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Ancient planetary system with its own sun-like star found in the Milky Way galaxy

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Planets in space and a spiral galaxy (Shutterstock.com)

The discovery of five archaic planets around one of the oldest stars in the galaxy has raised the possibility that the Milky Way might be home to extremely ancient forms of life.

Astronomers spotted the planets as they circled a star called Kepler 444, which lies 117 light years from Earth in the direction of Lyra, a constellation in the northern sky.

Researchers used variations in the brightness of the star to calculate its age and found that it was among the first generation of stars to illuminate the Milky Way 11.2bn years ago.

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The sun, Earth and other planets of the solar system formed much more recently, about 4.5bn years ago, making the Kepler 444 planetary system more than twice as old as our own. By the time the Earth had formed, the planets around Kepler 444 were already older than the Earth is today.

The planets that orbit Kepler 444 are not hospitable to life as we know it. But the discovery of such profoundly old and almost certainly rocky planets suggests that other ancient worlds might lurk around other stars in more habitable reaches of the Milky Way.

“This tells us that these kinds of planets formed very early in the history of the galaxy. If some fraction formed in the habitable zones around their host stars, then you have environments where life may develop, and it could have been there for a very long time,” said Bill Chaplin , professor of astrophysics at the University of Birmingham.

Writing in The Astrophysical Journal , the scientists add: “Earth-size planets have formed throughout most of the Universe’s 13.bn year history, leaving open the possibility for the existence of ancient life in the galaxy.”

The worlds that orbit Kepler 444 are small, at least by planetary standards, and range in size from Mercury to Venus. They are extremely close to their parent star, with all five planets closer in than Mercury is to the sun. A year on each planet lasts fewer than 10 Earth days.

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Kepler 444 is about three quarters the size and mass of the sun, and though 700C cooler, the planets circle so close to the star that their surfaces are permanently fried. The habitable zone around the star, where the temperature is just right for liquid water to flow, lies six times further out than the outermost of the five planets, said Chaplin.

Researchers measured the age of the star by using Nasa’s Kepler space telescope to observe minute changes in its brightness. The intensity of stars varies because sound waves trapped inside them make them contract and expand, as though they were breathing. When a star compresses it gets hotter and brighter. When it expands, it gets cooler and dimmer.

How a star’s brightness varies depends on the speed of sound waves within, and that is governed by the composition of its core. This material at the heart of the star changes as it grows old, for example, as the star converts its hydrogen fuel into helium.

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“As you change the composition of the core, you change the speed at which sound waves moves through the star, and that affects the periods at which it resonates,” said Chaplin. “Because we can do this astroseismology, we can get very precise measurement of the age. It’s a very old star, over a 11bn years old.”

Astronomers are now keen to discover other ancient planetary systems, in the hope of pinpointing the beginning of the era of planetary formation in the universe.

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guardian.co.uk © Guardian News and Media 2015


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2020 Election

Trump acts out his Superman fantasy for Florida seniors at campaign rally

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It's not the first time President Donald J. Trump has acted out his apparent Superman fixation at one of his superspreader rallies - and it certainly doesn't appear it will be his last.

“In several phone calls last weekend from the presidential suite at Walter Reed National Military Medical Center, Mr. Trump shared an idea he was considering: When he left the hospital, he wanted to appear frail at first when people saw him, according to people with knowledge of the conversations. But underneath his button-down dress shirt, he would wear a Superman T-shirt, which he would reveal as a symbol of strength when he ripped open the top layer,” The Times reported earlier this month.

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BLM activist details FBI visit to her home: ‘This is why this president is so dangerous’

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President Donald Trump's incitement of racism in his supporters was blasted by Black Lives Matter activist Alicia Garza on Friday.

"The FBI visited my house today," she revealed on Twitter.

"They arrested a man in Idaho on weapons charges who they believe was affiliated with white supremacist groups. They found my name on a list in his home, alongside others," she explained.

"This is why this President is so dangerous," she continued. "He is stoking fires he has no intention of controlling."

"I’m ok y’all, but this sh*t is not ok. Vote this muthaf*cka out," she suggested. "For real."

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2020 Election

Did a maskless Trump supporter flash a ‘white power’ sign at his The Villages rally?

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Did a maskless supporter of President Donald J. Trump really just flash a "white power" sign at his rally at The Villages in Florida?

The sign, with the thumb and index finger’s tips touching while the other three fingers are extended was traditionally known as the okay symbol.

Southern Poverty Law Center said the hand signal is "used ironically by a number of Trump supporters at far-right rallies. It’s been particularly prominent among far-right street protesters such as the Proud Boys and the Northwest-based Patriot Prayer, whose members have prominently displayed the sign in group photos and during street protests."

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