ESA reveals the future of our sun while building the ultimate Milky Way map

In 5 to 7 billion years, our sun will reach the end of its life. Its supply of hydrogen – the juice that keeps it going – will run out, and the star that once lit up all we know and love about our world will cool, darken, and turn into a stellar corpse or dwarf. white.

Don’t worry too much, though, as it’s obviously quite a distance from here. Right now, our sun is considered to be in its prime. It’s in its comfortable middle age, at 4.57 billion years, productively fusing hydrogen into helium and shining like a glorious paper lantern.

But scientists are still interested in understanding the future path of the sun.

Although we might expect our host star to be the easiest to study, it is actually much more difficult to analyze than more distant stars because it is so bright due to its proximity. We need special telescopes and instruments suitable for solar observations. Yet, “If we don’t understand our own sun – and there’s a lot we don’t know about it – how can we hope to understand all the other stars that make up our wondrous galaxy,” Orlagh Creevey, an astronomer of the Côte d’Azur Observatory in France, said in a press release.

Creevey is also part of the European Space Agency massive effort to map the entire Milky Way galaxy with unprecedented detail. It’s called Gaia – and of course, while constructing an ultimate diagram of our cosmic neighborhood, the Gaia collaborators figured out what will happen to the sun billions of years from now.

In short, the team found that the sun would reach its maximum temperature around 8 billion years, after which it would cool down but continue to increase in size. At around 10 to 11 billion years old, according to data from Gaia, the sun will become a spectacular red giant (like the 10th brightest star in the world). night sky, called Betelgeuse) before starting its eventual end-of-life sequence.

A visual representation of the lifespan of the sun can be seen below. It follows a line found on the Hertzsprung-Russell diagram, which plots a star’s intrinsic luminosity against its effective surface temperature. Note how, as the video progresses, the path of the sun begins to intensify. Exponentially.

The evolution of a sun-like star, as derived from the ESA Gaia mission data release 3, from the Hertzsprung-Russell diagram.


This version of a Hertzsprung-Russell diagram was obtained with a selection of stars from Gaia’s second catalog. It’s the most detailed to date made by mapping stars all over the sky, according to the ESA.


The way the team got this information was sort of by casting an ultra-wide net over all the Gaia data retrieved from the Milky Way so far, then identifying the stars with temperatures, surface gravities, chemical compositions, masses and rays similar to those of the sun. For example, the research focused on surface temperatures between 3,000 kelvins and 10,000 kelvins because the sun has a current surface temperature of 6,000 kelvins.

But when searching for these candidates, the team made sure to select stars similar to our sun but of different ages, so that a detailed timeline could be constructed. “We wanted to have a really pure sample of stars with high precision measurements,” Creevey said.

In total, they found 5,863 ideal solar lookalikes, according to the ESA.

In the future, according to the Gaia collaboration, not only will this be useful for developing a clear path of the sun, but it will also be useful for scientists who have other solar questions, such as “are all solar analogues have planetary systems similar to ours “Do all solar analogues spin at a similar rate to our sun?”

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