There would be many habitable Tatooine in the galaxy

Half of the stars similar to our sun are what astronomers call double stars. In reality, systems are formed by two stars orbiting each other. A configuration that is not without significance for the composition of the planets that surround them. Including planets that could host extraterrestrial life.

There are so manystarsstars in our UniverseUniverse. So many planets too. Looking for traces of extraterrestrial life is a bit like looking for a needle in a haystack. Except, perhaps, focusing primarily on planets that resemble the only planet we know has allowed life to evolve: our Earth. It is therefore astronomersastronomers search the sky for stars near the sun. At least its characteristics. However, half of them are double stars. Does this affect the chances of seeing life develop there?

Possible, say researchers from the University of Copenhagen (Denmark) today. They have just shown that planetary systems form very differently around binary stars. A process that could increase the chances of seeing habitable planets develop there.

Nine out of ten exo-Earths around binary stars would be conducive to life

As a starting point for this work, observations have been made thanks to the large selection of millimeter/submillimeter antennas from Atacama (Alma, Chile). They show a snapshot of a young binary star – it is only about 10,000 years old – surrounded by a disk of gasgas and dust. The system NGCNGC 1333-IRAS2A is located around 1,000 light yearslight years of our land. It consists of two stars separated from each other by about 200 astronomical units. Understand, about 200 times the Earth-Sun distance, or more than six times the Sun-Neptune distance.

A larger living area

From these observations launched astronomers computer simulationscomputer simulations which shows that the development of the disc of gas and dust – precisely the one that is destined to give rise to exoplanetsexoplanets – is not linear. About every 1,000. year and for ten to a hundred years it is shaken off movementsmovements strong. Parallel to this, the double star becomes very bright. Ten to a hundred times more than normal. Probably an effect of gravitygravity exerted on each other by the two stars that make up the system. And which at certain times causes huge amounts of matter to fall towards its main star, causing heating and therefore an increase in brightnessbrightness of the star in question.

These jerkjerk, say the researchers, could affect the structure of the formed planetary system. influence on the chemical composition of materialmaterial from which the planets will form. Because these heating phases will trigger the evaporation of dust grains and ice that may surround them. An influence, therefore, on the extent of what extraterrestrial scientists know as the habitable zone. An area where water can especially exist in a liquid state.

To better understand whether the process might give the ingredients of life a chance to meet in such binary star systems, astronomers will need more observational data. They also need to know if icy comets can bring the building blocks of life to planets that are ready for it. To respond to this, researchers still expect a lot from Alma, but also from the new instruments that will soon be available to them: James Webb Space TelescopeJames Webb Space Telescope (JWST), theEuropean Large Telescope (ELTELT) or that Square Kilometer Array (SKA). Astronomers will then have a combination of information sources that should produce interesting results.

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