A third of the planets orbiting red dwarfs in our galaxy ‘may have life’, study claims

The study claims that a third of the planets orbiting red dwarfs in our galaxy may be in the “habitable zone” – and they may have alien life.

  • The researchers used data from NASA’s Kepler telescope to study red dwarfs.
  • Red dwarfs have a very small mass and make up the majority of the stars in our galaxy.

The search for life on other planets has long been one of the biggest challenges for astronomers.

Now a new study suggests there are hundreds of millions of promising targets in the Milky Way galaxy to study for signs of life beyond our planet. solar system.

using NASAKepler telescope, researchers studied a small sample planets orbiting red dwarfs are low-mass stars common in our galaxy.

They found that a third of the planets, which corresponds to hundreds of millions in the entire Milky Way, probably have suitable conditions for life.

Scientists estimate that one-third of the planets orbiting red dwarfs in our galaxy

Scientists estimate that one-third of the planets orbiting red dwarfs in our galaxy “could be home to life.” Pictured is a planet orbiting a red dwarf, the most common type of star in our Milky Way galaxy.

A new study was conducted by specialists from the University of Florida and published in the journal Proceedings of the National Academy of Sciences.

What are red dwarfs?

Red dwarfs, also known as M dwarfs, are the smallest, most abundant, and longest-lived stars in the galaxy.

Red dwarfs are stars with a low mass – they have a mass of about 0.08 to 0.6 of the mass of the Sun.

Due to their low luminosity, individual red dwarfs are not easy to observe.

“I think this result is really important for the next decade of exoplanet research, because the view is shifting towards this population of stars,” said study author Sarah Sagir.

“These stars are excellent targets for finding small planets in orbit where water could be liquid and therefore the planet could be habitable.”

Our Milky Way galaxy is estimated to contain between 100 and 400 billion stars and at least as many planets.

Interestingly, only about 20 percent of the stars in the Milky Way galaxy are similar to our Sun, making it a “relative rarity” according to researchers.

By far the most common stars are red dwarfs, which are much smaller and colder, and their mass is no more than half the mass of our Sun.

Red dwarfs make up the bulk of the Milky Way’s stellar population – estimated at almost 75 percent – and are roughly the size of Jupiter.

For their study, the scientists used new data from NASA's Kepler telescope, which collected information about exoplanets moving in front of their stars, in what is known as a

For their study, the researchers used new data from NASA’s Kepler telescope, which will collect information about exoplanets moving in front of their stars, in what is known as a “transit.” This is an artist’s impression of the Kepler Space Telescope, which was decommissioned by NASA in 2018 after nearly a decade of service.

What’s more, there are billions of planets orbiting these common dwarf stars in our galaxy, making them a special target for astronomers.

Eccentric orbits and tidal heating

The more oval a planet’s orbit is, the more eccentric it is.

If a planet orbits close enough to its star, about the same distance as Mercury orbits the Sun, the eccentric orbit can subject it to a process known as tidal heating.

As the planet stretches and deforms under the changing gravitational forces in its irregular orbit, friction heats it up.

In a pinch, this could bake the planet, ending any chance of liquid water.

For their study, the Florida team measured the “eccentricity” of the orbits of a sample of more than 150 planets around red dwarfs in the Milky Way.

To measure the orbits of the planets, the researchers focused in particular on how long it takes the planets to move across the surface of stars, which is known as “transit”.

Their study also relied on new data from the European Space Agency’s Gaia telescope, which measured the distance to billions of stars in the galaxy.

“Distance is really a key piece of information that we were missing before and that allows us to do this analysis now,” Sagir said.

To trap enough heat to be habitable, astronomers say planets must be very close to their red dwarfs, making them vulnerable to extreme tidal forces.

In their analysis, based on data from the telescope, the team found that two-thirds of the planets around red dwarfs could be fried by these tidal extremes, sterilizing them.

But that leaves one-third of the planets – which equates to hundreds of millions across the galaxy – that could be in a “goldilocks” orbit close enough and flat enough to hold liquid water and possibly harbor life.

They also found that stars with multiple planets are more likely to have circular orbits that allow them to hold liquid water.

Meanwhile, single-planet stars are the most likely to encounter extreme tides that sterilize the surface.

The researchers say their findings have implications for planet formation and subsequent observations.

New telescopes such as James Webb will now be key to identifying water – a key signature of life – on “exoplanets” (planets outside our solar system).

PEOPLE OF THE EARTH PLEASE, OUR SUN WILL BECOME A RED GIANT IN APPROXIMATELY 5 BILLION YEARS BEFORE SHRINKING INTO A COMPACT WHITE Dwarf

The sun is only 4.6 billion years old with its approximately 10 billion years of life.

When the hydrogen fuel at the center of the star is depleted, nuclear reactions will begin to propagate outward into its atmosphere and burn the hydrogen contained in the shell surrounding the core.

As a result, the outer part of the star begins to expand and cool, becoming redder.

Over time, the star will turn into a red giant and grow to more than 400 times its original size.

As they expand, the red giants gobble up some of the planets in close orbit. In the case of the Sun, this will mean the fiery end of all the inner planets of our solar system, which may include the Earth.

But don’t worry, it won’t happen for another 5,000,000,000 years.

Once turned into a red giant, swallowing the inner planets and burning the surface of the Earth, it will shed its outer layers, and the open core of the Sun will remain as a slowly cooling white dwarf.

This stellar coal would be incredibly dense, packing most of the Sun’s mass into a sphere roughly the size of Earth.

Source: ESA/National Schools Observatory.