Feature of red dwarf star systems could help us resolve the red sky paradox.

(ORDO NEWS) — There is something special about the Earth, except for the many organisms that crawl on it. This is our star, the Sun, this is strange: this is a yellow dwarf.

Stars like the Sun are a minority in the Milky Way. It is estimated that less than 10 percent of the stars in our galaxy are G-type stars such as the Sun.

The most common stars are those we can’t even see with the naked eye: red dwarfs. Their mass is about half that of the Sun, they are cold, dim and have the longest lifespan of all stars.

These stellar lightweights make up 75 percent of all stars in the Milky Galaxy. Path. Thus, one could statistically assume that if life arose somewhere, it would be a planet around a red dwarf.

And yet we are here, with our yellow Sun. This discrepancy between expectations and reality is known as the red sky paradox, and scientists have yet to understand it.

A new paper, accepted by The Astrophysical Journal Letters and uploaded to the arXiv preprint server while it is peer-reviewed and published, may provide a clue.

In fact, it seems that life as we know it might be much more difficult to get started in red dwarf planetary systems because they lack the architecture of asteroids and gas giants to deliver the ingredients for life to Earth-like worlds.

The results could have implications for our search for life outside the solar system, especially given that exoplanets have been identified as “potentially habitable.” often found in orbit around red dwarfs.

Red dwarfs are in some respects one of the most promising targets in our search for habitable worlds. Because they are so small, they burn their hydrogen fuel much more slowly than stars like the Sun.

They could potentially exist for trillions of years – much longer than the estimated lifespan of 10 billion years. The sun and even the age of the universe at 13.8 billion years. This means that life has more time to emerge and potentially flourish.

Red dwarfs also represent an opportunity for our current detection methods. Because they burn so slowly, they are colder and dimmer than the Sun.

This means that the habitable zone the range of distances from a star where habitable temperatures can be found is much closer. Astronomers recently discovered an exoplanet in the habitable zone of a red dwarf with an orbital period of just 8.4 days.

But it seems that the emergence of life and the continuation of its existence may be a difficult task.

Previous research has suggested that red dwarfs may not be the most welcoming environment. For example, such stars are usually very active, often erupting with outbursts that can unleash radiation on any nearby planets.

The authors of the new paper, astronomers Anna Childs, Rebecca Martin and Mario Livio of the University of Nevada, Las Vegas, wanted to determine if red dwarf systems contain enough of the ingredients we think started life on Earth.

Current research indicates that the bombardment by asteroids and comets occurred relatively late in the solar system. the youth changed the earth’s crust in a way that made it more habitable and delivered many of the chemical ingredients needed for it.

Therefore, without the asteroid belt, the number of systems for terraforming and delivering chemicals for life has been greatly reduced.

Models suggest that the formation of a stable asteroid belt and late asteroid bombardment requires the presence of a gas giant beyond the distance from the star, known as the snowline, beyond which volatiles condense into solid ice.

This is because such a gas giant can interact gravitationally with the asteroid belt, causing instability that pushes asteroids into the habitable zone.

So the researchers studied red dwarf systems to see if they could find one of these gas giants.

There are currently 48 red dwarfs with confirmed rocky exoplanets orbiting the habitable zone. Of these, 27 have more than one exoplanet. Of this group, 16 have mass measurements of exoplanets in the system.

Defining a gas giant as a planet between 0.3 and 60 Jupiter masses and calculating the position of the snow line for these systems, the team set off in search of the gas giants.

They found that none of the rocky Earth-like planet systems had a known gas giant in the habitable zone either.

Statistically, the team calculated that there is a population of giant exoplanets orbiting red dwarfs beyond the snow line. This means that, theoretically, red dwarf stars could have asteroid belts.

It’s just that none of the known rocky planet habitable-zone red dwarf systems likely fall into this category, suggesting that the architecture of a red dwarf planetary system could be very different from the solar system we know and love.

There are many assumptions in the game. For example, maybe asteroid impacts aren’t all that important. Perhaps life on red dwarf exoplanets is nothing like life on Earth. We may be overestimating the importance of the habitable zone.

However, based on our current knowledge and understanding of life, things do not look good for red dwarf planets.

“The lack of giant planets in observed (so far) systems containing habitable zone exoplanets suggests that these systems are unlikely to contain an asteroid belt and the mechanism needed to deliver asteroids to the habitable zone in the late stages,” the researchers write. p>

“Therefore, if asteroid impacts are indeed necessary for life, it is unlikely that there is life on observable planets in the habitable zone.”

And, in turn, that may be at least partly why our home planet doesn’t orbit one of those naughty little red stars.


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