The European Space Agency has calculated the beginning and the end of the Sun (and therefore of our planet)

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The latest inventory of the Gaia mission has helped astronomers to calculate the life cycle of our own star. Thanks to this we can know with some precision that the Sun has already covered more than the first third of its existence. And with it, our own planet.


A stellar survey.
The third and most recent poll Gaia, the mission of the European Space Agency (ESA) in charge of cataloging and mapping stars, has allowed experts to make a more precise calculation of their life cycle. To achieve this, they have been based on different data compiled by Gaia such as temperature, size and mass.

The task of finding out various parameters of the stars based on two factors observed by Gaia (color and apparent magnitude) is not easy. Fortunately for the experts, color gives us a lot of information of a star thanks to the spectral lines.

Each element has, by issue or absorption, a unique “signature”. This is how astronomers manage to identify the elements present in space and this is how, based on Gaia data, it is possible to identify the temperature at which a star “burns”. The graph resulting from this classification is called the Hertzsprung-Russell (HR) diagram.

The Sun has always been a great mystery.  Now perhaps we have found the key: it rotates internally

Follow the example.
Thanks to this complete compendium of stars, we can draw the life of the stars in this graph, focusing on those that, having masses similar to that of the Sun, have comparable life cycles. A group of researchers has achieved precisely this and has published their results as a preprint in the ArXiv repository.

Orlagh Creevey, who leads this article, explained in a press release that the team “wanted to have a really pure sample of stars with very precise measurements.” With the Gaia data in hand, the team already had the required precision data.

The HR diagram of stars like the Sun starts from low luminosities and average temperatures. As they advance in their life cycle, stars like the Sun are constantly gaining in luminosity, although their temperature advances in the shape of an inverted U, gradually gaining temperature and then cooling.

Lack of fuel.
This dynamic comes regulated by the amount of fuel that the stars can burn It is when the hydrogen in the core of the star becomes scarce that its surface temperature begins to cool down and the star to expand. The rate at which this process occurs depends on some of the factors observed thanks to Gaia,

Nothing is eternal.
That the Sun had an expiration date is not new. What we now know better is what the Sun’s journey through its life will be like and how long it will take before it wipes out any vestige of life that may remain on our planet and in our environment in its last rales. Fortunately, calculations from Gaia put this date still far in time.

Sun It has about 4,570 million years of existence and it will continue as it is until it is 8,000 million years old. It will then enter the moment of maximum temperature. Thereafter it will begin to grow until it becomes a red giant star at a point between 10,000 and 11,000 million years of existence. From there it will begin to cool down and end its days as a white dwarf.

Parallel lives.
The life cycle of the Sun will irremediably affect that of the Earth. Our planet is, in astronomical terms, little younger than our star, about 4.54 billion years. On its way to becoming a red giant, the Sun will increase in size, gradually approaching our planet and predictably engulfing the planets between us and our star.

This will make life on Earth (if it continues to exist) impossible. Fortunately, there are still billions of years for that. It may not be that great in astronomical terms, but it is reassuring when we consider that human beings have only been inhabiting this planet for a few hundred thousand years.

Gaia Mission.
Gaia is an ESA mission in charge of mapping in three dimensions stars both inside and outside the Milky Way, our galaxy. The first batch of data obtained by this mission was published back in 2016 (the mission has been active since 2013). The second batch was published in 2018 and this third in June of this year (with a preview at the end of 2020).

The main apparatus with which the mission operates is a space telescope located at the second Lagrange point of our planet’s orbit. That is, it shares a neighborhood with another popular telescope, the James Webb.

The work carried out by Creevey and his colleagues will open a new way to understand our Sun, especially thanks to the task of identifying a catalog of stars similar to our Sun associated with a multitude of highly precise variables obtained thanks to the work of Gaia and the team at researchers. It is curious that our closest star is so unknown.

Image | NASA/Goddard/SDO

The latest inventory of the Gaia mission has helped astronomers to calculate the life cycle of our own star. Thanks…

The latest inventory of the Gaia mission has helped astronomers to calculate the life cycle of our own star. Thanks…

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