery will also help them test the theories that try to explain the origin of these mysterious objects: Are they “giant planets” that formed outside a stellar range, or “incomplete stars” that have not been able to reach the threshold necessary for ignition?
source: 961 today
