Madrid, 21 years old (European Press)
This remarkable discovery could revolutionize our understanding of these objects (a subset of B stars) and serve as an important “test” for developing theories about how stars evolve in general.
These Be stars are surrounded by a distinctive disk made of gas, similar to the rings of Saturn in our solar system. Although Be stars have been known for about 150 years (they were first identified by the famous Italian astronomer Angelo Cecchi in 1866), until now no one knew how they formed.
Until now, the consensus among astronomers has been that the disks form as a result of the rapid rotation of Be stars, and that this in turn may be caused by the interaction of stars with another star in a binary system.
“The best reference point for this is that if you’ve watched Star Wars, there are planets that have two suns,” said Jonathan Dodd, a physics and astronomy student at the University of Leeds and corresponding author of the paper.
But now, by analyzing data from the European Space Agency’s Gaia satellite, scientists say they have found evidence that these stars actually exist in triple systems, with three interacting objects instead of just two. Results: Monthly Notices of the Royal Astronomical Society.
“We look at the way the stars move across the night sky, for longer periods, like 10 years, and for shorter periods, about six months. If the star moves in a straight line, we know there’s only one star, but if the star moves in a straight line, We know that there is only one star. There are more than one, and we will see a slight wobble, or at best, a spiral.
“We applied this to the two groups of stars we look at, B stars and Be stars, and what we found, confusingly, is that initially Be stars seem to have a lower companion rate than B stars. “This is interesting because we expect them to have a lower companion rate than B stars. higher.”
However, lead researcher Professor Rene Odemeyer said: “The fact that we don’t see it may be because it is now too faint to detect.”
The researchers then looked at a different set of data, looking for companion stars that were far apart, and found that at these larger separation distances, the rate of companion stars is very similar between B and Be stars.
From this, they were able to deduce that in many cases a third star comes along, forcing the companion to move closer to the Be star, close enough that mass can be transferred from one to the other and form the star’s characteristic disk. He is. This could also explain why we do not see these companions; It became too small and faint to be detected after the “Vampire” star Be absorbed much of its mass.
This discovery could have huge implications for other areas of astronomy, including our understanding of black holes, neutron stars, and sources of gravitational waves.
Professor Odemeijer said: “There is currently a revolution happening in physics around gravitational waves. We have only been observing these gravitational waves for a few years, and they have been shown to be caused by merging black holes.”
“We know that these mysterious objects (black holes and neutron stars) exist, but we don’t know much about the stars they will become. Our findings provide a clue to understanding the sources of these gravitational waves.”
He added: “Over the past decade, astronomers have discovered that binaries are an incredibly important element in the evolution of stars. Now we are moving more towards the idea that they are more complex than that and that triple stars need to be considered.” .
“In fact, threes have become the new twos,” Odemeijer said.