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The Closest Star to Our Solar System Has Suffered an Insane Eruption

The Closest Star to Our Solar System Has Suffered an Insane Eruption 86

Our closest stellar neighbour, Proxima Centauri, knows how to belch ’em out. According to new research, in March of last year it erupted into an absolute beast of a stellar flare, 10 times brighter than the largest flares produced by our own Sun, even though it has only about one-eighth of the mass.

This puts a damper on the notion that the red dwarf is being orbited by a plethora of planets, as was determined by a team of researchers last year.

Based on a reanalysis of the same data, it now looks like there’s no dust ring after all, as previously thought.

In November last year, researchers from the Institute of Astrophysics of Andalusia (IAA) in Spain announced that they’d detected a glow coming from Proxima Centauri.

They attributed this glow to a ring of dust, like the asteroid belt orbiting the Sun on the far side of Mars, or the Kuiper belt out past Pluto.

This, they believed, could indicate the presence of an entire planetary system orbiting outside the exoplanet Proxima b, which had been confirmed in 2016.

This is because dust and asteroid belts are leftover from the accretion disc of dust that swirls around a forming star, and which can result in the formation of planets.

According to a team of researchers led by Carnegie’s Meredith MacGregor, this interpretation of the data now appears flawed.

The extra light detected by the IAA researchers, their new analysis suggests, wasn’t reflected light from a dust ring, but the result of a massive solar flare.

So how did the two teams arrive at such different conclusions based on the same data?

Both teams looked at 10 hours of data captured by the Atacama Large Millimeter/submillimeter Array, a radio telescope comprising 66 antennas, taken from 21 January through 25 April 2017.

The IAA team based its finding on the average amount of light over those three months, including the light of the star and the flare together to result in the dust cloud interpretation.

MacGregor’s team, on the other hand, did not average out the data, but analysed it as a function of observing time – resulting in a spike in the star’s emission.

On 24 March, 2017, they found, the star erupted into an absolutely massive solar flare – 1,000 times brighter than the star’s normal emissions, over a period of 10 seconds.

Overall, the event lasted less than two minutes.

We know Proxima Centauri has a great deal of flare activity, so this wouldn’t be entirely out of character for the star. But it also lowers the chances for finding life on Proxima b, a rocky planet about 1.3 times the mass of Earth.

Because the star is so cool and dim, the planet has to orbit very close to the star in order to be within the habitable zone. This means that it’s much more likely to get lashed by stellar flares, which could strip away its atmosphere, if it even had one to start with.

“It’s likely that Proxima b was blasted by high energy radiation during this flare,” MacGregor said.

“Over the billions of years since Proxima b formed, flares like this one could have evaporated any atmosphere or ocean and sterilised the surface, suggesting that habitability may involve more than just being the right distance from the host star to have liquid water.”

That doesn’t mean all hope is lost, however. There may still be planets orbiting Proxima Centauri that we can’t see.

In fact, we can’t even see Proxima b either. It was found back in 2015 using Doppler spectroscopy, which confirms planets based on the very small changes in light when a star moves towards or away from us, tugged by the gravitational pull of an orbiting body.

Because we can’t see the planet directly, any other planets on the same orbital plane would likewise be invisible. But, so far, there has been no indication that there are any more planets, especially now that the dust cloud finding has been called into significant doubt.

“There is now no reason to think that there is a substantial amount of dust around Proxima Cen[tauri],” said co-author Alycia Weinberger of Carnegie.

“Nor is there any information yet that indicates the star has a rich planetary system like ours.”

We’ll just have to keep looking.

The team’s paper has been published in The Astrophysical Journal Letters, and can be read in full on arXiv.

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Space

KOI-5Ab, the curious planet that orbits in a system of three suns

KOI-5Ab, the curious planet that orbits in a system of three suns 93
Photo: (Caltech / R. Hurt (IPAC))

To us, the Sun alone seems perfectly normal, but our solar system is actually a strange exception.

Most stars in the Milky Way galaxy have at least one companion star. In a system 1,800 light-years away, astronomers have finally confirmed the existence of a gas giant planet orbiting stars in a triple star system.

Called KOI-5, the system is located in the constellation Cygnus, and the exoplanet was confirmed ten years after it was first detected by the Kepler space telescope.

In fact, the planet – now known as KOI-5Ab – was discovered by Kepler when it began operations back in 2009.

“KOI-5Ab was dropped because it was difficult and we had thousands of other candidates,” astronomer David Siardi of NASA’s Exoplanet Science Institute said.

“There were lighter dives than the KOI-5Ab, and every day we learned something new from Kepler, so the KOI-5 was almost forgotten.”

Exoplanet hunters tend to avoid the complexities of multi-star systems; of the more than 4,300 exoplanets confirmed to date, less than 10 percent are multi-star systems, although such systems dominate the galaxy. As a result, little is known about the properties of exoplanets in multi-star systems compared to those orbiting a lone star.

After Kepler’s discovery, Chardy and other astronomers used ground-based telescopes such as the Palomar Observatory, Keck Observatory, and the Gemini North Telescope to study the system. By 2014, they had identified two companion stars, KOI-5B and KOI-5C.

Scientists were able to establish that the planet KOI-5Ab, is a gas giant that is about half the mass of Saturn and 7 times the size of Earth, and is in a very close five-day orbit around KOI-5A. KOI-5A and KOI-5B, both of roughly the same mass as the Sun, form a relatively close binary system with an orbital period of about 30 years.

KOI-5Ab, the curious planet that orbits in a system of three suns 94

A third star, KOI-5C, orbits the binary system at a much greater distance, with a period of about 400 years – slightly longer than Pluto’s 248-year orbit.

“By studying this system in more detail, perhaps we can understand how planets are created in the universe.”

The discovery was announced at the 237th meeting of the American Astronomical Society.

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Space

Why the universe does not fit into science

Why the universe does not fit into science 95
Photo: YouTube

Science can be compared to an artist painting what he has never seen, or to a writer describing other people’s travels: objects that he has never seen, places where he has never been. Sometimes such scientific “arts” turn out to be beautiful and interesting, but most of them will forever remain only theories, because they are beyond human capabilities.

In fact, science has the right only to speculate: how our universe appeared, how old it is, how many stars and other objects it contains.

Universe model

Why the universe does not fit into science 96

How many stars are there in the sky?

With an unarmed eye, a person can see about nine thousand stars in the sky in one cloudless and moonless night. And armed with binoculars or a telescope, much more – up to several million. However, this is much less than their true number in the universe. Indeed, only in our one galaxy (the Milky Way) there are about 400 billion stars. The exact amount, of course, is not known to science. And the visible universe contains about 170 billion galaxies.

It is worth clarifying that scientists can see the universe 46 billion light years deep in all directions. And the visible (observable) universe includes the space accessible to our eyes from the moment of the Big Explosion. In other words, only this (accessible to human perception) space science refers to our universe. Science does not consider everything that follows.

It is believed that there are supposedly a ceptillion (10 to 24 degrees) stars in our universe. These are theoretical calculations based on the approximate size and age of the universe. The origin of the universe is explained by the Big Bang theory. This is why the universe is constantly expanding and the more time passes, the more complex the universe and its components become.

Why the universe does not fit into science 97

It is not entirely correct to consider and perceive this scientific theory “head-on”. Scientists always claim that that explosion was not exactly an explosion, and the point that exploded was not the only one. After all, it was everywhere, because space did not exist then. And in general – everything happened quite differently from what is described in the Big Bang theory, but all other descriptions of the origin of the universe are even more incredible and inaccurate.

Separate but interconnected

That which is beyond the reach of human perception is usually discarded by science, or recognized as non-existent. Recognizing one thing, science does not want to recognize the existence of the other, although everything in our world is interconnected and is not able to exist separately – by itself.

Each object of the universe is a part of it much more than an independent, separate object.

Any person, like any material object of our world, consists of components: organs, cells, molecules, atoms. And each of its constituent parts can represent the whole world. Separate, and at the same time connected with all the others.

However, science, as a rule, perceives all the components of the universe – people, animals, plants, objects, the Earth, the Sun, other planets and stars – as separate subjects, thereby limiting itself.

Why the universe does not fit into science 98

Even what is considered the visible universe, one of the atoms of which could be called our solar system, is not subject to the boundaries of human perception. But perhaps the atom is an exaggeration, and our solar system is not even an atom, but one of its elements!

How, being so far from the truth, can one reason about something with the degree of probability with which science tries to reason about the origin of the universe?

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Space

An unexplained wobble shifts the poles of Mars

An unexplained wobble shifts the poles of Mars 99

The red planet sways from side to side like a whirligig when it loses speed. The new study allowed scientists to notice that the poles of Mars deviate slightly from the axis of rotation of the planet. On average, they move 10 cm from the center with a period of 200 days.

Such changes are called the Chandler Oscillations  – after the American astronomer Seth Chandler, who discovered them in 1891. Previously, they were only seen on Earth. It is known that the displacement of the poles of rotation of our planet occurs with a period of 433 days, while the amplitude reaches 15 meters. There is no exact answer why this is happening. It is believed that the fluctuations are influenced by processes in the ocean and the Earth’s atmosphere.

Chandler’s wobbles on Mars are equally perplexing. The authors of the study discovered them by comparing data from 18 years of studying the planet. The information was obtained thanks to three spacecraft that orbit the Red Planet: Mars Odyssey, Mars Reconnaissance Orbiter and Mars Global Surveyor. 

Since Mars has no oceans, it is likely that the Red Planet’s wobbly rotation is due to changes in atmospheric pressure. This is the first explanation that researchers have shared. In the future, there should be new details about the fluctuations that have so interested the scientific community.

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