Astronomers from Georgia State University have found an explanation for the strange appearance of massive stars located far from their place of origin in the disk of our galaxy Milky Way, stars with a mass greater than the Sun have extremely hot cores that drive nuclear power generation at very high rates, and are among the brightest objects in our galaxy.
According to the website,RTThese stars burn their hydrogen fuel very quickly, their lifespan is relatively short, perhaps 10 million years compared to 10 billion years for the sun, and their short life means that they do not have a long time to move away from their birth place.
Most of the massive stars are found in the flat disk portion of our galaxy, where gaseous clouds are dense enough to promote star birth, and where astronomers find small clusters of massive stars, when a massive star is found far from the galactic disk, it is natural to wonder how it got there..
Georgia State University astronomer Douglas Jess said: “Astronomers are finding massive stars far from where they originated, very far away, and in fact, it takes longer than the lifespan of the star to get there. And how this might happen is a topic of active debate among scientists..”
And this is the problem posed by the massive star known as HD93521It is located about 3,600 light-years above the galactic disk.
A new study by Jess and other astronomers from Georgia has revealed a profound contradiction: the flight time to reach this location far exceeds the life expectancy of this massive star..
The astronomers used a new distance estimate from the European Space Agency’s Gaia spacecraft, along with an investigation of the star’s spectrum, to determine the star’s mass and age as well as its movement through space..
And they found that HD93521 It has a mass about 17 times greater than the mass of the sun, and this leads to an expected lifespan of about 5 million years, and on the other hand, the movement of the star indicates that its journey from the disk took longer, about 39 million years..
Georgia astronomers explain this strange difference between a star’s age and travel time by suggesting that HD93521 The disc was left as two less massive and longer-lived stars, rather than the only massive star we see today.
These findings were published in the journal The Astronomical Journal.
The key to the puzzle is that HD93521 It is one of the fastest rotating stars in the galaxy. And stars can orbit through stellar mergers, where two stars that orbit each other can grow over time and collide to form one star..
Jess explains: “Maybe it started HD93521 Life as a close pair of mid-mass stars that supposedly swallowed each other and created the single, fast-spinning star we see today.“.
These medium-mass stars live long enough to match the long flight time ofHD93521.
It is indicated that HD93521 It’s not the only case of a massive star being found far from its birthplace. Georgia State graduate student Peter Wysocki is looking for an example of a large, remote binary system that might be representative of the period just before merger.
This dual system is known as IT Libra, and has a direction that creates a reciprocal eclipse as the two stars pass in front of each other. Investigation of differences in light output and motions detected in the spectra leads to estimates of stellar masses.
Weisuke found a similar mystery from the mass results, the life expectancy is much less than the transmission time IT Libra from disk.
But the study also revealed that the lowest-mass star in the binary had already begun to transfer much of its mass to the higher-mass star, starting the process that could eventually lead to a merger..
This means that the higher-mass star is actually older than it appears, and it started its life as a lower-mass star.
These distant massive stars provide stark evidence that binaries close to stars can fuse to form larger stars, and they are key clues about how quickly massive stars rotate to form massively spinning black holes, Jess said.