Groundbreaking research by scientists at the University of Leeds proposes that Be star is part of a triple star system, rather than a binary system as previously thought. This discovery from Gaia satellite data challenges traditional star formation theories and could impact our knowledge of black holes, neutron stars, and stars. gravitational waves.
A groundbreaking new discovery by scientists at the University of Leeds could change the way astronomers understand some of the largest and most common stars in the universe.
Research by Jonathan Dodd, a doctoral student in the University’s Department of Physics and Astronomy, and Professor René Oudmayer shows that massive Be stars, previously thought to exist mainly as double stars, are actually triple stars. They point to interesting new evidence that this is possible.
This remarkable discovery has implications for our understanding of astronomical objects (a subset of B stars) that are considered important “testbeds” for developing theories about how stars evolve more generally. It could bring about a revolution.
Nature of Be Stars
Be stars are surrounded by a distinctive disk of gas. This resembles a star ring. Saturn within our solar system. Be stars have been known for about 150 years since they were first identified by the famous Italian astronomer Angelo Secchi in 1866, but until now no one knows how they formed. I didn’t know either.
The consensus among astronomers so far is that the disk is formed by the rapid rotation of the Be star, which itself may be caused by the interaction of one star with another in a binary system.
Elucidation of the triple system
“If you’ve ever seen Star Wars, the best reference point for that is that there are planets with two suns,” said Dodd, lead author of the study.
But now, by analyzing data from the European Space Agency’s Gaia satellite, researchers have found evidence that these stars actually exist in a triple system, with three bodies interacting instead of just two. say the scientists.
Mr Dodd added: “We observed stars moving across the night sky over long periods of 10 years and short periods of about 6 months. We found that when stars move in a straight line, there is only one star. However, if there are multiple stars, you will see a slight wobble, and in the worst case you will see a spiral.
“We applied this to the two groups of stars we study, B and Be stars. And, confusingly, Be stars initially had a higher proportion of companion stars than B stars. We found that the performers appear to be lower. This is interesting because we would expect their rates to be higher.”
But lead researcher Professor Udmayr said: “The fact that we don’t find them may be because they are now too faint to detect.”
matter transfer
The researchers then looked at another dataset to look for more distant companions and found that at these larger distances, the proportion of companions was very similar between B and Be stars. discovered.
This suggests that in many cases a third star comes into play, bringing the companion star closer to the Be star, close enough that mass can be transferred from one to the other to form the characteristic Be star disk. I could guess that. This may also explain why we don’t see these friends anymore. After the “vampire” Bee stars sucked in most of their mass, they have become too small and faint to be detected.
broader astronomical impact
This discovery could have major implications for other areas of astronomy, including our understanding of black holes, neutron stars, and gravitational wave sources.
Professor Oedmeyer said: “There is currently a revolution in physics centered around gravitational waves. We have only started observing these gravitational waves in the last few years, and it turns out that they are caused by black hole mergers. Did.
“We know that mysterious objects such as black holes and neutron stars exist, but we don’t know much about the stars that become them. Our discovery provides clues to understanding the sources of these gravitational waves. Masu.”
He added: “Over the past decade or so, astronomers have discovered that binary stars are a very important factor in the evolution of stars. We’re moving towards the idea that we need to take into account.”
“Certainly,” Udmayer said. “Triple has become the new binary.”
reference: “Gaia “Uncovering the small-scale binary differences between B and Be stars: Evidence for mass transfer driving the Be phenomenon” Jonathan M. Dodd, René D. Oudmayer, Isaac C. Radley, Miguel – Vioque, Abigail J. Frost, October 12, 2023. Royal Astronomical Society Monthly Notices.
DOI: 10.1093/mnras/stad3105
In addition to Leeds PhD students Mr Dodd and Professor Udmyer, the team behind the discovery also includes Leeds University PhD student Isaac Radley and former Leeds academic Dr Miguel Vioque of ALMA in Chile. and Dr. Abigail Frost of the European Observatory. Southern Observatory in Chile. The team received funding from the Science and Technology Facilities Council (STFC).