(ORDO NEWS) — The inconvenient astronomical truth is that no one receives a personal invitation to witness the dying breath of a star. To see a star at the critical moment of its death is a matter of fate, which makes it a rare find.
With a little help from a conveniently located cluster of galaxies, an international team of researchers measured the burst of light emitted by a distant supernova at three different times.
This data will allow them to test theories about what a star’s fading light might tell us about its size.
The star itself is too far away for any telescope to see it in detail. It is so far away that its light has taken about 11.5 billion years to cross the gaping expanses and reach our doorstep, entangled in the bright glow of countless other stars in its home galaxy.
However, we can observe changes. in the glow of a star, and they reveal something about how she died. And he lived.
Somewhere between here and there, a jumble of starlight passed within part of the Abell 370 galaxy cluster, a hub of several hundred galaxies about 4 billion light-years away.
Having so many galaxies close together should leave a big hole in the cosmic landscape, causing the star’s light to bend slightly as it slips through.
The effect was something like a giant, galaxy-sized telescope, one with a scratched and wrinkled lens warped by uneven gravity.
Lubricated in a configuration called an Einstein’s cross, the original light was magnified and replicated, creating slightly different versions of the distant galaxy as it appeared at different points in time.
Researchers discovered a ring of gravitationally lensed light in a survey of stars taken by the Hubble Space Telescope back in 2010. light into something sensual, revealing three of the four points of the cross (the fourth was too dim to make out).
An analysis of the light inside each smear showed that somewhere within it, the glow of an exploding star grows, with an interval of eight days. On one of them, the light appeared only six hours after the initial flash.
Together, the three patches of light provide detailed information about how the supernova slowly cools over the course of a week, from a blazing 100,000 Kelvin to a much lower 10,000 K.
Dying stars of a certain size do not go quietly into the night. Having exhausted the atomic fuel needed to start the fire, they cool down just enough for their cores to shatter with a fury that leads to nuclear explosions.
Knowing exactly when a given star will explode is something. researchers are slowly making the process go further. While expanding shells of gas and light from supernova explosions are easy to find, catching a star at the moment of death is a stroke of luck.
Here, astronomers not only got the characteristic outburst of a dying star in a galaxy far, far away, but they also had important details of changes in its light over a short period.
This information helps validate models of how matter around stars interacts with the flare, radiating from within, heating up quickly, and then rapidly cooling down, allowing them to work backwards to determine the star’s original size from how it cools.
Based on what they learned in this case, the team is confident that the star they witnessed at the time of its death had a radius of more than 530 times that of our own Sun.
The study not only supports theoretical models for the evolution of supernovae and the stars that produce them, but also opens up a way to analyze an entirely new population of stars from the early universe.
And that’s how close to inviting the last fleeting star moments we’ll ever get.
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