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Type Be stars, called “vampire” stars, are believed to strip away the mass of a nearby star.
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Scientists are trying to figure out how this happens.
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New research shows that a third star may be facilitating mass transfer.
Giant “vampire” stars feasting on their celestial companions may be helped by a third hidden star, according to new research in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society to create.
Type Be stars are characterized by their large size and surrounding gas rings. B type starsThese are very warm, bright and blue. PhD student Jonathan Dodd says the subtype makes up about 20% of the population of type B stars. student and one of the study’s lead authors told Business Insider:
The nickname “vampire stars” comes from the most accepted theory of how Be-type stars form rings by sucking on the metaphorical neck of an intergalactic victim, the researchers said in the study.
According to the theory, as Type Be stars rotate rapidly, they collect matter from a companion star. This material then surrounds the star like a ring, causing the Be star to spin faster as it collects more of its companion. These companions, which become smaller due to loss of matter, can be anything from a neutron star to a white dwarf.
But how they began the process of rapidly spinning and collecting the matter was a mystery. Normal B-type stars also had companions they didn’t feast on, so what made the two different?
The researchers say that a hitherto unobserved third star facilitates mass transfer by bringing the Be star and its companion closer together, just as a vampire’s captivity can guide a victim to its master.
“We didn’t go into the study thinking we’d find triplets, instead we looked for how often these stars are doublets, but based on our results triplets were the most plausible explanation for what we saw,” Dodd said.
‘Triples are the new couples’
University of Leeds scientists used data from the European Space Agency satellites – Hipparcos and Gaia – to map the stars of the universe.
The team observed Be type stars by comparing the positions of various stars over longer and shorter periods. The team also looked at B-type stars to compare the two.
If the positions of stars move in a straight line, there is only one star in the system, the researchers said. If it was wobbling or spiraling, one of the stars had a companion star. This is because gravitational forces affect the movement of the star.
However, the team was surprised to learn that they detected a higher proportion of binary systems for B-type stars than for Be-type stars. Additionally, when the researchers found companions for Be-type stars, the distances between their companions and those of B-type stars that do not have the characteristic rings were quite similar.
The researchers then expanded their search to see if Be-type stars had companions at greater distances. That’s when the ratio of companions between B-type and Be-type stars began to equalize.
This led the researchers to believe that the distant companion they observed with Be-type stars was actually a third star.
Because three-star systems are inherently unstable, stars that start close together will eventually eject one star. The force of the third star rapidly emerging from the group may initiate feeding by bringing the Be type star and its companion star closer together.
Dodd told Business Insider that this phenomenon is most common in other triple star systems, lending credence to his statement that Be-type stars are no different.
Once Be-type stars absorb all the stars, this could also explain why Be-type stars are observed to have lower close friend ratios, the researchers said. stack The researchers suggested that the companion stars had become too faint to be detected.
The team is now looking at future research to observe these Be-type stars in more detail, and hopes their work will help inform astronomers about other phenomena such as black holes, neutron stars or gravitational wave sources. Dodd said these “close to each other” multi-star systems could be the “pioneers” of this phenomenon.
Dodd said their research also means scientists should start paying more attention to triple star systems.
“Triples are new binaries,” Dodd said, “and the lives of stars are affected by the presence of nearby stars more often than previously thought.”
Read the original article on Business Insider