New data debunks alien megastructure theory

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Researchers are one step closer to solving the enigma of the ‘most mysterious star in the universe’, also known as ‘Tabby’s Star’. 

Its dramatic dips in brightness has sparked countless theories since its discovery, with many suspecting an ‘alien megastructure’ could be behind the phenomenon.

But now, scientists say the real cause of the dimming seen at Tabby’s Star may be far more mundane.  

Experts believe dust is why it appears to dim and brighten as different colours of light are blocked by different intensities.

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It has baffled astronomers since it was first discovered in 2015, but now experts believe they may be one step closer to solving the mystery of Tabby's star (artist's impression pictured)

It has baffled astronomers since it was first discovered in 2015, but now experts believe they may be one step closer to solving the mystery of Tabby’s star (artist’s impression pictured)

TABBY’S STAR 

Tabby’s Star, known officially as KIC 8462852 but named for Tabetha Boyajian who first discovered it in 2015, has baffled experts ever since.

Observations revealed its light dimmed regularly, as do distant stars when their planets pass in front of them. 

But while the stars of most exoplanet systems are seen to dim by a few per cent, KIC 8462852 dimmed by more than 20 per cent over periods of months.

Some have claimed this dimming could be evidence of a Dyson Sphere – a hypothetical structure which could be used by an advanced alien race to harness the energy of a star.

But now, scientists say the real cause of the dimming seen at Tabby’s Star may be far more mundane.  

Experts believe dust is why it appears to dim and brighten as different colours of light are blocked by different intensities.

Tabby’s Star, known officially as KIC 8462852 but named for Tabetha Boyajian who first discovered it in 2015, has baffled experts.

While the stars of most exoplanet systems are seen to dim by a few per cent, KIC 8462852 dimmed by more than 20 per cent over periods of months.

Previous studies have claimed the strange dimming could be evidence of a Dyson Sphere – a hypothetical structure which could be used by an advanced alien race to harness the energy of a star. 

The mystery of Tabby’s Star is so compelling that more than 1,700 people donated over $100,000 (£73,800) through a Kickstarter campaign in support of dedicated ground-based telescope with the aim of observing and gathering more data on the star.

As a result, a new body of data has been collected by Dr Boyajia and colleagues from the Lousisiana State University Department of Physics & Astronomy in partnership with the Las Cumbres Observatory.

‘Dust is most likely the reason why the star’s light appears to dim and brighten’, said Dr Boyajian.

The new data shows that different colours of light are being blocked at different intensities’, she said.

‘Therefore, whatever is passing between us and the star is not opaque, as would be expected from a planet or alien megastructure,’ Dr Boyajian said.

Scientists closely observed the star through the Las Cumbres Observatory from March 2016 to December 2017.

Beginning in May 2017 there were four distinct episodes when the star’s light dipped.

Supporters from the crowdfunding campaign nominated and voted to name these episodes. 

The first two dips were named Elsie and Celeste. The last two were named after ancient lost cities – Scotland’s Scara Brae and Cambodia’s Angkor. 

Previous studies have claimed the strange dimming could be evidence of a Dyson Sphere – a hypothetical structure which could be used by an advanced alien race to harness the energy of a star (artist's impression pictured) 

Previous studies have claimed the strange dimming could be evidence of a Dyson Sphere – a hypothetical structure which could be used by an advanced alien race to harness the energy of a star (artist's impression pictured) 

Previous studies have claimed the strange dimming could be evidence of a Dyson Sphere – a hypothetical structure which could be used by an advanced alien race to harness the energy of a star (artist’s impression pictured) 

The authors write that in many ways what is happening with the star is like these lost cities.

‘They’re ancient; we are watching things that happened more than 1,000 years ago’, the authors wrote in the paper published in The Astrophysical Journal Letters.

‘They’re almost certainly caused by something ordinary, at least on a cosmic scale. 

‘And yet that makes them more interesting, not less. But most of all, they’re mysterious,’ the authors wrote.

However, the method in which this star is being studied signals a new era of astronomy.

WHAT IS A DYSON SPHERE? 

A suggested method for harnessing the power of an entire star is known as a Dyson sphere.

First proposed by theoretical physicist Freeman Dyson in 1960, this would be a swarm of satellites that surrounds a star.

They could be an enclosed shell, or spacecraft spread out to gather its energy – known as a Dyson swarm.

If such structures do exist, they would emit huge amounts of noticeable infrared radiation back on Earth.

But as of yet, such a structure has not been detected.

Creating a Dyson 'bubble' would be an incredible engineering challenge but it is considered to be far more feasible than surrounding a star in a rigid sphere 

Creating a Dyson 'bubble' would be an incredible engineering challenge but it is considered to be far more feasible than surrounding a star in a rigid sphere 

Creating a Dyson ‘bubble’ would be an incredible engineering challenge but it is considered to be far more feasible than surrounding a star in a rigid sphere 

Source: All About Space magazine 

‘We’re gathering so much data on a single target. This project is reflective of changes in astronomy with the access to this flood of data,’ said Tyler Ellis an LSU doctoral candidate studying this star.

Citizen scientists, the Planet Hunters, sifting through massive amounts of data from the NASA Kepler mission were the ones to detect the star’s unusual behaviour in the first place.

Still, there are more answers yet to be found.

‘It’s exciting. I am so appreciative of all of the people who have contributed to this in the past year – the citizen scientists and professional astronomers. It’s quite humbling to have all of these people contributing in various ways to help figure it out,’ Dr Boyajian said.

Another team of researchers from the University of Arizona, Tuscan, found similar results in a study released in October.    

Researchers collected observational data of Tabby’s star from two Nasa telescopes – Swift, which takes X-ray and UV measurements, and Spitzer, which measures objects in infrared.

They found that from UV, throughout the visible spectrum to IR, the star is dimming at every wavelength. 

The researchers also discovered that the dimming rate of Tabby’s star differed between UV and infrared.

The team suggested that ‘micro-sized dust screens’ are to blame for this irregular dimming, and not an alien megastructure.  

 





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